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| committer | Roger Frank <rfrank@pglaf.org> | 2025-10-15 02:34:25 -0700 |
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+ font-variant: normal;} /* page numbers in poems */ + + // --> + /* XML end ]]>*/ + </style> + </head> +<body> + + +<pre> + +The Project Gutenberg EBook of Manures and the principles of manuring, by +Charles Morton Aikman + +This eBook is for the use of anyone anywhere at no cost and with +almost no restrictions whatsoever. You may copy it, give it away or +re-use it under the terms of the Project Gutenberg License included +with this eBook or online at www.gutenberg.org + + +Title: Manures and the principles of manuring + +Author: Charles Morton Aikman + +Release Date: November 16, 2008 [EBook #27274] + +Language: English + +Character set encoding: ISO-8859-1 + +*** START OF THIS PROJECT GUTENBERG EBOOK MANURES, PRINCIPLES OF MANURING *** + + + + +Produced by Steven Giacomelli, Barbara Kosker and the +Online Distributed Proofreading Team at https://www.pgdp.net +(This file was produced from images produced by Core +Historical Literature in Agriculture (CHLA), Cornell +University) + + + + + + +</pre> + + +<br /> +<br /> +<br /> +<br /> + +<h1>PRINCIPLES OF MANURING</h1> +<br /> +<br /> +<br /> +<br /> + +<h2>MANURES</h2> + +<h2>AND THE</h2> + +<h2>PRINCIPLES OF MANURING</h2> + + +<h4>BY</h4> + + +<h2>C. M. AIKMAN, M.A., D.Sc., F.R.S.E., F.I.C.</h2> + +<h3>FORMERLY PROFESSOR OF CHEMISTRY, GLASGOW VETERINARY COLLEGE, AND +EXAMINER IN CHEMISTRY, GLASGOW UNIVERSITY; AUTHOR OF 'FARMYARD MANURE,' +ETC.</h3> +<br /> +<br /> +<br /> +<br /> + +<h5>THIRD IMPRESSION</h5> +<br /> +<br /> +<br /> +<br /> + +<h4>WILLIAM BLACKWOOD AND SONS<br /> +EDINBURGH AND LONDON<br /> +MCMX</h4> +<br /> + +<h4>D. VAN NOSTRAND COMPANY<br /> +NEW YORK</h4> +<br /> +<br /> + +<h5><i>All Rights reserved</i></h5> +<br /> +<br /> +<br /> +<br /> + + + +<h4>TO</h4> + +<h3>SIR JOHN BENNET LAWES, <span class="smcap">Bart.</span>, D.C.L., LL.D., F.R.S.,</h3> + +<h4>OF ROTHAMSTED,</h4> + +<h4>AND</h4> + +<h3>SIR J. HENRY GILBERT, M.A., LL.D., F.R.S.,</h3> + +<h4>FORMERLY SIBTHORPIAN PROFESSOR OF RURAL ECONOMY,<br /> +UNIVERSITY OF OXFORD,<br /> +WHOSE FAMOUS INVESTIGATIONS DURING THE LAST FIFTY YEARS<br /> +HAVE SO LARGELY CONTRIBUTED TO BUILD UP<br /> +THE SCIENCE OF MANURING,</h4> + +<h3>THIS WORK,</h3> + +<h4>EMBODYING MANY OF THE ROTHAMSTED RESULTS,<br /> + +IS DEDICATED.</h4> +<br /> +<br /> +<br /> +<br /> + + +<hr style="width: 65%;" /><span class='pagenum'><a name="Page_vii" id="Page_vii">[Pg vii]</a></span> +<br /> +<h2>PREFACE.</h2> + + +<p>When the present work was first undertaken there were but few works in +English dealing with its subject-matter, and hardly any which dealt with +the question of Manuring at any length. During the last few years, +however, owing to the greatly increased interest taken in agricultural +education, the demand for agricultural scientific literature has called +into existence quite a number of new works. Despite this fact, the +author ventures to believe that the gap which the present treatise was +originally designed to fill is still unfilled.</p> + +<p>Of the importance of the subject all interested in agriculture are well +aware. It is no exaggeration to say that the introduction of the +practice of artificial manuring has revolutionised modern husbandry. +Indeed, without the aid of artificial manures, arable farming, as at +present carried out, would be <span class='pagenum'><a name="Page_viii" id="Page_viii">[Pg viii]</a></span>impossible. Fifty years ago the practice +may be said to have been unknown; yet so widespread has it now become, +that at the present time the capital invested in the manure trade in +this country alone amounts to millions sterling. It need scarcely be +pointed out, therefore, that a practice in which such vast monetary +interests are involved is worthy of the most careful consideration by +all students of agricultural science, as well as, it may be added, by +political economists.</p> + +<p>The aim of the present work is to supply in a concise and popular form +the chief results of recent agricultural research on the question of +soil fertility, and the nature and action of various manures. It makes +no pretence to be an exhaustive treatise on the subject, and only +contains those facts which seem to the author to have an important +bearing on agricultural practice. In the treatment of its subject it may +be said to stand midway between Professor Storer's recently published +elaborate and excellent treatise on 'Agriculture in some of its +Relations to Chemistry'—a work which is to be warmly recommended to all +students of agricultural science, and to which the author would take +this opportunity of acknowledging his indebtedness—and Dr J. M. H. +Munro's admirable little work on 'Soils and Manures.'</p> + +<p>In order to render the work as intelligible to the ordinary agricultural +reader as possible, all tabular matter and matter of a more or less +technical nature <span class='pagenum'><a name="Page_ix" id="Page_ix">[Pg ix]</a></span>have been relegated to the Appendices attached to each +chapter.</p> + +<p>The author's somewhat wide experience as a University Extension +Lecturer, and as a Lecturer in connection with County Council schemes of +agricultural education, during the last few years, induces him to +believe that the work may be of especial value to those engaged in +teaching agricultural science.</p> + +<p>He has to express the deep obligation he is under, in common with all +writers on Agricultural Chemistry, to the classic researches of Sir John +Bennet Lawes, Bart., and Sir J. Henry Gilbert, now in progress for more +than fifty years at Sir John Lawes' Experiment Station at Rothamsted. +His debt of gratitude to these distinguished investigators has been +still further increased by their kindness in permitting him to dedicate +the work to them, and for having been good enough to read portions of +the work in proof. In addition to the free use which has been made +throughout the book of the results of these experiments, the last +chapter contains, in a tabular form, a short epitome of some of the more +important Rothamsted researches on the action of different manures.</p> + +<p>To the numerous German and French works on the subject, more especially +to Professor Heiden's encyclopædic 'Lehrbuch der Düngerlehre' and the +various writings of Dr Emil von Wolff, the author is further much +indebted.</p> + +<p><span class='pagenum'><a name="Page_x" id="Page_x">[Pg x]</a></span>Among English works he would especially mention the assistance he has +derived from the writings of Mr R. Warington, F.R.S., Professor S. W. +Johnson, Professor Armsby, the late Dr Augustus Voelcker, and others. He +would also tender his acknowledgments to the new edition of Stephens' +'Book of the Farm,' and he has to thank its editor, his friend Mr James +Macdonald, Secretary to the Highland and Agricultural Society of +Scotland, for having read parts of his proof-sheets.</p> + +<p>It is also his pleasing duty to thank his friends Dr Bernard Dyer, Hon +Secretary of the Society of Public Analysts, Dr A. P. Aitken, Chemist to +the Highland and Agricultural Society of Scotland; Professor Douglas +Gilchrist of Bangor; Mr F. J. Cooke, late of Flitcham; Mr Hermann Voss +of London; and Professor Wright of Glasgow, for having assisted him in +the revision of proof-sheets.</p> + +<p> +<span class="smcap"> Analytical Laboratory</span>,<br /> +<span class="smcap">128 Wellington Street, Glasgow</span>,<br /> +<span style="margin-left: 3em;"><i>January 1894.</i></span></p> +<br /> +<br /> +<br /> +<br /> + +<hr /><span class='pagenum'><a name="Page_xi" id="Page_xi">[Pg xi]</a></span> +<br /> +<h2>CONTENTS.</h2> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Table of Contents"> + <tr> + <td class="tdl" width="5%"> </td> + <td class="tdl" width="5%"> </td> + <td class="tdl" width="77%"> </td> + <td class="tdr" width="13%"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">PART I.—HISTORICAL INTRODUCTION.</td> + </tr> + <tr> + <td class="tdc" colspan="3"> </td> + <td class="tdr"><span style="font-size: 80%;">PAGE</span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Beginning of agricultural chemistry</td> + <td class="tdr"><a href="#Page_4">4</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Early theories regarding plant-growth</td> + <td class="tdr"><a href="#Page_4">4</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Van Helmont</td> + <td class="tdr"><a href="#Page_4">4</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Digby</td> + <td class="tdr"><a href="#Page_6">6</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Duhamel and Stephen Hales</td> + <td class="tdr"><a href="#Page_8">8</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Jethro Tull</td> + <td class="tdr"><a href="#Page_9">9</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Charles Bonnet's discovery of source of plants' carbon</td> + <td class="tdr"><a href="#Page_11">11</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Researches of Priestley, Ingenhousz, Sénébier, on assimilation of carbon</td> + <td class="tdrb"><a href="#Page_11">11-12</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Publication of first English treatise by Earl Dundonald</td> + <td class="tdr"><a href="#Page_13">13</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Publication of Theodore de Saussure, 'Chemical Researches on Vegetation,' + 1804</td> + <td class="tdrb"><a href="#Page_14">14</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Theories on source of plant-nitrogen</td> + <td class="tdr"><a href="#Page_15">15</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Early experiments on this subject</td> + <td class="tdr"><a href="#Page_16">16</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sir Humphry Davy's lectures (1802-1812)</td> + <td class="tdr"><a href="#Page_17">17</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">State of agricultural chemistry in 1812</td> + <td class="tdr"><a href="#Page_17">17</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Beginning of Boussingault's researches (1834)</td> + <td class="tdr"><a href="#Page_21">21</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Publication of Liebig's first report to the British Association</td> + <td class="tdr"><a href="#Page_24">24</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Refutation of "humus" theory</td> + <td class="tdr"><a href="#Page_26">26</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Liebig's mineral theory</td> + <td class="tdr"><a href="#Page_26">26</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Liebig's theory of source of plants' nitrogen</td> + <td class="tdr"><a href="#Page_27">27</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Publication of Liebig's second report to British Association</td> + <td class="tdr"><a href="#Page_30">30</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Liebig's services to agricultural chemistry</td> + <td class="tdr"><a href="#Page_31">31</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Development of agricultural research in Germany</td> + <td class="tdr"><a href="#Page_32">32</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">The Rothamsted Experiment Station</td> + <td class="tdr"><a href="#Page_33">33</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sir J. B. Lawes and Sir J. H. Gilbert, the nature and value of their + experiments</td> + <td class="tdrb"><a href="#Page_33">33</a><span class='pagenum'><a name="Page_xii" id="Page_xii">[Pg xii]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Review of the present state of our knowledge of plant-growth</td> + <td class="tdr"><a href="#Page_36">36</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Proximate composition of the plant</td> + <td class="tdr"><a href="#Page_36">36</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Fixation of carbon by plants</td> + <td class="tdr"><a href="#Page_37">37</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action of light on plant-growth, Dr Siemens' experiments</td> + <td class="tdr"><a href="#Page_38">38</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Source of oxygen and hydrogen in the plant</td> + <td class="tdr"><a href="#Page_39">39-40</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Source of nitrogen in the plant</td> + <td class="tdr"><a href="#Page_40">40</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Relation of the free nitrogen to leguminous plants</td> + <td class="tdr"><a href="#Page_42">42-44</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Relation of nitrogen in organic forms, as ammonia salts, and + nitrates to the plant</td> + <td class="tdrb"><a href="#Page_46">46-50</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrification and its conditions</td> + <td class="tdr"><a href="#Page_51">51</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Ash constituents of the plant</td> + <td class="tdr"><a href="#Page_53">53</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Methods of research for ascertaining essentialness of ash + constituents of plants</td> + <td class="tdrb"><a href="#Page_53">53</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">(<i>a</i>) Artificial soils, (<i>b</i>) water-culture</td> + <td class="tdr"><a href="#Page_53">53-55</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Method in which plants absorb their food-constituents</td> + <td class="tdr"><a href="#Page_55">55</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Endosmosis</td> + <td class="tdr"><a href="#Page_55">55</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Retention by soils of plant-food</td> + <td class="tdr"><a href="#Page_57">57</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Causes of retention by soils of plant-food</td> + <td class="tdr"><a href="#Page_59">59</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Manuring</td> + <td class="tdr"><a href="#Page_60">60</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">"Field" and "pot" experimentation</td> + <td class="tdr"><a href="#Page_60">60</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">PART II.—PRINCIPLES OF MANURING.</td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER I.—FERTILITY OF THE SOIL.</td> + </tr> + <tr> + <td class="tdl" colspan="3">What constitutes fertility in a soil</td> + <td class="tdr"><a href="#Page_65">65</a></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Physical properties of a soil</td> + <td class="tdr"><a href="#Page_65">65</a></td> + </tr> + <tr> + <td class="tdr"> </td> + <td class="tdl" colspan="2">Kinds of soils</td> + <td class="tdr"><a href="#Page_66">66</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Absorptive power for water of soils</td> + <td class="tdr"><a href="#Page_67">67</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Absorptive power for water of sand, clay, and humus</td> + <td class="tdr"><a href="#Page_68">68</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Fineness of particles of a soil</td> + <td class="tdr"><a href="#Page_69">69</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Limit of fineness of soil-particles</td> + <td class="tdr"><a href="#Page_69">69</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Importance of retentive power</td> + <td class="tdr"><a href="#Page_70">70</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Power of plants for absorbing water from a soil, experiments by + Sachs</td> + <td class="tdrb"><a href="#Page_73">73</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">How to increase absorptive power of soils</td> + <td class="tdr"><a href="#Page_74">74</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of water in a soil most favourable for plant growth</td> + <td class="tdr"><a href="#Page_75">75</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Hygroscopic power of soils</td> + <td class="tdr"><a href="#Page_75">75</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Capacity of soils for absorbing and retaining heat</td> + <td class="tdr"><a href="#Page_76">76</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Explanation of dew</td> + <td class="tdr"><a href="#Page_77">77</a><span class='pagenum'><a name="Page_xiii" id="Page_xiii">[Pg xiii]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Heat of soils</td> + <td class="tdr"><a href="#Page_78">78</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Heat in rotting farmyard manure</td> + <td class="tdr"><a href="#Page_78">78</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Causes of heat of fermentation</td> + <td class="tdr"><a href="#Page_79">79</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Influence of colour on heat-retaining power</td> + <td class="tdr"><a href="#Page_80">80</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Power of soils for absorbing gases</td> + <td class="tdr"><a href="#Page_81">81</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Gases found in soils</td> + <td class="tdr"><a href="#Page_81">81</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Variation in gas-absorbing power of soils</td> + <td class="tdr"><a href="#Page_82">82</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Absorption of nitrogen by soils</td> + <td class="tdr"><a href="#Page_82">82</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Requirements of plant-roots in a soil</td> + <td class="tdr"><a href="#Page_83">83</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Influence of tillage on number of plants in a certain area</td> + <td class="tdr"><a href="#Page_86">86</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Comparison of English and American farming</td> + <td class="tdr"><a href="#Page_86">86</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Chemical composition of a soil</td> + <td class="tdr"><a href="#Page_87">87</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Fertilising ingredients of a soil</td> + <td class="tdr"><a href="#Page_87">87</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Importance of <i>nitrogen</i>, <i>phosphoric acid</i>, and + <i>potash</i> in a soil</td> + <td class="tdr"><a href="#Page_88">88</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Chemical condition of fertilising ingredients in soils</td> + <td class="tdr"><a href="#Page_89">89</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of soluble fertilising ingredients in soils</td> + <td class="tdr"><a href="#Page_90">90</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Value of chemical analysis of soils</td> + <td class="tdr"><a href="#Page_90">90</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Biological properties of a soil</td> + <td class="tdr"><a href="#Page_92">92</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Bacteria of the soil</td> + <td class="tdr"><a href="#Page_92">92</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Recapitulation of Chapter I</td> + <td class="tdr"><a href="#Page_96">96</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER I.</span></td> + </tr> + <tr> + <td class="tdl"><span style="font-size: 60%;">NOTE</span></td> + <td class="tdl" colspan="3"> </td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Table of absorptive power of soil substances by Schübler</td> + <td class="tdr"><a href="#Page_98">98</a></td> + </tr> + <tr> + <td class="tdrt">II.</td> + <td class="tdl" colspan="2">Table of rate of evaporation of water in different soils by + Schübler</td> + <td class="tdrb"><a href="#Page_99">99</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Table of hygroscopic power of soils dried at 212° F. (Davy)</td> + <td class="tdr"><a href="#Page_99">99</a></td> + </tr> + <tr> + <td class="tdr">IV.</td> + <td class="tdl" colspan="2">Gases persent in soil</td> + <td class="tdr"><a href="#Page_100">100</a></td> + </tr> + <tr> + <td class="tdr">V.</td> + <td class="tdl" colspan="2">Amount of plant-food in soils</td> + <td class="tdr"><a href="#Page_100">100</a></td> + </tr> + <tr> + <td class="tdr">VI.</td> + <td class="tdl" colspan="2">Chemical composition of the soil</td> + <td class="tdr"><a href="#Page_101">101</a></td> + </tr> + <tr> + <td class="tdr">VII.</td> + <td class="tdl" colspan="2">Forms in which plant-foods are present in the soil</td> + <td class="tdr"><a href="#Page_107">107</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER II.—FUNCTIONS PERFORMED BY MANURES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Etymological meaning of word manure</td> + <td class="tdr"><a href="#Page_109">109</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Definition of manures</td> + <td class="tdr"><a href="#Page_110">110</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Different classes of manures</td> + <td class="tdr"><a href="#Page_111">111</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Action of different classes of manures</td> + <td class="tdr"><a href="#Page_113">113</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> <span class='pagenum'><a name="Page_xiv" id="Page_xiv">[Pg xiv]</a></span></td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER III.—POSITION OF NITROGEN IN AGRICULTURE.</td> + </tr> + <tr> + <td class="tdl" colspan="3">The Rothamsted experiments and the nitrogen question</td> + <td class="tdr"><a href="#Page_115">115</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Different forms in which nitrogen exists in nature</td> + <td class="tdr"><a href="#Page_116">116</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Relation of "free" nitrogen to the plant</td> + <td class="tdr"><a href="#Page_117">117</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Combined nitrogen in the air</td> + <td class="tdr"><a href="#Page_118">118</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of combined nitrogen falling in the rain</td> + <td class="tdr"><a href="#Page_119">119</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogen in the soil</td> + <td class="tdr"><a href="#Page_120">120</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogen in the subsoil</td> + <td class="tdr"><a href="#Page_121">121</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogen of surface-soil</td> + <td class="tdr"><a href="#Page_121">121</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrogen in the soil</td> + <td class="tdr"><a href="#Page_123">123</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Soils richest in nitrogen</td> + <td class="tdr"><a href="#Page_123">123</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nature of the nitrogen in the soil</td> + <td class="tdr"><a href="#Page_124">124</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Organic nitrogen in the soil</td> + <td class="tdr"><a href="#Page_125">125</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Differences of surface and subsoil nitrogen</td> + <td class="tdr"><a href="#Page_126">126</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogen as ammonia in soils</td> + <td class="tdr"><a href="#Page_127">127</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of ammonia in soils</td> + <td class="tdr"><a href="#Page_127">127</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogen present as nitrates in the soil</td> + <td class="tdr"><a href="#Page_128">128</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Position of nitric nitrogen in soil</td> + <td class="tdr"><a href="#Page_128">128</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrates in the soil</td> + <td class="tdr"><a href="#Page_129">120</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrates in fallow soils</td> + <td class="tdr"><a href="#Page_129">129</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrates in cropped soils</td> + <td class="tdr"><a href="#Page_130">130</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrates in manured wheat-soils</td> + <td class="tdr"><a href="#Page_131">131</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">The sources of soil-nitrogen</td> + <td class="tdr"><a href="#Page_131">131</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Accumulation of soil-nitrogen under natural conditions</td> + <td class="tdr"><a href="#Page_133">133</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Accumulation of nitrogen in pastures</td> + <td class="tdr"><a href="#Page_134">134</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Gain of nitrogen with leguminous crops</td> + <td class="tdr"><a href="#Page_135">135</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">The fixation of "free" nitrogen</td> + <td class="tdr"><a href="#Page_136">136</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Influence of manures in increasing soil-nitrogen</td> + <td class="tdr"><a href="#Page_136">136</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Sources of loss of nitrogen</td> + <td class="tdr"><a href="#Page_137">137</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss of nitrates by drainage</td> + <td class="tdr"><a href="#Page_137">137</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Prevention of loss of nitrogen by permanent pasture and<br /> + "catch-cropping"</td> + <td class="tdrb"><a href="#Page_138">138</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Other conditions diminishing loss of nitrates</td> + <td class="tdr"><a href="#Page_139">139</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of loss of nitrogen by drainage</td> + <td class="tdr"><a href="#Page_140">140</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss of nitrogen in form of "free" nitrogen</td> + <td class="tdr"><a href="#Page_141">141</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Total amount of loss of nitrogen</td> + <td class="tdr"><a href="#Page_142">142</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss of nitrogen by retrogression</td> + <td class="tdr"><a href="#Page_142">142</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Artificial sources of loss of nitrogen</td> + <td class="tdr"><a href="#Page_144">144</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrogen removed in crops</td> + <td class="tdr"><a href="#Page_144">144</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Losses of nitrogen incurred on the farm</td> + <td class="tdr"><a href="#Page_146">146</a><span class='pagenum'><a name="Page_xv" id="Page_xv">[Pg xv]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss in treatment of farmyard manure</td> + <td class="tdr"><a href="#Page_146">146</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogen removed in milk</td> + <td class="tdr"><a href="#Page_147">147</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Economics of the nitrogen question</td> + <td class="tdr"><a href="#Page_147">147</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss of nitrogen-compounds in the arts</td> + <td class="tdr"><a href="#Page_148">148</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss due to use of gunpowder</td> + <td class="tdr"><a href="#Page_148">148</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss due to sewage disposal</td> + <td class="tdr"><a href="#Page_149">149</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Our artificial nitrogen supply </td> + <td class="tdr"><a href="#Page_150">150</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrate of soda and sulphate of ammonia</td> + <td class="tdr"><a href="#Page_150">150</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Peruvian guano</td> + <td class="tdr"><a href="#Page_151">151</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Bones</td> + <td class="tdr"><a href="#Page_151">151</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Other nitrogenous manures</td> + <td class="tdr"><a href="#Page_152">152</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Oil-seeds and oilcakes</td> + <td class="tdr"><a href="#Page_15">153</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Other imported sources of nitrogen</td> + <td class="tdr"><a href="#Page_153">153</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Conclusion</td> + <td class="tdr"><a href="#Page_153">153</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER III.</span></td> + </tr> + <tr> + <td class="tdl"><span style="font-size: 60%;">NOTE</span></td> + <td class="tdl" colspan="3"> </td> + </tr> + <tr> + <td class="tdrt">I.</td> + <td class="tdl" colspan="2">Determination of the quantity of nitrogen supplied by rain, as + ammonia and nitric acid, to an acre of land during one year</td> + <td class="tdrb"><a href="#Page_155">155</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Nitrogen in soils at various depths</td> + <td class="tdr"><a href="#Page_156">156</a></td> + </tr> + <tr> + <td class="tdrt">III</td> + <td class="tdl" colspan="2">Nitrogen as nitrates in cropped soils receiving no nitrogenous + manures, in lb. per acre (Rothamsted soils)</td> + <td class="tdrb"><a href="#Page_157">157</a></td> + </tr> + <tr> + <td class="tdr">IV.</td> + <td class="tdl" colspan="2">Nitrogen as nitrates in Rothamsted soils</td> + <td class="tdr"><a href="#Page_157">157</a></td> + </tr> + <tr> + <td class="tdrt">V.</td> + <td class="tdl" colspan="2">Examples of increase of nitrogen in Rothamsted soils laid down in + pastures</td> + <td class="tdrb"><a href="#Page_158">158</a></td> + </tr> + <tr> + <td class="tdr">VI.</td> + <td class="tdl" colspan="2">Loss by drainage of nitrates</td> + <td class="tdr"><a href="#Page_158">158</a></td> + </tr> + <tr> + <td class="tdr">VII.</td> + <td class="tdl" colspan="2">Examples of decrease of nitrogen in Rothamsted soils</td> + <td class="tdr"><a href="#Page_159">159</a></td> + </tr> + <tr> + <td class="tdrt">VIII.</td> + <td class="tdl" colspan="2">Amount of drainage and nitrogen as nitrates in drainage-water + from unmanured bare soil, 20 and 60 inches deep</td> + <td class="tdrb"><a href="#Page_160">160</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER IV.—NITRIFICATION.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Process of nitrification</td> + <td class="tdr"><a href="#Page_161">161</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of nitrates in the soil</td> + <td class="tdr"><a href="#Page_162">162</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nitre soils of India</td> + <td class="tdr"><a href="#Page_162">162</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Saltpetre plantations</td> + <td class="tdr"><a href="#Page_163">163</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Cause of nitrification</td> + <td class="tdr"><a href="#Page_165">165</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Ferments effecting nitrification</td> + <td class="tdr"><a href="#Page_167">167</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Appearance of nitrous organisms</td> + <td class="tdr"><a href="#Page_168">168</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitric organism</td> + <td class="tdr"><a href="#Page_169">169</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Difficulty in isolating them</td> + <td class="tdr"><a href="#Page_169">169</a><span class='pagenum'><a name="Page_xvi" id="Page_xvi">[Pg xvi]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrifying organisms do not require organic matter</td> + <td class="tdr"><a href="#Page_169">169</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Conditions favourable for nitrification—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Presence of food-constituents</td> + <td class="tdr"><a href="#Page_170">170</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Presence of a salifiable base</td> + <td class="tdr"><a href="#Page_171">171</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Only takes place in slightly alkaline solutions</td> + <td class="tdr"><a href="#Page_172">172</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action of gypsum on nitrification</td> + <td class="tdr"><a href="#Page_173">173</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Presence of oxygen</td> + <td class="tdr"><a href="#Page_173">173</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Temperature</td> + <td class="tdr"><a href="#Page_175">175</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Presence of a sufficient quantity of moisture</td> + <td class="tdr"><a href="#Page_176">176</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Absence of strong sunlight</td> + <td class="tdr"><a href="#Page_176">176</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrifying organisms destroyed by poisons</td> + <td class="tdr"><a href="#Page_176">176</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Denitrification</td> + <td class="tdr"><a href="#Page_177">177</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Denitrification also effected by bacteria</td> + <td class="tdr"><a href="#Page_178">178</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Conditions favourable for denitrification</td> + <td class="tdr"><a href="#Page_178">178</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Takes place in water-logged soils</td> + <td class="tdr"><a href="#Page_179">179</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Distribution of the nitrifying organisms in the soil</td> + <td class="tdr"><a href="#Page_179">179</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Depth down at which they occur</td> + <td class="tdr"><a href="#Page_180">180</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action of plant-roots in promoting nitrification</td> + <td class="tdr"><a href="#Page_181">181</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nature of substances capable of nitrification</td> + <td class="tdr"><a href="#Page_181">181</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Rate at which nitrification takes place</td> + <td class="tdr"><a href="#Page_183">183</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrification takes place chiefly during summer</td> + <td class="tdr"><a href="#Page_183">183</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Process goes on most quickly in fallow fields</td> + <td class="tdr"><a href="#Page_184">184</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Laboratory experiments on rate of nitrification</td> + <td class="tdr"><a href="#Page_185">185</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Certain portions of soil-nitrogen more easily nitrifiable + than the rest</td> + <td class="tdrb"><a href="#Page_187">187</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Rate of nitrification deduced from field experiments</td> + <td class="tdr"><a href="#Page_187">187</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Quantity of nitrates formed in the soils of fallow fields</td> + <td class="tdr"><a href="#Page_188">188</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Position of nitrates depends on season</td> + <td class="tdr"><a href="#Page_188">188</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrates in drainage-waters</td> + <td class="tdr"><a href="#Page_188">188</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount produced at different times of year</td> + <td class="tdr"><a href="#Page_189">189</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrification of manures</td> + <td class="tdr"><a href="#Page_190">190</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Ammonia salts most easily nitrifiable</td> + <td class="tdr"><a href="#Page_191">191</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Sulphate of ammonia the most easily nitrifiable manure</td> + <td class="tdr"><a href="#Page_191">191</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Rate of nitrification of other manures</td> + <td class="tdr"><a href="#Page_192">192</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Soils best suited for nitrification</td> + <td class="tdr"><a href="#Page_192">192</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Absence of nitrification in forest-soils</td> + <td class="tdr"><a href="#Page_193">193</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Important bearing of nitrification on agricultural practice</td> + <td class="tdr"><a href="#Page_193">193</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Desirable to have soil covered with vegetation</td> + <td class="tdr"><a href="#Page_194">194</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Permanent pasture most economical condition of soil</td> + <td class="tdr"><a href="#Page_194">194</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrification and rotation of crops</td> + <td class="tdr"><a href="#Page_195">195</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> <span class='pagenum'><a name="Page_xvii" id="Page_xvii">[Pg xvii]</a></span> + </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER IV.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Old theories of nitrification</td> + <td class="tdr"><a href="#Page_196">196</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Nitrification takes place in solutions devoid of organic matter</td> + <td class="tdr"><a href="#Page_196">196</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Oxidising power of micro-organisms in soils</td> + <td class="tdr"><a href="#Page_197">197</a></td> + </tr> + <tr> + <td class="tdr">IV.</td> + <td class="tdl" colspan="2">Effect of urine on nitrification in soils</td> + <td class="tdr"><a href="#Page_197">197</a></td> + </tr> + <tr> + <td class="tdrt">V.</td> + <td class="tdl" colspan="2">Solution used by Professor Frankland in cultivating nitrificative + micro-organisms</td> + <td class="tdrb"><a href="#Page_198">198</a></td> + </tr> + <tr> + <td class="tdr">VI.</td> + <td class="tdl" colspan="2">Experiments by Boussingault on rate of nitrification</td> + <td class="tdr"><a href="#Page_198">198</a></td> + </tr> + <tr> + <td class="tdrt">VII.</td> + <td class="tdl" colspan="2">Nitrogen as nitrates in Rothamsted soils after bare fallow in + lb. per acre</td> + <td class="tdrb"><a href="#Page_198">198</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER V.—POSITION OF PHOSPHORIC ACID<br /> IN AGRICULTURE.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of phosphoric acid in nature</td> + <td class="tdr"><a href="#Page_199">199</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Mineral sources of phosphoric acid</td> + <td class="tdr"><a href="#Page_200">200</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Apatite and phosphorite</td> + <td class="tdr"><a href="#Page_200">200</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Coprolites</td> + <td class="tdr"><a href="#Page_201">201</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of phosphoric acid in guanos</td> + <td class="tdr"><a href="#Page_202">202</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Universal occurrence in common rocks</td> + <td class="tdr"><a href="#Page_202">202</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence in the soil</td> + <td class="tdr"><a href="#Page_203">203</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Condition in which phosphoric acid occurs in the soil</td> + <td class="tdr"><a href="#Page_203">203</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence in plants</td> + <td class="tdr"><a href="#Page_204">204</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence in animals</td> + <td class="tdr"><a href="#Page_205">205</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sources of loss of phosphoric acid in agriculture</td> + <td class="tdr"><a href="#Page_205">205</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Loss of phosphoric acid by drainage</td> + <td class="tdr"><a href="#Page_206">206</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Artificial sources of loss of phosphoric acid</td> + <td class="tdr"><a href="#Page_206">206</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Amount of phosphoric acid removed in milk</td> + <td class="tdr"><a href="#Page_207">207</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Loss of phosphoric acid in treatment of farmyard manure</td> + <td class="tdr"><a href="#Page_208">208</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Loss of phosphoric acid in sewage</td> + <td class="tdr"><a href="#Page_208">208</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sources of artificial gain of phosphoric acid</td> + <td class="tdr"><a href="#Page_208">208</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER V.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Composition of apatite (Voelcker)</td> + <td class="tdr"><a href="#Page_210">210</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Percentage of phosphoric acid in the commoner rocks</td> + <td class="tdr"><a href="#Page_211">211</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER VI.—POSITION OF POTASH IN AGRICULTURE.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Potash of less importance than phosphoric acid</td> + <td class="tdr"><a href="#Page_212">212</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of potash</td> + <td class="tdr"><a href="#Page_213">213</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Felspar and other potash minerals</td> + <td class="tdr"><a href="#Page_213">213</a><span class='pagenum'><a name="Page_xviii" id="Page_xviii">[Pg xviii]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Stassfurt salts</td> + <td class="tdr"><a href="#Page_214">214</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of saltpetre</td> + <td class="tdr"><a href="#Page_215">215</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of potash in the soil</td> + <td class="tdr"><a href="#Page_215">215</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Potash chiefly in insoluble condition in soils</td> + <td class="tdr"><a href="#Page_216">216</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Percentage of potash in plants and plant-ash</td> + <td class="tdr"><a href="#Page_216">216</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Occurrence of potash in animal tissue</td> + <td class="tdr"><a href="#Page_217">217</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sources of loss of potash</td> + <td class="tdr"><a href="#Page_217">217</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Amount of potash removed in crops</td> + <td class="tdr"><a href="#Page_218">218</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Amount of potash removed in milk</td> + <td class="tdr"><a href="#Page_218">218</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Potash manures</td> + <td class="tdr"><a href="#Page_218">218</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER VI.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Amount of potash in different minerals</td> + <td class="tdr"><a href="#Page_220">220</a></td> + </tr> + <tr> + <td class="tdrt">II.</td> + <td class="tdl" colspan="2">Quantity of potash obtained from 1000 lb. of different kinds of + vegetation in the manufacture of potashes</td> + <td class="tdrb"><a href="#Page_220">220</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">PART III.—MANURES.</td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER VII.—FARMYARD MANURE.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Variation in its composition</td> + <td class="tdr"><a href="#Page_223">223</a></td> + </tr> + <tr> + <td class="tdl"></td> + <td class="tdl" colspan="2">Made up of three classes of constituents</td> + <td class="tdr"><a href="#Page_224">224</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="3"><i>Solid excreta</i>—</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Its nature</td> + <td class="tdr"><a href="#Page_224">224</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Difference in composition of the solid excreta of the different farm animals</td> + <td class="tdrb"><a href="#Page_224">224</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Causes of this difference</td> + <td class="tdr"><a href="#Page_225">225</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Percentage of manurial ingredients in solid excreta of different animals</td> + <td class="tdrb"><a href="#Page_226">226</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2"><i>Urine</i>—</td> + <td class="tdr"><a href="#Page_228">228</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Its nature</td> + <td class="tdr"><a href="#Page_228">228</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Variation in its composition</td> + <td class="tdr"><a href="#Page_229">229</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Causes of this variation</td> + <td class="tdr"><a href="#Page_229">229</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Manurial value of the urine of the different farm animals</td> + <td class="tdr"><a href="#Page_230">230</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Percentage of the <i>organic matter</i>, <i>nitrogen</i>, and <i>mineral + substances</i> in the food, voided in the solid excreta and urine</td> + <td class="tdrb"><a href="#Page_232">232</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Comparison of manurial value of total excrements of the different farm animals</td> + <td class="tdrb"><a href="#Page_234">234</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Nature of changes undergone by food in process of digestion</td> + <td class="tdrb"><a href="#Page_235">235</a><span class='pagenum'><a name="Page_xix" id="Page_xix">[Pg xix]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2"><i>Litter</i>—</td> + <td class="tdr"><a href="#Page_236">236</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Its uses</td> + <td class="tdr"><a href="#Page_236">236</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Straw</i> as litter, and its qualifications</td> + <td class="tdr"><a href="#Page_237">237</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Composition of different kinds of straw</td> + <td class="tdr"><a href="#Page_238">238</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Loam</i> as litter</td> + <td class="tdr"><a href="#Page_239">239</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Peat</i> as litter</td> + <td class="tdr"><a href="#Page_240">240</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Comparison of properties of <i>peat-moss</i> and <i>straw</i></td> + <td class="tdr"><a href="#Page_241">241</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">The <i>bracken-fern</i> as litter</td> + <td class="tdr"><a href="#Page_241">241</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Dried leaves</i> as litter</td> + <td class="tdr"><a href="#Page_242">242</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Manures produced by the different animals—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="3"><i>Horse-manure</i>—</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount produced</td> + <td class="tdr"><a href="#Page_243">243</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Its nature and composition</td> + <td class="tdr"><a href="#Page_243">243</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount of straw used for litter</td> + <td class="tdr"><a href="#Page_244">244</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Sources of loss on keeping</td> + <td class="tdr"><a href="#Page_245">245</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">How to prevent loss</td> + <td class="tdr"><a href="#Page_245">245</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Use of "fixers," and the nature of their action</td> + <td class="tdr"><a href="#Page_245">245</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="3"><i>Cow-manure</i>—</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount produced</td> + <td class="tdr"><a href="#Page_248">248</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Its nature and composition</td> + <td class="tdr"><a href="#Page_248">249</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount of straw used as litter</td> + <td class="tdr"><a href="#Page_248">248</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Sources of loss on keeping</td> + <td class="tdr"><a href="#Page_249">249</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Advantages of <i>short dung</i></td> + <td class="tdr"><a href="#Page_249">249</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="3"><i>Pig-manure</i>—</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount produced</td> + <td class="tdr"><a href="#Page_250">250</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Its nature and composition</td> + <td class="tdr"><a href="#Page_250">250</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount of straw used as litter</td> + <td class="tdr"><a href="#Page_251">251</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="3"><i>Sheep-manure</i>—</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount produced</td> + <td class="tdr"><a href="#Page_251">251</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Nature and composition</td> + <td class="tdr"><a href="#Page_251">251</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Amount of straw used as litter</td> + <td class="tdr"><a href="#Page_252">252</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Methods of calculating amount of manure produced on the farm</td> + <td class="tdr"><a href="#Page_252">252, note</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Fermentation of farmyard manure—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action of <i>micro-organic</i> life in producing fermentation</td> + <td class="tdr"><a href="#Page_255">255</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Two classes of <i>bacteria</i> active in this work, <i>aerobies</i> + and <i>anaerobies</i></td> + <td class="tdrb"><a href="#Page_255">255</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="3">Conditions influencing fermentation—</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Temperature</i></td> + <td class="tdr"><a href="#Page_256">256</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Openness to the air</i></td> + <td class="tdr"><a href="#Page_256">256</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Dampness</i></td> + <td class="tdr"><a href="#Page_257">257</a><span class='pagenum'><a name="Page_xx" id="Page_xx">[Pg xx]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl"><i>Composition of manure</i></td> + <td class="tdr"><a href="#Page_257">257</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Products of fermentation</td> + <td class="tdr"><a href="#Page_257">257</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Analyses of farmyard manure—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Dr Voelcker's experiments</td> + <td class="tdr"><a href="#Page_259">259</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Variation in composition</td> + <td class="tdr"><a href="#Page_259">259</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amounts of <i>moisture</i>, <i>organic matter</i> (containing + <i>nitrogen</i>), and <i>mineral matter</i></td> + <td class="tdrb"><a href="#Page_260">260</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Its manurial value compared with <i>nitrate of soda</i>, <i>sulphate + of ammonia</i>, and <i>superphosphate</i></td> + <td class="tdrb"><a href="#Page_260">260</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Comparison of fresh and rotten manure—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">The nature and amount of loss sustained in the process of <i>rotting</i></td> + <td class="tdrb"><a href="#Page_261">261</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Ought manure to be appliled <i>fresh</i> or <i>rotten</i>?</td> + <td class="tdr"><a href="#Page_262">262</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Relative merits of <i>covered</i> and <i>uncovered</i> manure-heaps</td> + <td class="tdr"><a href="#Page_263">263</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Methods of application of farmyard manure to the field—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Merits and demerits of the different methods</td> + <td class="tdr"><a href="#Page_265">265</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Setting it out in <i>heaps</i></td> + <td class="tdr"><a href="#Page_265">265</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Spreading it <i>broadcast</i>, and letting it lie</td> + <td class="tdr"><a href="#Page_266">266</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Ploughing it in immediately</td> + <td class="tdr"><a href="#Page_267">267</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Value and function of farmyard manure—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">As a supplier of the necessary elements of plant-food</td> + <td class="tdr"><a href="#Page_268">268</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">As a "universal" manure</td> + <td class="tdr"><a href="#Page_269">269</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Proportion in which <i>nitrogen</i>, <i>phosphoric acid</i>, and + <i>potash</i> are required by crops</td> + <td class="tdrb"><a href="#Page_269">269</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Proportion in which they are present in farmyard manure</td> + <td class="tdr"><a href="#Page_270">270</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Farmyard manure <i>poor in nitrogen</i></td> + <td class="tdr"><a href="#Page_270">270</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Lawes' and Gilbert's experiments</td> + <td class="tdr"><a href="#Page_271">271</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">How it may be best reinforced by the use of "artificials"</td> + <td class="tdr"><a href="#Page_271">271</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Indirect value of farmyard manure as a supplier of <i>humus</i> + to the soil</td> + <td class="tdrb"><a href="#Page_273">273</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Its influence on soil-texture</td> + <td class="tdr"><a href="#Page_273">273</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Its influence in setting free inert fertilising matter in the soil</td> + <td class="tdr"><a href="#Page_274">274</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Rate at which farmyard manure ought to be applied</td> + <td class="tdr"><a href="#Page_275">275</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Lasting nature of farmyard manure</td> + <td class="tdr"><a href="#Page_276">276</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Its economic value</td> + <td class="tdr"><a href="#Page_276">276</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER VII.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Difference in amount of excreta voided for food consumed</td> + <td class="tdr"><a href="#Page_279">279</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Solid excreta voided by sheep, oxen, and cows</td> + <td class="tdr"><a href="#Page_279">279</a><span class='pagenum'><a name="Page_xxi" id="Page_xxi">[Pg xxi]</a></span></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Urine voided by sheep, oxen, and cows</td> + <td class="tdr"><a href="#Page_280">280</a></td> + </tr> + <tr> + <td class="tdr">IV.</td> + <td class="tdl" colspan="2">Percentage of food voided in the solid and liquid excrements</td> + <td class="tdr"><a href="#Page_281">281</a></td> + </tr> + <tr> + <td class="tdr">V.</td> + <td class="tdl" colspan="2">Pig excrements</td> + <td class="tdr"><a href="#Page_281">281</a></td> + </tr> + <tr> + <td class="tdr">VI.</td> + <td class="tdl" colspan="2">Manurial constituents in 1000 parts of ordinary foods</td> + <td class="tdr"><a href="#Page_282">282</a></td> + </tr> + <tr> + <td class="tdrt">VII.</td> + <td class="tdl" colspan="2">Analyses of stable-manure, made respectively with peat-moss litter + and wheat-straw</td> + <td class="tdrb"><a href="#Page_283">283</a></td> + </tr> + <tr> + <td class="tdr">VIII.</td> + <td class="tdl" colspan="2">Analyses of bracken</td> + <td class="tdr"><a href="#Page_283">283</a></td> + </tr> + <tr> + <td class="tdr">IX.</td> + <td class="tdl" colspan="2">Analyses of horse-manure</td> + <td class="tdr"><a href="#Page_283">283</a></td> + </tr> + <tr> + <td class="tdr">X.</td> + <td class="tdl" colspan="2">The nature of the chemical reactions of ammonia "fixers"</td> + <td class="tdr"><a href="#Page_284">284</a></td> + </tr> + <tr> + <td class="tdr">XI.</td> + <td class="tdl" colspan="2">Analyses of cow-manure</td> + <td class="tdr"><a href="#Page_286">286</a></td> + </tr> + <tr> + <td class="tdr">XII.</td> + <td class="tdl" colspan="2">Composition of fresh and rotten farmyard manure</td> + <td class="tdr"><a href="#Page_286">286</a></td> + </tr> + <tr> + <td class="tdr">XIII.</td> + <td class="tdl" colspan="2">Comparison of fresh and rotten manure</td> + <td class="tdr"><a href="#Page_288">288</a></td> + </tr> + <tr> + <td class="tdr">XIV.</td> + <td class="tdl" colspan="2">Lord Kinnaird's experiments</td> + <td class="tdr"><a href="#Page_289">289</a></td> + </tr> + <tr> + <td class="tdr">XV.</td> + <td class="tdl" colspan="2">Drainings of manure-heaps</td> + <td class="tdr"><a href="#Page_290">290</a></td> + </tr> + <tr> + <td class="tdrt">XVI.</td> + <td class="tdl" colspan="2">Amounts of potash and phosphoric acid removed by rotation from a + Prussian morgen (.631 acre)</td> + <td class="tdrb"><a href="#Page_290">290</a></td> + </tr> + <tr> + <td class="tdr">XVII.</td> + <td class="tdl" colspan="2">Composition of farmyard manure (fresh)</td> + <td class="tdr"><a href="#Page_291">291</a></td> + </tr> + <tr> + <td class="tdr">XVIII.</td> + <td class="tdl" colspan="2">The urine (quantity voided)</td> + <td class="tdr"><a href="#Page_291">291</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER VIII.—GUANO.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Importance in agriculture</td> + <td class="tdr"><a href="#Page_293">293</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Influence on British farming</td> + <td class="tdr"><a href="#Page_294">294</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Influence of guano not wholly good</td> + <td class="tdr"><a href="#Page_295">295</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of guano as a manure</td> + <td class="tdr"><a href="#Page_296">296</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Origin and occurrence of guano</td> + <td class="tdr"><a href="#Page_297">297</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Variation in composition of different guanos</td> + <td class="tdr"><a href="#Page_299">299</a></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="3">Nitrogenous guano—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">(<i>a</i>)</td> + <td class="tdl">Peruvian guano</td> + <td class="tdr"><a href="#Page_300">300</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Different deposits of Peruvian guano</td> + <td class="tdr"><a href="#Page_301">301</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Appearance, colour, and nature of Peruvian guano</td> + <td class="tdr"><a href="#Page_303">303</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Composition of Peruvian guano</td> + <td class="tdr"><a href="#Page_304">304</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">(<i>b</i>)</td> + <td class="tdl">Other nitrogenous manures: Angamos, Ichaboe</td> + <td class="tdr"><a href="#Page_306">306</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="3">Phosphatic guanos—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Occurrence of phosphatic guanos</td> + <td class="tdr"><a href="#Page_308">308</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Inequality in composition of phosphatic guanos</td> + <td class="tdr"><a href="#Page_309">309</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">"Dissolved" phosphatic guano</td> + <td class="tdr"><a href="#Page_310">310</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">"Equalised" or "rectified" guano</td> + <td class="tdr"><a href="#Page_311">311</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">The action of phosphatic guanos as manures</td> + <td class="tdr"><a href="#Page_312">312</a><span class='pagenum'><a name="Page_xxii" id="Page_xxii">[Pg xxii]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Proportion of fertilising constituents in guano</td> + <td class="tdr"><a href="#Page_314">314</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Mode of application of guanos</td> + <td class="tdr"><a href="#Page_315">315</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Quantity of guano to be used</td> + <td class="tdr"><a href="#Page_317">317</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Adulteration of guano</td> + <td class="tdr"><a href="#Page_318">318</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">So-called guanos—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Fish-guano</td> + <td class="tdr"><a href="#Page_320">320</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Value of fish-guano</td> + <td class="tdr"><a href="#Page_322">322</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Mean-meal guano</td> + <td class="tdr"><a href="#Page_324">324</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Value of meat-meal guano</td> + <td class="tdr"><a href="#Page_324">324</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Bat guano</td> + <td class="tdr"><a href="#Page_325">325</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Pigeon and fowl dung</td> + <td class="tdr"><a href="#Page_325">325</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER VIII.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Peruvian guano imported into United Kingdom, 1865-1893</td> + <td class="tdr"><a href="#Page_327">327</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Guano deposits of the world</td> + <td class="tdr"><a href="#Page_327">327</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Composition of concretionary nodules</td> + <td class="tdr"><a href="#Page_328">328</a></td> + </tr> + <tr> + <td class="tdrt">IV.</td> + <td class="tdl" colspan="2">Table showing gradual deterioration of Peruvian guano, 1867-1881</td> + <td class="tdrb"><a href="#Page_329">329</a></td> + </tr> + <tr> + <td class="tdr">V.</td> + <td class="tdl" colspan="2">Composition of different guanos</td> + <td class="tdr"><a href="#Page_329">329</a></td> + </tr> + <tr> + <td class="tdr">VI.</td> + <td class="tdl" colspan="2">Liebig's theory as to the action of oxalic acid in guano</td> + <td class="tdr"><a href="#Page_330">330</a></td> + </tr> + <tr> + <td class="tdr">VII.</td> + <td class="tdl" colspan="2">Analyses of dung of fowls, pigeons, ducks, and geese</td> + <td class="tdr"><a href="#Page_331">331</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER IX.—NITRATE OF SODA.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Amount of exports</td> + <td class="tdr"><a href="#Page_332">332</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Date of discovery of nitrate deposits</td> + <td class="tdr"><a href="#Page_333">333</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">The origin of nitrate deposits</td> + <td class="tdr"><a href="#Page_334">334</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Forbes and Darwin on the theory of their origin</td> + <td class="tdr"><a href="#Page_335">335</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Source of nitric acid in nitrate of soda</td> + <td class="tdr"><a href="#Page_337">337</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Guano theory of origin of nitrate of soda</td> + <td class="tdr"><a href="#Page_337">337</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nitric acid in nitrate of soda probably derived from sea-weed</td> + <td class="tdr"><a href="#Page_339">339</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Appearance of nitrate-fields</td> + <td class="tdr"><a href="#Page_340">340</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">The method of mining the nitrate of soda</td> + <td class="tdr"><a href="#Page_341">341</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Composition of <i>caliche</i></td> + <td class="tdr"><a href="#Page_342">342</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Extent of the nitrate deposits</td> + <td class="tdr"><a href="#Page_342">342</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Composition and properties of nitrate of soda</td> + <td class="tdr"><a href="#Page_343">343</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nitrate applied as a top-dressing</td> + <td class="tdr"><a href="#Page_344">344</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nitrate of soda encourages deep roots</td> + <td class="tdr"><a href="#Page_344">344</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Is nitrate of soda an exhausting manure?</td> + <td class="tdr"><a href="#Page_345">345</a><span class='pagenum'><a name="Page_xxiii" id="Page_xxiii">[Pg xxiii]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Crops for which nitrate of soda is suited</td> + <td class="tdr"><a href="#Page_346">346</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Method of application of nitrate of soda</td> + <td class="tdr"><a href="#Page_347">347</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Importance of having a sufficiency of other fertilising constituents</td> + <td class="tdr"><a href="#Page_348">348</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Conclusions drawn</td> + <td class="tdr"><a href="#Page_349">349</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER IX.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl" colspan="3">Total shipmentes from South America, 1830-1893</td> + <td class="tdr"><a href="#Page_351">351</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Total imports into Europe and United Kingdom, 1873-1892</td> + <td class="tdr"><a href="#Page_351">351</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER X.—SULPHATE OF AMMONIA.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of ammonia as a manure</td> + <td class="tdr"><a href="#Page_352">352</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sources of sulphate of ammonia</td> + <td class="tdr"><a href="#Page_353">353</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Ammonia from gas-works</td> + <td class="tdr"><a href="#Page_353">353</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Other sources</td> + <td class="tdr"><a href="#Page_354">354</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Composition, &c., of sulphate of ammonia</td> + <td class="tdr"><a href="#Page_355">355</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Application of sulphate of ammonia</td> + <td class="tdr"><a href="#Page_356">356</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER X.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl" colspan="3">Production of sulphate of ammonia in United Kingdom, 1870-1892</td> + <td class="tdr"><a href="#Page_358">358</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XI.—BONES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Early use of bones</td> + <td class="tdr"><a href="#Page_359">359</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Different forms in which bones are used</td> + <td class="tdr"><a href="#Page_360">360</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Composition of bones</td> + <td class="tdr"><a href="#Page_362">362</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">The organic matter of bones</td> + <td class="tdr"><a href="#Page_363">363</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">The inorganic matter of bones</td> + <td class="tdr"><a href="#Page_363">363</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Treatment of bones</td> + <td class="tdr"><a href="#Page_364">364</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Action of bones</td> + <td class="tdr"><a href="#Page_365">365</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Dissolved bones</td> + <td class="tdr"><a href="#Page_368">368</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Crops suited for bones</td> + <td class="tdr"><a href="#Page_368">368</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Bone-ash</td> + <td class="tdr"><a href="#Page_369">369</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Bone-char or bone-black</td> + <td class="tdr"><a href="#Page_369">369</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER XI.</span><span class='pagenum'><a name="Page_xxiv" id="Page_xxiv">[Pg xxiv]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Analysis of bone-meal</td> + <td class="tdr"><a href="#Page_371">371</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Analysis of dissolved bones</td> + <td class="tdr"><a href="#Page_371">371</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Composition of bone-ash</td> + <td class="tdr"><a href="#Page_372">372</a></td> + </tr> + <tr> + <td class="tdr">IV.</td> + <td class="tdl" colspan="2">Composition of bone-char</td> + <td class="tdr"><a href="#Page_372">372</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XII.—MINERAL PHOSPHATES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Coprolites</td> + <td class="tdr"><a href="#Page_373">373</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Canadian apatite or phosphorite</td> + <td class="tdr"><a href="#Page_374">374</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Estremadura or Spanish phosphates</td> + <td class="tdr"><a href="#Page_375">375</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Norwegian apatite</td> + <td class="tdr"><a href="#Page_376">376</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Charlestown or South Carolina phosphate</td> + <td class="tdr"><a href="#Page_376">376</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Belgian phosphate</td> + <td class="tdr"><a href="#Page_377">377</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Somme phosphate</td> + <td class="tdr"><a href="#Page_378">378</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Florida phosphate</td> + <td class="tdr"><a href="#Page_378">378</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Lahn phosphate</td> + <td class="tdr"><a href="#Page_379">379</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Bordeaux or French phosphate</td> + <td class="tdr"><a href="#Page_379">379</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Algerian phosphate</td> + <td class="tdr"><a href="#Page_379">379</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Crust guanos</td> + <td class="tdr"><a href="#Page_379">379</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of mineral phosphates as manures</td> + <td class="tdr"><a href="#Page_380">380</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER XII.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl" colspan="3">Imports of phosphates</td> + <td class="tdr"><a href="#Page_381">381</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XIII.—SUPERPHOSPHATES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Discovery of superphosphate by Liebig</td> + <td class="tdr"><a href="#Page_382">382</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Manufacture of superphosphate</td> + <td class="tdr"><a href="#Page_383">383</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nature of the reaction taking place</td> + <td class="tdr"><a href="#Page_385">385</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Phosphates of lime</td> + <td class="tdr"><a href="#Page_385">385</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Reverted phosphate</td> + <td class="tdr"><a href="#Page_389">389</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of reverted phosphate</td> + <td class="tdr"><a href="#Page_391">391</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Composition of superphosphates</td> + <td class="tdr"><a href="#Page_391">391</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Action of superphosphates</td> + <td class="tdr"><a href="#Page_392">392</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Action of superphosphate sometimes unfavourable</td> + <td class="tdr"><a href="#Page_395">395</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Application of superphosphate</td> + <td class="tdr"><a href="#Page_395">395</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of insoluble phosphates</td> + <td class="tdr"><a href="#Page_396">396</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Rate at which superphosphate is applied</td> + <td class="tdr"><a href="#Page_397">397</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%">APPENDIX TO CHAPTER XIII.</span><span class='pagenum'><a name="Page_xxv" id="Page_xxv">[Pg xxv]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%">NOTE</span></td> + </tr> + <tr> + <td class="tdrt">I.</td> + <td class="tdl" colspan="2">The formulæ, and molecular and percentage composition, of + the different phosphates</td> + <td class="tdrb"><a href="#Page_398">398</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Reactions of sulphuric acid and phosphate of lime</td> + <td class="tdr"><a href="#Page_398">398</a></td> + </tr> + <tr> + <td class="tdrt">III.</td> + <td class="tdl" colspan="2">Table for conversion of soluble phosphate into insoluble phosphate</td> + <td class="tdrb"><a href="#Page_399">399</a></td> + </tr> + <tr> + <td class="tdr">IV.</td> + <td class="tdl" colspan="2">Action of iron and alumina in causing reversion</td> + <td class="tdr"><a href="#Page_399">399</a></td> + </tr> + <tr> + <td class="tdr">V.</td> + <td class="tdl" colspan="2">Relative trade values of phosphoric acid in different manures</td> + <td class="tdr"><a href="#Page_400">400</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XIV.—PHOSPHATE OR BASIC SLAG.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Its manufacture</td> + <td class="tdr"><a href="#Page_401">401</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Not at first used</td> + <td class="tdr"><a href="#Page_403">403</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Discovery of its value as a manure</td> + <td class="tdr"><a href="#Page_403">403</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Composition of basic slag</td> + <td class="tdr"><a href="#Page_404">404</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Processes for preparing slag</td> + <td class="tdr"><a href="#Page_406">406</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Solubility of basic slag</td> + <td class="tdr"><a href="#Page_408">408</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Darmstadt experiments with basic slag</td> + <td class="tdr"><a href="#Page_410">410</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Results of other experiments</td> + <td class="tdr"><a href="#Page_413">413</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Soils most suited for slag</td> + <td class="tdr"><a href="#Page_414">414</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Rate of application</td> + <td class="tdr"><a href="#Page_414">414</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Method of application</td> + <td class="tdr"><a href="#Page_416">416</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER XIV.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl" colspan="3">Analysis of basic slag</td> + <td class="tdr"><a href="#Page_417">417</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XV.—POTASSIC MANURES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Relative importance</td> + <td class="tdr"><a href="#Page_418">418</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Scottish soils supplied with potash</td> + <td class="tdr"><a href="#Page_419">419</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Sources of potassic manures</td> + <td class="tdr"><a href="#Page_419">419</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Stassfurt potash salts</td> + <td class="tdr"><a href="#Page_420">420</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Relative merits of sulphate and muriate of potash</td> + <td class="tdr"><a href="#Page_421">421</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Application of potash manures</td> + <td class="tdr"><a href="#Page_422">422</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Soils and crops suited for potash manures</td> + <td class="tdr"><a href="#Page_423">423</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Rate of application</td> + <td class="tdr"><a href="#Page_423">423</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XVI.—MINOR ARTIFICIAL MANURES.<span class='pagenum'><a name="Page_xxvi" id="Page_xxvi">[Pg xxvi]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Scutch</td> + <td class="tdr"><a href="#Page_427">427</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Shoddy and wool-waste</td> + <td class="tdr"><a href="#Page_427">427</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Soot</td> + <td class="tdr"><a href="#Page_428">428</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XVII.—SEWAGE AS A MANURE.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Irrigation</td> + <td class="tdr"><a href="#Page_431">431</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Effects of continued application of sewage</td> + <td class="tdr"><a href="#Page_433">433</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Intermittent irrigation</td> + <td class="tdr"><a href="#Page_434">434</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Crops suited for sewage</td> + <td class="tdr"><a href="#Page_434">434</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Treatment of sewage by precipitation, &c.</td> + <td class="tdr"><a href="#Page_436">436</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of sewage sludge</td> + <td class="tdr"><a href="#Page_439">439</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="3">CHAPTER XVIII.—LIQUID MANURE</td> + <td class="tdr"><a href="#Page_442">442</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XIX.—COMPOSTS.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Farmyard manure a typical compost</td> + <td class="tdr"><a href="#Page_446">446</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Other composts</td> + <td class="tdr"><a href="#Page_447">447</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XX.—INDIRECT MANURES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Lime</td> + <td class="tdr"><a href="#Page_449">449</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Antiquity of lime as a manure</td> + <td class="tdr"><a href="#Page_449">449</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action of lime</td> + <td class="tdr"><a href="#Page_449">449</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Lime a necessary plant-food</td> + <td class="tdr"><a href="#Page_450">450</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Lime of abundant occurrence</td> + <td class="tdr"><a href="#Page_452">452</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Lime returned to the soil in ordinary agricultural practice</td> + <td class="tdr"><a href="#Page_452">452</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Different forms of lime</td> + <td class="tdr"><a href="#Page_453">453</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Caustic lime</td> + <td class="tdr"><a href="#Page_453">453</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Lime acts both mechanically and chemically</td> + <td class="tdr"><a href="#Page_455">455</a></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Mechanical functions of lime</td> + <td class="tdr"><a href="#Page_455">455</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action on soil's texture</td> + <td class="tdr"><a href="#Page_455">455</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Lime renders light soils more cohesive</td> + <td class="tdr"><a href="#Page_457">457</a></td> + </tr> + <tr> + <td class="tdr">II.</td> + <td class="tdl" colspan="2">Chemical action of lime</td> + <td class="tdr"><a href="#Page_457">457</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Biological action of lime</td> + <td class="tdr"><a href="#Page_459">459</a><span class='pagenum'><a name="Page_xxvii" id="Page_xxvii">[Pg xxvii]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Action of lime on nitrogenous organic matter</td> + <td class="tdr"><a href="#Page_460">460</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Recapitulation</td> + <td class="tdr"><a href="#Page_461">461</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XXI.—INDIRECT MANURES—GYPSUM, SALT, <span + class="smcap">Etc.</span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Gypsum</td> + <td class="tdr"><a href="#Page_462">462</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Mode in which gypsum acts</td> + <td class="tdr"><a href="#Page_462">462</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Salt</td> + <td class="tdr"><a href="#Page_465">465</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Antiquity of the use of salt</td> + <td class="tdr"><a href="#Page_465">465</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nature of its action</td> + <td class="tdr"><a href="#Page_465">465</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Salt not a necessary plant-food</td> + <td class="tdr"><a href="#Page_466">466</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Can soda replace potash?</td> + <td class="tdr"><a href="#Page_466">466</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Salt of universal occurrence</td> + <td class="tdr"><a href="#Page_467">467</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Special sources of salt</td> + <td class="tdr"><a href="#Page_468">468</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">The action of salt</td> + <td class="tdr"><a href="#Page_468">468</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Mechanical action on soils</td> + <td class="tdr"><a href="#Page_470">470</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Solvent action</td> + <td class="tdr"><a href="#Page_470">470</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Best used in small quantities along with manures</td> + <td class="tdr"><a href="#Page_472">472</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Affects quality of crop</td> + <td class="tdr"><a href="#Page_472">472</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Rate of application</td> + <td class="tdr"><a href="#Page_473">473</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XXII.—THE APPLICATION OF MANURES.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Influence of manures in increasing soil-fertility</td> + <td class="tdr"><a href="#Page_474">474</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Influence of farmyard manure on the soil</td> + <td class="tdr"><a href="#Page_475">475</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Farmyard manure <i>v.</i> artificials</td> + <td class="tdr"><a href="#Page_476">476</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Farmyard manure not favourable to certain crops</td> + <td class="tdr"><a href="#Page_477">477</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Conditions determining the application of artificial manures</td> + <td class="tdr"><a href="#Page_477">477</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nature of the manure</td> + <td class="tdr"><a href="#Page_478">478</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nitrogenous manures</td> + <td class="tdr"><a href="#Page_478">478</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Phosphatic manures</td> + <td class="tdr"><a href="#Page_480">480</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Potash manures</td> + <td class="tdr"><a href="#Page_480">480</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nature of soil</td> + <td class="tdr"><a href="#Page_481">481</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nature of previous manuring</td> + <td class="tdr"><a href="#Page_482">482</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nature of the crop</td> + <td class="tdr"><a href="#Page_483">483</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Amounts of fertilising ingredients removed from the soil by + different crops</td> + <td class="tdrb"><a href="#Page_484">484</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Capacity of crops for assimilating manures</td> + <td class="tdr"><a href="#Page_486">486</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Difference in root-systems of different crops</td> + <td class="tdr"><a href="#Page_488">488</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Period of growth</td> + <td class="tdr"><a href="#Page_489">489</a><span class='pagenum'><a name="Page_xxviii" id="Page_xxviii">[Pg xxviii]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Variation in composition of crops</td> + <td class="tdr"><a href="#Page_490">490</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Absorption of plant-food</td> + <td class="tdr"><a href="#Page_490">490</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Fertilising ingredients lodge in the seed</td> + <td class="tdr"><a href="#Page_491">491</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Forms in which nitrogen exists in plants</td> + <td class="tdr"><a href="#Page_491">491</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Bearing of above on agricultural practice</td> + <td class="tdr"><a href="#Page_492">492</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Influence of excessive manuring of crops</td> + <td class="tdr"><a href="#Page_492">492</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XXIII.—MANURING OF THE COMMON FARM CROPS.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Cereals</td> + <td class="tdr"><a href="#Page_493">493</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Especially benefited by nitrogenous manures</td> + <td class="tdr"><a href="#Page_494">494</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Power of absorbing silicates</td> + <td class="tdr"><a href="#Page_494">494</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Barley</td> + <td class="tdr"><a href="#Page_495">495</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Period of growth</td> + <td class="tdr"><a href="#Page_495">495</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Most suitable soil</td> + <td class="tdr"><a href="#Page_496">496</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Farmyard manure not suitable</td> + <td class="tdr"><a href="#Page_497">497</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Importance of uniform manuring of barley</td> + <td class="tdr"><a href="#Page_497">497</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Norfolk experiments on barley</td> + <td class="tdr"><a href="#Page_497">497</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Proportion of grain to straw</td> + <td class="tdr"><a href="#Page_498">498</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Wheat</td> + <td class="tdr"><a href="#Page_499">499</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Rothamsted experiments</td> + <td class="tdr"><a href="#Page_500">500</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Continuous growth</td> + <td class="tdr"><a href="#Page_500">500</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Flitcham experiments</td> + <td class="tdr"><a href="#Page_500">500</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Oats</td> + <td class="tdr"><a href="#Page_501">501</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">A very hardy crop</td> + <td class="tdr"><a href="#Page_502">502</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Require mixed nitrogenous manuring</td> + <td class="tdr"><a href="#Page_502">502</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Arendt's experiments</td> + <td class="tdr"><a href="#Page_503">503</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Avenine</td> + <td class="tdr"><a href="#Page_503">503</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Quantities of manures</td> + <td class="tdr"><a href="#Page_504">504</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Grass</td> + <td class="tdr"><a href="#Page_504">504</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Effect of manures on herbage of pastures</td> + <td class="tdr"><a href="#Page_505">505</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Influence of farmyard manure</td> + <td class="tdr"><a href="#Page_506">506</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Influence of soil and season on pastures</td> + <td class="tdr"><a href="#Page_507">507</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Manuring of meadow land</td> + <td class="tdr"><a href="#Page_508">508</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Bangor experiments</td> + <td class="tdr"><a href="#Page_508">508</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Norfolk experiments</td> + <td class="tdr"><a href="#Page_509">509</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Manuring of permanent pastures</td> + <td class="tdr"><a href="#Page_509">509</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Roots</td> + <td class="tdr"><a href="#Page_510">510</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Influence of manure on composition</td> + <td class="tdr"><a href="#Page_512">512</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogenous manures increase sugar</td> + <td class="tdr"><a href="#Page_512">512</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Amount of nitrogen recovered in increase of crop</td> + <td class="tdr"><a href="#Page_513">513</a><span class='pagenum'><a name="Page_xxix" id="Page_xxix">[Pg xxix]</a></span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Norfolk experiments</td> + <td class="tdr"><a href="#Page_513">513</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Manure for swedes</td> + <td class="tdr"><a href="#Page_514">514</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Highland Society's experiments</td> + <td class="tdr"><a href="#Page_515">515</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Manuring for rich crops of turnips</td> + <td class="tdr"><a href="#Page_516">516</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Experiments by the author on turnips</td> + <td class="tdr"><a href="#Page_516">516</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Potatoes</td> + <td class="tdr"><a href="#Page_517">517</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Highland Society's experiments</td> + <td class="tdr"><a href="#Page_518">518</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">The Rothamsted experiments</td> + <td class="tdr"><a href="#Page_519">519</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Effect of farmyard manure</td> + <td class="tdr"><a href="#Page_520">520</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Manuring of potatoes in Jersey</td> + <td class="tdr"><a href="#Page_521">521</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">The influence of manure on the composition</td> + <td class="tdr"><a href="#Page_521">521</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Leguminous crops</td> + <td class="tdr"><a href="#Page_522">522</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Leguminous plants benefit by potash</td> + <td class="tdr"><a href="#Page_523">523</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Nitrogenous manures may be hurtful</td> + <td class="tdr"><a href="#Page_523">523</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Clover sickness</td> + <td class="tdr"><a href="#Page_524">524</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Alternate wheat and bean rotation</td> + <td class="tdr"><a href="#Page_524">524</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Beans</td> + <td class="tdr"><a href="#Page_525">525</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Manure for beans</td> + <td class="tdr"><a href="#Page_525">525</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Relative value of manurial ingredients</td> + <td class="tdr"><a href="#Page_526">526</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Gypsum as a bean manure</td> + <td class="tdr"><a href="#Page_526">526</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Effect of manure on composition of crop</td> + <td class="tdr"><a href="#Page_527">527</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Peas</td> + <td class="tdr"><a href="#Page_527">527</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Hops</td> + <td class="tdr"><a href="#Page_528">528</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Cabbages</td> + <td class="tdr"><a href="#Page_528">528</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER XXIII.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl" colspan="3">Experiments on bean-manuring</td> + <td class="tdr"><a href="#Page_530">530</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XXIV.—ON THE METHOD OF APPLICATION,<br /> AND ON THE MIXING + OF MANURES</td> + </tr> + <tr> + <td class="tdl" colspan="3">Equal distribution of manures</td> + <td class="tdr"><a href="#Page_531">531</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Mixing manures</td> + <td class="tdr"><a href="#Page_532">532</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Risks of loss in mixtures</td> + <td class="tdr"><a href="#Page_533">533</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss of ammonia</td> + <td class="tdr"><a href="#Page_533">533</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Effects of lime on ammonia</td> + <td class="tdr"><a href="#Page_535">535</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Loss of nitric acid</td> + <td class="tdr"><a href="#Page_536">536</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Reversion of phosphates</td> + <td class="tdr"><a href="#Page_537">537</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Manurial ingredients should be applied separately</td> + <td class="tdr"><a href="#Page_538">538</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XXV.—ON THE VALUATION AND ANALYSIS OF MANURES. + <span class='pagenum'><a name="Page_xxx" id="Page_xxx">[Pg xxx]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of chemical analysis</td> + <td class="tdr"><a href="#Page_539">539</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Interpretation of chemical analysis</td> + <td class="tdr"><a href="#Page_539">539</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Nitrogen</td> + <td class="tdr"><a href="#Page_540">540</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Phosphoric acid</td> + <td class="tdr"><a href="#Page_541">541</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Importance of mechanical condition of phosphate</td> + <td class="tdr"><a href="#Page_542">542</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Potash</td> + <td class="tdr"><a href="#Page_542">542</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Other items in the chemical analysis of manures</td> + <td class="tdr"><a href="#Page_543">543</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Fertilisers and Feeding Stuffs Act</td> + <td class="tdr"><a href="#Page_543">543</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Different methods of valuing manures</td> + <td class="tdr"><a href="#Page_544">544</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Unit value of manurial ingredients</td> + <td class="tdr"><a href="#Page_544">544</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Intrinsic value of manures</td> + <td class="tdr"><a href="#Page_545">545</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Field experiments</td> + <td class="tdr"><a href="#Page_545">545</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Educational value of field experiments</td> + <td class="tdr"><a href="#Page_547">547</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of manures deduced from experiments</td> + <td class="tdr"><a href="#Page_548">548</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Value of unexhausted manures</td> + <td class="tdr"><a href="#Page_549">549</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Potential fertility of a soil</td> + <td class="tdr"><a href="#Page_549">549</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Tables of value of unexhausted manures</td> + <td class="tdr"><a href="#Page_551">551</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4"><span style="font-size: 90%;">APPENDIX TO CHAPTER XXV.</span></td> + </tr> + <tr> + <td class="tdl" colspan="4"><span style="font-size: 60%;">NOTE</span></td> + </tr> + <tr> + <td class="tdr">I.</td> + <td class="tdl" colspan="2">Factors for calculating compounds from manurial ingredients</td> + <td class="tdr"><a href="#Page_553">553</a></td> + </tr> + <tr> + <td class="tdrt">II.</td> + <td class="tdl" colspan="2">Units for determining commercial value of manures and cash prices + of manures</td> + <td class="tdrb"><a href="#Page_554">554, 555</a></td> + </tr> + <tr> + <td class="tdr">III.</td> + <td class="tdl" colspan="2">Manurial value of nitrogen and potash in different substances</td> + <td class="tdr"><a href="#Page_556">556</a></td> + </tr> + <tr> + <td class="tdrt">IV.</td> + <td class="tdl" colspan="2">Comparative manurial value of different forms of nitrogen and potash</td> + <td class="tdrb"><a href="#Page_557">557</a></td> + </tr> + <tr> + <td class="tdrt">V.</td> + <td class="tdl" colspan="2">Lawes' and Gilbert's tables for calculating unexhausted value of + manures</td> + <td class="tdrb"><a href="#Page_559">559</a></td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" colspan="4">CHAPTER XXVI.—THE ROTHAMSTED EXPERIMENTS.</td> + </tr> + <tr> + <td class="tdl" colspan="3">Nature of experiments on crops and manures</td> + <td class="tdr"><a href="#Page_561">561</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Soil of Rothamsted</td> + <td class="tdr"><a href="#Page_561">561</a></td> + </tr> + <tr> + <td class="tdlt" colspan="3">Table I. List of Rothamsted field experiments</td> + <td class="tdrb"><a href="#Page_562">562</a></td> + </tr> + <tr> + <td class="tdl" colspan="4">Wheat experiments—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Unmanured plots</td> + <td class="tdr"><a href="#Page_565">565</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Wheat grown continuously on same land (unmanured)</td> + <td class="tdr"><a href="#Page_562">562</a><span class='pagenum'><a name="Page_xxxi" id="Page_xxxi">[Pg xxxi]</a></span></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Table II. Results of first eight years</td> + <td class="tdr"><a href="#Page_562">562</a></td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdl">Table III. Results of subsequent forty years</td> + <td class="tdr"><a href="#Page_562">562</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Tablel IV. Wheat grown continuously with farmyard manure (14 tons + per annum)</td> + <td class="tdrb"><a href="#Page_564">564</a></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl" colspan="2">Table V. Wheat grown continuously with artificial manures</td> + <td class="tdr"><a href="#Page_565">565</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Table VI. Experiments on the growth of barley, forty years, 1852-91</td> + <td class="tdr"><a href="#Page_566">566</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Table VIII. Experiments on the growth of oats, 1869-78</td> + <td class="tdr"><a href="#Page_567">567</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Table IX. Experiments on mangel-wurzel</td> + <td class="tdr"><a href="#Page_568">568, 569</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Table X. Experiments with different manures on permanent meadow-land, + thirty-six years, 1856-91</td> + <td class="tdrb"><a href="#Page_570">570</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Table XI. Experiments on the growth of potatoes— average for + five seasons, 1876-80</td> + <td class="tdrb"><a href="#Page_571">571</a></td> + </tr> + <tr> + <td class="tdl" colspan="3">Table XII. Experiments on growth of potatoes (continued)—average + for twelve seasons, 1881-92</td> + <td class="tdrb"><a href="#Page_572">572</a></td> + </tr> + <tr> + <td class="tdc" colspan="4">_______________</td> + </tr> + <tr> + <td class="tdl" colspan="3"><span class="smcap">Index</span></td> + <td class="tdr"><a href="#Page_573">573</a></td> + </tr> + +</table> +</div> + +<br /> +<br /> +<br /> +<br /> + +<hr style="width: 65%;" /><span class='pagenum'><a name="Page_xxxii" id="Page_xxxii"></a></span> +<br /> +<h2><a name="PART_I" id="PART_I"></a>PART I.</h2> + +<h2>HISTORICAL INTRODUCTION</h2> + +<span class='pagenum'><a name="Page_xxxiii" id="Page_xxxiii"></a></span> +<br /> +<hr /><span class='pagenum'><a name="Page_3" id="Page_3">[Pg 3]</a></span> +<br /> +<h2>MANURES AND THE PRINCIPLES OF MANURING.</h2> + +<h2>HISTORICAL INTRODUCTION.</h2> +<br /> + +<p>Agricultural Chemistry, like most branches of natural science, may be +said to be entirely of modern growth. While it is true we have many old +speculations on the subject, they can scarcely be said to possess much +scientific value. The great questions which had first to be solved by +the agricultural chemist were,—What is the food of plants? and,—What +is the source of that food? The second of these two questions more +easily admitted of answer than the first. The source of plant-food could +only be the atmosphere or the soil. As the composition of the +atmosphere, however, was not discovered till the close of last century, +and the chemistry of the soil is a question which is still requiring +much work <span class='pagenum'><a name="Page_4" id="Page_4">[Pg 4]</a></span>ere we shall be in possession of anything like a full +knowledge of it, it will be at once obvious that the very fundamental +conditions for a solution of the question were awanting. The beginning, +then, of a true scientific agricultural chemistry may be said to date +from the brilliant discoveries associated with the names of Priestley, +Scheele, Lavoisier, Cavendish, and Black—that is, towards the close of +last century.</p> +<br /> + +<p class="cen"><i>Early Theories on Source of Plant-food.</i></p> + +<p>While this is so, and while we must regard the early attempts made +towards solving this question as being, for the most part, of little +scientific value, it is not without interest, from the historical point +of view, to glance briefly at some of these old interesting +speculations.</p> + +<p>The Aristotelian doctrine, regarding the possibility of dividing matter +into the so-called four primary elements, <i>fire</i>, <i>air</i>, <i>earth</i>, and +<i>water</i>, which obtained in one form or another till the birth of modern +chemistry, had naturally an important influence on these early theories.</p> +<br /> + +<p class="cen"><i>Van Helmont's Theory.</i></p> + +<p>Among the earliest and most important attempts made to solve the problem +of plant-growth was that by Jean Baptiste Van Helmont, one of the best +known of the alchemists, who flourished about the beginning of the +seventeenth century. Van Helmont believed <span class='pagenum'><a name="Page_5" id="Page_5">[Pg 5]</a></span>that he had proved by a +conclusive experiment that all the products of vegetables were capable +of being generated from water. The details of this classical experiment +were as follows:—</p> + +<p>"He took a given weight of dry soil—200 lb.—and into this soil he +planted a willow-tree that weighed 5 lb., and he watered this carefully +from time to time with pure rain-water, taking care to prevent any dust +or dirt falling on to the earth in which the plant grew. He allowed this +to go on growing for five years, and at the end of that period, thinking +his experiment had been conducted sufficiently long, he pulled up his +tree by the roots, shook all the earth off, dried the earth again, +weighed the earth and weighed the plant. He found that the plant now +weighed 169 lb. 3 ounces, whereas the weight of the soil remained very +nearly what it was—about 200 lb. It had only lost 2 ounces in +weight."<a name="FNanchor_1_1" id="FNanchor_1_1"></a><a href="#Footnote_1_1" class="fnanchor">[1]</a></p> + +<p>The conclusion, therefore, come to by Van Helmont was that the source of +plant-food was <i>water</i>.<a name="FNanchor_2_2" id="FNanchor_2_2"></a><a href="#Footnote_2_2" class="fnanchor">[2]</a></p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_6" id="Page_6">[Pg 6]</a></span><i>Digby's Theory.</i></p> + +<p>Some fifty years later an extremely interesting book was published +bearing the following title: 'A Discourse concerning the Vegetation of +Plants, spoken by Sir Kenelm Digby, at Gresham College, on the 23d of +January 1660. (At a meeting of the Society for promoting Philosophical +Knowledge by Experiments. London: Printed for John Williams, in Little +Britain, over against St Botolph's Church, 1669.)' The author attributes +plant-growth to the influence of a <i>balsam</i> which the air contains. This +book is especially interesting as containing the earliest recognition of +the value of saltpetre as a manure. The following is an extract from +this interesting old work:—</p> + +<p>"The sickness, and at last the death of a plant, in its natural course, +proceeds from the want of that balsamick saline juice; which, I have +said, makes it swell, germinate, and augment itself. This want may +proceed either from a destitution of it in the place where the plant +grows, as when it is in a barren soil or bad air, or from a defect in +the plant itself, that hath not vigour sufficient to attract it, though +it be within the sphere of it; as when the root has become <span class='pagenum'><a name="Page_7" id="Page_7">[Pg 7]</a></span>so hard, +obstructed and cold, as that it hath lost its vegetable functions. Now, +both these may be remedy'd, in a great measure, by one and the same +physick.... The watering of soils with cold hungray springs doth little +good; whereas muddy saline waters brought to overflow a piece of ground +enrich it much. But above all, well-digested dew makes all plants +luxuriate and prosper most. Now what may it be that endues these liquors +with such prolifick virtue? The meer water which is common to them all, +cannot be it; there must be something else enclosed within it, to which +the water serves but for a vehicle. Examine it by spagyric art, and you +will find that it is nothing else than a <i>nitrous salt</i>, which is +dilated in the water. It is this salt which gives fœcundity to all +things: and from this salt (rightly understood) not only all vegetables, +but also all minerals draw their origine. By the help of plain +<i>salt-peter</i>, dilated in water and mingled with some other fit earthy +substance, that may familiarize it a little with the corn into which I +endeavoured to introduce it, I have made the barrenest ground far out-go +the richest, in giving a prodigiously plentiful harvest. I have seen +hemp-seed soaked in this liquor, that hath in due time made such plants +arise, as, for the tallness and hardness of them, seemed rather to be +coppice-wood of fourteen years' growth at least, than plain hemp. The +fathers of the Christian doctrine at Paris still keep by them for a +monument (and indeed it is an admirable one) <span class='pagenum'><a name="Page_8" id="Page_8">[Pg 8]</a></span>a plant of barley +consisting of 249 stalks, springing from one root or grain of barley; in +which they counted above 18,000 grains or seeds of barley. But do you +think that it is barely the salt-peter, imbibed into the seed or root, +which causeth this fertility? no: that would be soon exhausted and could +not furnish matter to so vast a progeny. The salt-peter there is like a +magnet, which attracts a like salt which fœcundates the air, and gave +cause to the Cosmopolite to say there is in the air a hidden food of +life."<a name="FNanchor_3_3" id="FNanchor_3_3"></a><a href="#Footnote_3_3" class="fnanchor">[3]</a></p> +<br /> + +<p class="cen"><i>Duhamel and Hales.</i></p> + +<p>The names of the French writer, Duhamel, and of the English, Stephen +Hales, may be mentioned in passing as authors of works bearing on the +question of vegetable physiology. Both of these writers flourished about +the middle of the eighteenth century. The writings of the former +contained much valuable information on the effects of grafting, motion +of sap, and influence of light on vegetable growth, and also the results +of experiments which the author had carried out on the influence of +treating plants with certain substances. 'Statical Essays, containing +Vegetable Staticks; or an Account of some Statical Experiments on the +Sap of Vegetables, by Stephen Hales, D.D.' (2 <span class='pagenum'><a name="Page_9" id="Page_9">[Pg 9]</a></span>vols.), was published in +London in 1738; and contained, as will be seen from its title, records +of experiments of very much the same nature as those of Duhamel.</p> +<br /> + +<p class="cen"><i>Jethro Tull's Theory.</i></p> + +<p>Some reference may be made to a theory which created a considerable +amount of interest when it was first published—viz., that of Jethro +Tull. The chief value of Tull's contribution to the subject of +agricultural science was, that he emphasised the importance of tillage +operations by putting forward a theory to account for the fact, +universally recognised, that the more thoroughly a soil was tilled, the +more luxuriant the crops would be. As Tull's theory had a very +considerable influence in stirring up interest in many of the most +important problems in agricultural chemistry, and as it contained in +itself much, the value of which we have only of late years come to +understand, a brief statement of this theory may not be without +interest.</p> + +<p>According to Tull the food of plants consists of the particles of the +soil. These particles, however, must be rendered very minute before they +become available for the plant, which absorbs them by means of its +rootlets. This pulverisation of the soil goes on in nature independently +of the farmer, but only very slowly, and the farmer has therefore to +hasten it on by means of tillage operations. The more efficiently these +operations are carried on, the more abundant will the supply <span class='pagenum'><a name="Page_10" id="Page_10">[Pg 10]</a></span>of +plant-food be rendered in the soil. He consequently introduced and +advocated the system of horse-hoe husbandry. This theory, he informs us, +was suggested to him by the custom, which he had noticed on the +Continent, of growing vines in rows, and hoeing the intervals between +these rows from time to time. The excellent results which followed this +mode of cultivation induced him to adopt it in England for his farm +crops. He accordingly sowed his crops in rows or ridges, wide enough +apart to admit of thorough tillage of the intervals by ploughing as well +as by hand-hoeing. This he continued until the plant had reached +maturity. As to the exact width of the interval most suitable, he made a +large number of experiments. At first, in the cultivation of wheat, he +made this interval six feet wide; but latterly he adopted an interval of +lesser width, that finally arrived at being between four and five feet. +He likewise experimented on each separate ridge as to which was the best +number of rows of wheat to be sown, latterly adopting, as most +convenient, two rows at ten inches apart. The great success which he met +with in this system of cultivation induced him to publish the results of +his experiments in his famous work, 'Horse-Hoeing Husbandry.'</p> + +<p>While Tull's theory was based on principles at heart thoroughly sound, +he was carried away by his personal success into drawing unwarrantable +deductions. Thus he came to the conclusion that rotation <span class='pagenum'><a name="Page_11" id="Page_11">[Pg 11]</a></span>of crops was +unnecessary, provided that a thorough system of tillage was carried out. +Manures also, according to him, might be entirely dispensed with under +his system of cultivation, for the true function of all manures is to +aid in the pulverisation of the soil by fermentation.</p> + +<p>The first really valuable scientific facts contributed to the science +were made by Priestley, Bonnet, Ingenhousz, and Sénébier.</p> +<br /> + +<p class="cen"><i>Discovery of the Source of Plants' Carbon.</i></p> + +<p>To Charles Bonnet (1720-1793), a Swiss naturalist, is due the credit of +having made the first contribution to a discovery of very great +importance—viz., the true source of the <i>carbon</i>, which we now know +forms so large a portion of the plant-substance. Bonnet, who had devoted +himself to the question of the function of leaves, noticed that when +these were immersed in water bubbles were seen, after a time, to collect +on their surface. De la Hire, it ought to be pointed out, had noticed +this same fact about sixty years earlier. It was left to Priestley, +however, to identify these bubbles with the gas he had a short time +previously discovered—viz., oxygen. Priestley had observed, about this +time, the interesting fact that plants possessed the power of purifying +air vitiated by the presence of animal life.<a name="FNanchor_4_4" id="FNanchor_4_4"></a><a href="#Footnote_4_4" class="fnanchor">[4]</a> The <span class='pagenum'><a name="Page_12" id="Page_12">[Pg 12]</a></span>next step in this +highly interesting and important discovery was taken by John Ingenhousz +(1730-1799), an eminent physician and natural philosopher. In 1779, +Ingenhousz published a work in London entitled 'Experiments on +Vegetables.' In it he gives the results of some important experiments he +had made on the question already investigated by Bonnet and Priestley. +These experiments proved that plant-leaves only gave up their oxygen in +the presence of sunlight. In 1782 he published another work on 'The +Influence of the Vegetable Kingdom on the Animal Creation.'<a name="FNanchor_5_5" id="FNanchor_5_5"></a><a href="#Footnote_5_5" class="fnanchor">[5]</a></p> + +<p>The source of the gas, which Bonnet had first noticed to be given off +from plant-leaves, Priestley had identified as oxygen, and Ingenhousz +had proved to be only given off under the influence of the sun's rays, +was finally shown by a Swiss naturalist, Jean Sénébier<a name="FNanchor_6_6" id="FNanchor_6_6"></a><a href="#Footnote_6_6" class="fnanchor">[6]</a> (1742-1809), +to be the <i>carbonic acid gas</i> in the air, which the plant absorbed and +decomposed, giving out the oxygen and assimilating the carbon.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_13" id="Page_13">[Pg 13]</a></span><i>Publication of First English Treatise on Agricultural Chemistry.</i></p> + +<p>In 1795, a book dealing with the relations between chemistry and +agriculture was published. This work was written by a Scottish nobleman, +the Earl of Dundonald, and possesses especial interest from the fact +that it is the first book in the English language on agricultural +chemistry. The full title is as follows: 'A Treatise showing the +Intimate Connection that subsists between Agriculture and Chemistry.'</p> + +<p>In his introduction the author says: "The slow progress which +agriculture has hitherto made as a science is to be ascribed to a want +of education on the part of the cultivators of the soil, and to a want +of knowledge, in such authors as have written on agriculture, of the +intimate connection that subsists between the science and that of +chemistry. Indeed, there is no operation or process not merely +mechanical that does not depend on chemistry, which is defined to be a +knowledge of the properties of bodies, and of the effects resulting from +their different combinations."</p> + +<p>In quoting this passage Professor S. W. Johnson remarks:<a name="FNanchor_7_7" id="FNanchor_7_7"></a><a href="#Footnote_7_7" class="fnanchor">[7]</a> "Earl +Dundonald could not fail to see that chemistry was ere long to open a +splendid future for the ancient art that had always been and always will +be the prime supporter of the nations. But when he <span class='pagenum'><a name="Page_14" id="Page_14">[Pg 14]</a></span>wrote, how feeble +was the light that chemistry could throw upon the fundamental questions +of agricultural science! The chemical nature of the atmosphere was then +a discovery of barely twenty years' standing. The composition of water +had been known but twelve years. The only account of the composition of +plants that Earl Dundonald could give was the following: 'Vegetables +consist of mucilaginous matter, resinous matter, matter analogous to +that of animals, and some proportion of oil.... Besides these, +vegetables contain earthy matters, formerly held in solution in the +newly-taken-in juices of the growing vegetables.' To be sure, he +explains by mentioning in subsequent pages that starch belongs to the +mucilaginous matter, and that on analysis by fire vegetables yield +soluble alkaline salts and insoluble phosphate of lime. But these salts, +he held, were formed in the process of burning, their lime excepted; and +the fact of their being taken from the soil and constituting the +indispensable food of plants, his lordship was unacquainted with. The +gist of agricultural chemistry with him was, that plants 'are composed +of gases with a small proportion of calcareous matter; for although this +discovery may appear to be of small moment to the practical farmer, yet +it is well deserving of his attention and notice.'"</p> +<br /> + +<p class="cen"><i>De Saussure.</i></p> + +<p>The year 1804 witnessed the publication of by far the most important +contribution made to the science <span class='pagenum'><a name="Page_15" id="Page_15">[Pg 15]</a></span>up till this time. This was +'Recherches Chimique sur la Végétation,' by Theodore de Saussure, one of +the most illustrious agricultural chemists of the century. De Saussure +was the first to draw attention to the mineral or ash constituents of +the plant; and thus anticipate, to a certain extent, the subsequent +famous "mineral" theory of the great Liebig. The French chemist +maintained that these ash ingredients were essential; and that without +them plant-life was impossible. He also adduced fresh experiments of his +own in support of the theory, based on the experiments of Bonnet, +Priestley, Ingenhousz, and Sénébier, that plants obtain their carbon +from the carbonic acid gas in the air, under the influence of the +sunlight. He was of opinion that the <i>hydrogen</i> and <i>oxygen</i> of the +plant were, probably, chiefly derived from water. He showed that by far +the largest portion of the plant's substance was derived from the air +and from water, and that the ash portion was alone derived from the +soil. To Saussure we owe the first definite statement on the different +sources of the plant's food. It may be said that the lapse of nearly a +century has shown his views to be, in the main, correct.</p> +<br /> + +<p class="cen"><i>Source of Plant-nitrogen.</i></p> + +<p>There was one question, which, even at that remote period in the history +of the subject, engaged the attention of agricultural chemists—viz., +the question of the source of the plant's <i>nitrogen</i>—a question which +may <span class='pagenum'><a name="Page_16" id="Page_16">[Pg 16]</a></span>be fitly described at the present hour as still the burning +question of agricultural chemistry.<a name="FNanchor_8_8" id="FNanchor_8_8"></a><a href="#Footnote_8_8" class="fnanchor">[8]</a></p> + +<p>As soon as it was discovered that nitrogen was a constituent of the +plant's substance; speculations as to its source were indulged in. The +fact that the air furnished an unlimited storehouse of this valuable +element, and the analogy of the absorption of carbon (from the same +source by plant-leaves), naturally suggested to the minds of early +inquirers that the free nitrogen of the air was the source of the +plant's nitrogen. As, however, no direct experiments could be adduced to +prove this theory, and as, moreover, nitrogen was found in the soil, and +seemed to be a necessary ingredient of all fertile soils, the opinion +that the soil was the only source gradually supplanted the older theory. +Little value, however, must be attached to these early theories, as they +can scarcely be said to have been based on experiments of serious value. +Indeed it may be safely affirmed, in the light of subsequent +experiments, that it was impossible for this question to be decided at +this early period, from the fact that analytical apparatus, of a +sufficiently delicate nature, was then wholly unknown. Indeed it is only +within the last few years that it has been possible to carry out +experiments which may be regarded as at all crucial. A short sketch of +the development of our knowledge of the relation of nitrogen to the +plant will be given further on.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_17" id="Page_17">[Pg 17]</a></span><i>Sir Humphry Davy's Lectures.</i></p> + +<p>A series of lectures on agricultural chemistry, delivered by Sir Humphry +Davy during the years 1802-1812, for the Board of Agriculture, and +subsequently published in book form in the year 1813,<a name="FNanchor_9_9" id="FNanchor_9_9"></a><a href="#Footnote_9_9" class="fnanchor">[9]</a> affords us an +opportunity of gauging, pretty accurately, the state of knowledge on the +subject at the time.</p> +<br /> + +<p class="cen"><i>Position of Agricultural Chemistry at beginning of Century.</i></p> + +<p>In his opening lecture Davy says: "Agricultural chemistry has not yet +received a regular and systematic form. It has been pursued by competent +experimenters for a short time only. The doctrines have not as yet been +collected into any elementary treatise, ... and," he adds, "I am sure +you will receive with indulgence the first attempt made in this country +to illustrate it by a series of experimental demonstrations."</p> + +<p>He further on remarks: "It is evident that the study of agricultural +chemistry ought to be commenced by some general inquiries into the +composition and nature of material bodies, and the law of their changes. +The surface of the earth, the atmosphere, and the water deposited from +it, must either together, or separately, afford all the principles +concerned in <span class='pagenum'><a name="Page_18" id="Page_18">[Pg 18]</a></span>vegetation, and it is only by examining the chemical +nature of these principles that we are capable of discovering what is +the food of plants, and the manner in which this food is supplied and +prepared for their nourishment."</p> + +<p>Davy goes on further to say: "No general principles can be laid down +respecting the comparative merits of the different systems of +cultivation and the various systems of crops adopted in different +districts, unless the chemical nature of the soil, and the physical +circumstances to which it is exposed, are fully known."</p> + +<p>He recognises the enormous importance of experiments. "Nothing is more +wanting in agriculture than experiments, in which all the circumstances +are minutely and scientifically detailed."</p> + +<p>In dealing with the composition of plants he says: "It is evident that +the most essential vegetable substances consist of hydrogen, carbon, and +oxygen, in different proportions, generally alone; but in some few cases +combined as carbon and nitrogen. The acids, alkalies, earths, metallic +oxides, and saline compounds, though necessary in the vegetable economy, +must be considered as of less importance, particularly in their relation +to agriculture, than the other principles."</p> + +<p>Further on: "It will be asked, Are the pure earths in the soil merely +active as mechanical or indirect chemical agents, or do they actually +afford food to the plant?"</p> + +<p>This question he answers by saying that "water, <span class='pagenum'><a name="Page_19" id="Page_19">[Pg 19]</a></span>and the decomposing +animal and vegetable matter existing in the soil, constitute the true +nourishment of plants; and as the earthy parts of the soil are useful in +retaining water, so as to supply it in the proper proportion to the +roots of the vegetables, so they are likewise efficacious in producing +the proper distribution of the animal or vegetable matter. When equally +mixed with it, they prevent it from decomposing too rapidly; and by +their means the soluble parts are supplied in proper proportions."</p> +<br /> + +<p class="cen"><i>Value of Davy's Lectures.</i></p> + +<p>The chief value of these lectures is due to the fact that they form the +first attempt to connect in a systematic manner the various scattered +facts, up to that time ascertained, and to interpret their bearing on +agricultural practice. We have in them, it is true, a strange mixture of +facts belonging rather to botany and physiology than to agricultural +chemistry; still they undoubtedly furnished a great impetus to inquiry, +and at the same time they did much to popularise the science.</p> + +<p>But not merely did Davy summarise and systematise the various results +arrived at by others, he also made many valuable contributions to the +science himself. The conclusions he drew from the results he obtained +were, no doubt, in many cases false, and in other cases exaggerated; +still the results possess a permanent interest. He may be said to have +worked <span class='pagenum'><a name="Page_20" id="Page_20">[Pg 20]</a></span>out many of the most important <i>physical</i> or <i>mechanical</i> +properties of a soil, although exaggerating the importance of the +influence of these properties on the question of fertility.<a name="FNanchor_10_10" id="FNanchor_10_10"></a><a href="#Footnote_10_10" class="fnanchor">[10]</a></p> + +<p>These experiments had to do with the heat- and water-absorbing powers of +a soil. He experimented on a brown fertile soil, and a cold barren clay, +and found at what rate they lost heat. "Nothing," he says, "can be more +evident than that the genial heat of the soil, particularly in spring, +must be of the highest importance to the rising plant; ... so that the +temperature of the surface, when bare and exposed to the rays of the +sun, affords at least one indication of the degree of the fertility."</p> + +<p>Again he says: "The power of soils to absorb water from air is much +connected with fertility.... I have compared the absorbent powers of +many soils, with respect to atmospheric moisture, and I have always +found it greatest in the most fertile soils; so that it affords one +method of judging of the productiveness of land."</p> + +<p>Where he erred was in overestimating the functions of the mechanical +properties of a soil, and in considering fertility to be due to them +alone.</p> + +<p>During the next thirty years or so, little progress seems to have been +made in the way of fresh experimentation.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_21" id="Page_21">[Pg 21]</a></span><i>Boussingault.</i></p> + +<p>In 1834, Boussingault,<a name="FNanchor_11_11" id="FNanchor_11_11"></a><a href="#Footnote_11_11" class="fnanchor">[11]</a> the most distinguished French agricultural +chemist of the century, began that series of brilliant chemico-agricultural +experiments on his estate at Bechelbronn, in Alsace, the results of which +have added so much to agricultural science. It was the first instance of +the combination of "science with practice," of the institution of a +laboratory on a farm; a combination peculiarly fitted to promote the +interests of agricultural science, and an example which has been since +followed with such magnificent results in the case of Sir John Lawes's +famous Rothamsted Experiment Station, and other less known research +stations.</p> + +<p>Boussingault's first paper appeared in 1836, and was entitled, "The +amount of nitrogen in different kinds of foods, and on the equal value +of foods founded on these data."</p> + +<p>In the year following other papers were published on such subjects as +the amount of gluten in different kinds of wheat; on the meteorological +considerations of how far various agricultural operations—such as +extensive clearings of wood, the draining of large swamps, +&c.—influence of climate on a country; and on experiments on the +culture of the vine.</p> + +<p>Boussingault was the first observer to study the scientific principles +underlying the system of <i>rotation <span class='pagenum'><a name="Page_22" id="Page_22">[Pg 22]</a></span>of crops</i>. In 1838 he published +the results of some very elaborate experiments he had carried out on +this subject. He also was the first chemist to carry out elaborate +experiments with a view to deciding the question of the assimilation by +plants of free atmospheric nitrogen. His first contribution to the +subject was published in 1838, but can scarcely be regarded as +possessing much scientific value, except in so far as it stimulated +further research. Some thirteen years later he returned to this +question; and during the years 1851-1855 carried out most elaborate +experiments, the results of which, until quite recently, were generally +regarded as having, along with the experiments of Messrs Lawes, Gilbert, +and Pugh, definitely settled the question.<a name="FNanchor_12_12" id="FNanchor_12_12"></a><a href="#Footnote_12_12" class="fnanchor">[12]</a></p> + +<p>In 1839 Boussingault was elected a member of the French Institute, an +honour paid to him in recognition of his great services to agricultural +chemistry.<a name="FNanchor_13_13" id="FNanchor_13_13"></a><a href="#Footnote_13_13" class="fnanchor">[13]</a></p> + +<p><span class='pagenum'><a name="Page_23" id="Page_23">[Pg 23]</a></span>The foregoing is a brief epitome of the history of the development of +agricultural chemistry up to the year 1840, the year which witnessed the +publication of one of the most memorable works on the subject, which has +appeared during the present century—Liebig's first report to the +British Association, a work which may be described as constituting an +epoch in the history of the science. Liebig's position as an +agricultural chemist was so prominent, and his influence as a teacher so +potent, that a few biographical facts may not be out of place before +entering upon an estimate of his work.</p> +<br /> + +<p class="cen"><i>Liebig.</i></p> + +<p>Liebig was born at Darmstadt in the year 1803. He was the son of a +drysalter, and early devoted himself to the study of chemistry in the +only way at first at his disposal—viz., in an apothecary's shop. Soon +finding, however, his opportunities of study limited, he left the +apothecary's shop for the University of Bonn. He did not remain long at +Bonn, but in a short time left that university for Erlangen, where he +studied for some years, taking his Ph.D. degree in 1822. His subsequent +studies were carried on at Paris under Gay-Lussac, Thénard, Dulong, and +other distinguished chemists. Through the influence of A. Humboldt, who +was at that time in Paris, and whose acquaintance he was fortunate +enough to make, he <span class='pagenum'><a name="Page_24" id="Page_24">[Pg 24]</a></span>was received into Gay-Lussac's private laboratory. +In 1824—that is, when he was only twenty-one years of age—he was +appointed Professor <i>Extraordinarius</i> of Chemistry at the University of +Giessen. Two years later he was appointed to the post of Professor +<i>Ordinarius</i>—an appointment which he held for twenty-five years. In +1845 he was created Baron, and in 1852 appointed Professor at Munich. He +died in 1873.</p> +<br /> + +<p class="cen"><i>His First Report to British Association.</i></p> + +<p>The report above referred to was made by Liebig at the request of the +Chemical Section of the British Association. It was read to a meeting of +the Association held in Glasgow in 1840, and was subsequently published +in book form, under the title of 'Chemistry in its Application to +Agriculture and Physiology,' Liebig's position, past training and +experience were such as to peculiarly fit him for the part of pioneer in +the new science. As Sir J. H. Gilbert has remarked,<a name="FNanchor_14_14" id="FNanchor_14_14"></a><a href="#Footnote_14_14" class="fnanchor">[14]</a> "In the +treatment of his subject he not only called to his aid the previously +existing knowledge directly bearing upon his subject, but he also turned +to good account the more recent triumphs of organic chemistry, many of +which had been won in his own laboratory."</p> + +<p>In his dedication to the British Association at the beginning of the +book, Liebig says: "Perfect agriculture is the true foundation of all +trade and <span class='pagenum'><a name="Page_25" id="Page_25">[Pg 25]</a></span>industry—it is the foundation of the riches of States. But a +rational system of agriculture cannot be formed without the application +of scientific principles; for such a system must be based on an exact +acquaintance with the means of nutrition of vegetables, and with the +influence of soils and actions of manure upon them. This knowledge we +must seek from chemistry, which teaches the mode of investigating the +composition and of studying the characters of the different substances +from which plants derive their nourishment."</p> +<br /> + +<p class="cen"><i>His criticism of the "Humus" Theory.</i></p> + +<p>The first subject which Liebig discusses is the scientific basis of the +so-called "humus" theory. The humus theory seems to have been first +promulgated by Einhof and Thaer towards the close of last century. Thaer +held that humus was the source of plant-food. He stated in his published +writings that the fertility of a soil depended really upon its humus; +for this substance, with the exception of water, is the only source of +plant-food. De Saussure, however, by his experiments—the results of +which he had published in 1804—had shown the fallacy of this humus +theory; and his statements had been further developed and substantiated +by the investigations of the French chemist Braconnot and the German +chemist Sprengel. Despite, however, the experiments of Saussure, +Braconnot, and Sprengel, the belief that plants derived the +<span class='pagenum'><a name="Page_26" id="Page_26">[Pg 26]</a></span>carbonaceous portion of their substance from humus still seemed to be +commonly held in 1840.</p> + +<p>While Liebig, therefore, can scarcely be said to have been the first to +controvert the humus theory, he certainly dealt it its death-blow. He +reasserted de Saussure's conclusions, and by some simple calculations +showed very clearly that it was wholly untenable. One of the most +striking of the arguments he brought forward was the fact that the humus +of the soil itself consisted of the decayed vegetable matter of +preceding plants. This being so, how, he asked, could it be the original +source of the carbon of plants? To reason thus was simply to reason in a +circle. He pointed out, further, that the comparative insolubility of +humus in water, or even in alkaline solutions, told against its +acceptance as correct.</p> +<br /> + +<p class="cen"><i>His Mineral Theory.</i></p> + +<p>Having thus controverted the humus theory, he then goes on to deal with +the question of the source of the various plant constituents. In +treating of the relation of the soil to the plant, he puts forward his +"mineral" theory. It cannot be doubted that, while the advance of +science since Liebig's time has induced us to considerably modify his +mineral theory, it contained the statement of one of the most important +facts in the chemistry of plant physiology. He was the first to fully +estimate the enormous importance of the mineral portion of the plant's +food, and point the way to one of <span class='pagenum'><a name="Page_27" id="Page_27">[Pg 27]</a></span>the chief sources of a soil's +fertility. Up to this period the ash constituents had been generally +considered to be of minor importance. By emphasising the contrary +opinion, and insisting upon their essentialness to plant-life, he gave +to agricultural research a fresh impetus upon the right lines. His +statement of his mineral theory was in the main true, but was not the +whole truth.</p> + +<p>De Saussure, as has already been pointed out, to a certain extent, +anticipated Liebig's mineral theory. He was of the opinion that whatever +might be the case with some of the mineral constituents of plants, +others were necessary, inasmuch as they were always found in the ash. Of +these he instanced the alkaline phosphates. "Their small quantity does +not indicate their inutility," he sagaciously remarks. Sir Humphry Davy, +as has already been pointed out, missed recognising the true importance +of the ash constituents. It was left to Liebig, then, to restate the +important doctrine of the essentialness of the mineral matter, already +implied to some extent by de Saussure.</p> + +<p>Liebig says: "Carbonic acid, water, and ammonia are necessary for the +existence of plants, because they contain the elements from which their +organs are formed; but other substances are likewise necessary for the +formation of certain organs destined for special functions, peculiar to +each family of plants. Plants obtain these substances from inorganic +nature."</p> + +<p>While insisting on the importance of the mineral <span class='pagenum'><a name="Page_28" id="Page_28">[Pg 28]</a></span>constituents, he did +so in a more or less general way not sufficiently distinguishing one +mineral constituent from another.</p> + +<p>As all plants contained certain organic acids, and as these organic +acids were nearly always found in a neutral state—<i>i.e.</i>, in +combination with bases, such as potash, soda, lime, and magnesia—the +plant must be in a position to take up sufficient of these alkaline +bases to neutralise these acids. Hence the necessity of these mineral +constituents in the soil. According to him, however, the exact nature of +the bases was a point of not so much importance. He assumed, in short, +as has been pointed out by Sir J. H. Gilbert, a greater amount of mutual +replaceability amongst the bases than can be now admitted.</p> + +<p>Passing on to a consideration of the difference of the mineral +composition of different soils, he attributes this to the difference in +the rocks forming the soils. "Weathering" is the great agent at work in +rendering available the otherwise locked-up stores of fertility. He +attributes the benefits of fallow exclusively to the increased supply of +these incombustible compounds which were thus rendered available to the +plant. Treating of this subject, he says: "From the preceding part of +this chapter" (in which he has been explaining weathering) "it will be +seen that fallow is that period of culture when the land is exposed to +progressive disintegration by the action of the weather, for the purpose +of liberating a certain <span class='pagenum'><a name="Page_29" id="Page_29">[Pg 29]</a></span>quantity of alkalies and silica, to be absorbed +by future plants."</p> +<br /> + +<p class="cen"><i>His Theory of Manures.</i></p> + +<p>Treating of manures, he showed how the most important constituents of +manures were <i>potash</i> and <i>phosphates</i>. In the first edition of his work +he also insisted on the value of <i>nitrogen</i> in manures, condemning the +want of precautions, in the treatment of animal manures, against loss of +nitrogen.</p> + +<p>In the later editions of his work he seems to have receded from that +opinion, and considered that there was no necessity for supplying +nitrogen in manures, since the ammonia washed down in rain was a +sufficient source of all the nitrogen the plant required. It was here +that Liebig went astray, first in denying the importance of supplying +nitrogen as a manure; and secondly, in overestimating the amount of +ammonia washed down in rain, which has subsequently been shown to be +entirely inadequate to supply plants with the whole of their +nitrogen.<a name="FNanchor_15_15" id="FNanchor_15_15"></a><a href="#Footnote_15_15" class="fnanchor">[15]</a></p> +<br /> + +<p class="cen"><i>His Theory of Rotation of Crops.</i></p> + +<p>In explaining the benefits of the rotation of crops, Liebig propounded a +very ingenious theory, but one <span class='pagenum'><a name="Page_30" id="Page_30">[Pg 30]</a></span>which was largely of a speculative +nature, and which has since been shown to be unfounded on any scientific +basis. It was to the effect that one kind of crop excreted matters which +were especially favourable to another kind of crop. He did not say +whether he considered such excretion positively injurious to the crop +which excreted them; but he inferred that what was excreted by the crop +was what was not required, and what could, therefore, be of little +benefit to a crop of the same nature following it.</p> + +<p>The second portion of Liebig's report dealt with the processes of +fermentation, decay, and putrefaction.</p> +<br /> + +<p class="cen"><i>Publication of Liebig's Second Report to British Association.</i></p> + +<p>In 1842 Liebig contributed his second famous report to the British +Association, subsequently published under the title of 'Animal +Chemistry; or, Organic Chemistry in its Applications to Physiology and +Pathology.' The publication of this report created even greater interest +than the publication of his first work. In it he may be said to have +contributed as much to animal physiology, as, in his first, he did to +agricultural chemistry. His subsequent principal works on agricultural +chemistry were—'Principles of Agricultural Chemistry,' published in +1855, and 'On Theory and Practice in Agriculture,' 1856.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_31" id="Page_31">[Pg 31]</a></span><i>Liebig's services to Agricultural Chemistry.</i></p> + +<p>An attempt has been made to sketch in the very briefest manner some of +the main points in Liebig's teaching, as contained in his famous report +to the British Association in 1840. Agricultural chemistry up till that +year can scarcely be described as having a distinct existence as a +branch of chemistry. Much valuable work, it is true, had already been +done, especially by his two great predecessors, de Saussure and +Boussingault; but it was, down to the year 1840, a science made up of +isolated facts. Liebig's genius formed it into an important branch of +chemistry, supplied the necessary connection between the facts, and by a +series of brilliant generalisations formed the principles upon which all +subsequent advance has been built.</p> + +<p>As has already been indicated, Liebig's chief claim to rank as the +greatest agricultural chemist of the century does not rest upon the +number or value of his actual researches, but on the formative power he +exercised in the evolution of the science. His master-mind surveyed the +whole field of agricultural chemistry, and saw laws and principles where +others saw simply a confusion of isolated, and, in many cases, seemingly +contradictory facts.</p> + +<p>But great as the direct value of Liebig's work was, it may be questioned +whether its indirect value was not even greater. The publication of his +famous <span class='pagenum'><a name="Page_32" id="Page_32">[Pg 32]</a></span>work had the effect of giving a general interest to questions +which up till then had possessed a special interest, and that for +comparatively few. Both on the Continent and in England a very large +amount of discussion took place regarding his various theories.</p> +<br /> + +<p class="cen"><i>Development of Agricultural Research in Germany.</i></p> + +<p>It was especially in Germany, however, that Liebig's work bore its +greatest and most immediate fruit. Thanks to the great chemist, the +German Government recognised the importance of forwarding scientific +research by State aid. Agricultural Departments were added to some of +the universities, largely at State expense, while agricultural research +stations were, one after another, instituted in different parts of the +country.</p> + +<p>The first of the agricultural research stations to be founded was the +now famous one of Möckern, near Leipzig. It was instituted in the year +1851. Others followed, until at the present day there are some seventy +to eighty of these <i>Versuchs-Stationen</i> scattered throughout Germany, +all well equipped and doing excellent work. Some idea of the activity of +the German stations may be inferred when it is stated that up to the +year 1877 the total number of papers embodying the results of their +experiments published by them amount to over 2000.<a name="FNanchor_16_16" id="FNanchor_16_16"></a><a href="#Footnote_16_16" class="fnanchor">[16]</a></p> + +<p><span class='pagenum'><a name="Page_33" id="Page_33">[Pg 33]</a></span>To trace the development of agricultural chemistry, subsequent to +Liebig's time, in the way it has been done prior to the year 1840, is no +longer possible. This is due to the enormous increase in the number of +workers in the field, as also to the overlapping nature of their work, +which renders a strict chronological record wellnigh an impossibility. +It will be better, therefore, to attempt to give a brief statement of +our present knowledge on the subject, naming the chief workers in the +various departments of the subject.</p> +<br /> + +<p class="cen"><i>The Rothamsted Experiments.</i></p> + +<p>Before doing so, it is fitting that reference should be made to the work +and experiments of two living English chemists, who have done much to +contribute to our knowledge in every branch of the science—viz., Sir +John Lawes, Bart., and Sir J. H. Gilbert, F.R.S.</p> + +<p>The fame of the Rothamsted experiments is now world-wide; and no single +experiment station has ever produced such an amount of important work as +the magnificently equipped research station at Rothamsted. The +Rothamsted station may be said to date from 1843, although Sir John +Lawes was <span class='pagenum'><a name="Page_34" id="Page_34">[Pg 34]</a></span>engaged in carrying out field experiments for ten years +previous to that date.<a name="FNanchor_17_17" id="FNanchor_17_17"></a><a href="#Footnote_17_17" class="fnanchor">[17]</a> In 1843 Sir John Lawes associated with +himself the distinguished chemist Sir J. H. Gilbert, and the numerous +papers since published have almost invariably borne the two names. The +expense of working the station has been borne entirely by Sir John Lawes +himself; who has further set aside a sum of £100,000, the Laboratory, +and certain areas of land, for the continuance of the investigations +after his death. The fields under experimentation amount to about fifty +acres. By a Trust-deed, which was signed on February 14, 1889, Sir John +Lawes has made over the Rothamsted Experimental Station to the English +nation, to be managed by trustees.</p> + +<p>It is impossible to enter, in any detail, into the nature and scope of +the Rothamsted experiments.<a name="FNanchor_18_18" id="FNanchor_18_18"></a><a href="#Footnote_18_18" class="fnanchor">[18]</a> It may be stated that, since the year +1847, some eighty papers have been published on field experiments, and +experiments on vegetation; while thirty papers have been published +recording experiments on the feeding of animals.<a name="FNanchor_19_19" id="FNanchor_19_19"></a><a href="#Footnote_19_19" class="fnanchor">[19]</a></p> + +<p><span class='pagenum'><a name="Page_35" id="Page_35">[Pg 35]</a></span>What has all along characterised these valuable experiments has been +their practical nature. While their aim has been entirely scientific, +the scale of the experiments and the conditions under which they have +been carried out, have been such as to render them essentially +<i>technical</i> experiments. For this reason their results possess, and will +always possess, a peculiar interest for every practical farmer.</p> + +<p>The greatest services the Rothamsted experiments have rendered +agricultural chemistry have been the valuable contributions they have +made to our knowledge of the function of nitrogen in agriculture; its +relation in its different chemical forms to plant-life; and the sources +of the nitrogen found in plants. Researches of a most elaborate nature +have been carried out on what is still one of the most keenly debated +questions of the present hour—viz., the relation of the "free" nitrogen +in the atmosphere to the plant. Of the very highest value also have been +the elaborate researches of Mr R. Warington, F.R.S., on the important +question of <i>Nitrification</i>, which have been in course in the Rothamsted +Laboratory for the last fifteen years, and to which full reference will +be made in the chapter on Nitrification.</p> + +<p>To the Rothamsted experiments also we owe the <span class='pagenum'><a name="Page_36" id="Page_36">[Pg 36]</a></span>refutation of Liebig's +mineral theory. In fact it may safely be said that no experimenters in +the field of agricultural chemistry have made more numerous or valuable +contributions to the science than these illustrious investigators.</p> +<br /> + +<p class="cen"><i>Review of our present Knowledge of Agricultural Chemistry.</i></p> + +<p>Some attempt may now be made to indicate briefly our present knowledge +of the more important facts regarding plant physiology, agronomy, and +manuring.</p> +<br /> + +<p class="cen"><i>Proximate Composition of the Plant.</i></p> + +<p>The great advance made in the direction of the improvement of the +accuracy of old analytical processes and the discovery of numerous new +ones have furnished us with elaborate analyses of the composition of +plants. We now know that the plant-substance is made up of a large +number of complex organic substances, formed out of carbon, hydrogen, +oxygen, and nitrogen,<a name="FNanchor_20_20" id="FNanchor_20_20"></a><a href="#Footnote_20_20" class="fnanchor">[20]</a> and that these substances form, on an average, +about 95 per cent of the dry vegetable matter; the other 5 per cent +being made up of mineral substances. As to the source of these different +substances, our knowledge is, on the whole, pretty complete. With regard +to the carbon of green-leaved plants, which amounts to from 40 to 50 per +cent, subsequent research has confirmed Sénébier and de <span class='pagenum'><a name="Page_37" id="Page_37">[Pg 37]</a></span>Saussure's +conclusions, that its source is the carbonic acid gas of the air. The +decomposition of the carbonic acid gas is effected by the leaves under +the influence of sunlight. That a certain quantity of carbon may be +obtained from the carbonic acid absorbed by plant-roots, is indeed +probable. Especially during the early stages of plant-growth this source +of carbon may be of considerable importance. Generally speaking, +however, it may be said of all green-leaved plants, that the chief +source of their carbon is the carbonic acid gas in the atmosphere.</p> +<br /> + +<p class="cen"><i>Carbon Fixation by Plants.</i></p> + +<p>The exact way in which this decomposition of carbonic acid gas is +effected by the leaves is not yet clear. It seems to be directly +dependent, in some way or other, on the chlorophyll, or green colouring +matter. This decomposition of carbonic acid, and the fixation of the +carbon by the plant with the formation of starch, takes place only under +the influence of sunlight. During the night a reflex action takes place, +which is commonly known as <i>respiration</i>, and which is exactly analogous +to animal respiration.<a name="FNanchor_21_21" id="FNanchor_21_21"></a><a href="#Footnote_21_21" class="fnanchor">[21]</a> The rate at which the fixation of carbon +takes place depends on the strength of the sun's rays. It seems to take +<span class='pagenum'><a name="Page_38" id="Page_38">[Pg 38]</a></span>place very rapidly under a strong tropical sun.<a name="FNanchor_22_22" id="FNanchor_22_22"></a><a href="#Footnote_22_22" class="fnanchor">[22]</a> The action of +sunlight on the absorption of carbon has been studied by a number of +observers, among others by Sachs, Draper, Cloez, Gratiolet, Caillet, +Prillieux, Lommel, &c.</p> +<br /> + +<p class="cen"><i>Action of Light on Plant-growth.</i></p> + +<p>Experiments made by several observers, more especially Pfeffer, have +shown that the yellow rays of the solar spectrum are the most potent in +inducing this decomposition.</p> + +<p>Some interesting experiments have been carried out by different +observers on the possibility of growing plants under the influence of +artificial light. While it would seem that the light from oil-lamps or +gaslight is unable to promote growth, except in very exceptional cases, +the electric light, or other strong artificial light, seems to be +capable of taking the place of sunlight. Heinrich was the first to show +that sunlight could be replaced by the magnesium light.</p> + +<p>Experiments with the electric light have been carried out by +Hervé-Mangon in France and Dr Siemens in England. The plants grown under +the influence of the electric light were observed to be of a lighter +green colour than those grown under normal conditions, thus indicating a +feebler growth; in fact, <span class='pagenum'><a name="Page_39" id="Page_39">[Pg 39]</a></span>Siemens was of the opinion that the electric +light was about half as effective as daylight.<a name="FNanchor_23_23" id="FNanchor_23_23"></a><a href="#Footnote_23_23" class="fnanchor">[23]</a></p> + +<p>These experiments are interesting from an industrial point of view; for +it is conceivable that at some distant time electricity might be called +to the aid of the agriculturist.</p> +<br /> + +<p class="cen"><i>Source of Plants' Oxygen.</i></p> + +<p>With regard to the source of the oxygen, which, next to carbon, is the +element most largely present in the plant's substance—amounting to, +roughly speaking, about 40 per cent—all evidence seems to indicate that +it is chiefly derived from water, which is also the source of the +plant's hydrogen. In addition to water, carbonic acid and nitric acid +may also furnish small quantities. It has been pretty conclusively +proved that the atmospheric oxygen, while necessary to plant-growth, and +promoting the various chemical vital processes, is not a direct source +of the plant's oxygen. The important function played by atmospheric +oxygen in certain stages of the plant's growth has been long recognised. +Malpighi, nearly two hundred years ago, observed that for the process of +germination atmospheric air was necessary; and shortly after the +discovery of the composition of the air was made, oxygen was identified +as the important gas in promoting this <span class='pagenum'><a name="Page_40" id="Page_40">[Pg 40]</a></span>process. Oxygen is also +especially necessary during the period of ripening.</p> +<br /> + +<p class="cen"><i>Source of Plants' Hydrogen.</i></p> + +<p>Hydrogen, which amounts to about 6 per cent, is, as has already been +pointed out, chiefly derived from water. It is possible that ammonia +also may form a source.</p> +<br /> + +<p class="cen"><i>Source of Plants' Nitrogen.</i></p> + +<p>When we come to treat of the source of the nitrogen, which is found in +the plant's substance to an extent varying from a fraction of a per cent +to about 4 per cent, we enter on a much more debated question.</p> + +<p>What is the source, or, what are the sources, of plant-nitrogen? is a +question to the solution of which more time and more research have been +devoted than to the solution of any other question connected with +agricultural chemistry.</p> + +<p>The most obvious source is the free nitrogen, which forms four-fifths of +the atmospheric air. Reference has already been made to this +question.<a name="FNanchor_24_24" id="FNanchor_24_24"></a><a href="#Footnote_24_24" class="fnanchor">[24]</a> Priestley was the first of the long list of experimenters +on this interesting question.</p> + +<p>As far back as 1771 he affirmed that certain plants had the power of +absorbing free nitrogen; and this opinion he supported by the results of +certain <span class='pagenum'><a name="Page_41" id="Page_41">[Pg 41]</a></span>experiments he had made on the subject. Eight years +later,—viz., in 1779—Ingenhousz further supported this conclusion, and +stated that all plants could absorb, within the space of a few hours, +noticeable quantities of nitrogen gas. The first to oppose this theory +was de Saussure, who, in 1804, carried out experiments which showed that +plants were unable to utilise free nitrogen.</p> + +<p>Subsequent experiments, carried out by Woodhouse and Sénébier, supported +de Saussure's conclusions. Mention has already been made of +Boussingault's elaborate researches on the subject.<a name="FNanchor_25_25" id="FNanchor_25_25"></a><a href="#Footnote_25_25" class="fnanchor">[25]</a> His first +experiments were carried out in 1838. He concluded that plants did not +absorb free nitrogen. Georges Ville was the first to reassert the older +theory, put forward by Priestley and Ingenhousz. His opinion was founded +on experiments he had carried out during the years 1849-52. The subject +created so much interest at the time, that a committee of the French +Academy—consisting of Dumas, Regnault, Péligot, Chevreul, and +Decaisne—were appointed to investigate Ville's experiments. The result +of the investigation of the Commission was to confirm Ville's +experiments. It is a significant fact, however, that the plant +experimented with by the Commission was <i>cress</i>—<i>a non-leguminous +plant</i>. It has been commonly assumed that the results of recent +experiments have confirmed Ville's experiments. It is only proper to +<span class='pagenum'><a name="Page_42" id="Page_42">[Pg 42]</a></span>point out that this is not a necessary inference. The assimilation of +free nitrogen by the <i>leguminosæ</i>, so far as modern research has +revealed, only takes place under the influence of micro-organic life. +Ville's experiments, however, were supposed to be conducted under +<i>sterilised</i> conditions.</p> + +<p>In the meantime the results of Boussingault's second series of +experiments, carried out between the years 1851 and 1855, were +published, and confirmed his earlier experiments.</p> + +<p>The results of a large number of experiments subsequently carried out +were in support of Boussingault's conclusions. Among them may be +mentioned Mène, Harting, Gunning, Lawes, Gilbert and Pugh, Roy, +Petzholdt, and Bretschneider.</p> + +<p>Such an amount of overwhelming evidence might naturally have been +regarded as conclusively proving that the free nitrogen of the air is +not an available source of nitrogen to the plant. The question, however, +was not decided. In 1876 Berthelot reopened it. From experiments he had +carried out, he concluded that free nitrogen was fixed by various +organic compounds, under the influence of silent electric discharges. In +1885 he carried out further experiments, from which he concluded that +argillaceous soils had the power of fixing the free nitrogen of the +atmosphere. This they effected, he was of opinion, through the agency of +micro-organisms. Schloesing has recently shown that this fixation of +free nitrogen <span class='pagenum'><a name="Page_43" id="Page_43">[Pg 43]</a></span>by soils is extremely doubtful.<a name="FNanchor_26_26" id="FNanchor_26_26"></a><a href="#Footnote_26_26" class="fnanchor">[26]</a> The gain of nitrogen +observed under such conditions can be explained by the absorption by the +soil of combined nitrogen—viz., ammonia—from the air.</p> + +<p>Berthelot's early experiments in 1876 had the effect of stimulating a +number of other experiments, with the result that we now possess the +solution of this long-debated and most important problem.</p> + +<p>The names of the better known investigators on this subject, in addition +to Berthelot's, are those of Hellriegel, Wilfarth, Dehérain, Joulie, +Dietzell, Frank, Emil von Wolff, Atwater, Woods, Nobbe, Ward, Breal, +Boussingault, Wagner, Schultz-Lupitz, Fleischer, Pagnoul, Schloesing, +Laurent, Petermann, Pradmowsky, Beyrenick, Lawes, and Gilbert.</p> + +<p>It is impossible to enter into the details of these most important +experiments. An attempt may be made, instead, briefly to epitomise them.</p> +<br /> + +<p class="cen"><i>Recent Experiments on Nitrogen question.</i></p> + +<p>In the first place, it may be asked, How is it possible that the +previous elaborate experiments, published prior to 1876, should now +prove unreliable? A satisfactory explanation may be found in the fact, +as Lawes and Gilbert have recently pointed out, that the fixation of the +free nitrogen by the plant, or within the soil, takes place, if at all, +through the agency of electricity or of micro-organisms, or of both. +<span class='pagenum'><a name="Page_44" id="Page_44">[Pg 44]</a></span>The earlier experiments, however, were so arranged as to exclude the +influence of either of those agencies.</p> + +<p>The question has further been limited in its scope. It is now supposed +that only plants of the <i>leguminous</i> order have the power of drawing +upon the free atmospheric nitrogen. Of the experiments above referred +to, those of Hellriegel and Wilfarth are the most striking and +important. They found in their experiments, that while the legumes have +the power of obtaining their nitrogen from the air, cereals have not. +Similar experiments by Atwater in America, and others, support this +conclusion.</p> + +<p>Their conclusions may be briefly epitomised as follows:—</p> + +<p>(<i>a</i>) That the leguminous plants—such as peas, &c.—have the power of +drawing their nitrogen supplies from the free nitrogen of the air in a +way not possessed by other plants; and that they thus possess two +sources of nitrogen—the soil and the air.</p> + +<p>(<i>b</i>) That this absorption of free nitrogen is not effected directly by +the plant, but is the result, so to speak, of the joint action of +certain micro-organisms present in certain soils and in the plant +itself, (<i>symbiosis</i>).</p> + +<p>(<i>c</i>) That this fixation is connected with the formation of minute +tubercles on the roots of the plants of the leguminous class; and that +these tubercles may be the home of the fixing organism.</p> + +<p><span class='pagenum'><a name="Page_45" id="Page_45">[Pg 45]</a></span>(<i>d</i>) That these fixing micro-organisms are not present in all +soils.<a name="FNanchor_27_27" id="FNanchor_27_27"></a><a href="#Footnote_27_27" class="fnanchor">[27]</a></p> + +<p>While the relation of free nitrogen to the plant has long been, and +still is, a very obscure problem, it was early recognised that the +combined nitrogen present in soils and manures was an important source +of plant-food. Reference has already been made to the early theory of +Sir Kenelm Digby regarding the value of nitrates.<a name="FNanchor_28_28" id="FNanchor_28_28"></a><a href="#Footnote_28_28" class="fnanchor">[28]</a> De Saussure, as we +have also already seen, was fully impressed with the importance of +applying nitrogen to the soil as a manure. Liebig's early attitude on +this question was to the effect, that to apply nitrogen in manures was +quite unnecessary, as the plant had a sufficient source in the ammonia +present in the air, which he erroneously supposed was sufficient in +quantity to supply all the needs of the crops. Despite this early +recognition of the value of combined nitrogen to the plant, it is only +of recent years that we have obtained any definite knowledge as to the +respective value of its different compounds as manures, or as to the +form in which it is assimilated by the plant. It exists in three +forms—(1) as organic nitrogen; (2) as ammonia salts; (3) as nitrates +and nitrites. Much experimental work has during late years been devoted +to studying the comparative action and merits of these three forms.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_46" id="Page_46">[Pg 46]</a></span><i>Relation of Organic Nitrogen to the Plant.</i></p> + +<p>First, as to the relation of organic nitrogen to the plant. There is a +large number of different organic compounds which contain nitrogen. That +the plant is able to assimilate certain of these organic compounds, +seems, from several experiments, to be extremely probable. From certain +researches, carried out as far back as the year 1857, Sir Charles +Cameron concluded that the plant could assimilate one of them—viz., +<i>urea</i>. From what, however, we have subsequently learned regarding the +process of "nitrification," it is quite probable that the nitrogen in +these experiments was first converted into nitrates before being +assimilated. At any rate, as the plants were not tested for urea, the +experiments must be regarded as leaving the problem unsolved.</p> + +<p>Other experiments were carried out of a similar nature by Professor S. +W. Johnson, the different kinds of nitrogen experimented with being +<i>uric acid</i>, <i>hippuric acid</i>, and <i>guanine</i>. But here, again, no +definite conclusion can be drawn, as no analyses were made of the +plants. More recently, however, Dr Hampe has carried out experiments +with <i>urea</i>, <i>uric acid</i>, <i>hippuric acid</i>, and <i>glycocoll</i>. These +experiments may be held as demonstrating the fact that at least one +organic compound of nitrogen is capable of being assimilated, as urea +was actually identified as being present in the plants experimented +with. From further experiments, <span class='pagenum'><a name="Page_47" id="Page_47">[Pg 47]</a></span>carried out by Dr Paul Wagner and +Wolff, <i>glycin</i>, <i>tyrosin</i>, and <i>kreatin</i> are able to be assimilated by +the plant.</p> +<br /> + +<p class="cen"><i>Plants able to absorb certain Forms of Organic Nitrogen.</i></p> + +<p>We may conclude, then, from these interesting experiments, that plants +are able to absorb certain organic forms of nitrogen. That they do so in +nature to any extent is extremely improbable, such organic forms of +nitrogen being rarely present in the soil, or if present, being +converted into ammonia or nitrate salts before assimilation.</p> +<br /> + +<p class="cen"><i>Nature of Humus in the Soil.</i></p> + +<p>While on the subject of organic nitrogen, reference may be briefly made +to that substance known as <i>humus</i>,—the name applied to the organic +portion of soils,—a substance which figures so largely in early +theories of plant-nutrition. The most elaborate investigation of the +composition of humus has been carried out by Mulder. According to +Mulder, it is composed of a number of organic bodies, and he has +identified the following substances—ulmin, humin, ulmic, humic, geic +acids, &c. These bodies are composed of carbon, hydrogen, and oxygen, +which are invariably associated with nitrogen. Detmer and Simon have +further investigated the subject. The true function of humus, it would +seem, in addition to its numerous mechanical properties, is to furnish, +by <span class='pagenum'><a name="Page_48" id="Page_48">[Pg 48]</a></span>its decomposition, carbonic acid and nitrogen—in the form of +ammonia and nitric acid—to the soil; the former acting as a solvent of +the mineral food, the latter as the source of the plant's nitrogen. The +old theory, therefore, that the presence of humus in a soil is a +condition of fertility, is not so far removed from the truth. Where +there is an abundance of humus in the soil there is likely also to be an +abundance of nitrogen.</p> +<br /> + +<p class="cen"><i>Relation of Ammonia to the Plant.</i></p> + +<p>It seems to be beyond doubt that nitrogen is directly absorbed by plants +in the form of ammonia. Liebig, as we have seen, concluded that this was +the great source of nitrogen for the plant, and that the ammonia +compounds present in the air were an all-sufficient supply. Subsequent +research, while confirming his belief so far as regards the capability +of plants to assimilate nitrogen in the form of ammonia, has proved that +the amount of ammonia present in the air is very minute, and utterly +inadequate to supply the plant with the whole of its nitrogen. +Investigations have been made on this subject by Graeger, Fresenius, +Pierre, Bineau, and Ville. According to Ville's researches, which are +among the most recent, the amount does not exceed 30 <i>parts per thousand +million parts of air</i>.<a name="FNanchor_29_29" id="FNanchor_29_29"></a><a href="#Footnote_29_29" class="fnanchor">[29]</a> Some conception <span class='pagenum'><a name="Page_49" id="Page_49">[Pg 49]</a></span>of the value of this source +of nitrogen may be gained by estimating the quantity falling, dissolved +in rain, on an acre of soil throughout the year. Various estimations of +the total amount of combined nitrogen, which is in this way brought to +the soil, have been made. A certain amount of discrepancy, it is true, +is to be found in these various estimations, no doubt largely due to the +difference in the circumstances under which the investigations were +carried out. Mr Warington has made several investigations at Rothamsted, +and, according to his most recently published figures, the total +quantity only amounts to 3.37 lb. per acre per annum—of which only 2.53 +lb. is as ammonia itself.<a name="FNanchor_30_30" id="FNanchor_30_30"></a><a href="#Footnote_30_30" class="fnanchor">[30]</a></p> + +<p>As already mentioned, there can be little doubt that plants can absorb +nitrogen in the form of ammonia. The question of how far plant-leaves +are able to absorb ammonia is a much debated one. It is probable that if +they can do so, it is only to a very small extent.<a name="FNanchor_31_31" id="FNanchor_31_31"></a><a href="#Footnote_31_31" class="fnanchor">[31]</a> The question as +to whether the plant's roots can absorb ammonia or not, is also a very +keenly debated one. The point is a very <span class='pagenum'><a name="Page_50" id="Page_50">[Pg 50]</a></span>difficult one to decide, and is +much complicated by the consideration that ammonia, when applied to the +the soil, is so speedily converted into nitric acid. Despite, however, +these difficulties, and the vast amount of controversy on the point, the +experiments of Ville, Hosäus and Lehmann, seem to indicate beyond doubt +that ammonia is a direct source of nitrogen. Lehmann's experiments would +seem, further, to indicate that there are certain periods of a plant's +growth when its preference for ammonia salts seems to be greater than at +other times. The point, however, it must be confessed, is still an +obscure one. The great difficulty in deciding it, as has just been said, +lies in the fact that ammonia salts, when applied to a soil, are, by the +process of nitrification, converted into nitrates. In experimenting, +therefore, with ammonia, and noting the results, it is wellnigh +impossible to say, except by subsequent analyses, whether the nitrogen +in the ammonia salts has not been converted into nitrates before +assimilation.</p> +<br /> + +<p class="cen"><i>Relation of Nitric Acid to the Plant.</i></p> + +<p>Thirdly, as to nitrogen in the form of nitrates. While it is true that +plants can absorb nitrogen in certain organic forms and as ammonia +salts, it is now a well-known fact that the chief, and by far the most +important, source of nitrogen is nitric acid. Probably more than 90 per +cent of the nitrogen absorbed by <span class='pagenum'><a name="Page_51" id="Page_51">[Pg 51]</a></span>green-leaved plants from the soil is +absorbed as nitrates. The tendency of all nitrogen compounds in the soil +is towards conversion into nitric acid. It is the final form of nitrogen +in the soil. The precise method in which this conversion takes place is +a discovery of only a few years' standing. The great economic importance +of this discovery, made by the French chemists Schloesing and Müntz, and +associated in this country with the names of Warington, Munro, and P. F. +Frankland, is only gradually being appreciated. It is without doubt one +of the most interesting made in the domain of agricultural chemistry of +late years.</p> +<br /> + +<p class="cen"><i>Nitrification.</i></p> + +<p>It was in the year 1877 that the two French chemists above referred to +published the results of some experiments they had carried out, which +proved that nitrification—the name given to the process by which +ammonia or other nitrogen salts are converted in the soil into nitric +acid—was due to the action of micro-organic life.</p> + +<p>The basis of the theory rests upon the fact that dilute solutions of +ammonia salts or urine, containing all the necessary constituents of +plant-food, if previously sterilised, may be kept for an indefinitely +long period of time, provided the air supplied be filtered through +cotton wool,—so as to prevent the entrance of micro-organisms—without +any formation of nitrates. <span class='pagenum'><a name="Page_52" id="Page_52">[Pg 52]</a></span>Introduce, however, into such a solution a +little fresh soil, and nitrification will soon follow.</p> + +<p>The conditions under which the nitrification ferment acts, as well as +the nature of the ferment, or rather ferments, have subsequently been +carefully studied by Schloesing and Müntz, Winogradsy, Dehérain, +Kellner, and other Continental observers, and especially by Warington, +Munro, and P. F. Frankland in this country. These conditions cannot be +gone into here. They will be fully discussed in the chapter on +Nitrification. Briefly stated, they are a certain range of temperature +(between slightly above freezing-point and 50° C., the maximum activity +taking place, according to Schloesing and Müntz, at about 30° C.); a +plentiful supply of atmosphere oxygen (hence the fact observed by +Warington, that nitrification is chiefly limited to the surface-soil); a +certain amount of moisture; and the presence of certain of the necessary +mineral plant constituents, and the presence of carbonate of lime.</p> + +<p>The light which these discoveries throw upon the extremely complicated +question of the fertility of the soil is considerable, as it follows +that no soil can be regarded as really a fertile one in which the +process of nitrification does not freely take place. They furthermore +explain many facts, hitherto observed but not well understood, with +regard to the action of different nitrogenous manures.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_53" id="Page_53">[Pg 53]</a></span><i>Ash Constituents of the Plant.</i></p> + +<p>We now come to consider the present state of our knowledge on the +essentialness of the ash or mineral portion of the plant. While a +portion of the plant's substance which, up to Liebig's time, had +obtained little notice, it has, since the publication of his famous +"mineral" theory, obtained an ever-increasing amount of investigation.</p> + +<p>Up till 1800 practically nothing was known of the function of the ash +constituents. In 1802 de Saussure wrote that it was unknown whether the +constituents of many plants were due to the soils on which they grew, or +whether they were the products of vegetable growth. Some two years +later, however, he was enabled to carry out a number of experiments +which really placed the subject on a firm scientific basis. The +essentialness of the ash constituents was only, however, placed beyond +all doubt by Wiegmann and Polstorff's researches, carried out in 1840.</p> + +<p>Reference has already been made to the great stimulus given to research +by the promulgation of Liebig's mineral theory.</p> +<br /> + +<p class="cen"><i>Methods of Research.</i></p> + +<p>In epitomising the vast amount of work carried on since 1840, with the +view of ascertaining the essentialness of the various substances found +in the ash of plants, two methods of experimentation have been +followed.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_54" id="Page_54">[Pg 54]</a></span><i>Artificial Soils.</i></p> + +<p>The first of these two methods was that adopted in the famous +experiments, carried out by Prince Salm-Horstmar, which have done so +much to further our knowledge on this question. It consisted in growing +plants on an artificial soil—formed out of sugar-charcoal, pulverised +quartz or purified sand—to which were added the different food +constituents.</p> +<br /> + +<p class="cen"><i>Water-culture.</i></p> + +<p>While the results obtained by Prince Salm-Horstmar by this method were +of a most valuable nature, subsequent experimenters have abandoned his +method for the other method—viz., "water-culture." The medium used in +this process is pure water; and it is from experiments carried out in +water-culture that much of our present knowledge, in regard to the +relation of the ash constituents to the plant, is due.</p> + +<p>The names of those who have worked in this department are very numerous. +Among them may be mentioned Knop, Sachs, Stohmann, Nobbe, Rautenberg, +Kühn, Lucanus, W. Wolff, Hampe, Beyer, E. Wolff, P. Wagner, +Bretschneider and Lehmann. The results obtained by these and other +experimenters have demonstrated the following facts.</p> + +<p>The substances which have been found in the ash of plants are: <i>potash</i>, +<i>soda</i>, <i>lime</i>, <i>magnesia</i>, <i>oxide of iron</i>, <i>oxide of manganese</i>, +<i>phosphoric acid</i>, <i>sulphuric acid</i>, <span class='pagenum'><a name="Page_55" id="Page_55">[Pg 55]</a></span><i>silica</i>, <i>carbonic acid</i>, +<i>chlorine</i>, <i>lithia</i>, <i>rubidia</i>, <i>alumina</i>, <i>oxide of copper</i>, +<i>bromine</i>, <i>iodine</i>, and occasionally even other substances. Of these, +however, only six are probably absolutely necessary for +plant-growth—viz., <i>potash</i>, <i>lime</i>, <i>magnesia</i>, <i>oxide of iron</i>, +<i>phosphoric acid</i>, and <i>sulphuric acid</i>. Three other substances seem +also to be almost invariably present, and may possibly be essential—in +very minute quantities at any rate—viz., <i>chlorine</i>, <i>soda</i>, and +<i>silica</i>. With regard to <i>alumina</i> and <i>oxide of copper</i>, these +constituents must be regarded as accidental; while <i>iodine</i> and +<i>bromine</i> only occur in the ash of marine plants.</p> +<br /> + +<p class="cen"><i>Method of Absorption of Plant-food.</i></p> + +<p>A department of vegetable physiology which has had much work devoted to +it is the method in which plant-roots absorb their food. The plant's +nourishment is absorbed in solution by means of the roots. Its +absorption takes place, according to Fischer and Dutrochet, who have +investigated the subject at great length, by the process known as +<i>endosmosis</i>. It has also been established by numerous experiments, that +different plants require different constituents in different +proportions.</p> +<br /> + +<p class="cen"><i>Water as a Carrier of Plant-food.</i></p> + +<p>The function performed by water, as the carrier of plant-food, and the +motion of the sap of the plant, are questions which have also received +much <span class='pagenum'><a name="Page_56" id="Page_56">[Pg 56]</a></span>attention. The motion of the plant's sap seems to have attracted a +great deal of attention at a very early stage of the study of plant +physiology. As far back as 1679, Marriotte studied it. Among other old +experimenters were Hales, Guettard, Sénébier, Saint-Martin, de Candolle, +and Miguel. In more recent times, it has been investigated by Schübler, +Lawes and Gilbert, Knop, Sachs, Unger, and Hosäus. Some idea of the +enormous amount of water transpired by plant-leaves may be gained by the +statement that from 233 lb. to 912 lb. of water are transpired for every +pound of plant-tissue formed.<a name="FNanchor_32_32" id="FNanchor_32_32"></a><a href="#Footnote_32_32" class="fnanchor">[32]</a></p> +<br /> + +<p class="cen"><i>Agronomy.</i></p> + +<p>When we come to deal with questions relating to the chemistry of the +soil, we find that so much investigation has been devoted to this one +branch of agricultural chemistry as to constitute it a special branch by +itself—known in France under the name of <i>agronomie</i>—and being taught +in the large agricultural colleges by special professors of the subject. +The value of studying the properties of soils was recognised at an early +period. This study was for long largely confined to their <i>physical</i>, +or, what are popularly known as their <i>mechanical</i> properties. Thus <span class='pagenum'><a name="Page_57" id="Page_57">[Pg 57]</a></span>Sir +Humphry Davy ascertained many important facts with regard to the heat +and water absorbing and retaining properties of soils.</p> +<br /> + +<p class="cen"><i>Retention by Soil of Plant-food.</i></p> + +<p>It was not till a later period that the power soils possess of fixing +from their watery solutions various plant-foods, both organic and +inorganic, was discovered. The earliest recognition of this most +important property of soils was made by Gazzeri, who, in 1819, called +attention to the fact that the dark fluid portion of farmyard manure was +purified on passing through clay. He concluded that soils, more +especially clayey soils, possessed the property of being able to fix +from their watery solutions the necessary plant-food constituents, and +fix them beyond risk of loss, only affording a gradual supply to the +plant as required.</p> + +<p>The first experiments carried out on this subject were those by Huxtable +and Thompson in 1850. The liquid portion of farmyard manure was filtered +through soil and subsequently examined, when it was found to have not +only lost its colour, but also to have lost its smell. Ammonia and +ammonia salts were also experimented with, and it was found that soils +possessed the power of fixing ammonia.</p> + +<p>To Thomas Way, however, we are indebted for the most valuable +contribution on this important subject made by any one single +investigator. His experiments were not merely carried out with regard +<span class='pagenum'><a name="Page_58" id="Page_58">[Pg 58]</a></span>to ammonia, but also with regard to other bases—such as potash, lime, +magnesia, soda, &c. Since Way's experiments much work has been done by +Liebig, Stohmann, Henneberg, and Heiden, as also by Voelcker, Eichhorn, +Knop, Rautenberg, Pochwissnew, Warington, Beyer, Bretschneider, Sestini, +Laskowsky, Strehl, Pillnitz, Peters, W. Wolff, Lehmann, and Biedermann.</p> +<br /> + +<p class="cen"><i>Bases and Acids fixed by Soil.</i></p> + +<p>From these experiments it may be taken as proved beyond doubt that soils +have the power of fixing, to a greater or less extent, the following +bases: ammonia, potash, lime, magnesia and soda; as well as the two +acids, phosphoric and silicic. The order in which the different bases +are fixed is an important point. It would seem that the soil has a +greater affinity for the more valuable manurial substances, such as +ammonia, potash, and lime, and that these substances are first fixed. +That in fixing any one of the above-mentioned bases from its solution, +it can only do so at the expense of another base. Thus, in fixing +potash, either lime, magnesia, or soda must be given up. Further, when a +base in solution, as sulphate or chloride, is absorbed by a soil, the +base is alone fixed, while the sulphuric acid or chlorine is left in +solution. Lastly, the amount of base absorbed by a soil depends on the +concentration of its solution, on the nature of its combination, and the +temperature. <span class='pagenum'><a name="Page_59" id="Page_59">[Pg 59]</a></span>Way found in his experiments that a clay soil has more +power than a peaty soil, and that a peaty soil has more power than a +sandy soil.</p> +<br /> + +<p class="cen"><i>Causes of this Fixation.</i></p> + +<p>So much for the fact of soil absorption; as to the cause or causes of +this absorption, a great number of theories have been put forward. Those +may be divided into two classes—those accounting for it as due to +physical properties of the soil; and those, on the other hand, +explaining it as due to chemical action.</p> + +<p>To the latter class Way's belonged. He explained it as due to the +formation in the soil of hydrated double silicates, consisting of a +silicate of alumina, along with a silicate of the base fixed. Brüstlein +and Peters, on the other hand, were of the opinion that it was purely +physical in its nature. A theory has been advanced that it is due to the +formation of insoluble ulmates and humates, formed by the union of ulmic +and humic acids, along with the bases fixed. Among others who devoted +investigation to this interesting question, may be mentioned Rautenberg +and Heiden.</p> + +<p>On reviewing the evidence, it seems to be pretty well established that +it really is mainly a chemical act, due chiefly to the formation of +double silicates, and doubtless to a certain extent to the formation of +insoluble humates and ulmates. Heiden's <span class='pagenum'><a name="Page_60" id="Page_60">[Pg 60]</a></span>experiments would seem to +indicate, however, that it is also partly of a physical nature.</p> + +<p>With regard to the absorption of phosphoric acid, this has been shown to +be a chemical act, and depends on the formation of insoluble phosphates +of calcium, iron, aluminium, and magnesium, the percentage of iron +especially determining this.</p> + +<p>Much analytical work has been accomplished of late years with a view of +ascertaining the amount of ash in different kinds of plants, and in the +different parts of the plant.</p> +<br /> + +<p class="cen"><i>Action of Manures.</i></p> + +<p>The department of agricultural chemistry which has been most largely +developed of late years is that connected with the problems of +<i>manuring</i>. It is, from a practical point of view, of most value. It is +some considerable time since we have recognised that the only three +ingredients it is, as a rule, expedient to apply as artificial manures, +are <i>nitrogen</i>, <i>phosphoric acid</i>, and <i>potash</i>. The nature, mode of +action of the different compounds, and properties of these three +substances, and their comparative influence in fostering plant-growth, +together with the economic question of which form is, under various +circumstances, the most economical for the farmer to use, have together +given rise to a large number of "field" and "pot" experiments. As the +principles underlying this <span class='pagenum'><a name="Page_61" id="Page_61">[Pg 61]</a></span>practice form the subject of the following +treatise, any further discussion of the question must be left to the +following chapters.</p> + +<div class="blockquot"><p><i>Note.</i>—The reader interested in the historical development of +agricultural chemistry is referred to Sir J. H. Gilbert's +Presidential Address to the Chemical Section of the British +Association, 1880.</p></div> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_1_1" id="Footnote_1_1"></a><a href="#FNanchor_1_1"><span class="label">[1]</span></a> The History of the Chemical Elements. By Sir Henry E. +Roscoe, F.R.S. (Wm. Collins, Sons, & Co.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_2_2" id="Footnote_2_2"></a><a href="#FNanchor_2_2"><span class="label">[2]</span></a> Van Helmont's science was, however, of an extremely +rudimentary nature, as may be evidenced by the belief he entertained +that the smells which arise from the bottom of morasses produce frogs, +slugs, leeches, and other things; as well as by the following recipe +which he gave for the production of a pot of mice: "Press a dirty shirt +into the orifice of a vessel containing a little corn, after about +twenty-one days the ferment proceeding from the dirty shirt, modified by +the odour of the corn, effects a transmutation of the wheat into mice." +The crowning point in this recipe, however, lay in the fact that he +asserted that he had himself witnessed the fact, and, as an interesting +and corroborative detail, he added that the mice were born full-grown. +See 'Louis Pasteur: His Life and Labours.' By his Son-in-law. Translated +by Lady Claud Hamilton. (Longmans, Green, & Co.) P. 89.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_3_3" id="Footnote_3_3"></a><a href="#FNanchor_3_3"><span class="label">[3]</span></a> He then goes on to relate a number of experiments by +Cornelius Drebel and Albertus Magnus, showing the refreshing power of +this balsam, and then those of Quercitan with roses and other flowers, +and his own with nettles.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_4_4" id="Footnote_4_4"></a><a href="#FNanchor_4_4"><span class="label">[4]</span></a> Priestley, however, did not realise that <i>carbonic acid +gas</i> was a necessary plant-food; on the contrary, he considered it to +have a deleterious action on plant-growth. Percival was really the first +to point out that carbonic acid gas was a plant-food.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_5_5" id="Footnote_5_5"></a><a href="#FNanchor_5_5"><span class="label">[5]</span></a> It is recorded as an instance of the scientific enthusiasm +of the man, that he was wont to carry about with him bottles containing +oxygen, which he had obtained from cabbage-leaves, as also coils of iron +wire, with which he could illustrate the brilliant combustion which +ensued on burning the latter in oxygen gas.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_6_6" id="Footnote_6_6"></a><a href="#FNanchor_6_6"><span class="label">[6]</span></a> For a full account of Sénébier's researches, see +'Physiologie végétale, contenant une description des organes des +plantes, et une exposition des phénomenes produits par leur +organisation, par Jean Sénébier.' (5 tomes. Genève, 1800.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_7_7" id="Footnote_7_7"></a><a href="#FNanchor_7_7"><span class="label">[7]</span></a> How Crops Grow. By Professor S. W. Johnson. Macmillan & Co. +(Introduction, p. 4.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_8_8" id="Footnote_8_8"></a><a href="#FNanchor_8_8"><span class="label">[8]</span></a> See p. 40 to 45.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_9_9" id="Footnote_9_9"></a><a href="#FNanchor_9_9"><span class="label">[9]</span></a> Elements of Agricultural Chemistry, in a course of Lectures +for the Board of Agriculture. By Sir Humphry Davy. (London, 1831.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_10_10" id="Footnote_10_10"></a><a href="#FNanchor_10_10"><span class="label">[10]</span></a> This department of agricultural research was subsequently +carried on by Sprengel, Schübler, and others.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_11_11" id="Footnote_11_11"></a><a href="#FNanchor_11_11"><span class="label">[11]</span></a> Born in Paris, 1802; died 11th May 1887.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_12_12" id="Footnote_12_12"></a><a href="#FNanchor_12_12"><span class="label">[12]</span></a> See p. 40.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_13_13" id="Footnote_13_13"></a><a href="#FNanchor_13_13"><span class="label">[13]</span></a> While much of Boussingault's work was carried out previous +to the year 1840, he continued to enrich agricultural chemistry with +numerous valuable contributions up till the time of his death. It may be +well here to mention the names of his most important contributions to +agricultural science, made subsequent to 1840.</p> + +<p class="noin">In 1843 he published, in a work entitled 'Economie Rurale,' the results +of his numerous experiments and researches. This work is well known to +English agriculturists from an English translation which appeared in +1845 (Boussingault's 'Rural Economy,' translated by G. Law. H. Ballière, +London).</p> + +<p class="noin">In 1860 appeared the first volume of his last great work, 'Agronomie +Chimie Agricole et Physiologie' This work, which consisted of seven +volumes, was not finished till 1884. He died on the 11th of May 1887. It +may be added that the Royal Society of London awarded him the Copley +medal in 1887.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_14_14" id="Footnote_14_14"></a><a href="#FNanchor_14_14"><span class="label">[14]</span></a> See British Association Proceedings, 1880, p. 511.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_15_15" id="Footnote_15_15"></a><a href="#FNanchor_15_15"><span class="label">[15]</span></a> It may be pointed out that, while the amount of ammonia +washed down by the rain is small, Schloesing has found in some recent +experiments that a damp soil may absorb from the air in the course of a +year 38 lb. of combined nitrogen, chiefly ammonia, per acre. See p. +132.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_16_16" id="Footnote_16_16"></a><a href="#FNanchor_16_16"><span class="label">[16]</span></a> The example, set by Germany, has been followed by other +countries in which well-equipped research stations now exist. Perhaps +the most striking example of the rapid development of the means of +agricultural research is furnished by the United States of America. At +present over fifty agricultural experiment stations, more or less well +equipped, exist at present in that country, all liberally supplied by +State aid. The earliest to be founded, it may be added, was that at +Middletown, Connecticut, the date of its institution being 1875.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_17_17" id="Footnote_17_17"></a><a href="#FNanchor_17_17"><span class="label">[17]</span></a> It may thus claim to be the second oldest experimental +station, that instituted by Boussingault at Bechelbronn in Alsace being the oldest.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_18_18" id="Footnote_18_18"></a><a href="#FNanchor_18_18"><span class="label">[18]</span></a> For an account of the Rothamsted experiments, and a short +biography of Sir John Lawes, the reader is referred to a pamphlet by the +present writer, entitled 'Sir J. B. Lawes, Bart., LL.D., F.R.S., and the +Rothamsted Experiments' ('Scottish Farmer' Office, 93 Hope Street, +Glasgow).</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_19_19" id="Footnote_19_19"></a><a href="#FNanchor_19_19"><span class="label">[19]</span></a> Of these numerous elaborate experiments, perhaps those +which have attracted the most widespread interest amongst agriculturists +have been those carried out on the growth of wheat on the same land year +after year for a period of nearly fifty years. The important light which +this series of experiments has thrown upon the theory of the rotation of +crops, and the subject of the manuring of cereals, is very great.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_20_20" id="Footnote_20_20"></a><a href="#FNanchor_20_20"><span class="label">[20]</span></a> Associated in some cases with phosphorus and sulphur.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_21_21" id="Footnote_21_21"></a><a href="#FNanchor_21_21"><span class="label">[21]</span></a> It must be pointed out that plant-respiration does not +take place <i>only</i> during the night-time. It probably goes on at all +times, but it is only during the night-time that its action is apparent, +as the reverse process of carbon assimilation, which goes on at an +incomparably greater rate, masks its action during the daytime.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_22_22" id="Footnote_22_22"></a><a href="#FNanchor_22_22"><span class="label">[22]</span></a> The length of the day has an important influence on +plant-growth, as is evidenced by the rapid growth of vegetation in +Norway and Sweden. In these countries there is a late spring, and a +short and by no means hot summer, but a very long period of daylight.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_23_23" id="Footnote_23_23"></a><a href="#FNanchor_23_23"><span class="label">[23]</span></a> A point of great interest which these experiments +elucidated is that nocturnal repose is not absolutely necessary for the +growth and development of all plants.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_24_24" id="Footnote_24_24"></a><a href="#FNanchor_24_24"><span class="label">[24]</span></a> See pp. 15 and 22.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_25_25" id="Footnote_25_25"></a><a href="#FNanchor_25_25"><span class="label">[25]</span></a> See p. 22.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_26_26" id="Footnote_26_26"></a><a href="#FNanchor_26_26"><span class="label">[26]</span></a> See Chapter III., pp. 120 and 131.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_27_27" id="Footnote_27_27"></a><a href="#FNanchor_27_27"><span class="label">[27]</span></a> Further reference is made to this subject in Chapter III., +p. 136.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_28_28" id="Footnote_28_28"></a><a href="#FNanchor_28_28"><span class="label">[28]</span></a> See p. 6.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_29_29" id="Footnote_29_29"></a><a href="#FNanchor_29_29"><span class="label">[29]</span></a> See Phil. Trans., Part II., 1861, pp. 444-446. Lawes & +Gilbert. Schloesing has found in the air in the neighbourhood of Paris 1 +lb. of ammonia in 26,000,000 cubic yards; while Müntz found only about +half that amount in a similar quantity of air on the top of the Pic du +Midi.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_30_30" id="Footnote_30_30"></a><a href="#FNanchor_30_30"><span class="label">[30]</span></a> See Chapter III., pp. 119, 120; Appendix, p. 155.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_31_31" id="Footnote_31_31"></a><a href="#FNanchor_31_31"><span class="label">[31]</span></a> Some recent experiments by Dyer and Smetham would seem to +show that comparatively small quantities of ammonia in the air prove +actually hurtful to plant-life. Thus they found that one volume of +ammonia in 1000 volumes of air was fatal to hardy plants; while one +volume in 3000 volumes killed tender ones.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_32_32" id="Footnote_32_32"></a><a href="#FNanchor_32_32"><span class="label">[32]</span></a> According to the experiments of Hellriegel and Wollny. The +quantity, it may be added, varies with the leaf-surface and the length +of the period of growth of the plant. It is greatest with clovers and +grasses, and least in the potatoes and roots.</p></div> + +<span class='pagenum'><a name="Page_62" id="Page_62">[Pg 62]</a></span> + +<br /> +<br /> +<br /> +<br /> + +<hr style="width: 65%;" /><span class='pagenum'><a name="Page_63" id="Page_63">[Pg 63]</a></span> +<br /> +<h2>PART II.</h2> + +<h2>PRINCIPLES OF MANURING</h2> + +<span class='pagenum'><a name="Page_64" id="Page_64">[Pg 64]</a></span> +<br /> +<hr /><span class='pagenum'><a name="Page_65" id="Page_65">[Pg 65]</a></span> +<br /> +<h2>CHAPTER I.</h2> + +<h2>FERTILITY OF THE SOIL.</h2> +<br /> + +<p>It is necessary to clearly understand to what the fertility of a soil is +due ere we can hope to master the theory of manuring.</p> +<br /> + +<p class="cen"><i>What constitutes Fertility in a Soil.</i></p> + +<p>The question, What constitutes fertility in a soil? is by no means an +easy one to answer. If we say, The presence of a plentiful supply of the +constituents which form the plant's food, our answer will be incomplete. +Similarly, if we reply, A certain physical condition of the soil—here, +again, it will be found equally unsatisfactory; for fertility of a soil +depends both on its physical condition and on its chemical composition, +and indeed even on other circumstances. It may be well, then, before +proceeding to treat of the nature and action of the different manures, +to offer a brief statement of the conditions of fertility so far, at any +rate, as we at present know <span class='pagenum'><a name="Page_66" id="Page_66">[Pg 66]</a></span>them. For it may be well to warn the reader +that, despite the great amount of work carried out on this subject by +experimenters, we still have much to learn before we shall be in a +position fully and clearly to understand the subject of soil-fertility +in all its bearings.</p> + +<p>Apart altogether from the influence exerted by climate, latitude, +altitude, and exposure, the fertility of a soil may be said to depend on +the following properties. These we may divide into three groups or +classes:—</p> + +<div style="margin-left: 40%; margin-right: 15%;"> +1. Physical or mechanical.<br /> +2. Chemical.<br /> +3. Biological.<br /> +</div> + +<br /> +<p><b>I. Physical Properties of a Soil.</b>—The physical properties of a soil +are generally admitted to have a very important bearing on its +fertility. This has been long practically recognised, and perhaps has in +the past been unduly exalted in importance, at the expense of the no +less important functions of the chemical.<a name="FNanchor_33_33" id="FNanchor_33_33"></a><a href="#Footnote_33_33" class="fnanchor">[33]</a> The reason of this is +doubtless to be ascribed to the fact <span class='pagenum'><a name="Page_67" id="Page_67">[Pg 67]</a></span>that it is much easier to study +the physical properties of a soil than it is to study the chemical; and +that, while we are in possession of a very large amount of useful +information with regard to the former, we are at present only on the +threshold of our knowledge of the latter.</p> +<br /> + +<p class="cen"><i>Variety of Soils.</i></p> + +<p>It is a matter of common observation that soils differ widely in their +mechanical nature. The early recognition of this fact is evidenced by +the large number of technical terms which have been long in vogue among +farmers descriptive of these differences. Thus soils are in the habit of +being described as "heavy," "light," "stiff," "strong," "warm," "cold," +"wet," "damp," "peaty," "clayey," "sandy," "loamy," &c., &c.</p> +<br /> + +<p class="cen"><i>Absorptive Power for Water.</i></p> + +<p>One of the most important of the physical properties of a soil is its +power to absorb water.</p> + +<p>Water to the plant economy is just as important and necessary as it is +to the animal economy. Consequently it is of primary importance to +examine into the conditions which regulate the absorption of this +important plant-food by the soil.</p> + +<p>By the absorptive power of a soil is meant its capacity for drinking in +any water with which its particles may come in contact. This power +depends, first, on the predominance of its proximate constituents—viz., +<span class='pagenum'><a name="Page_68" id="Page_68">[Pg 68]</a></span><i>sand</i>, <i>clay</i>, <i>carbonate of lime</i>, and <i>humus</i>; and secondly on the +fineness of the soil-particles.</p> +<br /> + +<p class="cen"><i>Absorptive Power of Sand, Clay, Humus.</i></p> + +<p>First, then, with regard to the absorptive power of sand, clay, and +humus. Of these, sand possesses this power to the least extent, clay to +a greater extent, while humus possesses it most of all.<a name="FNanchor_34_34" id="FNanchor_34_34"></a><a href="#Footnote_34_34" class="fnanchor">[34]</a></p> + +<p>The extent, therefore, of the absorptive power of a soil depends very +much on the proportions in which it possesses these three ingredients. +The more sandy a soil is, the less will its power be of absorbing water; +and this, there is little doubt, is one of the reasons why a sandy soil +is, as a rule, an unfertile soil. Of course there are other and even +more important reasons; but that this absorptive power has an important +bearing on the question is conclusively proved by the fact that sandy +soils are more fertile in a climate where rain is frequent than in one +where much dry weather prevails. The incapacity of a sandy soil to +absorb a large quantity of moisture is not fraught with such evil +effects to the crops in the former case, because it is counteracted by +the climatic conditions, which obviate the necessity, in a soil, of +possessing great absorptive powers.</p> + +<p><span class='pagenum'><a name="Page_69" id="Page_69">[Pg 69]</a></span>The converse, of course, we may mention in passing, holds good of clayey +soils.</p> +<br /> + +<p class="cen"><i>Fineness of Soil-particles.</i></p> + +<p>The second quality in a soil on which its absorptive power depends is +the fineness of its particles. The great benefit which a soil derives +from a good tilth, in this respect, was one of the reasons why Tull's +system of horse-hoeing husbandry was so successful in its results.<a name="FNanchor_35_35" id="FNanchor_35_35"></a><a href="#Footnote_35_35" class="fnanchor">[35]</a> +The finer the soil-particles, it may be said generally, the greater is +the absorptive power of the soil.</p> +<br /> + +<p class="cen"><i>Limit to Fineness.</i></p> + +<p>There is, however, a limit to the fineness to which the particles of a +soil ought to be reduced; for it has been found by experiment that when +a certain degree of fineness is reached, the absorptive power decreases +with any further pulverisation. A German experimenter found, for +example, that a garden loam, capable of absorbing 114 per cent of water +in its natural state, when pulverised very fine was able to absorb only +62 per cent of water. Here, clearly, the limit <span class='pagenum'><a name="Page_70" id="Page_70">[Pg 70]</a></span>to which it is advisable +to pulverise a soil had been exceeded.</p> +<br /> + +<p class="cen"><i>Reason of the above.</i></p> + +<p>It is not difficult to see why this should be so. The amount of water +that a soil can soak up is due to the number of pores, or air-spaces, it +contains of a certain size. If these pores are large and few in number, +the amount of water absorbed will be naturally less than when they are +numerous and smaller in size. Up to a certain extent, the more a soil is +broken the greater will be the number of pores created, of a size to +permit the water to soak in. Beyond that point the pores become too +minute, and the soil becomes too compact, each particle clinging +together too closely.</p> +<br /> + +<p class="cen"><i>Retentive Power of Soils for Water.</i></p> + +<p>Now closely connected with this absorptive power of soils, which we have +just been considering, is the power soils possess of holding or +retaining the water they absorb. This power, it will be seen at a +glance, must have an important bearing on the fertility of a soil.</p> +<br /> + +<p class="cen"><i>Importance of Retentive Power.</i></p> + +<p>As a considerable interval often elapses between the periods of +rainfall, soils, if they are to support vegetable growth, must be able +to store up their water-supply against periods of drought. This is <span class='pagenum'><a name="Page_71" id="Page_71">[Pg 71]</a></span>all +the more necessary when we remember that, in the case of heavy crops, +the rainfall would often be inadequate to supply the water necessary for +their growth. In fact, it has been estimated that the average +evaporation from soils bare of any cultivation is equal to the rainfall. +That the evaporation from soils covered with vegetation is very much +greater, has been strikingly shown by a calculation made by the late +eminent American botanist, Professor Asa Gray, who calculated that a +certain elm-tree offered a leaf-surface, from which active transpiration +constantly went on, of some five acres in extent; while it has further +been calculated that a certain oak-tree, within a period of six months, +transpired during the daytime eight and a half times more water than +fell as rain on an area equal in circumference to the tree-top.<a name="FNanchor_36_36" id="FNanchor_36_36"></a><a href="#Footnote_36_36" class="fnanchor">[36]</a> Just +as the state of the fineness of the soil-particles has an important +influence on the absorptive power of soils, so, too, it is found, it has +an important bearing on the rate at which evaporation takes place. +Evaporation goes on to the greatest extent in soils whose particles are +compacted together, capillary action in this case taking place more +freely, and effecting evaporation from a greater depth of soil. The +stirring of the surface portion of the soil, as for example by hoeing or +harrowing, has for this reason an important influence in lessening the +amount of evaporation, and <span class='pagenum'><a name="Page_72" id="Page_72">[Pg 72]</a></span>minimising the risks of drought, by breaking +the capillary attraction. The amount of evaporation which takes place +from a soil covered with a crop, depends largely on the nature of the +crop; a deep-rooted crop, since it draws its moisture from a wider area +of soil, being more effective in drying a soil than a shallow-rooted +crop. The difference in the amounts evaporated from a cropped and a bare +fallow soil has been shown at Rothamsted to equal a rainfall of nine +inches, the crop being barley. The increase, of course, is due to the +water which the crop transpires.<a name="FNanchor_37_37" id="FNanchor_37_37"></a><a href="#Footnote_37_37" class="fnanchor">[37]</a></p> + +<p>It may be generally said that the greater the absorptive power of a +soil, the greater is its retentive power; for soils that most largely +absorb water are the most reluctant to part with it.</p> + +<p>While these properties are undoubtedly necessary for fertile soils, it +is needless to add that they may be possessed by a soil to too great an +extent. The soil that is unable to throw off any excess of water becomes +cold and damp, and does not admit of proper tillage. Its pores become +entirely choked up, and the circulation of air, which, as we shall see, +is of so much importance, is rendered impossible. Plants in such a soil +are apt to sicken and die, the water becomes stagnant, and certain +chemical actions are caused which give rise to poisonous gases, such as +sulphuretted hydrogen, &c. A stiff clayey soil offers a good example of +the disadvantage of <span class='pagenum'><a name="Page_73" id="Page_73">[Pg 73]</a></span>over-retentiveness. Owing to the difficulty such +soils experience in throwing off their excessive water, they are +extremely difficult to till; and sowing operations are on that account +apt to be delayed.</p> +<br /> + +<p class="cen"><i>Power Plants have of absorbing Water from a Soil.</i></p> + +<p>It is a strange fact, and one worth noticing in this connection, that +the power plant-roots have of drawing their moisture from a soil, seems +to depend on the retentive power of the soil. By this is meant that +plants have not the means of exhausting the water in a retentive soil to +such an extent as in a non-retentive soil.</p> + +<p>In some extremely interesting experiments, carried out by the well-known +German botanist Sachs, it was found that plants wilted in a loamy soil, +whose water-holding capacity was 52 per cent, when its moisture reached +8 per cent; while in a sandy soil—water-holding capacity 21 per +cent—the same species of plant did not wilt until its moisture reached +1-1/2 per cent. Here, then, we see that on one kind of soil the plant +was able to live, and obtain sufficient water for its needs, while it +died of thirst in another soil, although that soil contained quite as +much moisture.</p> + +<p>Speaking generally, we may say that Hellriegel's experiments have shown +that any soil can supply plants with all the water they need so long as +its <span class='pagenum'><a name="Page_74" id="Page_74">[Pg 74]</a></span>moisture is not reduced below one-third of the whole amount it can +hold.<a name="FNanchor_38_38" id="FNanchor_38_38"></a><a href="#Footnote_38_38" class="fnanchor">[38]</a></p> +<br /> + +<p class="cen"><i>How to increase Absorptive Power of Soils.</i></p> + +<p>The absence or presence, in excess, of the above properties, suggests a +word or two on how these natural defects may, to a certain extent, be +remedied artificially. It stands to reason, that if organic matter in a +soil renders its absorptive power greater, a simple method of improving +a soil defective in this property is by the addition of organic matter. +One of the benefits of ploughing-in green crops on sandy soils is +undoubtedly due to this fact; the addition of farmyard manure having +also a similar effect. The absence of a sufficient amount of +retentiveness, such as is found in sandy soils, in the same way +suggests, as a remedy, the addition of clay; and, <i>vice versâ</i>, where +the soil is too clayey, the natural method of improvement will be the +addition of sand.<a name="FNanchor_39_39" id="FNanchor_39_39"></a><a href="#Footnote_39_39" class="fnanchor">[39]</a></p> +<br /> + +<p class="cen"><i>Shrinkage of Soils.</i></p> + +<p>In drying, soils shrink. Those which shrink least are sandy and chalky +soils. Humus soils, on the other hand, shrink most.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_75" id="Page_75">[Pg 75]</a></span><i>Most favourable Amount of Water in a Soil.</i></p> + +<p>The amount of water in a soil most favourable for plant-growth is a +question of considerable difficulty. Too great an amount of moisture +renders the land cold; air cannot obtain access to the soil-particles, +and the plants sicken and die. Hellriegel has found that as much as 80 +per cent of what the soil can hold is hurtful to plants, and that from +50 to 60 per cent is the best amount.<a name="FNanchor_40_40" id="FNanchor_40_40"></a><a href="#Footnote_40_40" class="fnanchor">[40]</a></p> +<br /> + +<p class="cen"><i>Hygroscopic Power.</i></p> + +<p>A property possessed by soils in relation to water, which is quite +distinct from absorptive power, is their hygroscopic power. By this is +meant their power of absorbing water from the air where it is present in +the gaseous form. This property is identical with the property which +will be adverted to immediately—viz., capacity for absorbing gases. The +extent to <span class='pagenum'><a name="Page_76" id="Page_76">[Pg 76]</a></span>which soils possess this hygroscopic property seems to be +regulated very much by the same conditions as regulate their ordinary +absorptive power.<a name="FNanchor_41_41" id="FNanchor_41_41"></a><a href="#Footnote_41_41" class="fnanchor">[41]</a> This property is considered to be of great +importance in the case of soils in hot climates, where their +agricultural value may be said to depend to a large extent upon it. The +amount of water, however, absorbed in this way is, comparatively +speaking, insignificant. Lastly, it may be observed that there are +certain methods of drying soils afflicted with too much moisture. These +consist in making open ditches, and thus relieving them of their +superabundance of water, or in planting certain kinds of trees, such as +willows and poplars. The amount of green surface presented by the large +number of leaves of trees, from which the constant evaporation of water +goes on, is very great. The consequence is that trees may be regarded as +pumping-engines. It is from this cause that foresters have noticed that +clay lands are apt to become wetter after the trees growing upon them +have been cut down.<a name="FNanchor_42_42" id="FNanchor_42_42"></a><a href="#Footnote_42_42" class="fnanchor">[42]</a></p> +<br /> + +<p class="cen"><i>Capacity for Heat in Soils.</i></p> + +<p>A property which depends largely on those we have just been considering +is the capacity soils possess of absorbing and retaining heat.<a name="FNanchor_43_43" id="FNanchor_43_43"></a><a href="#Footnote_43_43" class="fnanchor">[43]</a> The +temperature of <span class='pagenum'><a name="Page_77" id="Page_77">[Pg 77]</a></span>a soil, of course, largely depends on the temperature of +the air; but this, we must not forget, depends also on the soil itself. +The heat given forth by the sun's rays strikes the soil, with the result +that, while so much of its heat is absorbed, a certain portion—and this +will vary according to the nature of the soil—of its heat is radiated +into the air.</p> + +<p>The changes in the temperature of the soil naturally take place more +slowly than the changes in the temperature of the air; the depth of soil +thus affected by those changes varies also in different climes. It has +been calculated that in temperate climes the changes of temperature +occurring from day to night are not felt much below three feet down.</p> +<br /> + +<p class="cen"><i>The Explanation of Dew.</i></p> + +<p>We have, it may be stated, generally two processes going on. During the +day the soil is engaged in absorbing its heat from the sun's rays; when +night comes, and the sun goes below the horizon, the air is chilled +below the temperature of the soil, which radiates out its stored-up heat +into the air. The result is that the temperature of the soil is soon +reduced below the temperature of the air, and the moisture, present in +the air in the form of vapour, coming in contact with the cold surface +of the earth, <span class='pagenum'><a name="Page_78" id="Page_78">[Pg 78]</a></span>is condensed into dew, which is deposited, and is seen +best early in the morning before the sun has had time to evaporate it +again. Dew is most abundant in summer-time, for the reason that the +difference in temperature of the day and night is then greatest. In +winter-time it is seen as hoar-frost.</p> +<br /> + +<p class="cen"><i>Heat of Soils.</i></p> + +<p>The temperature of a soil, however, is due to other sources than the +sun's rays. Whenever vegetable matter decays, there is always a certain +amount of heat generated. Soils, therefore, in which there is a large +amount of decaying vegetable matter, are certain to receive more heat +from this source than soils of more purely mineral nature.</p> +<br /> + +<p class="cen"><i>Heat in Farmyard Manure.</i></p> + +<p>A good example of the amount of heat that accompanies fermentation, or +decay of vegetable matter, is seen in the case of rotting farmyard +manure. The danger of loss of the volatile ammonia from this cause is +often great, and care must be taken to prevent fermentation going on too +quickly, and the temperature from becoming too high.<a name="FNanchor_44_44" id="FNanchor_44_44"></a><a href="#Footnote_44_44" class="fnanchor">[44]</a> The actual +increase in the temperature of a soil effected by the addition of +certain bulky organic manures, such as <span class='pagenum'><a name="Page_79" id="Page_79">[Pg 79]</a></span>farmyard manure, may thus be +considerable. In some experiments carried out at Tokio, Japan, it was +found that the application of 20 tons of farmyard manure per acre +increased the temperature of the soil to a depth of five inches, for a +period of nearly a month, on an average, one and a half degrees +Fahrenheit. The amount of water present in a soil, it may be noticed in +passing, will have a considerable effect in regulating its temperature, +a damp soil being, as a rule, a cold soil.</p> +<br /> + +<p class="cen"><i>The Cause of the Heat of Fermentation.</i></p> + +<p>It may be asked, How is the decay, or fermentation, of vegetable matter, +such as farmyard manure, caused? or rather, To what is it due? Decay of +any substance is just its slow combustion or burning. When a substance +unites with the active chemical element in air—the oxygen gas—it is +said to be oxidised. Now, this union of a substance with oxygen is the +explanation of burning, and the phenomena of burning and decay are +explained by the same chemical operation. When bodies decay, or when +they burn, they unite with oxygen: when this union of a body and oxygen +takes place very quickly, and the result is a flame and very great heat, +then we call it burning; when, however, it takes place slowly, it is not +called burning, but simply oxidation or decay. The ultimate products are +the same, however, whether the body burns or decays; and the <span class='pagenum'><a name="Page_80" id="Page_80">[Pg 80]</a></span>process of +decay is always accompanied by heat, as well as the process of +burning.<a name="FNanchor_45_45" id="FNanchor_45_45"></a><a href="#Footnote_45_45" class="fnanchor">[45]</a> It is not, of course, only the vegetable or organic matter +in a soil that decays, but also the mineral matter. The oxidation, +however, of the mineral matter in the soil takes place so slowly, and +the amount of heat generated by this oxidation is so slight, that the +temperature of the soil can scarcely be said to be much affected by it.</p> +<br /> + +<p class="cen"><i>Influence of Colour of a Soil.</i></p> + +<p>There is still another quality of a soil on which its temperature +depends, and that is its colour. This may seem at first sight to be +scarcely worth taking into account, and yet it has been shown to have a +very striking influence on the temperature of a soil. This naturally is +best seen in climates where there is a good deal of sun. Dark-coloured +soils have a greater heat-absorbing capacity than light-coloured soils; +and experiments carried out for the purpose of determining the extent of +this influence have shown that under certain conditions the difference +between a soil covered with a black substance, and one covered with a +white substance, amounted to from 13° to 14° Fahr. Other things being +equal, a crop on a dark-coloured soil will be sooner ripened than one on +a light-coloured soil. A soil covered by a crop is cooler than one +without any crop.</p> +<br /> + +<p class="cen"><span class='pagenum'><a name="Page_81" id="Page_81">[Pg 81]</a></span><i>The Power Soils have for absorbing Gases.</i></p> + +<p>We have just seen that one cause of the heat of soils is the oxidation +which is constantly going on in all soils, but more rapidly in soils +containing a large quantity of vegetable matter. This suggests a word or +two on the power soils have of absorbing gases.</p> + +<p>The chief gases in the atmosphere are oxygen and nitrogen. Both these +gases are absorbed by soils, although not in similar proportions.<a name="FNanchor_46_46" id="FNanchor_46_46"></a><a href="#Footnote_46_46" class="fnanchor">[46]</a> +With regard to the former, it is well known that a plentiful supply of +oxygen in the pores of the soil is a necessary condition of fertility. +This was long ago experimentally proved by de Saussure, who showed that +plants absorbed oxygen through their roots. At certain periods of their +growth this demand for oxygen on the part of the plant is greater than +at other times. For example, seeds in the process of germination require +to have free access to a plentiful supply of oxygen. This fact +emphasises the enormous importance of providing a good seed-bed, and of +seeing that the seed is not buried too deeply.</p> +<br /> + +<p class="cen"><i>Carbonic Acid and Ammonia.</i></p> + +<p>In addition to oxygen and nitrogen, the air contains other gases which +are absorbed by the soil. Of these, carbonic acid is the most abundant. +By far the largest portion of the carbonic acid which the <span class='pagenum'><a name="Page_82" id="Page_82">[Pg 82]</a></span>soil obtains +from the air, is washed down in solution in the rain.<a name="FNanchor_47_47" id="FNanchor_47_47"></a><a href="#Footnote_47_47" class="fnanchor">[47]</a> Of the other +constituents of the atmosphere, the combined forms of nitrogen—viz., +<i>ammonia</i>, <i>nitric</i>, and <i>nitrous acids</i>—are the most important. These +are all absorbed by the soil, but, like carbonic acid, they are chiefly +washed down by the rain. The amount of ammonia which may be absorbed by +a soil from the air, is very much greater than was formerly supposed. +Some recent experiments by Schloesing, referred to in a following +chapter,<a name="FNanchor_48_48" id="FNanchor_48_48"></a><a href="#Footnote_48_48" class="fnanchor">[48]</a> show this. A damp soil may in the course of a year absorb +far more ammonia than that washed down in rain.</p> +<br /> + +<p class="cen"><i>Gas-absorbing Power of Soils varies.</i></p> + +<p>The power of different soils to absorb these gases varies. This +variation depends not only on their physical properties, but also on +their chemical as well. Soils containing much organic matter have a +greater capacity for absorbing gases than the more purely mineral ones.</p> + +<br /> +<p class="cen"><i>Absorption of Nitrogen.</i></p> + +<p>The absorption of nitrogen by the soil is a question of considerable +importance. It will be referred to later on under the heading of the +biological <span class='pagenum'><a name="Page_83" id="Page_83">[Pg 83]</a></span>properties of soils, as it is fixed by the agency of +micro-organisms.<a name="FNanchor_49_49" id="FNanchor_49_49"></a><a href="#Footnote_49_49" class="fnanchor">[49]</a></p> + +<p>To recapitulate, the chief physical or mechanical properties of a soil +are its absorptive and retentive powers for water; its capacity for +heat; and its power of absorbing gases. It will be easily seen how +tillage operations are calculated to influence these physical properties +of a soil. Thus, in the case of a stiff soil, tillage increases its +power for absorbing the atmospheric gases, chiefly oxygen, which are so +necessary for rendering its fertilising matters available. On the other +hand, in a light and too open soil it may exert quite a contrary effect.</p> + +<p>It may be also well to refer here to the important influence these +physical properties exercise on the growth of the plant.</p> + +<br /> +<p class="cen"><i>Plant-roots require a certain Openness in the Soil.</i></p> + +<p>One of the functions of the soil is to support the plant in an upright +position, and this is a function which requires in the soil a certain +amount of compactness or firmness. On the other hand, however, a soil +must not possess too great compactness, otherwise the plant-roots will +experience a difficulty in pushing their way downwards. This is +especially the case during the earlier periods of growth, when the +plant-roots are as yet extremely tender, and experience great difficulty +in overcoming much resistance. The <span class='pagenum'><a name="Page_84" id="Page_84">[Pg 84]</a></span>importance of preparing a mellow +seed-bed will be thus at once seen to be based on sound scientific +principles; and this for a double reason. Not only does the young plant +require every facility for developing its roots, but also, as has just +been pointed out, an abundant supply of oxygen is of paramount +importance during the process of germination.</p> + +<br /> +<p class="cen"><i>Soil and Plant-roots.</i></p> + +<p>The whole question of the influence of the mechanical condition of the +soil on the development of plant-roots is one of the highest importance +and interest, and is not so generally recognised as it ought to be.</p> + +<br /> +<p class="cen"><i>Natural tendency of Plant-roots to grow downwards.</i></p> + +<p>It may be taken as certain that the tangled condition of plant-roots is +due to the resistance offered by the soil-particles, and that the +natural tendency of the plant-root is to grow downwards. The roots, in +short, would probably grow in as symmetrical a form as do the stalks or +branches, were it not that they are hindered from so doing by the +soil-particles. Where, then, the soil is such as to offer much +hindrance, the growth of the plant cannot but be retarded. Some +extremely interesting experiments have been performed by the eminent +German chemist Hellriegel on the influence which the closeness of the +soil-particles has on root-development. In these experiments peas <span class='pagenum'><a name="Page_85" id="Page_85">[Pg 85]</a></span>and +beans were grown in moistened sawdust, more or less compactly +compressed. It was found that when the sawdust Was compressed to any +extent, plant-growth took place very slowly, or entirely ceased.</p> + +<p>The importance of having plant-roots as widely developed in the soil as +possible, will be at once seen when we reflect that this means that the +area of soil from which the plant derives its soil-food is thereby +greatly increased. Another important consideration is, that the deeper +plant-roots can penetrate in a soil, the more able—other conditions +being equal—is the plant to withstand the action of drought, as it can +draw water for its needs from the deeper layers of the soil, long after +a plant, whose roots do not penetrate so deeply, has wilted.</p> + +<br /> +<p class="cen"><i>Plants require Room.</i></p> + +<p>Another important bearing tillage has on plant-growth may here be +discussed. A problem of considerable difficulty is presented in the +question, How many individual plants will a certain piece of soil +support in a healthy way? For as plants require room, it is imperative +that they be not too closely crowded together.</p> + +<p>The question resolves itself pretty much into one of quality against +quantity.</p> + +<p>Experiments on this subject have shown that a certain area of soil is +only able to support the healthy growth of a certain number of plants. +If the limit be exceeded, the result is imperfect development.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_86" id="Page_86">[Pg 86]</a></span><i>Number of Plants on certain Area increased by Tillage.</i></p> + +<p>It is obvious, however, that the more thoroughly tilled a soil is, the +greater will be the number of plants it will be possible to grow on it. +The roots, instead of being forced to spread themselves along the +surface-soil, and thus take up a large amount of room, will find no +difficulty in striking downwards. Two or three plants may thus be +enabled to grow in a thoroughly tilled soil in the same space as only +one could before tillage.</p> + +<br /> +<p class="cen"><i>American and English Farming.</i></p> + +<p>The above considerations throw considerable light on what seems to many +farmers a strange anomaly—viz., the fact that the return of farm +produce per acre on American farms is, as a rule, very much less than +that from our own impoverished soils in this country. To many, at first +sight, this seems to be in direct contradiction to our common belief, +and to point to the conclusion that the virgin soils of America are, +after all, actually inferior in fertility to the soils of Britain.</p> + +<p>It is not, however, necessary to draw this conclusion, as the facts of +the case admit of another explanation. The inferior returns obtained +from American farms are due, not to the fact that the American soil is +less fertile than the British—for this is not true—but to the fact +that it is less <i>intensively</i> cultivated.</p> + +<p><span class='pagenum'><a name="Page_87" id="Page_87">[Pg 87]</a></span>In America land is cheap and labour is dear; it is consequently found to +be more economical to cultivate a large tract of land less thoroughly +than a small area more thoroughly. In Britain the reverse is the case, +labour being cheap and land being dear. It is thus necessary to make the +land go as far as possible, and produce as heavy a crop as it is +possible to produce. There can be little doubt, that were American +farming to be carried on as intensively as is British farming, the +present yield would be at least probably doubled.</p> + +<p>We have now to consider the second class of properties which influence +the fertility of a soil. These are <i>chemical</i>.</p> + +<br /> +<p><b>II. Chemical Composition of a Soil.</b>—Chemically considered, the soil +is a body of great complexity. It is made up of a great variety of +substances. The relations existing between these substances and the +plant are not all of equal importance; some—and these form by far the +largest proportion of the soil-substance—are concerned in acting simply +as a mechanical support for the plant, and in helping to maintain those +physical properties in the soil which, as we have just seen, exercise +such important functions in the plant's development.</p> + +<br /> +<p class="cen"><i>Fertilising Ingredients.</i></p> + +<p>A small portion of the soil-substance, however, takes a very much more +active part in promoting <span class='pagenum'><a name="Page_88" id="Page_88">[Pg 88]</a></span>plant-growth, by acting as direct food of the +plant. As we have already seen in the Introductory Chapter,<a name="FNanchor_50_50" id="FNanchor_50_50"></a><a href="#Footnote_50_50" class="fnanchor">[50]</a> the +substances which have been found in the ash of plants are the following: +<i>potash</i>, <i>lime</i>, <i>magnesia</i>, <i>oxide of iron</i>, <i>phosphoric acid</i>, +<i>sulphuric acid</i>, soda, silica, chlorine, oxide of manganese, lithia, +rubidia, alumina, oxide of copper, bromine, and iodine. The general +presence of some of these substances is doubtful; the presence of +others, again, probably purely accidental; while some are only found in +plants of a special nature, as, for instance, iodine and bromine, which +are only found in the ash of marine plants.</p> + +<p>Of these ash constituents, only the first six substances—those marked +in italics—are absolutely necessary to plant-growth. In addition to +these six ash constituents, the plant also derives its <i>nitrogen</i>, which +is a necessary plant-food, chiefly from the soil.<a name="FNanchor_51_51" id="FNanchor_51_51"></a><a href="#Footnote_51_51" class="fnanchor">[51]</a></p> + +<br /> +<p class="cen"><i>Importance of Nitrogen, Phosphoric Acid, and Potash.</i></p> + +<p>But of these seven constituents of the soil which are necessary to +plant-growth, some have come to be regarded by the agriculturist with +very much greater interest than others. This is due to the fact that +they are normally present in the soil in very much smaller quantities +than is the case with the other equally necessary food ingredients; +that, in short, they are nearly invariably present in the soil, in a +readily available form, in lesser quantities than the plant is able to +<span class='pagenum'><a name="Page_89" id="Page_89">[Pg 89]</a></span>avail itself of, and often, as in impoverished or barren soils, in +quantities too small for even normal growth. These ingredients are +<i>nitrogen</i>, <i>phosphoric acid</i>, and <i>potash</i>.<a name="FNanchor_52_52" id="FNanchor_52_52"></a><a href="#Footnote_52_52" class="fnanchor">[52]</a></p> + +<p>The importance of seeing that all the necessary plant ingredients are +present in a soil in proper quantities will be at once properly +estimated when it is stated that the absence or insufficiency in amount +of one single ingredient is capable of preventing the growth of the +plant, although the other necessary ingredients may be even abundantly +present.</p> + +<p>With lime, magnesia, iron, and sulphuric acid, most soils are abundantly +supplied. The substances with which the farmer has to concern himself, +then, are nitrogen, phosphates, and potash. It is these substances +therefore, that, as a rule, are alone added as manures.</p> + +<br /> +<p class="cen"><i>Chemical Condition of Fertilising Ingredients in Soil.</i></p> + +<p>But in considering the chemical properties of a soil, a simple +consideration of the quantity of the different ingredients present is +not enough. A very important consideration is their chemical condition. +Ere any plant-food can be assimilated by the plant's roots, it must +first be rendered soluble. The quantity of soluble, or, as it is known, +<i>available</i>, plant-food in a soil is very small. It is, of course, being +steadily added to each day by the process of disintegration constantly +going on in soils.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_90" id="Page_90">[Pg 90]</a></span><i>Amount of Soluble Fertilising Ingredients.</i></p> + +<p>The exact nature and dissolving capacity of the soil-water, charged as +it is, to a greater or less extent, with different acids and salts, as +well as the dissolving power of the sap of the rootlets of the plant +itself, render the exact estimation of the available fertilising +constituents wellnigh impossible. An approximate estimate, however, may +be obtained by treating the soil with pure water and dilute acid +solutions. The treatment of the soil with dilute acid solutions is for +the purpose of simulating, as nearly as may be done, the conditions it +is submitted to in the soil. By treating a soil with water, we obtain a +certain amount of plant-food dissolved in the water. This can only be +regarded as indicating approximately the amount available at that moment +to the plant. But every day, thanks to the numberless complicated +reactions going on in the soil, this soluble plant-food is constantly +being added to. Considerations such as the above, together with our +ignorance as to the exact combinations in which the necessary minerals +enter the plant, will serve to indicate the great difficulty of this +part of the subject.<a name="FNanchor_53_53" id="FNanchor_53_53"></a><a href="#Footnote_53_53" class="fnanchor">[53]</a></p> + +<br /> +<p class="cen"><i>Value of Chemical Analysis of Soils.</i></p> + +<p>It is largely for these reasons that a chemical analysis of a soil is +from one point of view of little <span class='pagenum'><a name="Page_91" id="Page_91">[Pg 91]</a></span>value in giving evidence of its actual +fertility. What it demonstrates more satisfactorily is its potential +fertility. It is useful in revealing what there is present in it, not +necessarily, however, in an available condition. Under certain +circumstances it may be made of great value, as, for example, when we +are anxious to know what will be the result of certain kinds of +treatment, such as the application of lime, &c.</p> + +<p>It is hardly advisable, therefore, to place before the reader a number +of soil analyses. That he may obtain an approximate idea of the +composition of a soil, one or two representative analyses will be found +in the Appendix,<a name="FNanchor_54_54" id="FNanchor_54_54"></a><a href="#Footnote_54_54" class="fnanchor">[54]</a> along with a short account of the chief minerals +out of which soils are formed.</p> + +<p>A point of considerable interest is the quantity per acre different +soils contain of nitrogen, phosphoric acid, and potash. Although the +amount of these ingredients when stated in percentage seems very +trifling, yet when calculated in lb. per acre, it is seen to be in large +excess of the amount removed by the different crops. This question will +be dealt with in succeeding chapters.</p> + +<p>A point of further interest is the chemical form in which the necessary +plant constituents are present in the soil. For information on this +point the reader is referred to the Appendix.<a name="FNanchor_55_55" id="FNanchor_55_55"></a><a href="#Footnote_55_55" class="fnanchor">[55]</a></p> + +<p>The third class of properties which affect the <span class='pagenum'><a name="Page_92" id="Page_92">[Pg 92]</a></span>fertility of a soil are +those which have been termed the <i>biological</i>.</p> + +<br /> +<p><b>III. Biological Properties of a Soil.</b>—The important functions which +modern discoveries have shown to be discharged by minute organic life in +the terrestrial economy are nowhere more strikingly exemplified than in +the important <i>rôle</i> they perform in the soil.</p> + +<br /> +<p class="cen"><i>Bacteria of the Soil.</i></p> + +<p>The soil of every cultivated field is teeming with bacteria whose +function is to aid in supplying plants with their necessary food. The +nature of, and the functions performed by, these organisms differ very +widely. Regarding many of them we know very little; every day, however, +our knowledge is being extended by the laborious researches of +investigators in all parts of the world, and it is to be anticipated +that ere long we shall be in possession of many facts regarding the +nature and the method of the development of these most interesting +agents in terrestrial economy. That they are present, however, in +enormous numbers in all soils we have every reason to believe, one class +of organism connected with the oxidation of carbonic acid gas being +estimated to be present to the extent of over half a million in one +gramme of soil<a name="FNanchor_56_56" id="FNanchor_56_56"></a><a href="#Footnote_56_56" class="fnanchor">[56]</a> (Wollny and Adametz). One class—and their +<span class='pagenum'><a name="Page_93" id="Page_93">[Pg 93]</a></span>importance is very great in agriculture—prepare the food of plants by +decomposing the organic matter in the soil into such simple substances +as are easily assimilated by the plant. The so-called "ripening" of +various organic fertilisers is effected, we now know, entirely through +the agency of bacteria of this class. Plant-life is unable to live upon +the complex nitrogenous compounds of the organic matter of the soil, and +were it not for bacteria these substances would remain unavailable. +Attention will be drawn in the Chapter on Farmyard Manure to this +question more in detail. Of these bacteria, among the most important are +those which are the active agents in the process known as +"nitrification"—<i>i.e.</i>, the process whereby organic nitrogen and +ammonia salts are converted into nitrites and nitrates. The presence of +these organisms, it would appear, is indispensable to the fertility of +any soil. There are organisms, on the other hand, which have the power +of reversing the work of the nitrification bacteria by converting +nitrates into other forms of nitrogen. The reduction of nitrates in the +soil is often the source of much loss of valuable nitrogen, which +escapes in the free state, so that the action of bacteria is not +altogether of a beneficial nature.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_94" id="Page_94">[Pg 94]</a></span><i>Three Classes of Organisms in the Soil.</i></p> + +<p>So far as the subject has been at present studied, the micro-organisms +in the soil may be divided into three classes.<a name="FNanchor_57_57" id="FNanchor_57_57"></a><a href="#Footnote_57_57" class="fnanchor">[57]</a></p> + +<br /> +<p class="cen"><i>First Class of Organisms.</i></p> + +<p>We have, first of all, those whose function it is to oxidise the soil +ingredients. Organisms of this class may act in different ways. They may +assimilate the organic matter of the soil and convert it into carbonic +acid gas and water; or, on the other hand, they may oxidise it by giving +off oxygen. Some of these organisms, whose action is of the first kind, +choose most remarkable materials for assimilation. One has been found to +require ferrous carbonate for its development, which it oxidises into +the oxide (Winogradsky); while another,<a name="FNanchor_58_58" id="FNanchor_58_58"></a><a href="#Footnote_58_58" class="fnanchor">[58]</a> the so-called sulphur +organism, converts sulphur into sulphuretted hydrogen according to some, +and according to others into sulphates. To this class of organism the +nitrifying organisms belong. As will be seen more fully in a subsequent +chapter, two distinct organisms connected with this process have already +been isolated and studied—one of these effecting the formation of +nitrites from <span class='pagenum'><a name="Page_95" id="Page_95">[Pg 95]</a></span>organic nitrogen or ammonia salts, and the other the +conversion of nitrites into nitrates. The second method in which these +oxidising organisms act is by giving off oxygen. There is much interest +attaching to this fact, as it was supposed till quite recently that all +evolution of oxygen in vegetable physiology was dependent on the +presence of light, and also intimately connected with chlorophyll, or +the green colouring matter of plants. It would seem, however, that among +the soil organisms these conditions are not necessary, and the evolution +of oxygen may be carried on in the case of colourless organisms as well +as in the case of light. With organisms of this kind every soil is +probably teeming. A typical example is the organism which is the active +agent in the oxidation of carbonic acid gas, and which has already been +referred to as existing in the soil in such numbers.<a name="FNanchor_59_59" id="FNanchor_59_59"></a><a href="#Footnote_59_59" class="fnanchor">[59]</a></p> + +<br /> +<p class="cen"><i>The Second Class of Organisms in the Soil.</i></p> + +<p>The second class of organisms are those which reduce or destroy the soil +constituents. The most important of these, from the agricultural point +of view, are those which effect the liberation of nitrogen from its +compounds. In the putrefaction of organic matter the organisms chiefly +act, it is probable, in the <span class='pagenum'><a name="Page_96" id="Page_96">[Pg 96]</a></span>entire absence of atmospheric oxygen; but +it would seem, however, that they may also act in the presence of +oxygen. It is through their agency that the soil may lose some of its +nitrogen in the "free" form. To this class belong the denitrifying +organisms already referred to which reduce the nitrates and nitrites in +the soil.<a name="FNanchor_60_60" id="FNanchor_60_60"></a><a href="#Footnote_60_60" class="fnanchor">[60]</a></p> + +<br /> +<p class="cen"><i>Third Class of Organisms.</i></p> + +<p>The third class of organisms are those by whose agency the soil is +enriched. Of this class those fixing the free nitrogen from the air are +the most important. The nature of these organisms is still somewhat +obscure, but that leguminous plants have the power of drawing upon this +source of nitrogen is now a firmly established fact. Further reference +to these interesting organisms may be delayed to another chapter.</p> + +<p>The important point to be emphasised is, that for the healthy +development of these organisms, which are so necessary in every fertile +soil, certain conditions must exist. These necessary conditions will be +treated more in detail later on. It is sufficient to notice that they +have to do with the physical properties as well as the chemical +composition of the soil. This furnishes a further reason for the +necessity of having the mechanical condition of a soil satisfactory.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_97" id="Page_97">[Pg 97]</a></span><i>Recapitulation.</i></p> + +<p>From what we have said, it will be seen that the question of +soil-fertility is a very complicated one, and depends on numerous and +varied conditions; that the properties which constitute fertility, while +seemingly very widely different in their nature, in reality influence +one another to a very great extent; that not merely is the presence in a +soil of the necessary plant constituents necessary to fertility, but +that the possession by the soil of certain physical or mechanical +properties is equally necessary; while, lastly, we have seen that the +presence of certain micro-organic life is bound up with the problem of +fertility in a very direct and practical manner.</p> + +<p>The importance of the conditions, other than those of a purely chemical +nature, have been thus far somewhat prominently emphasised, for the +reason that in what follows attention will be almost exclusively devoted +to the purely chemical conditions of fertility. It is well, then, to +realise that, while the latter conditions are by far the most important, +so far as the farmer is practically concerned, inasmuch as they are most +under his control, they are not the only conditions, and are not by +themselves able to control fertility.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_33_33" id="Footnote_33_33"></a><a href="#FNanchor_33_33"><span class="label">[33]</span></a> This statement perhaps needs qualification. While the +important <i>rôle</i> played by the physical qualities of the soil were in +the early years of the science recognised, of more recent years the +chemical composition of the soil has been engaging almost exclusive +investigation. Physical properties of the soil have recently acquired a +further importance in the eyes of the agricultural chemist, from the +important influence they exert on what we have here called the +biological properties of a soil—viz., the development of those +fermentative processes whereby plant-food is prepared to a large +extent.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_34_34" id="Footnote_34_34"></a><a href="#FNanchor_34_34"><span class="label">[34]</span></a> A good example of the absorptive capacity of a soil +containing a large quantity of vegetable matter is furnished by +peat-bogs, which, sponge-like, can absorb enormous quantities of water. +(See Appendix, Note I., p. 98.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_35_35" id="Footnote_35_35"></a><a href="#FNanchor_35_35"><span class="label">[35]</span></a> Jethro Tull, an early well-known agricultural writer, who +lived about the middle of last century, propounded the theory, that as +the food of plants consisted of the minute earthy particles of the soil, +all that was required by the skilful farmer was to see that his soil was +properly tilled. He accordingly published a work entitled 'Horse-hoeing +Husbandry,' in which he advocated a system of thorough tillage. (See +Historical Introduction, p. 10.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_36_36" id="Footnote_36_36"></a><a href="#FNanchor_36_36"><span class="label">[36]</span></a> See Introduction, p. 55.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_37_37" id="Footnote_37_37"></a><a href="#FNanchor_37_37"><span class="label">[37]</span></a> See Introductory Chapter, p. 55.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_38_38" id="Footnote_38_38"></a><a href="#FNanchor_38_38"><span class="label">[38]</span></a> It is not exactly known why excess of water should prevent +normal growth in the plant. Probably it is on account of the fact that +free access of oxygen is hindered in such a case. The roots are thus not +freely enough exposed to this necessary gas, and fermentative processes +of the nature of nitrification are not promoted. It may be also due to +the fact that the solution of plant-food is too dilute when such excess +of water prevails.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_39_39" id="Footnote_39_39"></a><a href="#FNanchor_39_39"><span class="label">[39]</span></a> See Appendix, Note II., p. 98.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_40_40" id="Footnote_40_40"></a><a href="#FNanchor_40_40"><span class="label">[40]</span></a> Some experiments by E. Wollny show this. He found, when +experimenting with <i>summer rape</i>, that the best results were obtained +when the soil contained only 40 per cent of its total water-holding +power; when the amount was either lessened or increased the results +obtained fell off. The effect of either too little or too much water is +seen in the development of the different organs of the plant as well as +on its period of growth, much water seeming to retard the growth. The +quality of the plant seems also to be influenced by this condition. +Experiments on cereal grains by Wollny show that not merely is the +texture of the grain influenced, but that much moisture lessens the +percentage of nitrogen. Wollny is of the opinion that for crops +generally, the best amount is from 40 to 75 per cent of the total +water-holding capacity of the soil.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_41_41" id="Footnote_41_41"></a><a href="#FNanchor_41_41"><span class="label">[41]</span></a> See Appendix, Note III., p. 99.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_42_42" id="Footnote_42_42"></a><a href="#FNanchor_42_42"><span class="label">[42]</span></a> See p. 55.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_43_43" id="Footnote_43_43"></a><a href="#FNanchor_43_43"><span class="label">[43]</span></a> The effect of the temperature of the soil on the +development of the plant is most important. This is especially marked at +the period of germination, but is felt at subsequent periods of growth. +Up to a certain temperature the warmer the soil the more rapid the +plant's development. In this country the temperature most favourable to +growth is rarely exceeded, or indeed reached.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_44_44" id="Footnote_44_44"></a><a href="#FNanchor_44_44"><span class="label">[44]</span></a> See Chapter on Farmyard Manure.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_45_45" id="Footnote_45_45"></a><a href="#FNanchor_45_45"><span class="label">[45]</span></a> As will be seen further on, the fermentation of organic +substances is caused by the action of micro-organic life.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_46_46" id="Footnote_46_46"></a><a href="#FNanchor_46_46"><span class="label">[46]</span></a> See Appendix, Note IV., p. 100.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_47_47" id="Footnote_47_47"></a><a href="#FNanchor_47_47"><span class="label">[47]</span></a> Of course it must be remembered that a large amount of +carbonic acid in soils comes from the decay of vegetable matter. Soils +are twenty to one hundred times richer in carbonic acid than the air.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_48_48" id="Footnote_48_48"></a><a href="#FNanchor_48_48"><span class="label">[48]</span></a> See Chapter III., p. 119.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_49_49" id="Footnote_49_49"></a><a href="#FNanchor_49_49"><span class="label">[49]</span></a> See Introduction, p. 40.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_50_50" id="Footnote_50_50"></a><a href="#FNanchor_50_50"><span class="label">[50]</span></a> See Introductory Chapter, p. 54.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_51_51" id="Footnote_51_51"></a><a href="#FNanchor_51_51"><span class="label">[51]</span></a> See pp. 44 and 135.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_52_52" id="Footnote_52_52"></a><a href="#FNanchor_52_52"><span class="label">[52]</span></a> Occasionally also <i>lime</i>.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_53_53" id="Footnote_53_53"></a><a href="#FNanchor_53_53"><span class="label">[53]</span></a> See Appendix, Notes V. and VI., pp. 100, 101.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_54_54" id="Footnote_54_54"></a><a href="#FNanchor_54_54"><span class="label">[54]</span></a> Note VI., p. 101.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_55_55" id="Footnote_55_55"></a><a href="#FNanchor_55_55"><span class="label">[55]</span></a> Note VII., p. 107.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_56_56" id="Footnote_56_56"></a><a href="#FNanchor_56_56"><span class="label">[56]</span></a> Even larger estimates of the number of germs in a gramme +of soil have been made—from three-quarters to one million (Koch, +Fülles, and others).</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_57_57" id="Footnote_57_57"></a><a href="#FNanchor_57_57"><span class="label">[57]</span></a> These organisms consist of molds, yeast, and bacteria, the +last-named being most abundant. In the surface-soil, among the bacteria, +bacilli are most abundant. Micrococei are not abundant.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_58_58" id="Footnote_58_58"></a><a href="#FNanchor_58_58"><span class="label">[58]</span></a> Investigated by Winogradsky, Olivier, De Rey Pailhade, and +others.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_59_59" id="Footnote_59_59"></a><a href="#FNanchor_59_59"><span class="label">[59]</span></a> Organisms of this kind have been investigated among others +by Heraüs, Hueppe, and E. Wollny. According to the two first-mentioned +investigators, certain colourless bacteria effect the formation in the +absence of light from humus and carbonates a body resembling in its +nature cellulose.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_60_60" id="Footnote_60_60"></a><a href="#FNanchor_60_60"><span class="label">[60]</span></a> Investigated by Springer, Gayon and Dupetit, Dehérain, and +Marguenne.</p></div> + + +<br /> +<br /> +<br /> +<br /> + +<hr /><span class='pagenum'><a name="Page_98" id="Page_98">[Pg 98]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER I.</h2> +<br /> + +<p class="cen">NOTE I. (p. 68).</p> + +<p>The following determinations by Schübler show the absorptive power of +different kinds of soil-substances. These were obtained by soaking +weighed quantities of the soil in water, and allowing the excess of +liquid to drain away, and weighing the wet earth.</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Per cent"> + <tr> + <td class="tdl" width="60%"> </td> + <td class="tdc" width="40%">Per cent of water<br />absorbed by 100<br />parts of earth.</td> + </tr> + <tr> + <td class="tdl">Siliceous sand</td> + <td class="tdc">25</td> + </tr> + <tr> + <td class="tdl">Gypsum</td> + <td class="tdc">27</td> + </tr> + <tr> + <td class="tdl">Calcareous sand</td> + <td class="tdc">29</td> + </tr> + <tr> + <td class="tdl">Sandy clay</td> + <td class="tdc">40</td> + </tr> + <tr> + <td class="tdl">Strong clay</td> + <td class="tdc">50</td> + </tr> + <tr> + <td class="tdl">Arable soil</td> + <td class="tdc">52</td> + </tr> + <tr> + <td class="tdl">Fine calcareous</td> + <td class="tdc">85</td> + </tr> + <tr> + <td class="tdl">Garden-earth</td> + <td class="tdc">89</td> + </tr> + <tr> + <td class="tdl">Humus</td> + <td class="tdc">190</td> + </tr> +</table> +</div> + +<p>It has been calculated that the absorptive power of a mixture of +different substances is not simply equal to the sum of their separate +ingredients.</p> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 74).</p> + +<p class="cen"><span class="smcap">Evaporation</span>.</p> + +<p>The retentive property of a soil for water tends to retard evaporation. +The following table by Schübler shows the rate at which evaporation +proceeds in different soils. The <span class='pagenum'><a name="Page_99" id="Page_99">[Pg 99]</a></span>experiment was conducted in the +following way. The soil experimented upon was saturated with water and +spread over a disc, and allowed to evaporate for four hours, when it was +weighed. The amount of time required for the evaporation of 90 per cent +of the water was also estimated. Of 100 parts of water in the wet soil +there evaporated, at 60° Fahr.—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Time"> + <tr> + <td class="tdl" width="49%"></td> + <td class="tdc" width="25%"></td> + <td class="tdc" width="18%"></td> + <td class="tdc" width="18%"></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcb">In four hours—</td> + <td class="tdc" colspan="2">Time required to<br />evaporate 90 per cent.</td> + </tr> + <tr> + <td class="tdl">From—</td> + <td class="tdc">per cent.</td> + <td class="tdc">Hours.</td> + <td class="tdc">Minutes</td> + </tr> + <tr> + <td class="tdl">Quartz</td> + <td class="tdc">88</td> + <td class="tdc">4</td> + <td class="tdc">4</td> + </tr> + <tr> + <td class="tdl">Limestone</td> + <td class="tdc">76</td> + <td class="tdc">4</td> + <td class="tdc">44</td> + </tr> + <tr> + <td class="tdl">Sandy clay</td> + <td class="tdc">52</td> + <td class="tdc">5</td> + <td class="tdc">1</td> + </tr> + <tr> + <td class="tdl">Stiffish clay</td> + <td class="tdc">46</td> + <td class="tdc">6</td> + <td class="tdc">55</td> + </tr> + <tr> + <td class="tdl">Loamy clay</td> + <td class="tdc">46</td> + <td class="tdc">7</td> + <td class="tdc">52</td> + </tr> + <tr> + <td class="tdl">Pure grey clay</td> + <td class="tdc">32</td> + <td class="tdc">11</td> + <td class="tdc">17</td> + </tr> + <tr> + <td class="tdl">Loam</td> + <td class="tdc">32</td> + <td class="tdc">11</td> + <td class="tdc">15</td> + </tr> + <tr> + <td class="tdl">Fine calcium carbonate</td> + <td class="tdc">28</td> + <td class="tdc">12</td> + <td class="tdc">51</td> + </tr> + <tr> + <td class="tdl">Humus</td> + <td class="tdc">21</td> + <td class="tdc">17</td> + <td class="tdc">33</td> + </tr> + <tr> + <td class="tdl">Magnesium carbonate</td> + <td class="tdc">11</td> + <td class="tdc">33</td> + <td class="tdc">20</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE III. (p. 76).</p> + +<p class="cen"><span class="smcap">Hygroscopic Power of Soils.</span></p> + +<p>Davy found the hygroscopic power of soils to be as follows. He found +that 100 parts by weight of three samples of different sands absorbed 3, +8, and 11 parts of water, respectively, in one hour; while three loams +absorbed similarly 1.3, 1.6, and 1.8 parts.</p> + +<p>The following samples of soil were dried at 212° Fahr., and exposed to +an atmosphere saturated with water and a temperature of 62° Fahr., when +it was found they absorbed the following amounts in twelve hours' +time:—</p> + + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Quartz"> + <tr> + <td class="tdl" width="85">Quartz sand</td> + <td class="tdr" width="15%">0.0</td> + </tr> + <tr> + <td class="tdl">Limestone sand</td> + <td class="tdr">0.3</td> + </tr> + <tr> + <td class="tdl">Lean clay</td> + <td class="tdr">2.1</td> + </tr> + <tr> + <td class="tdl">Fat clay</td> + <td class="tdr">2.5</td> + </tr> + <tr> + <td class="tdl">Clay soil</td> + <td class="tdr">3.0</td> + </tr> + <tr> + <td class="tdl">Pure clay</td> + <td class="tdr">3.7</td> + </tr> + <tr> + <td class="tdl">Garden-loam</td> + <td class="tdr">3.5</td> + </tr> + <tr> + <td class="tdl">Humus</td> + <td class="tdr">8.0</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_100" id="Page_100">[Pg 100]</a></span>NOTE IV. (p. 81).</p> + +<p class="cen"><span class="smcap">Gases present in Soils.</span></p> + +<p>The air which we find enclosed in the pores of the soil is distinctly +<i>poorer</i> in oxygen than ordinary air. Boussingault found the percentage +of oxygen in a sandy soil, freshly manured and wet with rain, to be as +low as 10.35 per cent; while the air in forest-soil contained 19.5 per +cent of oxygen, and .93 per cent of carbonic acid. The percentage of +oxygen in soils depends on the rate of decay of the organic portions. +The depth of the soil-layer also determines the quantity. This is owing +to the fact that diffusion takes place more slowly deep down than near +the surface.</p> + +<br /> +<br /> +<p class="cen">NOTE V. (p. 90).</p> + +<p class="cen"><span class="smcap">Amount of Soluble Plant-food in the Soil.</span></p> + +<p>Two of the most reliable methods of ascertaining an approximation of the +quantity of soluble soil constituents are (1) by treating the soil with +distilled water, and (2) by analysing the drainage-water. With regard to +the former of these two methods, it has been found that even the amount +of fertilising matter dissolved out by pure distilled water varies. This +variation depends on the amount of distilled water used, as well as the +length of time the soil is left in contact with the solvent. By washing +the soil with different quantities of water, different amounts of +soluble soil ingredients will be found to have been washed out; for +although the first washings contain by far the greater portion of the +soluble matter, each subsequent washing will be found to contain further +quantities.</p> + +<p>A number of experiments have shown that 1000 parts of distilled water +dissolved out from different soils from one half to one and a half parts +of soluble constituents; or <span class='pagenum'><a name="Page_101" id="Page_101">[Pg 101]</a></span>from .05 to .15 per cent. Of this soluble +matter from 30 to 67 per cent is mineral in its nature, and from 33 to +70 per cent organic. Poor sandy soils yield the minimum quantity, while +peaty soils yield the maximum. The quantity of soluble matter in a +regular peaty soil may vary from .4 to 1.4 per cent; this consists +chiefly, however, of organic matter. (See Johnson's 'How Crops Feed,' p. +312.)</p> + +<p>Perhaps a more satisfactory method is by analysing the drainage-water of +a soil. This has been found to vary very considerably in composition. +The average of a large number of analyses are .04 to .05 per cent of +dissolved matter. Of this dissolved matter the largest proportion is +made up of organic matter, nitric acid, lime, and soda salts. It must be +borne in mind, however, that even the drainage-water does not furnish an +exact indication of the amount of dissolved matter in a soil. Much, +perhaps the largest proportion of dissolved matter, never finds its way +into the drainage-water. That contained by the drainage-water really +represents the surplus quantity of dissolved matter which the soil is +unable to retain, and which is thus washed by the rain into the drains. +The composition of drainage-water is interesting, as it shows that, +practically speaking, all the necessary plant ingredients are in a state +of solution in the soil.</p> + +<br /> +<br /> +<p class="cen">NOTE VI. (p. 90).</p> + +<p class="cen"><span class="smcap">Chemical Composition of the Soil</span>.</p> + +<p>The most important substances present in soils are as follows: silica, +alumina, lime, magnesia, potash, soda, ferric oxide, manganese oxide, +sulphuric acid, phosphoric acid, and chlorine. Of these substances the +presence of alumina, silica, lime, and, in certain cases, magnesia, +along with the organic portion of the soil—the humus—has the chief +influence in determining the nature and the physical properties of a +soil.</p> + +<p><span class='pagenum'><a name="Page_102" id="Page_102">[Pg 102]</a></span>In order to clearly understand to what it is soils owe the nature of +their chemical composition, it is necessary to consider the composition +of some of the chief minerals out of the disintegration of which soils +are formed.</p> + +<p>While we know of some seventy elements present in the earth's crust, it +is practically made up of only some sixteen. These sixteen are—oxygen, +silicon, carbon, sulphur, hydrogen, chlorine, phosphorus, iron, +aluminium, calcium, magnesium, sodium, potassium, fluorine, manganese, +and barium.<a name="FNanchor_61_61" id="FNanchor_61_61"></a><a href="#Footnote_61_61" class="fnanchor">[61]</a> Of these, oxygen is by far the largest constituent, +forming, roughly speaking, about 50 per cent.</p> + +<p>The main mass of the rocks consists of silica, and this is generally +combined with alumina, as in clay, forming aluminium silicate, and with +the commoner alkalies and alkaline earths. Another extremely abundant +compound is carbonate of lime, which, as limestone, chalk, and marl, +forms one-sixth of the earth's total rocks.</p> + +<p>The word "mineral" means a definite chemical compound of natural +occurrence. The number of minerals is very great, and it is impossible +to go into the subject here. Reference can only be made to a few of the +more prominent ones, which are chiefly concerned in the formation of +soils.</p> + +<p>Those formed out of silicates are, from the agricultural point of view, +the most important, as they form a very large group; and it is by their +disintegration that soils are chiefly formed. They consist of silica and +alumina, along with various other substances, chiefly alkalies and +alkaline earths. It is important to note one peculiarity about the +solubility of silicates. We have two classes of silicates: the one, +which is called "acid," and contains an excess of <span class='pagenum'><a name="Page_103" id="Page_103">[Pg 103]</a></span>silica; the other, +"basic," and which contains an excess of base. Now, while the former of +these is more or less insoluble, the second is soluble. This fact has an +important signification in the process of the disintegration of the +silicate minerals we are about to consider.</p> + +<p>The first and most important class are the <i>Felspars</i>. Felspar is not +really a definite mineral, with a definite chemical composition, but +rather the name of a class of minerals of which there are several +different kinds. The felspars are composed of silica and alumina, along +with potash, soda, and lime, with traces of iron and magnesia. Their +principal constituents, however, are silica and alumina, along with +either potash, soda, or lime. According as the base potash, soda, or +lime predominates, the felspar is known as Orthoclase, Albite, and +Oligoclase, respectively.</p> + +<p>The following are the analyses of the three minerals (by the late Dr +Anderson):—</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Orthoclase"> + <tr> + <td class="tdl" width="22%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdctlb" colspan="2">Orthoclase.</td> + <td class="tdctlb" colspan="2">Albite.</td> + <td class="tdctlb" colspan="2">Oligoclase.</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1.</td> + <td class="tdclb">2.</td> + <td class="tdclb">1.</td> + <td class="tdclb">2.</td> + <td class="tdclb">1.</td> + <td class="tdclb">2.</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdcl"> 65.72</td> + <td class="tdcl">65.00</td> + <td class="tdcl"> 67.99</td> + <td class="tdcl">68.23</td> + <td class="tdcl"> 62.70</td> + <td class="tdcl"> 63.51</td> + </tr> + <tr> + <td class="tdl">Alumina</td> + <td class="tdcl"> 18.57</td> + <td class="tdcl">18.64</td> + <td class="tdcl"> 19.61</td> + <td class="tdcl">18.30</td> + <td class="tdcl"> 23.80</td> + <td class="tdcl"> 23.09</td> + </tr> + <tr> + <td class="tdl">Peroxide of iron</td> + <td class="tdcl">traces</td> + <td class="tdcl"> 0.83</td> + <td class="tdcl"> 0.70</td> + <td class="tdcl"> 1.01</td> + <td class="tdcl"> 0.62</td> + <td class="tdcl">none</td> + </tr> + <tr> + <td class="tdl">Oxide of manganese</td> + <td class="tdcl">traces</td> + <td class="tdcl"> 0.13</td> + <td class="tdcl">none</td> + <td class="tdcl">none</td> + <td class="tdcl">none</td> + <td class="tdcl">none</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdcl"> 0.34</td> + <td class="tdcl"> 1.23</td> + <td class="tdcl"> 0.66</td> + <td class="tdcl"> 1.26</td> + <td class="tdcl"> 4.60</td> + <td class="tdcl"> 2.44</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdcl"> 0.10</td> + <td class="tdcl"> 1.03</td> + <td class="tdcl">none</td> + <td class="tdcl"> 0.51</td> + <td class="tdcl"> 0.02</td> + <td class="tdcl"> 0.77</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdcl"> 14.02</td> + <td class="tdcl"> 9.12</td> + <td class="tdcl">none</td> + <td class="tdcl"> 2.53</td> + <td class="tdcl"> 1.05</td> + <td class="tdcl"> 2.19</td> + </tr> + <tr> + <td class="tdl">Soda</td> + <td class="tdcl" style="border-bottom: .5pt black solid;"> 1.25</td> + <td class="tdcl" style="border-bottom: .5pt black solid;"> 3.49</td> + <td class="tdcl" style="border-bottom: .5pt black solid;"> 11.12</td> + <td class="tdcl" style="border-bottom: .5pt black solid;"> 7.99</td> + <td class="tdcl" style="border-bottom: .5pt black solid;"> 8.00</td> + <td class="tdcl" style="border-bottom: .5pt black solid;"> 9.37</td> + </tr> + <tr> + <td class="tdl" style="border-bottom: .5pt black solid;"> </td> + <td class="tdcl" style="border-bottom: .5pt black solid;">100.00</td> + <td class="tdcl" style="border-bottom: .5pt black solid;">99.47</td> + <td class="tdcl" style="border-bottom: .5pt black solid;">100.08</td> + <td class="tdcl" style="border-bottom: .5pt black solid;">99.83</td> + <td class="tdcl" style="border-bottom: .5pt black solid;">100.79</td> + <td class="tdcl" style="border-bottom: .5pt black solid;">101.37</td> + </tr> +</table> +</div> + +<p>According as these various felspars are present in a soil, so will the +quality of the soil be. It stands to reason that as the presence of +potash in a soil is one of the distinguishing features of its fertility, +much will depend on the <span class='pagenum'><a name="Page_104" id="Page_104">[Pg 104]</a></span>extent to which the orthoclase felspar is +present; and also, not only on the extent, but on the state and degree +of its disintegration. It is important to note the method of this +disintegration. It is effected by the absorption of water. This water is +not merely absorbed mechanically, but actually enters into the +composition of the mineral. It is not present as moisture merely, +capable of being expelled at ordinary boiling temperature, but it forms +what is known as water of composition. In this process of hydration, the +mineral loses its lustre and crystalline appearance, crumbles away into +a more or less—according to its state of disintegration—powdery mass. +A very great change is also effected in its chemical composition; it +loses nearly all its base. This is effected in the following way. As +water enters into the mineral's composition, it sets free a certain +portion of the base; there is thus formed a basic silicate, which, being +soluble in water, is washed away in solution. This change may be +illustrated by quoting the analysis of a kaolin clay formed by the +disintegration of orthoclase felspar.</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="Kaolin"> + <tr> + <td class="tdl" width="85%"></td> + <td class="tdr" width="15%"></td> + </tr> + <tr> + <td class="tdc" colspan="2"><i>Kaolin Clay formed by disintegration of Orthoclase.</i></td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdc"> 46.80</td> + </tr> + <tr> + <td class="tdl">Alumina</td> + <td class="tdc">36.83</td> + </tr> + <tr> + <td class="tdl">Peroxide of iron</td> + <td class="tdc"> 3.11</td> + </tr> + <tr> + <td class="tdl">Carbonate of lime</td> + <td class="tdc"> 0.55</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc"> 0.27</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc" style="text-decoration: underline;">12.44</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc" style="text-decoration: underline;">100.00</td> + </tr> +</table> +</div> + +<p>The chief difference here is the almost total loss of potash and a +portion of the silica, and the gain of water. The other constituents +practically remain insoluble.</p> + +<p>Another important mineral is <i>Mica</i>. Its composition is not unlike +felspar. It contains silica, alumina, and iron, in considerable +quantities, also magnesia and potash. There are two kinds of mica—that +containing potash, and that containing magnesia, in excess. The analyses +of <span class='pagenum'><a name="Page_105" id="Page_105">[Pg 105]</a></span>these two kinds are as follows (by the late Dr Anderson):—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Micas"> + <tr> + <td class="tdl" width="52%"></td> + <td class="tdr" width="24%"></td> + <td class="tdr" width="24%"></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="2"><span class="smcap">Micas.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">(<i>a</i>) Potash.</td> + <td class="tdc">(<i>b</i>) Magnesia.</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdc">46.36</td> + <td class="tdc">42.65</td> + </tr> + <tr> + <td class="tdl">Alumina</td> + <td class="tdc">36.80</td> + <td class="tdc">12.96</td> + </tr> + <tr> + <td class="tdl">Peroxide of iron</td> + <td class="tdc"> 4.53</td> + <td class="tdc">none</td> + </tr> + <tr> + <td class="tdl">Protoxide of iron</td> + <td class="tdc">none</td> + <td class="tdc"> 7.11</td> + </tr> + <tr> + <td class="tdl">Oxide of manganese</td> + <td class="tdc"> 0.02</td> + <td class="tdc"> 1.06</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdc">none</td> + <td class="tdc">25.75</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc"> 9.22</td> + <td class="tdc"> 6.03</td> + </tr> + <tr> + <td class="tdl">Hydrofluoric acid</td> + <td class="tdc"> 0.70</td> + <td class="tdc"> 0.62</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc" style="text-decoration: underline;"> 1.84</td> + <td class="tdc" style="text-decoration: underline;"> 3.17</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc" style="text-decoration: underline;">99.47</td> + <td class="tdc" style="text-decoration: underline;">99.35</td> + </tr> +</table> +</div> + +<p>The decomposition of mica is very slow, however, as it is a peculiarly +hard mineral.</p> + +<p>Other important minerals are <i>Hornblende</i> and <i>Augite</i>. These are +composed of silica, alumina, iron oxide, manganese oxide, lime and +magnesia. These are the chief minerals out of which soils are formed. It +is scarcely necessary to say that few soils are made up out of any of +these three minerals alone. Nearly all rocks are formed out of a mixture +of these minerals. Where, however, any one mineral predominates over the +rest, the nature of the soil will be thereby affected. In order to +illustrate this, it may be well to mention the composition of one or two +of the commoner rocks.</p> + +<p>1. <i>Granite</i>, which is so abundant in certain parts of the north of +Scotland, and which gives rise to the soils in the neighbourhood of +Aberdeen, is made up of a mixture of quartz, felspar, and mica. It +depends on the felspar present—<i>i.e.</i>, whether it is orthoclase, +oligoclase, or albite—whether the soil will be rich in potash or not. +Granite containing orthoclase felspar produces a fairly fertile soil. An +important consideration, which is apt to complicate this question, is +the situation of such soils. They are generally so high above sea-level, +that their fertility is seriously impaired on these grounds.</p> + +<p><span class='pagenum'><a name="Page_106" id="Page_106">[Pg 106]</a></span>2. <i>Gneiss</i>, another common rock, is similar in composition, only that +it contains very little felspar, and a correspondingly greater amount of +mica.</p> + +<p>3. <i>Syenite</i> contains quartz, felspar, and hornblende.</p> + +<p>The rocks of which greenstone and trap are types, are found very largely +scattered over the country. They are of two kinds, diorite and dolorite.</p> + +<p>4. <i>Limestone</i> is of two great classes. We have (1) Common, (2) +Magnesian. The following are the analyses of these two classes by Dr +Anderson:—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Common"> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdctlb" colspan="2">Common.</td> + <td class="tdctlb" colspan="2">Magnesian.</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">Mid-Lothian</td> + <td class="tdclb">Sutherland.</td> + <td class="tdclb">Sutherland.</td> + <td class="tdclb">Dumfries.</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdcl"> 2.00</td> + <td class="tdcl"> 7.43</td> + <td class="tdcl"> 6.00</td> + <td class="tdcl"> 2.31</td> + </tr> + <tr> + <td class="tdl">Iron oxide and alumina</td> + <td class="tdcl"> 0.45</td> + <td class="tdcl"> 0.76</td> + <td class="tdcl"> 1.57</td> + <td class="tdcl"> 2.00</td> + </tr> + <tr> + <td class="tdl">Carbonate of lime</td> + <td class="tdcl">93.61</td> + <td class="tdcl">84.11</td> + <td class="tdcl">50.21</td> + <td class="tdcl">58.81</td> + </tr> + <tr> + <td class="tdl">Carbonate of magnesia</td> + <td class="tdcl"> 1.62</td> + <td class="tdcl"> 7.45</td> + <td class="tdcl">41.22</td> + <td class="tdcl">36.41</td> + </tr> + <tr> + <td class="tdl">Phosphate of lime</td> + <td class="tdcl"> 0.56</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">Sulphate of lime</td> + <td class="tdcl"> 0.92</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdcl"> 0.20</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdclb"> 0.50</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">99.86</td> + <td class="tdclb">99.75</td> + <td class="tdclb">99.00</td> + <td class="tdclb">99.53</td> + </tr> +</table> +</div> + +<p>Clays are formed by the disintegration of any of the crystalline rocks; +the purest clays being formed from felspar. A pure clay consists simply +of silica and alumina, all the other constituents having been washed +out. Disintegration, however, seldom reaches such an extent; otherwise +clay soils would be completely barren, which they are notably not. The +impurities present in clay, which consist of alkalies, especially potash +and other mineral ingredients of the plant, are what confer on clay +soils their fertility. <span class='pagenum'><a name="Page_107" id="Page_107">[Pg 107]</a></span>Clays differ, however, very considerably in +their composition. The following is an analysis of a clay soil by Dr +Anderson:—</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="Silica"> + <tr> + <td class="tdl" width="80%">Silica</td> + <td class="tdr" width="20%">60.03</td> + </tr> + <tr> + <td class="tdl">Alumina</td> + <td class="tdr">14.91</td> + </tr> + <tr> + <td class="tdl">Peroxide of iron</td> + <td class="tdr">8.94</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdr">2.08</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdr">4.22</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdr">3.87</td> + </tr> + <tr> + <td class="tdl">Soda</td> + <td class="tdr">0.06</td> + </tr> + <tr> + <td class="tdl">Water and carbonic acid</td> + <td class="tdr" style="text-decoration: underline;">5.67</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr" style="text-decoration: underline;">99.72</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE VII. (p. 91).</p> + +<p class="cen"><span class="smcap">Forms in which Plant-foods are present in Soil.</span></p> + +<p>The forms in which the bases necessary for plant-food are present in the +soil, are chiefly as <i>hydrated silicates</i>, and in combination with +organic acids, forming humates, &c., as well as in the form of sulphates +and chlorides.</p> + +<p>Phosphoric acid is present in combination with iron, alumina, or lime, +or possibly also as magnesium-ammonium-phosphate. Sulphuric acid is +generally present in a more or less insoluble condition, in combination +with iron and lime; whereas chlorine is combined with the alkali bases +in an easily soluble form. An important point is as to the form in which +the plant absorbs these food constituents. In this connection reference +may be made to a theory put forward by a very distinguished French +agricultural chemist, Professor Grandeau. His theory is that the +necessary ingredients of plant-food are absorbed into the plant as +humates, or, at any rate, that the medium of this transference is humic +acid, and organic acids of a similar nature. This theory, however, while +ingenious, has not yet been supported by sufficient evidence to make its +acceptance advisable. It is probable that it is only in <span class='pagenum'><a name="Page_108" id="Page_108">[Pg 108]</a></span>the form of +soluble salts that the plant can absorb its food. It is quite probable, +however, at the same time, that the exact form in which the different +food substances enter the plant may be largely determined by +circumstances. According to Nobbe, chloride of potassium is the most +suitable form of potassium salts, although the plant may absorb its +potassium as sulphate, phosphate, or even silicate.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_61_61" id="Footnote_61_61"></a><a href="#FNanchor_61_61"><span class="label">[61]</span></a> Composition of the earth's solid crust in 100 parts by +weight:—</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="Oxygen"> + <tr> + <td class="tdl" width="40%">Oxygen</td> + <td class="tdr" width="60%">44.0 to 48.7</td> + </tr> + <tr> + <td class="tdl">Silicon</td> + <td class="tdr">22.8 to 36.2</td> + </tr> + <tr> + <td class="tdl">Aluminum</td> + <td class="tdr"> 9.9 to 6.1</td> + </tr> + <tr> + <td class="tdl">Iron</td> + <td class="tdr"> 9.9 to 2.4</td> + </tr> + <tr> + <td class="tdl">Calcium</td> + <td class="tdr"> 6.6 to 0.9</td> + </tr> + <tr> + <td class="tdl">Magnesium</td> + <td class="tdr"> 2.7 to 0.1</td> + </tr> + <tr> + <td class="tdl">Sodium</td> + <td class="tdr"> 2.4 to 2.5</td> + </tr> + <tr> + <td class="tdl">Potassium</td> + <td class="tdr"> 1.7 to 3.1</td> + </tr> +</table> +</div> + +<p class="cen"> +(Roscoe's 'Lessons in Elementary Chemistry,' p. 8.)</p> +</div> + +<br /> +<br /> +<br /> +<br /> + +<hr /><span class='pagenum'><a name="Page_109" id="Page_109">[Pg 109]</a></span> +<br /> +<h2>CHAPTER II.</h2> + +<h2>FUNCTIONS PERFORMED BY MANURES.</h2> +<br /> + +<p>Having now considered the general conditions on which fertility of soil +depends, we are in a position to deal with the nature and function of +manures.</p> + +<p>Manures may be classified in several different ways, and a considerable +amount of confusion is sometimes caused by the variety of classification +adopted by different writers on this subject.</p> + +<br /> +<p class="cen"><i>Etymological meaning of the word Manure.</i></p> + +<p>Let us, in the first place, clearly understand what we mean by a manure. +The word manure comes from the French word <i>manœuvrer</i>, which simply +means "to work with the hand," hence "to till," and this etymological +meaning of the word illustrates the old belief in the function of +manures. We have already seen in the historical introduction that, +according to Tull, the true and only function of manures was to aid in +the pulverisation of the soil by fermentation. In advancing <span class='pagenum'><a name="Page_110" id="Page_110">[Pg 110]</a></span>his system +of <i>thorough tillage</i>, he claimed that since tillage effected the +pulverisation of the soil, where it was practised, manures could be +dispensed with.</p> + +<br /> +<p class="cen"><i>Definition of Manures.</i></p> + +<p>We no longer, of course, attach this old meaning to the word. The word +manure is now applied to any substance which by its application +contributes to the fertility of a soil. As has been shown in the +previous chapter, the substances necessary for plant-growth which are +apt to be lacking in a soil, are only generally three in number—viz., +<i>nitrogen</i>, <i>phosphoric acid</i>, and <i>potash</i>. A manure, therefore, is +understood to be any substance containing these ingredients, either +singly or together, and its commercial value is determined by the amount +it contains of these substances. But while this is so, it must not be +forgotten that if we define a manure to be a substance which contributes +in any way to the fertility of the soil, substances other than these +above mentioned may be fairly regarded as manures. The fertility of a +soil, we have seen, depends not merely on the presence of certain +constituents, but also on their chemical condition—<i>i.e.</i>, whether they +are easily soluble or not. It further depends, as we have also seen, on +the possession by the soil of certain mechanical and biological +properties. Thus there are substances which act upon the soil's inert +fertilising matter, and by their action convert it into a more speedily +available form. There are other <span class='pagenum'><a name="Page_111" id="Page_111">[Pg 111]</a></span>substances which by their application +exert a considerable effect on the texture of the soil, and thereby +influence its physical and biological properties. All such substances, +according to the above definition of a manure, must be included under +the term. It will thus be seen that since fertility in a soil can be +promoted in a variety of ways, and the functions performed by manures +are of different kinds, we can divide them into different classes, +according to their respective action.</p> + +<br /> +<p class="cen"><i>Different Classes of Manures.</i></p> + +<p>In the first place, we can divide manures into two great classes,—(1) +those supplying to the soil necessary plant-food constituents, and thus +contributing directly to fertility; and (2) those influencing +soil-fertility in an indirect manner. The first class we may call +<i>direct</i> manures, and the second <i>indirect</i>. Those two classes admit +further of being subdivided into other smaller classes. Among the direct +manures we have a number of subdivisions in use. They may be divided +into <i>general</i> manures and <i>special</i> manures, according as they contain +all the elements necessary for plant-growth, or only some of them; or +they may be divided according to their source into <i>natural</i> and +<i>artificial</i>, <i>mineral</i> and <i>vegetable</i>. Similarly we have a number of +subdivisions among the second class, depending on the special nature of +the action they exert. Some manures act in both capacities—both +directly <span class='pagenum'><a name="Page_112" id="Page_112">[Pg 112]</a></span>and indirectly—and in order that their value be fully +appreciated must be studied under both heads. The most striking example +of such a manure is farmyard manure. There are other manures which may +in certain circumstances act in two different ways. Such a substance is +lime. There are soils which are actually lacking in a sufficiency of +lime for the needs of crops. On such soils an application of lime would +act both as a direct and also as an indirect manure. There may also be +cases of an exceptional nature, in which magnesia salts or even iron +salts may act as direct manures. Many manures commonly regarded as +purely direct manures would exert an indirect influence were the +quantities in which they were applied sufficiently large. This is the +case, indeed, with many artificial manures, such as guano, bones, +nitrate of soda, and basic slag. It has been claimed for nitrate of soda +that it not merely promotes fertility by supplying nitrogen in its most +available form to the soil, but that the soda it contains exerts a +valuable indirect influence in consolidating the soil and increasing its +absorptive powers. When we reflect, however, on the small quantity of +this manure which is applied per acre, its mechanical influence must be +insignificant. The same applies to basic slag, which contains a +considerable quantity of free lime in its composition. As this manure, +however, is sometimes applied in considerable quantities, it is +reasonable to suppose that its indirect value may not be altogether +<span class='pagenum'><a name="Page_113" id="Page_113">[Pg 113]</a></span>insignificant. Indeed we have proof of this in the fact that its most +favourable action has been found to be on soils rich in organic +matter.<a name="FNanchor_62_62" id="FNanchor_62_62"></a><a href="#Footnote_62_62" class="fnanchor">[62]</a> The action of bones and guano, and indeed of all other +manures containing a large percentage of decomposable organic matter, is +likewise of a double nature, inasmuch as their decomposition or +putrefaction in the soil gives rise to the formation of carbonic and +organic acids, which are capable of exerting a chemical action on the +soil ingredients. There is one point in connection with the action of +these manures which is worthy of notice, and it is that, however slight +their indirect value may be, their action as a direct manure is very +much accelerated by the way in which their organic matter putrefies. In +short, they may be described as providing, to a certain extent, the +solvents which render them available for the requirements of the plant. +It may be here convenient to classify the manures which we intend +subsequently to deal with.</p> + +<p>I. Manures, action of which is both direct and indirect—<i>e.g.</i>, <i>green +manures</i>, <i>farmyard manure</i>, <i>composts</i>, and <i>sewage</i>.</p> + +<p>II. Manures which may be regarded as having only a direct +action—<i>e.g.</i>, <i>guano</i> of all kinds, <i>bones</i> in all forms, <i>nitrate of +soda</i>, <i>sulphate of ammonia</i>, <i>dried blood</i>, <i>superphosphates</i>, <i>mineral +phosphates</i> of all kinds, <i>horns</i> and <i>hoofs</i>, <i>shoddy</i>, <i>wool-waste</i>, +<i>fish-guano</i>, <i>muriate of potash</i>, <i>sulphate of potash</i>, and <i>kainit</i>.</p> + +<p><span class='pagenum'><a name="Page_114" id="Page_114">[Pg 114]</a></span>III. Manures which may be regarded as having only an indirect +value—<i>e.g.</i>, <i>lime</i>, <i>mild</i> and <i>caustic</i>, <i>marl</i>, <i>gypsum</i>, <i>salt</i>, +&c.</p> + +<p>We shall now proceed to discuss the nature and action of these different +manures, starting with those exercising both a <i>direct</i> and <i>indirect</i> +influence. Before doing so it may be well to consider the occurrence and +natural sources of the three important soil constituents, nitrogen, +phosphoric acid, and potash, with a view of seeing to what extent these +are being removed from our soils by the various natural processes +constantly going on, as well as by the crops, and how far their natural +sources are capable of making good this loss—in short, to clearly +understand the economic reasons for the application of artificial +manures.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_62_62" id="Footnote_62_62"></a><a href="#FNanchor_62_62"><span class="label">[62]</span></a> See Chapter on Basic Slag.</p></div> + +<br /> +<br /> +<br /> +<br /> + +<hr /><span class='pagenum'><a name="Page_115" id="Page_115">[Pg 115]</a></span> +<br /> +<h2>CHAPTER III.</h2> + +<h2>THE POSITION OF NITROGEN IN AGRICULTURE.</h2> +<br /> + +<p>Of manurial ingredients, nitrogen is by far the most important, and on +the presence and character of the nitrogen it contains, the fertility of +a soil may be said to be most largely dependent. Most soils, as a rule, +are better supplied with available ash ingredients than with available +nitrogen compounds. The expensive nature of most artificial nitrogenous +manures also gives to nitrogen the first position from an economic point +of view. A thorough study, therefore, of the different forms in which it +exists in nature, of the numerous and complicated changes it undergoes +in the soil, by which it is prepared for the plant's needs, of the +relation of its different forms to plant-life, and of the natural +sources of its loss and gain, is of the highest importance if we are to +hope to understand the difficult question of soil-fertility.</p> + +<br /> +<p class="cen"><i>The Rothamsted Experiments and the Nitrogen question.</i></p> + +<p>The position of nitrogen in agriculture is a question <span class='pagenum'><a name="Page_116" id="Page_116">[Pg 116]</a></span>of great +difficulty and complexity. It has engaged much attention, and has had +devoted to its elucidation much elaborate and painstaking research. To +the Rothamsted experiments we owe most of the information we possess on +the subject, and the facts contained in this chapter are almost entirely +derived from the results of these famous experiments, as embodied in the +memoirs and writings of Messrs Lawes, Gilbert, and Warington.</p> + +<br /> +<p class="cen"><i>Different forms in which Nitrogen exists in Nature.</i></p> + +<p>We have already referred to the nitrogen question in the historical +introduction. In order, however, to have a comprehensive view of the +subject, it may be well to recapitulate some of the facts there +mentioned.</p> + +<p>Nitrogen, as we have already seen, exists in the "free" or elementary +condition, as nitrates and nitrites, as ammonia, and in a large number +of different organic forms.</p> + +<br /> +<p class="cen"><i>Nitrogen in the Air.</i></p> + +<p>It occurs in greatest abundance (amounting to about 80 per cent) in the +first of these forms in the air. That this free nitrogen, which is +practically unlimited in quantity,<a name="FNanchor_63_63" id="FNanchor_63_63"></a><a href="#Footnote_63_63" class="fnanchor">[63]</a> has originally been the source of +all its <span class='pagenum'><a name="Page_117" id="Page_117">[Pg 117]</a></span>other forms, is of course obvious. But this conversion of free +nitrogen into the various compound forms in which it occurs throughout +the mineral, vegetable, and animal kingdoms, has been a process effected +by a variety of indirect methods, and only at the expense of a vast +amount of time. For practical purposes, the free nitrogen of the air may +be regarded chiefly as a non-available source for most bodies containing +it. It may be described as of all forms of nitrogen the least active, as +far as plant-life is concerned.</p> + +<br /> +<p class="cen"><i>Relation of "free" Nitrogen to the Plant.</i></p> + +<p>The relation of the "free" nitrogen to the plant has formed the subject +of much research, more especially during the last few years, and a brief +epitome of the main results arrived at has already been given in the +Introductory Chapter.<a name="FNanchor_64_64" id="FNanchor_64_64"></a><a href="#Footnote_64_64" class="fnanchor">[64]</a></p> + +<p>That this source of nitrogen is not so inaccessible to the plant as was +formerly believed, has now been abundantly proved. As the considerations +which have led to this conclusion, and have suggested the very recent +elaborate experiments on the fixation of free nitrogen by the plant—the +results of which bid fair, it would seem, to largely revolutionise our +agricultural practice—have been due to the study of the relation of the +soil-nitrogen to the plant, it will be best to defer further discussion +of this question till we have dealt with the other sources of nitrogen.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_118" id="Page_118">[Pg 118]</a></span><i>Combined Nitrogen in the Air.</i></p> + +<p>In addition to nitrogen in the free state, air contains very small +quantities of this element in combined forms. We have it in minute +traces as nitrates and nitrites, as ammonia,<a name="FNanchor_65_65" id="FNanchor_65_65"></a><a href="#Footnote_65_65" class="fnanchor">[65]</a> and also in still +smaller traces as organic nitrogen in the minute dust-particles which +modern researches have revealed as being present in such enormous +numbers in our atmosphere. What the sources of these nitrates and +nitrites (which exist in quantities so minute that accurate +determination of their amount is rendered extremely difficult) are is a +disputed point. That nitrogen and oxygen unite together to form nitric +and nitrous oxides under the influence of intense heat, such as the +electric spark, has been proved beyond doubt. One source, therefore, is +probably the electrical discharges which are taking place more or less +frequently on different parts of the earth's surface. Nitrates may also +be formed in the combustion of nitrogenous bodies.<a name="FNanchor_66_66" id="FNanchor_66_66"></a><a href="#Footnote_66_66" class="fnanchor">[66]</a> In the burning of +coal-gas, for example, it is probable that small quantities of nitrates +may be produced. Similarly the slow combustion or decay of nitrogenous +<span class='pagenum'><a name="Page_119" id="Page_119">[Pg 119]</a></span>organic matter, which constantly takes place all over the earth's +surface, may be regarded as another source of this form of combined +nitrogen. Ammonia may be similarly formed by the combustion, either +quick or slow, of nitrogenous organic matter. It exists in the air as +nitrate or nitrite of ammonia, and also as carbonate of ammonia.<a name="FNanchor_67_67" id="FNanchor_67_67"></a><a href="#Footnote_67_67" class="fnanchor">[67]</a></p> + +<br /> +<p class="cen"><i>Amount of combined Nitrogen falling in the Rain.</i></p> + +<p>The importance of the combined nitrogen in the air as a source of +soil-nitrogen is best gauged by the amount falling annually on the soil +dissolved in rain. This has been found to vary considerably. In the rain +falling in the vicinity of large towns the amount is greater than in +rain falling in the country. Thus at Rothamsted, in England, the average +amount for several years was only 3.37 lb. nitrogen per annum per acre, +of which 2.53 lb. were as ammonia,.84 being as nitric acid. At Lincoln, +in New Zealand, 1.74 lb. fell annually per acre—as ammonia,.74, as +nitric acid, 1.00; while at Barbadoes the amount was 3.77 lb., of which +.93 was as ammonia, and 2.84 as nitric acid.<a name="FNanchor_68_68" id="FNanchor_68_68"></a><a href="#Footnote_68_68" class="fnanchor">[68]</a> That the combined +nitrogen derived from the <span class='pagenum'><a name="Page_120" id="Page_120">[Pg 120]</a></span>air by the soil may be considerably in excess +of this is highly probable. Soils, especially when damp, may absorb much +larger quantities from the air of the combined nitrogen it contains. We +must remember that the air in contact with the soil-surface is +constantly being changed, and that there is thus a constant renewal of +the air passed over the ground. The result is that the amount of air +from which combined nitrogen may be removed is very great.<a name="FNanchor_69_69" id="FNanchor_69_69"></a><a href="#Footnote_69_69" class="fnanchor">[69]</a></p> + +<br /> +<p class="cen"><i>Nitrogen in the Soil.</i></p> + +<p>It has been remarked as a fact worthy of notice that nitrogen is +essentially a superficial element. By this is meant that it is only +found, as a rule, on the earth's immediate surface. This statement can +only be admitted to be true within certain limits. The chief source of +nitrogen, in addition to the atmosphere, is, of course, vegetable and +animal tissue.<a name="FNanchor_70_70" id="FNanchor_70_70"></a><a href="#Footnote_70_70" class="fnanchor">[70]</a> As vegetable and animal tissue are only found to any +extent on the earth's surface, nitrogen is therefore chiefly found +there. The natural deposits of nitrogen salts, such as the +nitrate-fields of Chili and the saltpetre <span class='pagenum'><a name="Page_121" id="Page_121">[Pg 121]</a></span>soils of India, &c., also +only occur superficially. Notwithstanding these facts, however, the +amount of nitrogen which exists at probably considerable depths from the +surface must be very great. There are few sedimentary rocks which do not +contain it. At Rothamsted a sample of calcareous clay, taken from a +depth of 500 feet, contained .04 per cent—that is, as much as is found, +on an average, in the Rothamsted clay subsoils.</p> + +<br /> +<p class="cen"><i>Nitrogen in the Subsoil.</i></p> + +<p>On the whole, however, as we have said, nitrogen is chiefly found in the +surface-soil. The amount found in the subsoil at Rothamsted seems to +vary very slightly at different depths, the percentage amounting to from +.06 to .03.<a name="FNanchor_71_71" id="FNanchor_71_71"></a><a href="#Footnote_71_71" class="fnanchor">[71]</a> Unlike the nitrogen of the surface-soil, that in the +subsoil seems to be of very ancient origin, being probably derived from +the remains of animal and vegetable life in the mud deposited at the +bottom of the ocean. It is more abundant in the case of a clay subsoil +than in a sandy subsoil.</p> + +<br /> +<p class="cen"><i>Nitrogen of Surface-Soil.</i></p> + +<p>Nitrogen has a tendency to collect on the top layers of the +surface-soil, the first 9 inches or foot containing <span class='pagenum'><a name="Page_122" id="Page_122">[Pg 122]</a></span>by far the largest +proportion of it. In the table given in the Appendix,<a name="FNanchor_72_72" id="FNanchor_72_72"></a><a href="#Footnote_72_72" class="fnanchor">[72]</a> the rate at +which it decreases in amount the further down we go is clearly shown. +Determinations of the respective amounts of nitrogen in every 3 inches +of the soil, taken to a depth of one foot of the experimental +wheat-field at Rothamsted, showed that the percentage between the first +3 inches and the second 3 inches varied very slightly. A more marked +difference, however, was shown to exist between the nitrogen in the +second and third 3 inches; while the fourth 3 inches were distinctly +poorer—differing very little in their percentage of nitrogen from the +subsoil. This was the case in unmanured soil. In the case of heavily +manured soil, the increase in the soil's percentage, due to manure, was +shown to be felt to the depth of a foot, but not much below it.<a name="FNanchor_73_73" id="FNanchor_73_73"></a><a href="#Footnote_73_73" class="fnanchor">[73]</a></p> + +<p>A careful perusal of the tables in the Appendix will show that the +quantity of nitrogen in the case of both arable and pasture soils +steadily decreases for the first 3 feet, but that below this depth +little decrease is seen, the percentage evidently becoming fairly +constant.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_123" id="Page_123">[Pg 123]</a></span><i>The amount of Nitrogen in the Soil.</i></p> + +<p>Very considerable difference exists in the amount of nitrogen present in +different soils. The majority of analyses refer only to the amount found +in the surface-soil—generally in the first 9 or 12 inches. As the soil, +further, is not a body exactly homogeneous in its character, very +considerable difficulty exists in obtaining reliable results. A great +deal depends, therefore, on the method of sampling and the basis of +calculation adopted; and it may be that this may occasionally explain, +to some extent at least, the great discrepancies in the estimation of +the quantities of nitrogen present in different soils as found by +different investigators.</p> + +<br /> +<p class="cen"><i>Peat-soils richest in Nitrogen.</i></p> + +<p>Of all soils, peat-soils are richest in nitrogen. Professor S. W. +Johnson found the nitrogen in fifty separate samples of peat to range +from .4 per cent to 2.9 per cent, the average being 1.5 per cent. On the +other hand, marls and sandy soils are poorest, the analyses of a number +of these soils showing only from .004 to .083 per cent for the former, +and .025 to .074 for the latter. As a general rule most arable soils +contain over one-tenth per cent of nitrogen, or, say, over 3500 lb. per +acre. A good pasture-soil, taken to a depth of 9 inches at Rothamsted, +was found to contain about a quarter per cent. In ten samples of soil, +taken to a depth of 9 inches, from different parts of <span class='pagenum'><a name="Page_124" id="Page_124">[Pg 124]</a></span>Great Britain and +Ireland, Munro found from .128 to .695 per cent of nitrogen, the average +being .3278 per cent. The Rothamsted soils, it may be pointed out, are +probably poor in nitrogen compared with most soils. A. Müller's +investigations showed that in some of the soils he has analysed, the +nitrogen amounted to little short of one per cent, while for the others +the average was over half a per cent; even the poorer soils he examined +contained about one quarter per cent on an average. Anderson's analyses +of Scottish wheat-soils showed a variation of from .074 to .22 in the +surface-soil, while he found in their subsoil from .15 to .92 per cent. +Boussingault's results are also very much higher. The amount of nitrogen +in a number of loams coming from widely different localities he examined +contained from 6000 to 30,000 lb. per acre—the soil taken to a depth of +17 inches.<a name="FNanchor_74_74" id="FNanchor_74_74"></a><a href="#Footnote_74_74" class="fnanchor">[74]</a></p> + +<br /> +<p class="cen"><i>Nature of the Nitrogen in the Soil.</i></p> + +<p>When we compare the amount of nitrogen removed by different crops +(which, even in the case of those most exhaustive of nitrogen, does not +often amount to more than 150 lb. per acre), with the amount contained +in the soil, the former amount seems very insignificant when compared to +the latter. Such being <span class='pagenum'><a name="Page_125" id="Page_125">[Pg 125]</a></span>the case, it would seem at first sight that the +addition of nitrogen in the form of manures is quite superfluous. We +must remember, however, that while the <i>total</i> amount of nitrogen is +relatively large when compared to that removed by crops, only a very +small proportion is in a condition <i>available</i> to the plant. This leads +us to consider the different forms in which nitrogen is present in the +soil, and their respective quantities.</p> + +<br /> +<p class="cen"><i>Organic Nitrogen in the Soil.</i></p> + +<p>Nitrogen occurs in the soil as organic nitrogen, nitric acid, nitrous +acid, and ammonia. By far the largest proportion is present in the first +of these forms. This is a wise provision, for otherwise the soil would +be apt to become very speedily impoverished in nitrogen; for that +present as nitrates it has scarcely any power to retain, while that +present as ammonia is soon converted into nitrates by the process of +<i>nitrification</i>.</p> + +<p>The organic nitrogen of the soil, although we are apt to think of it as +such, is by no means of a homogeneous character, or of equal value as a +source of plant-food. Some of it, it would seem from recent +investigations, is in a condition more susceptible of being converted +into an available form than the rest. Thus in the process of +nitrification, a process which we shall consider at length immediately, +there seems to be generally a certain small proportion more ready to +undergo this change than the rest; so that when this small amount <span class='pagenum'><a name="Page_126" id="Page_126">[Pg 126]</a></span>is +used up nitrification proceeds more slowly. In short, although we as yet +know very little of the nature of the organic nitrogen of soils, we +cannot doubt but that there is a constant series of changes in its +composition taking place, resulting in the gradual elaboration of more +available forms, until ultimately these are converted into ammonia and +nitrates.</p> + +<p>The great bulk of the organic nitrogen, however, in the soil must be +regarded as in an <i>inert</i> condition, and by no means available for the +crop. What the exact chemical form of this nitrogen is it is extremely +difficult to say. Mulder was of the opinion that a considerable +proportion was in the form of humate of ammonia. This opinion, as we +shall have occasion to see immediately, was based on false grounds. It +is highly probable that it may be in some form approximating to amide +nitrogen. Its inert character is against the belief that it long remains +as albuminoid nitrogen.</p> + +<br /> +<p class="cen"><i>Different Character of Surface and Subsoil Nitrogen.</i></p> + +<p>A point of very considerable importance to notice is, that the +nitrogenous organic matter of the surface-soil is very different from +that found in the subsoil. This difference is shown by the variation in +the ratio of nitrogen to carbon, which points to the fact that, just as +we should naturally suppose, the origin of the latter is very much more +ancient than the origin of the former. Thus in the first 9 inches of old +<span class='pagenum'><a name="Page_127" id="Page_127">[Pg 127]</a></span>pasture-soil at Rothamsted, the ratio was 1:13; while in the subsoil, 3 +feet from the surface, it was only 1:6. In the surface-soil it thus +approaches more nearly in composition ordinary vegetable matter.</p> + +<br /> +<p class="cen"><i>Nitrogen as Ammonia in Soils.</i></p> + +<p>The second form in which nitrogen is present in soil is as ammonia. A +very considerable misapprehension has existed in the past as to the +amount of nitrogen in this form in soils. This mistake was due to the +method adopted in estimating it, which consisted in treating the soil +with boiling caustic alkalies and counting as ammonia what was given off +as such. It is now known that certain forms of organic nitrogen—as, for +example, amides—if treated in this way are slowly converted into +ammonia. Statements, therefore, which are found in the older text-books, +representing the amount of ammonia in soils as at over a tenth per cent, +must be regarded as utterly unreliable. Indeed it is highly probable +that ammonia only occurs in most soils in very minute traces. From what +we know of the process of nitrification, we see how it is wellnigh +impossible that ammonia should exist to any extent in the soil except +under very exceptional circumstances.</p> + +<br /> +<p class="cen"><i>Amount of Ammonia present in the Soil.</i></p> + +<p>In ordinary soils it probably does not amount to more than from .0002 +per cent to .0008 per cent, or <span class='pagenum'><a name="Page_128" id="Page_128">[Pg 128]</a></span>an average of .0006 per cent.<a name="FNanchor_75_75" id="FNanchor_75_75"></a><a href="#Footnote_75_75" class="fnanchor">[75]</a> In +rich soils, or in garden-soils, the amount may be considerably more. +Thus Boussingault found in a garden-soil .002 per cent. In peat and in +peat-mould even a higher percentage has been found—viz.,.018 for the +former and .05 for the latter.</p> + +<br /> +<p class="cen"><i>Nitrogen present as Nitrates in the Soil.</i></p> + +<p>The third form of nitrogen in the soil is nitric acid. It is more +abundant in this form than as ammonia; but still, compared with the +organic nitrogen, its amount is trifling. Probably not more than 5 per +cent of the total nitrogen of a soil is ever present as nitrates. The +reason of this is twofold. First, as we have already remarked, the soil +has very little power to retain nitrogen in this form; and secondly, +where the soil is covered with growing vegetation the nitrates are +quickly assimilated by the plant as they are formed. It is for this +reason that we find the quantity of nitrogen as nitrates very much +greater in fallow soils than in those covered with a crop.</p> + +<br /> +<p class="cen"><i>Position of Nitric Nitrogen in Soil.</i></p> + +<p>As we shall have occasion to see more fully in the following chapter on +Nitrification, the formation of nitrates is chiefly limited to the +surface-soil, the largest proportion being formed within the first 9 or +12 inches. For this reason we find the largest quantity <span class='pagenum'><a name="Page_129" id="Page_129">[Pg 129]</a></span>of nitrates in +the surface-soil. But inasmuch as they are easily washed into the lower +layers of the soil after formation, we often find a considerable +proportion beyond the first 9 inches. The position of nitrates in the +soil thus depends very considerably on the season of the year and the +weather. In dry weather, where the evaporation of the soil-water takes +place at a considerable rate, the tendency will be to concentrate the +nitrates in the superficial portion of the soil. In wet weather, on the +other hand, the tendency will be to wash the nitrates into the lower +layers.</p> + +<br /> +<p class="cen"><i>Amount of Nitrates in the Soil.</i></p> + +<p>The determination of the amount of nitrates in a soil is not of very +great economic importance; as this varies so much, and depends on such a +number of different conditions, such as the season, the condition of the +land, and prevailing weather. A point of very much greater economic +importance is the total amount formed in the year, and the rate at which +nitrification takes place. These questions will be discussed elsewhere, +and therefore need not here be referred to. Some interesting analyses +made at Rothamsted, however, of the amount of nitrates in soils at +different depths, merit careful consideration.</p> + +<br /> +<p class="cen"><i>Nitrates in Fallow Soils.</i></p> + +<p>In the Appendix to the chapter on Nitrification,<a name="FNanchor_76_76" id="FNanchor_76_76"></a><a href="#Footnote_76_76" class="fnanchor">[76]</a> <span class='pagenum'><a name="Page_130" id="Page_130">[Pg 130]</a></span>will be found a +table containing the amounts of nitrates found in the first 27 inches of +fallow soils. The amounts vary from 33.7 lb. to 59.9 lb. per acre. The +analyses were made in September or October. In four out of the six +analyses, it will be found that by far the largest proportion is found +in the first 9 inches. In these cases the preceding summer had been dry, +and thus the nitrates had not been washed down to any depth. In the +other two cases the largest amount is found in the second 9 inches of +soil, and a considerable amount is also found in the third 9 inches.</p> + +<br /> +<p class="cen"><i>Nitrates in Cropped Soils.</i></p> + +<p>In the case of cropped soils we find the amount of nitrates very much +less. A table containing an elaborate series of determinations of +nitrates in cropped soils, receiving, however, no manure, and taken to a +depth of 9 feet, will be found in the Appendix.<a name="FNanchor_77_77" id="FNanchor_77_77"></a><a href="#Footnote_77_77" class="fnanchor">[77]</a> The first 27 inches +only contain some 5 to 14 lb. per acre, and the most of that is found in +the first 9 inches. This shows how speedily nitrates are assimilated by +the growing crop. An interesting point shown by these analyses is that +nitrates almost entirely cease in cropped soils a certain depth down, +but that at a still lower depth they again occur in small quantities.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_131" id="Page_131">[Pg 131]</a></span><i>Nitrates in manured Wheat-soils.</i></p> + +<p>Lastly, we give in the Appendix<a name="FNanchor_78_78" id="FNanchor_78_78"></a><a href="#Footnote_78_78" class="fnanchor">[78]</a> the amount of nitrates found in +wheat and barley soils, differently manured, at Rothamsted. From a +perusal of these tables, it will be seen that the amount (under various +conditions of manuring) of nitrates in the first 27 inches varies from +21.2 lb. per acre to 52.2 lb. for the wheat-soils, and 20.1 to 44.1 lb. +per acre for the barley-soils.</p> + +<br /> +<p class="cen"><span class="smcap">The Sources of Soil-nitrogen.</span></p> + +<p>We shall now consider the sources of soil-nitrogen, the conditions which +determine its increase, and the amount of that increase, as well as the +sources of loss, and the conditions which determine this loss.</p> + +<br /> +<p class="cen"><i>That dissolved in Rain.</i></p> + +<p>The natural sources of the soil-nitrogen are several. We have first of +all the atmospheric nitrogen. Of this let us first consider that present +as combined nitrogen. This, as we have already seen, consists chiefly of +nitrates, nitrites, and ammonia, and reaches the soil dissolved in rain +or in other meteoric forms of water, such as snow, hail, fog, +hoar-frost, &c.</p> + +<br /> +<p class="cen"><i>That absorbed by the Soil from the Air.</i></p> + +<p>It is also absorbed by the soil from the air, especially when the soil +is in a damp condition, as has been <span class='pagenum'><a name="Page_132" id="Page_132">[Pg 132]</a></span>proved by Schloesing's experiments, +already referred to. The total amount which falls dissolved in the rain, +per acre per annum, varies very considerably in different parts of the +world, but in any case only amounts yearly to a few pounds per acre.<a name="FNanchor_79_79" id="FNanchor_79_79"></a><a href="#Footnote_79_79" class="fnanchor">[79]</a> +That absorbed by the soil from the air may be probably very much more +considerable. Schloesing in his experiments found that this latter might +amount to 38 lb. per acre per annum. These results, however, were +obtained under circumstances most favourable for absorption—viz., with +a damp soil and in the vicinity of Paris, where the air is presumably +richer in combined nitrogen than it is in the country. The nitrogen +absorbed, it may be mentioned, was almost entirely in the form of +ammonia. It is to be noted that the nitrogen the soil obtains in this +way from the combined nitrogen of the air is not all pure gain. With +regard to the nitrates and nitrites, no doubt most of these are formed +by electrical discharge, although a small portion of them may be formed +by the oxidation of ammonia by means of ozone and peroxide of hydrogen. +With regard to the ammonia and the combined nitrogen present in the +organic particles in the air, a not inconsiderable proportion is +probably derived from the soil. Schloesing considers the chief source of +the ammonia present in the air to be the tropical ocean; but we must +remember that the source of much of the nitrogen in the tropical ocean +is, after all, the soil.</p> + +<p><span class='pagenum'><a name="Page_133" id="Page_133">[Pg 133]</a></span>Leaving aside for a moment the question of the availability of the free +nitrogen of the air, let us consider the other sources of soil-nitrogen.</p> + +<br /> +<p class="cen"><i>Accumulation of Soil-nitrogen under Natural Conditions.</i></p> + +<p>The chief source is of course the remains of vegetable and animal +tissue.<a name="FNanchor_80_80" id="FNanchor_80_80"></a><a href="#Footnote_80_80" class="fnanchor">[80]</a> Plants are the great conservers of soil-nitrogen. By +assimilating such available forms of it as nitrates, and converting them +into organic nitrogen, they prevent the loss of this most valuable of +all soil constituents that would otherwise take place.</p> + +<p>They also serve to collect the nitrogen from the lower soil-layers and +concentrate it in the surface portion. In a state of nature, where the +soil is constantly covered with vegetation, the process going on, +therefore, will be one of steady accumulation of nitrogen in the +surface-soil. To what extent this accumulation goes on, and how far it +is limited by the conditions of loss, will be considered immediately. +That it may go on to a very great extent is amply proved by the +existence of the so-called <i>virgin</i> soils <span class='pagenum'><a name="Page_134" id="Page_134">[Pg 134]</a></span>of countries like America and +Australia. There are cases, also, where the accumulation of nitrogen is +practically unlimited, although the result in such cases is not +necessarily a fertile soil. Such cases are peat-bogs. But let us pass on +to the accumulation of soil-nitrogen under the ordinary conditions of +husbandry.</p> + +<br /> +<p class="cen"><i>Accumulation of Nitrogen in Pastures.</i></p> + +<p>The case which, under the conditions of ordinary farming, most resembles +a state of nature, is that of permanent pasture. It will be best, +therefore, to study first the conditions under which gain of nitrogen +takes place in this case.</p> + +<br /> +<p class="cen"><i>Increase of Nitrogen in the soil of Pasture-land.</i></p> + +<p>That there is a steady increase of nitrogen in the soil of land under +pasture is a fact of universal experience. The older a pasture is the +richer is its soil in nitrogen. The comparison of the analyses of the +soil of arable land with the soil of pastures of different ages shows +this in a striking way.<a name="FNanchor_81_81" id="FNanchor_81_81"></a><a href="#Footnote_81_81" class="fnanchor">[81]</a> Thus at Rothamsted it was found that while +the amount of nitrogen in an ordinary arable soil was .140 per cent, +that in pastures eight, eighteen, twenty-one, and thirty years old was +respectively .151, .174, .204, and .241 per cent. In the last two +analyses we have a record of the actual gain in nitrogen made by the +<span class='pagenum'><a name="Page_135" id="Page_135">[Pg 135]</a></span>same pasture, this being .04 per cent in nine years' time. From these +statistics it may be inferred that the surface-soil of a pasture may +increase at the rate of 50 lb. per acre per annum. A point of great +interest in connection with this subject is the fact that there seems to +be a limit to the accumulation of nitrogen in pastures; for it would +seem that pastures centuries old are not any richer in nitrogen than +those thirty to forty years old.</p> + +<br /> +<p class="cen"><i>Gain of Nitrogen with Leguminous Crops.</i></p> + +<p>Another case where the gain of nitrogen to the surface-soil is very +striking is in that of leguminous crops, such as clover, beans, peas, +&c. This fact has been long recognised—especially with regard to +clover—by farmers, and has been largely instrumental in leading to the +investigation of the "free" nitrogen question. That a soil bearing a +leguminous crop increases in nitrogen at a very striking rate is a +problem that requires to be solved. A partial explanation of the +phenomenon is found in the extraordinary capacity such a crop as clover +has, by means of its multitudinous and ramifying roots, for collecting +nitrogen from the subsoil. This, however, would only account for the +increase in nitrogen to a certain extent. There must be some other +source, and the only other source is the air. That the free nitrogen of +the air is, after all, available for the plant's needs, is a supposition +which has long seemed extremely <span class='pagenum'><a name="Page_136" id="Page_136">[Pg 136]</a></span>probable, and which, within the last +few years, has been proved beyond doubt to be a fact in the case of +leguminous plants.</p> + +<br /> +<p class="cen"><i>The Fixation of "Free" Nitrogen.</i></p> + +<p>The method in which these plants are able to make use of the free +nitrogen is still a point requiring much research. So far as the +question is at present investigated, it would seem that the fixation is +effected by means of micro-organisms present in tubercles or root +excrescences found on the roots of leguminous plants.<a name="FNanchor_82_82" id="FNanchor_82_82"></a><a href="#Footnote_82_82" class="fnanchor">[82]</a> Not merely has +this been placed beyond doubt, but attempts have been made to isolate +and study the bacteria effecting this fixation. From Nobbe's exceedingly +interesting experiments, recently carried out, it would seem that the +different kinds of leguminous plants have different bacteria. Thus the +bacteria in the tubercle on the pea seems to be of a different order +from the bacteria in the tubercles of the lupin, and so on. This +discovery is of great importance, it need scarcely be pointed out, as it +throws much light on the principles of the rotation of crops.</p> + +<br /> +<p class="cen"><i>Influence of Manures in increasing Soil-nitrogen.</i></p> + +<p>It may be doubted, however, if under any other conditions there is a +positive gain of soil-nitrogen. In other cases the amount in the soil is +only <i>maintained</i> under liberal manuring. In connection with <span class='pagenum'><a name="Page_137" id="Page_137">[Pg 137]</a></span>this point +a very striking fact has been observed with regard to the effect of +continuous large applications of farmyard manure. It has been found at +Rothamsted that in such a case, after a while, the manure does not seem +to increase the soil-nitrogen, although where the nitrogen goes to +remains a mystery. In the case of the application of artificial manures, +there does not seem to be almost any appreciable gain to the +soil-nitrogen. The soil-nitrogen is only increased by means of the +residue of crops. In this way, of course, by increasing the amount of +this crop-residue, artificial manures may be said indirectly to increase +the soil-nitrogen.<a name="FNanchor_83_83" id="FNanchor_83_83"></a><a href="#Footnote_83_83" class="fnanchor">[83]</a></p> + +<br /> +<p class="cen"><span class="smcap">Sources of Loss of Nitrogen.</span></p> + +<p>We now come to consider the sources of loss. The chief source, of +course, is that by drainage. Land under cultivation will suffer very +much more from this source of loss than in a state of nature. Our modern +system of husbandry, involving as it does thorough drainage, can +scarcely fail to very considerably increase this source of loss.</p> + +<br /> +<p class="cen"><i>Loss of Nitrates by Drainage.</i></p> + +<p>The form in which nitrogen is lost in this way is as nitrates. It is a +somewhat striking fact, and one <span class='pagenum'><a name="Page_138" id="Page_138">[Pg 138]</a></span>worthy of note, that of the three +important manurial ingredients—nitrogen, phosphoric acid, and potash, +the first of these, in its final and most valuable form, is alone +incapable of being fixed by the soil, and thus retained from loss by +drainage.</p> + +<p>As nitrates are constantly being formed in the soil, the loss to its +total nitrogen must be considerable. It is due to the fact of the great +solubility of nitrates, as well as to the fact, as already mentioned, of +the incapacity of the soil-particles to fix them. To this one exception +must be made. According to Knop, small quantities of nitric acid are +held in the <i>insoluble</i> condition in soils in the form of highly <i>basic +nitrates of iron and alumina</i>. The quantity, however, of these insoluble +compounds probably amounts to a very minute trace indeed.</p> + +<br /> +<p class="cen"><i>Permanent Pasture and "Catch-cropping" prevents Loss.</i></p> + +<p>The amount of loss varies, and will depend on a number of different +circumstances—thus the nature of the soil, climate, and season of the +year will all influence its quantity. The way in which the soil is +cultivated is also another important factor. Where it is constantly +covered with vegetation, as in the case of permanent pasture, the loss +will be at a minimum. Under such conditions, plant-roots are always +there ready to fix, in the insoluble organic form, the soluble nitrates +as they are formed. A consideration of this <span class='pagenum'><a name="Page_139" id="Page_139">[Pg 139]</a></span>fact forms one of the +strongest arguments in favour of the practice of what is known as +"catch-cropping." The practice consists in sowing some quickly-growing +green crop—<i>e.g.</i>, <i>mustard</i>, <i>vetches</i>, &c.—so as to occupy the soil +immediately after harvest, and subsequently to plough it in. The +nitrates, which it is known are most abundantly formed towards the end +of summer,<a name="FNanchor_84_84" id="FNanchor_84_84"></a><a href="#Footnote_84_84" class="fnanchor">[84]</a> and which are allowed to accumulate in the soil from the +period at which the active growth of, and consequently assimilation of +nitrates by, the cereal crop have ceased, are thus fixed in the organic +matter of the plant, and removed from danger of loss by drainage +incidental to autumn rains.</p> + +<br /> +<p class="cen"><i>Other Conditions diminishing Loss of Nitrates.</i></p> + +<p>The nature of the soil is another important condition regulating this +loss. Some soils are very much opener and more porous than others; in +such soils, of course, the loss by drainage will be greatest. We are apt +at first sight, however, knowing the great solubility of nitrates, to +overrate this source of loss. We have to remember that while nitrates +are constantly being washed down to the lower layers of the soil, there +is likewise an upward compensating movement of the soil-water constantly +taking place. This is due to the evaporation of water from the surface +of the soil, which induces an upward capillary <span class='pagenum'><a name="Page_140" id="Page_140">[Pg 140]</a></span>movement of water from +its lower to its higher layers.<a name="FNanchor_85_85" id="FNanchor_85_85"></a><a href="#Footnote_85_85" class="fnanchor">[85]</a> This upward movement of water is +very much increased, in the case of soil covered with vegetation, by the +transpiration of the plants. The climate and the season of the year will +affect the extent of this upward movement. Where there is a heavy +rainfall it will be very much less than in dry climates. After a long +period of drought the nitrates will be found to be concentrated in the +top few inches of the soil; and in hot climates this sometimes takes +place to such an extent that the surface of the soil has been actually +covered with a saline crust, caused by the rapid evaporation of +soil-water under the influence of a burning tropical sun. From this +point of view it will be seen how very much less powerful a single +shower of rain is—even although at the time it is heavy—in causing +loss of nitrates by drainage, than a continuance of wet weather. In the +former case, where the showers are separated by an interval of dry +weather, the nitrates washed down into the lower layers of the soil are +slowly brought up again by the capillary action caused by evaporation.</p> + +<br /> +<p class="cen"><i>Amount of Loss by Drainage.</i></p> + +<p>What the actual amount of loss is which takes place in this way it is +wellnigh impossible to say. What it amounts to under certain definite +<span class='pagenum'><a name="Page_141" id="Page_141">[Pg 141]</a></span>circumstances has been discovered by actual experiment at Rothamsted. +Taking the circumstances most favourable to extreme loss—viz., +unmanured fallow land—the highest amount registered at Rothamsted for a +year is 54.2 lb. per acre from soil 20 inches deep, while the smallest +amount is 20.9 lb. In the former case, the drainage-water was equivalent +to 21.66 inches, while in the latter, to 8.96 inches. The average for +thirteen years on unmanured fallow soil has been 37.3 lb. (for 20 +inches), 32.6 lb. (for 40 inches), 35.6 lb. (for 60 inches). The point +of especial interest in this connection is that an annual loss of +nitrogen, equal to over 2 cwt. of nitrate of soda, may take place from a +comparatively poor arable soil lying fallow.</p> + +<p>The loss on cropped soils is of course very much less—in short, should +amount to very little—especially in permanent pasture, where it is +reduced to a minimum. Taking an average, Mr Warington is of opinion that +the loss in England may be put at 8 lb. per annum per acre.<a name="FNanchor_86_86" id="FNanchor_86_86"></a><a href="#Footnote_86_86" class="fnanchor">[86]</a></p> + +<br /> +<p class="cen"><i>Loss in Form of Free Nitrogen.</i></p> + +<p>The other chief natural source of loss of nitrogen is due to its escape +from the soil in its "free" state. This source of loss is very much less +important than that by drainage, and probably amounts to very little. +<span class='pagenum'><a name="Page_142" id="Page_142">[Pg 142]</a></span>That, however, it takes place is beyond a doubt; and that it may—as we +shall see by-and-by—under certain circumstances amount to something +very considerable is also proved. Where large quantities of nitrogenous +organic matter decay, and where, consequently, the supply of atmospheric +oxygen is insufficient to effect complete oxidation, "free" nitrogen may +be evolved in considerable quantities. Similarly, it may be evolved in +the case of vegetable matter decaying under water. In soils rich in +organic matter the reduction of even nitrates may take place, +accompanied with the evolution of free nitrogen, which is thus lost.</p> + +<br /> +<p class="cen"><i>Total Amount of Loss of Nitrogen.</i></p> + +<p>What the rate of total loss of nitrogen is from these different sources +does not admit of easy calculation. Sir John Lawes, in dealing with the +question of soil-fertility, estimated some years ago, by comparing the +soil of old pasture at Rothamsted with that which had been under arable +culture for 250 years, that during that period some 3000 lb. of nitrogen +per acre had disappeared from the arable land. Examples of decrease of +nitrogen in Rothamsted soils, under various conditions of culture, will +be found in the Appendix.<a name="FNanchor_87_87" id="FNanchor_87_87"></a><a href="#Footnote_87_87" class="fnanchor">[87]</a></p> + +<br /> +<p class="cen"><i>Loss of Nitrogen by Retrogression.</i></p> + +<p>A source of loss of nitrogen may be here <span class='pagenum'><a name="Page_143" id="Page_143">[Pg 143]</a></span>mentioned which has to do with +diminution of amount of available nitrogen, rather than absolute loss of +nitrogen to the soil, and which we may term <i>loss by retrogression</i>. +Nitrogen in an available form, such as nitrates, has been found to be +converted into a less available form. This retrogression may be +effected, as in the case of nitrates, by reduction—<i>i.e.</i>, by removal +of the oxygen in combination with the nitrogen, which in many cases may +be set free, and thus partially although not necessarily entirely lost. +Such reduction is due to the action of bacteria of the denitrifying +order.<a name="FNanchor_88_88" id="FNanchor_88_88"></a><a href="#Footnote_88_88" class="fnanchor">[88]</a> Or, on the other hand, nitrogen may be converted into some +kind of insoluble form which seems to resist decomposition and lies in +an inert condition in the soil utterly unavailable for the plants' +needs. A striking example of this retrogression of nitrogen seems to be +afforded in the case of farmyard manure. It has been found in the +Rothamsted experiments, as has been pointed out in the preceding pages, +that when farmyard manure is applied, year after year, to the same land +in large quantities, a very considerable percentage of its nitrogen does +not (<i>i.e.</i>, within a reasonable number of years) become available for +the crop's uses. What, indeed, becomes of the nitrogen is a mystery; but +it is highly probable that some such kind of retrogression as that above +referred to, whereby the nitrogen is converted into some inert organic +form, takes place.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_144" id="Page_144">[Pg 144]</a></span><i>Artificial Sources of Loss of Nitrogen.</i></p> + +<p>So far, the sources of loss of nitrogen considered have been what we may +term <i>natural</i> sources. By this is meant that the loss of nitrogen from +the above sources takes place in a state of nature, and not merely under +conditions of cultivation. No doubt the loss due to drainage is very +much greater under arable farming than would be the case where +artificial drainage does not obtain; still, under any conditions, this +loss must be reckoned with. On the other hand, by <i>artificial</i> sources +of loss are meant those entirely dependent on our modern system of +agriculture and our modern system of sewage disposal, whereby the +nitrogen contained in that portion of the produce of the farm which goes +to supply our food is not returned to the soil, but is totally lost.</p> + +<br /> +<p class="cen"><i>Amount of Nitrogen removed in Crops.</i></p> + +<p>The modern tendency towards centralisation in large towns has rendered +this loss—despite all that has been said to the contrary—a necessity. +It is extremely difficult, however, to form any estimate of its amount. +We know, of course, the amount of nitrogen removed from the soil by +different crops. We cannot, however, estimate how much of this may find +its way back again to the soil. The amount of nitrogen contained in the +different crops will be fully dealt with in the chapter on the manuring +of different crops. <span class='pagenum'><a name="Page_145" id="Page_145">[Pg 145]</a></span>It may be, however, not without interest to give +here some approximate indication of the amount of this loss, in order to +render the view of the subject as comprehensive as possible.</p> + +<p>Recent agricultural returns for Great Britain give the total produce of +<i>wheat</i> at over 76 million bushels, that of <i>barley</i> at over 69 million, +and that of <i>oats</i> at over 150 million. Calculating the amount of +nitrogen, these quantities of wheat, barley, and oats respectively and +collectively contain, and calculating also how much <i>sulphate of +ammonia</i> and <i>nitrate of soda</i> these amounts of nitrogen represent, the +following are the results:—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Nitrogen"> + <tr> + <td class="tdl" width="20%"> </td> + <td class="tdc" width="20%"> </td> + <td class="tdc" width="20%">Nitrogen.</td> + <td class="tdc" width="20%">Sulphate of Ammonia.</td> + <td class="tdc" width="20%">Nitrate of Soda.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Bushels.</td> + <td class="tdc">Tons.</td> + <td class="tdc">Tons.</td> + <td class="tdc">Tons.</td> + </tr> + <tr> + <td class="tdl">Wheat</td> + <td class="tdc"> 76,224,940</td> + <td class="tdc"> 37,432</td> + <td class="tdc">176,465</td> + <td class="tdc">227,266</td> + </tr> + <tr> + <td class="tdl">Barley</td> + <td class="tdc"> 69,948,266</td> + <td class="tdc"> 27,324</td> + <td class="tdc">128,813</td> + <td class="tdc">165,896</td> + </tr> + <tr> + <td class="tdl">Oats</td> + <td class="tdc" style="text-decoration: underline;">150,789,416</td> + <td class="tdc" style="text-decoration: underline;"> 56,835</td> + <td class="tdc" style="text-decoration: underline;">267,936</td> + <td class="tdc" style="text-decoration: underline;">345,068</td> + </tr> + <tr> + <td class="tdl">Total</td> + <td class="tdc" style="text-decoration: underline;">296,962,622</td> + <td class="tdc" style="text-decoration: underline;">121,591</td> + <td class="tdc" style="text-decoration: underline;">573,214</td> + <td class="tdc" style="text-decoration: underline;">738,230</td> + </tr> +</table> +</div> + +<p>Of course these figures, so far as the amounts of nitrogen are +concerned, can only be regarded as approximate, as it is only possible +in such calculations to obtain approximate results. Accepting these +calculations as merely approximate, they are, nevertheless, of the +highest interest and importance. It is of great importance to understand +that in the annual produce of our three common cereal crops—supposing +them to be all consumed off the farm—there is removed from the soil a +quantity of nitrogen equal to that contained in over <i>half a million +tons of sulphate <span class='pagenum'><a name="Page_146" id="Page_146">[Pg 146]</a></span>of ammonia, and three quarters of a million tons of +nitrate of soda.</i></p> + +<p>As has already been remarked, it is impossible to estimate exactly what +proportion of this total nitrogen finds its way back to the soil. In the +case of wheat, it may be pointed out that the portion which is used as a +feeding-stuff—viz., <i>bran</i>—is very much richer in nitrogen than the +flour. While, then, we are unable to estimate with any exactitude this +source of loss of nitrogen, it cannot for a moment be doubted that it is +enormous, from what has been already stated. We must remember that the +portion of the crop richest in nitrogen is that which is generally +removed—the straw which is grown in producing a bushel of wheat, +barley, or oats, containing less than half the amount of nitrogen +contained by a bushel of the grain itself.</p> + +<br /> +<p class="cen"><i>Losses of Nitrogen incurred on the Farm.</i></p> + +<p>In addition to the loss due to removal of crops from the farm, there are +one or two other sources of loss which it may be well to briefly refer +to.</p> + +<br /> +<p class="cen"><i>Loss in Treatment of Farmyard Manure.</i></p> + +<p>There can be little doubt that in the past a very considerable source of +loss was the improper treatment of farmyard manure. The way in which +this loss may take place will be fully considered in the chapter on +farmyard manure. Suffice it to say here, that this may take place by +volatilisation of the nitrogen as <span class='pagenum'><a name="Page_147" id="Page_147">[Pg 147]</a></span>carbonate of ammonia, caused by +carelessness in allowing the temperature of the manure-heap to rise too +high; or by drainage of the soluble nitrogen compounds, caused by +allowing the rich black liquor of the manure-heap to be washed away, and +not properly conserved.</p> + +<br /> +<p class="cen"><i>Nitrogen removed in Milk.</i></p> + +<p>Another source of loss which is apt to be overlooked is the amount of +nitrogen removed in milk. Professor Storer has calculated that in the +case of a cow giving 2000 quarts, or 4300 lb., of milk in a year, and +the milk being all sold as such, there would be carried away from the +farm 22 lb. of nitrogen.<a name="FNanchor_89_89" id="FNanchor_89_89"></a><a href="#Footnote_89_89" class="fnanchor">[89]</a></p> + +<br /> +<p class="cen"><i>Economics of the Nitrogen question.</i></p> + +<p>And here, before concluding our survey of the different sources of loss +of nitrogen, it may be well to regard for a moment the subject from a +somewhat wider standpoint than that from which we have been considering +it. The total supply of nitrogen in a combined form is limited. As we +have pointed out, it may be regarded as the element on which, more than +any other, life, animal as well as vegetable, depends. To animal life it +is alone available in combined form; to vegetable life it is chiefly +also only <span class='pagenum'><a name="Page_148" id="Page_148">[Pg 148]</a></span>available in combined form. In the air we have an unlimited +quantity of nitrogen, but it is almost entirely in an <i>uncombined</i> form, +and therefore largely unavailable. The conversion of nitrogen from the +free state to a combined form is a process which takes place only very +slowly. Any source which diminishes the sum-total of our already all too +limited supply of combined nitrogen must be regarded as worthy of most +serious consideration. The question, therefore, of the artificial waste +of nitrogen daily taking place around us, is one which ought to possess +for economists a very great interest indeed. This waste has, of late +years, enormously increased, and would seem to threaten us at no very +distant date with a nitrogen famine. It is incidental to the use of +certain nitrogenous substances in the manufacture of various articles, +and to our present system of sewage disposal.</p> + +<br /> +<p class="cen"><i>Loss of Nitrogen-compounds in the Arts.</i></p> + +<p>The articles referred to are such as explosives, starch, textile +substances, malt liquors, &c. The question is strikingly dealt with in +an able paper on "The Economy of Nitrogen" in the 'Quarterly Journal of +Science.'<a name="FNanchor_90_90" id="FNanchor_90_90"></a><a href="#Footnote_90_90" class="fnanchor">[90]</a></p> + +<br /> +<p class="cen"><i>Loss due to Use of Gunpowder.</i></p> + +<p>The explosives—more particularly gunpowder—are the most important of +these articles. Gunpowder <span class='pagenum'><a name="Page_149" id="Page_149">[Pg 149]</a></span>contains 75 per cent of saltpetre, which in +its turn contains about 10 per cent of nitrogen. When gunpowder +explodes, practically the whole of this nitrogen is converted into +"free" nitrogen. The loss is thus in a sense irreparable. In the paper +above, referred to, our total annual exports of this substance are +estimated at 19,000,000 lb.; while the total annual production of the +world is estimated at not less than 100,000,000 lb. The annual loss of +nitrogen due to this source alone would amount to about 10,000,000 +lb.<a name="FNanchor_91_91" id="FNanchor_91_91"></a><a href="#Footnote_91_91" class="fnanchor">[91]</a> Similarly, loss of nitrogen, although to a less extent, is +caused by the use of other explosives, as well as in the manufacture of +the other articles above mentioned.</p> + +<br /> +<p class="cen"><i>Loss due to Sewage Disposal.</i></p> + +<p>The loss due to our present system of sewage disposal has been already +taken into account in dealing with the loss due to removal of crops. It +may be well, however, to treat it from the sewage aspect. Taking the +amount of nitrogen in the excreta of every individual as, on an average, +half an ounce, the annual amount voided in the excreta of the total +population of the British Isles would amount to 365,000,000 lb.<a name="FNanchor_92_92" id="FNanchor_92_92"></a><a href="#Footnote_92_92" class="fnanchor">[92]</a>—of +this, the amount in the London sewage alone being 91,000,000 lb.<a name="FNanchor_93_93" id="FNanchor_93_93"></a><a href="#Footnote_93_93" class="fnanchor">[93]</a> By +the water system, which is almost <span class='pagenum'><a name="Page_150" id="Page_150">[Pg 150]</a></span>universally adopted in this country, +the above quantity of nitrogen is entirely lost to the soil. A small +portion of it, it may be argued, is eventually recovered in sea weed and +fish, which may be used for manure. This, however, is to argue too much +<i>sub specie æternitatis</i>. Not all the nitrogen originally present in the +excreta finds its way into the sea; for it is highly probable that a +considerable quantity escapes in the process of the decomposition of the +sewage as "free" nitrogen.</p> + +<p>From the above statement of the sources of loss and gain of nitrogen +taking place in the soil, it may be pretty safe to conclude that while +in a state of nature the gain balances the loss, if indeed it does not +do more, under conditions of arable farming such is very far from being +the case; and that if fertility of the land is to be maintained, +recourse to nitrogenous manures must be had,—in short, that the +application of artificial nitrogenous manures is a necessary condition +of modern husbandry.</p> + +<br /> +<p class="cen"><i>Our Artificial Nitrogen Supply.</i></p> + +<p>Before concluding this chapter, it may be interesting to enumerate very +briefly the chief sources of our artificial nitrogen supply.</p> + +<br /> +<p class="cen"><i>Nitrate of Soda and Sulphate of Ammonia.</i></p> + +<p>The most important artificial nitrogenous manures in use at present are +nitrate of soda and sulphate of ammonia. Of the former, the annual +exportation from <span class='pagenum'><a name="Page_151" id="Page_151">[Pg 151]</a></span>Chili is close on one million tons, of which quantity +about 120,000 tons is imported into the United Kingdom. Of sulphate of +ammonia, on the other hand, the total production in this country is +about 130,000 tons per annum,<a name="FNanchor_94_94" id="FNanchor_94_94"></a><a href="#Footnote_94_94" class="fnanchor">[94]</a> the greater proportion of which is +exported, leaving only from 30,000 to 40,000 tons for consumption. +Nitrate of soda, it must be remembered, is not entirely used for +manurial purposes, a small proportion of the above imports being used +for chemical manufacturing purposes.</p> + +<br /> +<p class="cen"><i>Peruvian Guano.</i></p> + +<p>Peruvian guano is another important nitrogenous manure very much less +abundant now than formerly, as the different guano-beds have become +nearly exhausted. While the imports of this important manure into the +United Kingdom amounted in 1870 to nearly 250,000 tons, at present not +more than 11,000 tons are being imported.</p> + +<br /> +<p class="cen"><i>Bones.</i></p> + +<p>A further source of nitrogen is bones, which, of course, are chiefly +valuable as a phosphatic manure, but which contain also some 3 to 4 per +cent of nitrogen. Of this valuable manure we import at present about +30,000 tons, while about 60,000 tons are collected in this country, +bringing up our total consumption to 100,000 tons.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_152" id="Page_152">[Pg 152]</a></span><i>Other Nitrogenous Manures.</i></p> + +<p>The above mentioned are the most important of nitrogenous manures; there +are, however, a number of other nitrogenous manures used in this country +in very much smaller quantities. As most of these substances are made in +this country, it is very difficult to estimate the amount of their +annual production with exactness. These substances are as follows: +fish-guano, meat-meal guano, dried blood, shoddy, scutch, horns and +hoofs, hair, bristles, feathers, leather-scrap, &c. Of fish-guano, the +total consumption per annum may be put down at about 8000 tons, of which +a fourth is imported into this country, the remaining 6000 tons being +manufactured at home. Of meat-meal guano, dried blood, hoof-guano, &c., +about 2500 tons are annually imported, the home production bringing up +the total amount to some 10,000 tons. Of shoddy, some 12,000 tons are +manufactured in this country; while scutch—the name given to a manure +manufactured from the waste products incidental to the manufacture of +glue and the dressing of skins—is produced only to the extent of a few +thousand tons annually.</p> + +<p>It is a fact worthy of notice, that while the use of phosphatic manures +has increased very considerably of late years, the same cannot be said +of nitrogen. According to Mr Hermann Voss, some 34,000<a name="FNanchor_95_95" id="FNanchor_95_95"></a><a href="#Footnote_95_95" class="fnanchor">[95]</a> tons <span class='pagenum'><a name="Page_153" id="Page_153">[Pg 153]</a></span>of +nitrogen were used in the form of artificial manures in 1873, while now +only about 28,000 tons are used—<i>i.e.</i>, some 6000 tons less.</p> + +<br /> +<p class="cen"><i>Oil-seeds and Oilcakes.</i></p> + +<p>There still remains a very important source of nitrogen which has not +yet been mentioned, in the shape of oil-seeds and oilcakes, used for +feeding purposes. Oilcakes are both manufactured in this country and +imported in large quantities. Recent Agricultural Returns show the total +imports of oilcakes at 256,296 tons; that of linseed at 370,000 tons; +that of rape-seed at 80,000 tons; and that of cotton-seed at 289,413 +tons.</p> + +<br /> +<p class="cen"><i>Other imported Sources of Nitrogen.</i></p> + +<p>We have further, in considering this question, to take into account the +large amount of maize, peas, beans, wheat, and oats which are imported +into this country, a certain quantity of which is used as cattle-food, +and will therefore go to enrich their manure. Also the imported straw +used for purposes of litter must not be forgotten. In 1887 this amounted +to 52,393 tons.</p> + +<br /> +<p class="cen"><i>Conclusion.</i></p> + +<p>In conclusion, it may be asked how far are the artificial sources of +nitrogen able to make good the loss? In the opinion of such a reliable +authority as <span class='pagenum'><a name="Page_154" id="Page_154">[Pg 154]</a></span>Sir John Lawes, they do not. There are some soils which +depend almost entirely upon imported fertility, and could not be +cultivated without it. Upon some of them it is possible that the imports +of nitrogen are in excess of the exports. Taking the agricultural +acreage as a whole, however, he is of opinion that there is a decided +loss of nitrogen, which he estimates at <i>from 15 lb. to 20 lb. per acre +per annum</i>.<a name="FNanchor_96_96" id="FNanchor_96_96"></a><a href="#Footnote_96_96" class="fnanchor">[96]</a></p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_63_63" id="Footnote_63_63"></a><a href="#FNanchor_63_63"><span class="label">[63]</span></a> The total amount of nitrogen in the air has been estimated +approximately at four million billion tons.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_64_64" id="Footnote_64_64"></a><a href="#FNanchor_64_64"><span class="label">[64]</span></a> See Introductory Chapter, pp. 40 to 45.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_65_65" id="Footnote_65_65"></a><a href="#FNanchor_65_65"><span class="label">[65]</span></a> Although ammonia is more abundant than nitrates and +nitrites, it only amounts to a few parts per million of air. According +to Müntz, the air at great heights contains more ammonia than in its +lower strata. The opposite, however, is the case with regard to +nitrates, which are only found in air near the surface of the earth. See +p. 49.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_66_66" id="Footnote_66_66"></a><a href="#FNanchor_66_66"><span class="label">[66]</span></a> Nitric acid may also be formed by the oxidation of ammonia +by ozone, or peroxide of hydrogen.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_67_67" id="Footnote_67_67"></a><a href="#FNanchor_67_67"><span class="label">[67]</span></a> According to Schloesing, the chief source of the ammonia +present in the air is the tropical ocean, which yields gradually to the +atmosphere, under the action of the powerful evaporation constantly +going on, a large amount of nitrogen in this form. The sources of the +nitrogen of the ocean are the nitrates which it receives from the +drainage of land, animal and vegetable matter, sewage, &c.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_68_68" id="Footnote_68_68"></a><a href="#FNanchor_68_68"><span class="label">[68]</span></a> See Appendix, Note I., p. 155.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_69_69" id="Footnote_69_69"></a><a href="#FNanchor_69_69"><span class="label">[69]</span></a> To illustrate this point, it may be mentioned that on the +least windy of days, when the wind is only moving at the rate of two +miles an hour—and this, it may he added, is so slow as to be scarcely +noticeable—the air in a space of 20 feet is changed over five hundred +times in an hour. The combined nitrogen thus absorbed is probably +entirely in the form of ammonia. It would seem so at any rate, from some +experiments by Schloesing. See p. 132.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_70_70" id="Footnote_70_70"></a><a href="#FNanchor_70_70"><span class="label">[70]</span></a> No vegetable or animal cell exists which does not contain +nitrogen.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_71_71" id="Footnote_71_71"></a><a href="#FNanchor_71_71"><span class="label">[71]</span></a> This is less on the whole than what has been found in +subsoils by Continental investigators. Thus, for example, A. Müller +found the average of a number of analyses of subsoils to be .15 per +cent., and the late Dr Anderson found the nitrogen in the subsoil of +different Scottish wheat-soils to run from .15 per cent to .97 per +cent.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_72_72" id="Footnote_72_72"></a><a href="#FNanchor_72_72"><span class="label">[72]</span></a> See Appendix, Note II., p. 156.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_73_73" id="Footnote_73_73"></a><a href="#FNanchor_73_73"><span class="label">[73]</span></a> "Under prolonged kitchen-garden culture the subsoil +becomes enriched with nitrogenous matter to a far more considerable +depth; this has been shown by the analyses of the soil of the old +kitchen-garden at Rothamsted. This is doubtless due to the practice of +deep trenching employed by gardeners."—R. Warington, 'Lectures on +Rothamsted Experiments.' U.S.A. Bulletin, p. 24.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_74_74" id="Footnote_74_74"></a><a href="#FNanchor_74_74"><span class="label">[74]</span></a> The comparatively insignificant effect the addition of +various nitrogenous manures have in increasing the total soil-nitrogen +is strikingly illustrated in the tables given in the Appendix, Note IV., +p. 157.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_75_75" id="Footnote_75_75"></a><a href="#FNanchor_75_75"><span class="label">[75]</span></a> See Storer's Agric. Chem., vol. i. p. 357.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_76_76" id="Footnote_76_76"></a><a href="#FNanchor_76_76"><span class="label">[76]</span></a> See Chapter IV., Appendix, Note VII., p. 198.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_77_77" id="Footnote_77_77"></a><a href="#FNanchor_77_77"><span class="label">[77]</span></a> See Appendix, Note III., p. 157.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_78_78" id="Footnote_78_78"></a><a href="#FNanchor_78_78"><span class="label">[78]</span></a> See Appendix, Note IV., p. 157.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_79_79" id="Footnote_79_79"></a><a href="#FNanchor_79_79"><span class="label">[79]</span></a> See Appendix, Note I., p. 155.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_80_80" id="Footnote_80_80"></a><a href="#FNanchor_80_80"><span class="label">[80]</span></a> The original source of the nitrogen in the soil must have +been the nitrogen in the air. When plants first begin to grow on a +purely mineral soil, they must obtain nitrogen from some source. The +small traces washed down in the rain will supply sufficient nitrogen to +enable a scanty growth of the lower forms of vegetable life; whereas +these by their decay furnish their successors with a more abundant +source, which rapidly increases, until we have a fair percentage of +humus accumulated.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_81_81" id="Footnote_81_81"></a><a href="#FNanchor_81_81"><span class="label">[81]</span></a> See Appendix, Note V., p. 158.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_82_82" id="Footnote_82_82"></a><a href="#FNanchor_82_82"><span class="label">[82]</span></a> See Historical Introduction, pp. 40-45.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_83_83" id="Footnote_83_83"></a><a href="#FNanchor_83_83"><span class="label">[83]</span></a> The evidence demonstrating this is to be found in the fact +that the amount of carbon found in different soils rises or falls in +proportion to the nitrogen. See p. 126.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_84_84" id="Footnote_84_84"></a><a href="#FNanchor_84_84"><span class="label">[84]</span></a> See Chapter IV. on Nitrification.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_85_85" id="Footnote_85_85"></a><a href="#FNanchor_85_85"><span class="label">[85]</span></a> Diffusion as well as capillary attraction is a means of +bringing nitrates again to the surface-soil after rain.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_86_86" id="Footnote_86_86"></a><a href="#FNanchor_86_86"><span class="label">[86]</span></a> See Appendix, Note VI., p. 158, and Note VIII., p. 160; +also p. 154.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_87_87" id="Footnote_87_87"></a><a href="#FNanchor_87_87"><span class="label">[87]</span></a> See Appendix, Note VII., p. 159.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_88_88" id="Footnote_88_88"></a><a href="#FNanchor_88_88"><span class="label">[88]</span></a> See following Chapter on Nitrification, p. 178.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_89_89" id="Footnote_89_89"></a><a href="#FNanchor_89_89"><span class="label">[89]</span></a> According to the Agricultural Returns for 1888, the number +of cows in milk in Great Britain amounted to 2,450,444. If we multiply +this number by 22 the result is 54,000,000 lb., or in tons 24,107. This +quantity represents 154,067 tons of ordinary commercial nitrate of +soda.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_90_90" id="Footnote_90_90"></a><a href="#FNanchor_90_90"><span class="label">[90]</span></a> For 1878 (p. 146 <i>et seq.</i>) The reader interested in the +subject is referred to the paper itself.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_91_91" id="Footnote_91_91"></a><a href="#FNanchor_91_91"><span class="label">[91]</span></a> In tons 4464, and represents 28,530 tons of nitrate of +soda.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_92_92" id="Footnote_92_92"></a><a href="#FNanchor_92_92"><span class="label">[92]</span></a> This in tons 162,946, which represents 1,041,384 tons of +nitrate of soda.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_93_93" id="Footnote_93_93"></a><a href="#FNanchor_93_93"><span class="label">[93]</span></a> This in tons 40,625, which represents 259,633 tons of +nitrate of soda. See paper in 'Journal of Science' already referred to.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_94_94" id="Footnote_94_94"></a><a href="#FNanchor_94_94"><span class="label">[94]</span></a> Europe's total production may be stated at 200,000 tons.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_95_95" id="Footnote_95_95"></a><a href="#FNanchor_95_95"><span class="label">[95]</span></a> 10,500 tons of which were as guano.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_96_96" id="Footnote_96_96"></a><a href="#FNanchor_96_96"><span class="label">[96]</span></a> Mr Warington estimates this at about 8 lb. See p. 141.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_155" id="Page_155">[Pg 155]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER III.</h2> +<br /> + +<p class="cen">NOTE I. (p. 119).</p> + +<p class="cen"><span class="smcap">Determinations of the Quantity of Nitrogen supplied by Rain, as +Ammonia and Nitric Acid, to an Acre of Land, during One Year.</span></p> + +<p class="cen">(<i>From Dr Fream's 'Soils and their Properties</i>,' p. 62.)</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="million"> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + <td class="tdc" width="15%"> </td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;">Nitrogen per</td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdclb" colspan="2">million, as</td> + <td class="tdcl">Total</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Nitric</td> + <td class="tdcl">Nitrogen</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">Year.</td> + <td class="tdclb">Rainfall.</td> + <td class="tdclb">Ammonia.</td> + <td class="tdclb">Acid.</td> + <td class="tdclb">per acre.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl">Kuschen</td> + <td class="tdcl">1864-65</td> + <td class="tdcl">11.85</td> + <td class="tdcl">0.54</td> + <td class="tdcl">0.16</td> + <td class="tdcl"> 1.86</td> + </tr> + <tr> + <td class="tdl">Kuschen</td> + <td class="tdcl">1865-66</td> + <td class="tdcl">17.70</td> + <td class="tdcl">0.44</td> + <td class="tdcl">0.16</td> + <td class="tdcl"> 2.50</td> + </tr> + <tr> + <td class="tdl">Insterburg</td> + <td class="tdcl">1864-65</td> + <td class="tdcl">27.55</td> + <td class="tdcl">0.55</td> + <td class="tdcl">0.30</td> + <td class="tdcl"> 5.49</td> + </tr> + <tr> + <td class="tdl">Insterburg</td> + <td class="tdcl">1865-66</td> + <td class="tdcl">23.79</td> + <td class="tdcl">0.76</td> + <td class="tdcl">0.49</td> + <td class="tdcl"> 6.81</td> + </tr> + <tr> + <td class="tdl">Dahme</td> + <td class="tdcl">1865</td> + <td class="tdcl">17.09</td> + <td class="tdcl">1.42</td> + <td class="tdcl">0.30</td> + <td class="tdcl"> 6.66</td> + </tr> + <tr> + <td class="tdl">Regenwalde</td> + <td class="tdcl">1864-65</td> + <td class="tdcl">23.48</td> + <td class="tdcl">2.03</td> + <td class="tdcl">0.80</td> + <td class="tdcl">15.09</td> + </tr> + <tr> + <td class="tdl">Regenwalde</td> + <td class="tdcl">1865-66</td> + <td class="tdcl">19.31</td> + <td class="tdcl">1.88</td> + <td class="tdcl">0.48</td> + <td class="tdcl">10.38</td> + </tr> + <tr> + <td class="tdl">Regenwalde</td> + <td class="tdcl">1866-67</td> + <td class="tdcl">25.37</td> + <td class="tdcl">2.28</td> + <td class="tdcl">0.56</td> + <td class="tdcl">16.44</td> + </tr> + <tr> + <td class="tdl">Ida-Marienhütte,</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> mean of six years</td> + <td class="tdcl">1865-70</td> + <td class="tdcl">22.65</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + <td class="tdcl"> 9.92</td> + </tr> + <tr> + <td class="tdl">Proskau</td> + <td class="tdcl">1864-65</td> + <td class="tdcl">17.81</td> + <td class="tdcl">3.21</td> + <td class="tdcl">1.73</td> + <td class="tdcl">20.91</td> + </tr> + <tr> + <td class="tdl">Florence</td> + <td class="tdcl">1870</td> + <td class="tdcl">36.55</td> + <td class="tdcl">1.17</td> + <td class="tdcl">0.44</td> + <td class="tdcl">13.36</td> + </tr> + <tr> + <td class="tdl">Florence</td> + <td class="tdcl">1871</td> + <td class="tdcl">42.48</td> + <td class="tdcl">0.81</td> + <td class="tdcl">0.22</td> + <td class="tdcl"> 9.89</td> + </tr> + <tr> + <td class="tdl">Florence</td> + <td class="tdcl">1872</td> + <td class="tdcl">50.82</td> + <td class="tdcl">0.82</td> + <td class="tdcl">0.26</td> + <td class="tdcl">12.51</td> + </tr> + <tr> + <td class="tdl">Vallombrosa</td> + <td class="tdcl">1872</td> + <td class="tdcl">79.83</td> + <td class="tdcl">0.42</td> + <td class="tdcl">0.15</td> + <td class="tdcl">10.38</td> + </tr> + <tr> + <td class="tdl">Montsouris, Paris</td> + <td class="tdcl">1877-78</td> + <td class="tdcl">23.62</td> + <td class="tdcl">1.91</td> + <td class="tdcl">0.24</td> + <td class="tdcl">11.54</td> + </tr> + <tr> + <td class="tdl">Montsouris, Paris</td> + <td class="tdcl">1878-79</td> + <td class="tdcl">25.79</td> + <td class="tdcl">1.20</td> + <td class="tdcl">0.70</td> + <td class="tdcl">11.16</td> + </tr> + <tr> + <td class="tdl">Montsouris, Paris</td> + <td class="tdcl">1879-80</td> + <td class="tdclb">15.70</td> + <td class="tdclb">1.36</td> + <td class="tdclb">1.60</td> + <td class="tdclb">10.52</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Mean of</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdlb"></td> + <td class="tdclb">22 years</td> + <td class="tdclb">27.63</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">10.23</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_156" id="Page_156">[Pg 156]</a></span>NOTE II. (p. 122).</p> + +<p class="cen"><span class="smcap">Nitrogen in Soils at Various Depths.</span></p> + +<p class="cen">(1) <i>Rothamsted Soils.</i></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Depth"> + <tr> + <td class="tdl" width="28%"> </td> + <td class="tdc" width="18%"> </td> + <td class="tdc" width="18%"> </td> + <td class="tdc" width="18%"> </td> + <td class="tdc" width="18%"> </td> + </tr> + <tr> + <td class="tdcb" style="border-top: .5pt black solid; border-bottom: .5pt black solid;">Depth.</td> + <td class="tdclb" colspan="2" style="border-top: .5pt black solid;">Arable soil.</td> + <td class="tdclb" colspan="2" style="border-top: .5pt black solid;">Old pasture soil.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">per cent.</td> + <td class="tdcl">lb. per acre.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">lb. per acre.</td> + </tr> + <tr> + <td class="tdl"> 1st 9 inches</td> + <td class="tdcl">0.120</td> + <td class="tdcl"> 3,015</td> + <td class="tdcl">0.245</td> + <td class="tdcl"> 5,351</td> + </tr> + <tr> + <td class="tdl"> 2d 9 inches</td> + <td class="tdcl">0.068</td> + <td class="tdcl"> 1,629</td> + <td class="tdcl">0.082</td> + <td class="tdcl"> 2,313</td> + </tr> + <tr> + <td class="tdl"> 3d 9 inches</td> + <td class="tdcl">0.059</td> + <td class="tdcl"> 1,461</td> + <td class="tdcl">0.053</td> + <td class="tdcl"> 1,580</td> + </tr> + <tr> + <td class="tdl"> 4th 9 inches</td> + <td class="tdcl">0.051</td> + <td class="tdcl"> 1,228</td> + <td class="tdcl">0.046</td> + <td class="tdcl"> 1,412</td> + </tr> + <tr> + <td class="tdl"> 5th 9 inches</td> + <td class="tdcl">0.045</td> + <td class="tdcl"> 1,090</td> + <td class="tdcl">0.042</td> + <td class="tdcl"> 1,301</td> + </tr> + <tr> + <td class="tdl"> 6th 9 inches</td> + <td class="tdclb">0.044</td> + <td class="tdclb"> 1,131</td> + <td class="tdclb">0.039</td> + <td class="tdclb"> 1,186</td> + </tr> + <tr> + <td class="tdl">Total, 54 inches</td> + <td class="tdclb">—</td> + <td class="tdclb"> 9,554</td> + <td class="tdclb">—</td> + <td class="tdclb">13,143</td> + </tr> + <tr> + <td class="tdl"> 7th 9 inches</td> + <td class="tdcl">0.042</td> + <td class="tdcl"> 1,049</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl"> 8th 9 inches</td> + <td class="tdcl">0.041</td> + <td class="tdcl"> 1,095</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl"> 9th 9 inches</td> + <td class="tdcl">0.044</td> + <td class="tdcl"> 1,173</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">10th 9 inches</td> + <td class="tdcl">0.043</td> + <td class="tdcl"> 1,076</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">11th 9 inches</td> + <td class="tdcl">0.043</td> + <td class="tdcl"> 1,112</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">12th 9 inches</td> + <td class="tdclb">0.045</td> + <td class="tdclb"> 1,198</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> + <tr> + <td class="tdlb">Total, 9 feet</td> + <td class="tdclb">—</td> + <td class="tdclb">16,257</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">(2) <i>Manitoba Soils.</i></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Brandon"> + <tr> + <td class="tdl" width="28%"> </td> + <td class="tdc" width="18%"> </td> + <td class="tdc" width="18%"> </td> + <td class="tdc" width="18%"> </td> + <td class="tdc" width="18%"> </td> + </tr> + <tr> + <td class="tdcb" style="border-top: .5pt black solid; border-bottom: .5pt black solid;">Depth.</td> + <td class="tdclb" style="border-top: .5pt black solid;">Brandon.</td> + <td class="tdclb" style="border-top: .5pt black solid;">Niverville.</td> + <td class="tdclb" style="border-top: .5pt black solid;">Winnipeg.</td> + <td class="tdclb" style="border-top: .5pt black solid;">Selkirk.</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + </tr> + <tr> + <td class="tdc">1st foot</td> + <td class="tdcl">0.187</td> + <td class="tdcl">0.261</td> + <td class="tdcl">0.428</td> + <td class="tdcl">0.618</td> + </tr> + <tr> + <td class="tdc">2d foot</td> + <td class="tdcl">0.109</td> + <td class="tdcl">0.169</td> + <td class="tdcl">0.327</td> + <td class="tdcl">0.264</td> + </tr> + <tr> + <td class="tdc">3d foot</td> + <td class="tdcl">0.072</td> + <td class="tdcl">0.069</td> + <td class="tdcl">0.158</td> + <td class="tdcl">0.076</td> + </tr> + <tr> + <td class="tdc" style="border-bottom: .5pt black solid;">4th foot</td> + <td class="tdclb">0.019</td> + <td class="tdclb">0.038</td> + <td class="tdclb">0.107</td> + <td class="tdclb">0.042</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_157" id="Page_157">[Pg 157]</a></span>NOTE III. (p. 130).</p> + +<p class="cen"><span class="smcap">Nitrogen as Nitrates in Cropped Soils receiving no Nitrogenous +Manure, in Lb. per Acre</span> (<i>Rothamsted Soils</i>).</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Wheat"> + <tr> + <td class="tdl" width="22%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + <td class="tdc" width="13%"> </td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdctlb" colspan="2">Wheat.</td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">After</td> + <td class="tdcl">After</td> + <td class="tdcl">Bokhara</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">White</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">fallow,</td> + <td class="tdcl">clover,</td> + <td class="tdcl">clover,</td> + <td class="tdcl">Vetches,</td> + <td class="tdcl">Lucern,</td> + <td class="tdcl">clover,</td> + </tr> + <tr> + <td class="tdc" style="border-bottom: .5pt black solid;">Depth.</td> + <td class="tdclb">1883.</td> + <td class="tdclb">1883.</td> + <td class="tdclb">1882.</td> + <td class="tdclb">1883.</td> + <td class="tdclb">1885.</td> + <td class="tdclb">1885.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl"> 1st 9 inches</td> + <td class="tdcl">3.4</td> + <td class="tdcl">6.1</td> + <td class="tdcl">3.4</td> + <td class="tdcl">10.2</td> + <td class="tdcl">8.9</td> + <td class="tdcl">11.5</td> + </tr> + <tr> + <td class="tdl"> 2d 9 inches</td> + <td class="tdcl">3.1</td> + <td class="tdcl">4.4</td> + <td class="tdcl">1.0</td> + <td class="tdcl"> 2.7</td> + <td class="tdcl">1.1</td> + <td class="tdcl"> 1.4</td> + </tr> + <tr> + <td class="tdl"> 3d 9 inches</td> + <td class="tdcl">0.8</td> + <td class="tdcl">1.6</td> + <td class="tdcl">0.6</td> + <td class="tdcl"> 1.1</td> + <td class="tdcl">0.8</td> + <td class="tdcl"> 0.9</td> + </tr> + <tr> + <td class="tdl"> 4th 9 inches</td> + <td class="tdcl">1.0</td> + <td class="tdcl">1.3</td> + <td class="tdcl">1.0</td> + <td class="tdcl"> 1.5</td> + <td class="tdcl">0.8</td> + <td class="tdcl"> 1.9</td> + </tr> + <tr> + <td class="tdl"> 5th 9 inches</td> + <td class="tdcl">0.8</td> + <td class="tdcl">1.5</td> + <td class="tdcl">0.8</td> + <td class="tdcl"> 2.5</td> + <td class="tdcl">1.0</td> + <td class="tdcl"> 7.1</td> + </tr> + <tr> + <td class="tdl"> 6th 9 inches</td> + <td class="tdcl">0.6</td> + <td class="tdcl">0.8</td> + <td class="tdcl">1.7</td> + <td class="tdcl"> 4.4</td> + <td class="tdcl">0.9</td> + <td class="tdcl">11.3</td> + </tr> + <tr> + <td class="tdl"> 7th 9 inches</td> + <td class="tdcl">0.8</td> + <td class="tdcl">2.2</td> + <td class="tdcl">—</td> + <td class="tdcl"> 4.5</td> + <td class="tdcl">0.6</td> + <td class="tdcl">13.1</td> + </tr> + <tr> + <td class="tdl"> 8th 9 inches</td> + <td class="tdcl">0.9</td> + <td class="tdcl">1.7</td> + <td class="tdcl">—</td> + <td class="tdcl"> 4.9</td> + <td class="tdcl">0.8</td> + <td class="tdcl">12.6</td> + </tr> + <tr> + <td class="tdl"> 9th 9 inches</td> + <td class="tdcl">0.7</td> + <td class="tdcl">2.4</td> + <td class="tdcl">—</td> + <td class="tdcl"> 4.8</td> + <td class="tdcl">0.7</td> + <td class="tdcl">11.2</td> + </tr> + <tr> + <td class="tdl">10th 9 inches</td> + <td class="tdcl">2.0</td> + <td class="tdcl">2.1</td> + <td class="tdcl">—</td> + <td class="tdcl"> 5.1</td> + <td class="tdcl">0.6</td> + <td class="tdcl">10.7</td> + </tr> + <tr> + <td class="tdl">11th 9 inches</td> + <td class="tdcl">1.5</td> + <td class="tdcl">2.1</td> + <td class="tdcl">—</td> + <td class="tdcl"> 6.4</td> + <td class="tdcl">0.4</td> + <td class="tdcl">11.1</td> + </tr> + <tr> + <td class="tdlb">12th 9 inches</td> + <td class="tdclb">3.8</td> + <td class="tdclb">2.8</td> + <td class="tdclb">—</td> + <td class="tdclb"> 6.5</td> + <td class="tdclb">0.4</td> + <td class="tdclb">10.0</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE IV. (p. 124 and p. 131).</p> + +<p class="cen"><span class="smcap">Nitrogen as Nitrates in Wheat-soils variously manured, October 1881, +in Lb. per Acre</span> (<i>Rothamsted Soils</i>).</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Manuring"> + <tr> + <td class="tdl" width="5%"> </td> + <td class="tdl" width="48%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="11%"> </td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;">Excess</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Total</td> + <td class="tdcl">over</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl">1st 9</td> + <td class="tdcl">2nd 9</td> + <td class="tdcl">3rd 9</td> + <td class="tdcl">27</td> + <td class="tdcl">plots</td> + </tr> + <tr> + <td class="tdlb">Plot.</td> + <td class="tdclb">Manuring.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">3 and 4.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl"> 3</td> + <td class="tdll">No manure, 38 years</td> + <td class="tdcl"> 9.7</td> + <td class="tdcl"> 5.3</td> + <td class="tdcl"> 2.8</td> + <td class="tdcl">17.8</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl"> 4</td> + <td class="tdll">No manure, 30 years</td> + <td class="tdcl"> 9.2</td> + <td class="tdcl"> 4.0</td> + <td class="tdcl"> 1.8</td> + <td class="tdcl">15.0</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">16<i>a</i></td> + <td class="tdll">No manure, 17 years</td> + <td class="tdcl">10.6</td> + <td class="tdcl"> 5.0</td> + <td class="tdcl"> 2.3</td> + <td class="tdcl">17.9</td> + <td class="tdcl"> 1.5</td> + </tr> + <tr> + <td class="tdl"> 5<i>a</i></td> + <td class="tdll">Ash constituents, 30 years</td> + <td class="tdcl">12.6</td> + <td class="tdcl"> 7.1</td> + <td class="tdcl"> 4.6</td> + <td class="tdcl">24.3</td> + <td class="tdcl"> 7.9</td> + </tr> + <tr> + <td class="tdl">17<i>a</i></td> + <td class="tdll">Ash constituents, 1 year</td> + <td class="tdcl">10.3</td> + <td class="tdcl"> 7.5</td> + <td class="tdcl"> 3.4</td> + <td class="tdcl">21.2</td> + <td class="tdcl"> 4.8</td> + </tr> + <tr> + <td class="tdl"> 6<i>a</i></td> + <td class="tdll">Ash and ammonium salts, 200 lb.</td> + <td class="tdcl">16.5</td> + <td class="tdcl"> 7.5</td> + <td class="tdcl"> 4.7</td> + <td class="tdcl">28.7</td> + <td class="tdcl">12.3</td> + </tr> + <tr> + <td class="tdl"> 7<i>a</i></td> + <td class="tdll">Ash and ammonium salts, 400 lb.</td> + <td class="tdcl">22.8</td> + <td class="tdcl">11.3</td> + <td class="tdcl"> 5.7</td> + <td class="tdcl">39.8</td> + <td class="tdcl">23.4</td> + </tr> + <tr> + <td class="tdl"> 8<i>a</i></td> + <td class="tdll">Ash and ammonium salts, 600 lb.</td> + <td class="tdcl">21.1</td> + <td class="tdcl">13.9</td> + <td class="tdcl"> 7.8</td> + <td class="tdcl">42.8</td> + <td class="tdcl">26.4</td> + </tr> + <tr> + <td class="tdl"> 9<i>a</i></td> + <td class="tdll">Ash and sodium nitrate, 550 lb.</td> + <td class="tdcl">19.7</td> + <td class="tdcl">10.0</td> + <td class="tdcl"> 8.2</td> + <td class="tdcl">37.9</td> + <td class="tdcl">21.5</td> + </tr> + <tr> + <td class="tdl"> 9<i>b</i></td> + <td class="tdll">Sodium nitrate, 550 lb.</td> + <td class="tdcl">16.3</td> + <td class="tdcl">20.1</td> + <td class="tdcl">17.7</td> + <td class="tdcl">54.1</td> + <td class="tdcl">37.7</td> + </tr> + <tr> + <td class="tdl">10<i>a</i></td> + <td class="tdll">Ammonium salts, 400 lb.</td> + <td class="tdcl">14.2</td> + <td class="tdcl">11.9</td> + <td class="tdcl"> 7.3</td> + <td class="tdcl">33.4</td> + <td class="tdcl">17.0</td> + </tr> + <tr> + <td class="tdl" style="vertical-align: top;">11<i>a</i></td> + <td class="tdll">Superphosphate and ammonium salts, 400 lb.</td> + <td class="tdcly">17.9</td> + <td class="tdcly"> 9.3</td> + <td class="tdcly"> 3.6</td> + <td class="tdcly">30.8</td> + <td class="tdcly">14.4</td> + </tr> + <tr> + <td class="tdl">19</td> + <td class="tdll">Rape-cake, 1700 lb.</td> + <td class="tdcl">14.1</td> + <td class="tdcl">13.0</td> + <td class="tdcl"> 7.1</td> + <td class="tdcl">34.2</td> + <td class="tdcl">17.8</td> + </tr> + <tr> + <td class="tdlb"> 2</td> + <td class="tdllb">Farmyard manure, 14 tons—38years</td> + <td class="tdclb">30.0</td> + <td class="tdclb">15.4</td> + <td class="tdclb"> 6.8</td> + <td class="tdclb">52.2</td> + <td class="tdclb">35.8</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_158" id="Page_158">[Pg 158]</a></span><span class="smcap">Nitrogen as Nitrates in Barley-soils variously manured, March 1892, +in Lb. per Acre</span> (<i>Rothamsted Soils</i>).</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Nitrogen"> + <tr> + <td class="tdl" width="10%"> </td> + <td class="tdl" width="45%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + <td class="tdc" width="9%"> </td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;">Excess</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Total</td> + <td class="tdcl">over</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> 1st 9</td> + <td class="tdcl"> 2d 9</td> + <td class="tdcl"> 3d 9</td> + <td class="tdcl">27</td> + <td class="tdcl">plot</td> + </tr> + <tr> + <td class="tdcb" style="border-bottom: .5pt black solid;">Plot.</td> + <td class="tdclb">Manuring.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">inches.</td> + <td class="tdclb">10</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdc">10</td> + <td class="tdll">No manure</td> + <td class="tdcl"> 5.9</td> + <td class="tdcl"> 4.7</td> + <td class="tdcl"> 5.1</td> + <td class="tdcl">15.1</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdc">20-40</td> + <td class="tdll">Ash constituents (mean)</td> + <td class="tdcl"> 6.7</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl"> 6.4</td> + <td class="tdcl">20.1</td> + <td class="tdcl"> 4.4</td> + </tr> + <tr> + <td class="tdc">1A</td> + <td class="tdll">Ammonium salts, 200 lb.</td> + <td class="tdcl"> 6.1</td> + <td class="tdcl"> 8.3</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl">21.4</td> + <td class="tdcl"> 5.7</td> + </tr> + <tr> + <td class="tdc" style="vertical-align: top;">2A-4A</td> + <td class="tdll">Ammonium and ash constituents (mean)</td> + <td class="tdcly"> 7.7</td> + <td class="tdcly"> 7.8</td> + <td class="tdcly"> 7.6</td> + <td class="tdcly">23.1</td> + <td class="tdcly"> 7.4</td> + </tr> + <tr> + <td class="tdc">1AA</td> + <td class="tdll">Sodium nitrate, 275 lb.</td> + <td class="tdcl"> 9.7</td> + <td class="tdcl"> 6.8</td> + <td class="tdcl"> 9.0</td> + <td class="tdcl">25.5</td> + <td class="tdcl"> 9.8</td> + </tr> + <tr> + <td class="tdc" style="vertical-align: top;">2AA-4AA</td> + <td class="tdll">Sodium nitrate and ash constituents (mean)</td> + <td class="tdcly"> 8.3</td> + <td class="tdcly"> 7.4</td> + <td class="tdcly"> 7.5</td> + <td class="tdcly">23.2</td> + <td class="tdcly"> 7.5</td> + </tr> + <tr> + <td class="tdc">1C</td> + <td class="tdll">Rape-cake, 1000 lb.</td> + <td class="tdcl">10.6</td> + <td class="tdcl">13.7</td> + <td class="tdcl"> 7.9</td> + <td class="tdcl">32.2</td> + <td class="tdcl">16.5</td> + </tr> + <tr> + <td class="tdc" style="vertical-align: top;">2C-4C</td> + <td class="tdll">Rape-cake and ash constituents (mean)</td> + <td class="tdcly"> 8.8</td> + <td class="tdcly">11.9</td> + <td class="tdcly"> 8.7</td> + <td class="tdcly">29.4</td> + <td class="tdcly">13.7</td> + </tr> + <tr> + <td class="tdc" style="vertical-align: top;">7-1</td> + <td class="tdll">No manure, 10 years—formerly dung</td> + <td class="tdcly">14.8</td> + <td class="tdcly">11.8</td> + <td class="tdcly">10.9</td> + <td class="tdcly">37.5</td> + <td class="tdcly">21.8</td> + </tr> + <tr> + <td class="tdc" style="border-bottom: .5pt black solid;">7-2</td> + <td class="tdllb">Farmyard manure, 14 tons</td> + <td class="tdclb">18.6</td> + <td class="tdclb">14.6</td> + <td class="tdclb">10.9</td> + <td class="tdclb">44.1</td> + <td class="tdclb">28.4</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE V. (p. 134).</p> + +<p class="cen"><span class="smcap">Examples of Increase of Nitrogen in Rothamsted Soils laid down in +Pasture</span>.</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Age"> + <tr> + <td class="tdl" width="60%" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" width="20%" style="border-top: .5pt black solid;">Age of</td> + <td class="tdcl" width="20%" style="border-top: .5pt black solid;">Nitrogen in</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">pasture.</td> + <td class="tdclb">1st 9 inches.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Years.</td> + <td class="tdcl">Per cent.</td> + </tr> + <tr> + <td class="tdl">Arable land</td> + <td class="tdcl">—</td> + <td class="tdcl">0.140</td> + </tr> + <tr> + <td class="tdl">Barn-field pasture</td> + <td class="tdcl"> 8</td> + <td class="tdcl">0.151</td> + </tr> + <tr> + <td class="tdl">Apple-tree pasture</td> + <td class="tdcl">18</td> + <td class="tdcl">0.174</td> + </tr> + <tr> + <td class="tdl">Dr Gilbert's meadow</td> + <td class="tdcl">21</td> + <td class="tdcl">0.204</td> + </tr> + <tr> + <td class="tdlb">Dr Gilbert's meadow</td> + <td class="tdclb">30</td> + <td class="tdclb">0.241</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE VI. (p. 141).</p> + +<p>In connection with the loss by drainage of nitrogen in the form of +nitrates, it may be mentioned that the water of many of the famous +rivers contains large quantities of nitrates. Thus the water of the +Seine has been found to contain fifteen parts of nitrates per million of +water, and the Rhine eight parts per million. Some idea of what this +<span class='pagenum'><a name="Page_159" id="Page_159">[Pg 159]</a></span>amounts to per annum may be obtained by the statement that "the Rhine +discharges daily 220 tons of saltpetre into the ocean, the river Seine +270, and the Nile 1100 tons."—(Storer's Agric. Chem., vol. i. p. 318.)</p> + +<br /> +<br /> +<p class="cen">NOTE VII. (p. 142).</p> + +<p class="cen"><span class="smcap">Examples of Decrease of Nitrogen in Rothamsted Soils.</span></p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Age"> + <tr> + <td class="tdl" width="70%" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" width="30%" style="border-top: .5pt black solid;">Nitrogen in</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1st 9 inches.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Per cent.</td> + </tr> + <tr> + <td class="tdl">Old pasture</td> + <td class="tdcl">0.250</td> + </tr> + <tr> + <td class="tdl">Arable land in ordinary culture</td> + <td class="tdcl">0.140</td> + </tr> + <tr> + <td class="tdl">Wheat unmanured, 38 years</td> + <td class="tdcl">0.105</td> + </tr> + <tr> + <td class="tdl">Wheat and fallow unmanured, 31 years</td> + <td class="tdcl">0.096</td> + </tr> + <tr> + <td class="tdl">Barley unmanured, 30 years</td> + <td class="tdcl">0.093</td> + </tr> + <tr> + <td class="tdlb">Turnips unmanured, 25 years</td> + <td class="tdclb">0.085</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class="smcap">Manuring, Produce of Wheat, and Alteration in the Composition of the +Soil in Broadbalk Field, Rothamsted, from 1865 to 1881.</span></p> + +<div class="centered"> +<table border="0" width="90%" cellpadding="2" cellspacing="0" summary="Nitrogen"> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;" colspan="2">Average</td> + <td class="tdcl" style="border-top: .5pt black solid;" colspan="3">Nitrogen per acre</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="2">produce</td> + <td class="tdcl" colspan="3">in 1st 9 inches</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdclb" colspan="2">per acre.</td> + <td class="tdclb" colspan="3">of soil.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Gain or</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Manures per acre, annually</td> + <td class="tdcl">Dressed</td> + <td class="tdcl">Total</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">loss in</td> + </tr> + <tr> + <td class="tdlb">Plot.</td> + <td class="tdclb">applied, 16 years, 1865-81.</td> + <td class="tdclb">grain.</td> + <td class="tdclb">produce.</td> + <td class="tdclb">1865.</td> + <td class="tdclb">1881.</td> + <td class="tdclb">16 years.</td> + </tr> + <tr> + <td class="tdl" width="5%"> </td> + <td class="tdcl" width="48%"> </td> + <td class="tdcl" width="9%">bush.</td> + <td class="tdcl" width="9%">lb.</td> + <td class="tdcl" width="9%">lb.</td> + <td class="tdcl" width="9%">lb.</td> + <td class="tdcl" width="11%">lb.</td> + </tr> + <tr> + <td class="tdl"> 3</td> + <td class="tdll">Unmanured</td> + <td class="tdcl">11-7/8</td> + <td class="tdcl">1715</td> + <td class="tdcl">2507</td> + <td class="tdcl">2404</td> + <td class="tdcl">- 103</td> + </tr> + <tr> + <td class="tdl"> 5<i>a</i></td> + <td class="tdll">Mixed mineral manure</td> + <td class="tdcl">12-3/4</td> + <td class="tdcl">1963</td> + <td class="tdcl">2574</td> + <td class="tdcl">2328</td> + <td class="tdcl">- 246</td> + </tr> + <tr> + <td class="tdl">10<i>a</i></td> + <td class="tdll">Ammonium salts, 400 lb.</td> + <td class="tdcl">17-7/8</td> + <td class="tdcl">2881</td> + <td class="tdcl">2548</td> + <td class="tdcl">2471</td> + <td class="tdcl">- 77</td> + </tr> + <tr> + <td class="tdl">11<i>a</i></td> + <td class="tdll">Ammonium salts, with superphosphate</td> + <td class="tdcl">23-1/4</td> + <td class="tdcl">3856</td> + <td class="tdcl">2693</td> + <td class="tdcl">2676</td> + <td class="tdcl">- 17</td> + </tr> + <tr> + <td class="tdl" style="vertical-align: top;"> 7<i>a</i></td> + <td class="tdll">Ammonium salts, with mixed mineral manure</td> + <td class="tdcly">28 </td> + <td class="tdcly">4993</td> + <td class="tdcly">2829</td> + <td class="tdcly">2908</td> + <td class="tdcly">+ 79</td> + </tr> + <tr> + <td class="tdl" style="vertical-align: top;"> 9<i>a</i></td> + <td class="tdll">Nitrate of soda, 550 lb., and mixed mineral manure</td> + <td class="tdcly">36 </td> + <td class="tdcly">6949</td> + <td class="tdcly">2834</td> + <td class="tdcly">2883</td> + <td class="tdcly">+ 49</td> + </tr> + <tr> + <td class="tdl">16<i>a</i></td> + <td class="tdll">Unmanured*</td> + <td class="tdcl">13-1/2</td> + <td class="tdcl">2194</td> + <td class="tdcl">2907</td> + <td class="tdcl">2557</td> + <td class="tdcl">- 350</td> + </tr> + <tr> + <td class="tdlb"> 2</td> + <td class="tdllb">Farmyard manure, 14 tons</td> + <td class="tdclb">31-1/2</td> + <td class="tdclb">5356</td> + <td class="tdclb">4329</td> + <td class="tdclb">4502</td> + <td class="tdclb">+ 173</td> + </tr> + <tr> + <td class="tdl" colspan="7">* During 1852-64 received annually ammonium salts, 800 lb., + with mixed mineral manure, and yielded an average product of 39-1/2 bushels of grain and + 46-5/8 cwt. of straw.</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_160" id="Page_160">[Pg 160]</a></span>NOTE VIII. (p. 141).</p> + +<p class="cen"><span class="smcap">Amount of Drainage and Nitrogen as Nitrates in Drainage-water from +unmanured Bare Soil, 20 and 60 inches deep—average of Thirteen +Years.</span></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Rainfall"> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;" colspan="2"> </td> + <td class="tdclb" style="border-top: .5pt black solid;" colspan="4">Nitrogen per acre</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="2">Amount of</td> + <td class="tdcl" colspan="2">Per million</td> + <td class="tdcl" colspan="2"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdclb" colspan="2">drainage</td> + <td class="tdclb" colspan="2">of water</td> + <td class="tdclb" colspan="2">Per acre.</td> + </tr> + <tr> + <td class="tdl" width="16%"> </td> + <td class="tdcl" width="12%"> </td> + <td class="tdcl" width="12%">20-inch</td> + <td class="tdcl" width="12%">60-inch</td> + <td class="tdcl" width="12%">20-inch</td> + <td class="tdcl" width="12%">60-inch</td> + <td class="tdcl" width="12%">20-inch</td> + <td class="tdcl" width="12%">60-inch</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">Rainfall.</td> + <td class="tdclb">gauge.</td> + <td class="tdclb">gauge.</td> + <td class="tdclb">gauge.</td> + <td class="tdclb">gauge.</td> + <td class="tdclb">gauge.</td> + <td class="tdclb">gauge.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Inches.</td> + <td class="tdcl">Inches.</td> + <td class="tdcl">Inches.</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl">March</td> + <td class="tdcl"> 1.70</td> + <td class="tdcl"> 0.85</td> + <td class="tdcl"> 0.94</td> + <td class="tdcl"> 7.3</td> + <td class="tdcl"> 8.9</td> + <td class="tdcl"> 1.41</td> + <td class="tdcl"> 1.89</td> + </tr> + <tr> + <td class="tdl">April</td> + <td class="tdcl"> 2.25</td> + <td class="tdcl"> 0.72</td> + <td class="tdcl"> 0.79</td> + <td class="tdcl"> 8.3</td> + <td class="tdcl"> 9.0</td> + <td class="tdcl"> 1.35</td> + <td class="tdcl"> 1.61</td> + </tr> + <tr> + <td class="tdl">May</td> + <td class="tdcl"> 2.48</td> + <td class="tdcl"> 0.80</td> + <td class="tdcl"> 0.79</td> + <td class="tdcl"> 8.4</td> + <td class="tdcl"> 9.1</td> + <td class="tdcl"> 1.53</td> + <td class="tdcl"> 1.63</td> + </tr> + <tr> + <td class="tdl">June</td> + <td class="tdcl"> 2.59</td> + <td class="tdcl"> 0.78</td> + <td class="tdcl"> 0.78</td> + <td class="tdcl"> 9.2</td> + <td class="tdcl"> 9.1</td> + <td class="tdcl"> 1.62</td> + <td class="tdcl"> 1.60</td> + </tr> + <tr> + <td class="tdl">July</td> + <td class="tdcl"> 2.85</td> + <td class="tdcl"> 0.68</td> + <td class="tdcl"> 0.62</td> + <td class="tdcl">13.5</td> + <td class="tdcl">11.8</td> + <td class="tdcl"> 2.08</td> + <td class="tdcl"> 1.66</td> + </tr> + <tr> + <td class="tdl">August</td> + <td class="tdcl"> 2.69</td> + <td class="tdcl"> 0.84</td> + <td class="tdcl"> 0.76</td> + <td class="tdcl">15.1</td> + <td class="tdcl">13.3</td> + <td class="tdcl"> 2.87</td> + <td class="tdcl"> 2.28</td> + </tr> + <tr> + <td class="tdl">September</td> + <td class="tdcl"> 2.70</td> + <td class="tdcl"> 0.97</td> + <td class="tdcl"> 0.82</td> + <td class="tdcl">17.7</td> + <td class="tdcl">13.4</td> + <td class="tdcl"> 3.86</td> + <td class="tdcl"> 2.50</td> + </tr> + <tr> + <td class="tdl">October</td> + <td class="tdcl"> 3.12</td> + <td class="tdcl"> 1.86</td> + <td class="tdcl"> 1.68</td> + <td class="tdcl">13.8</td> + <td class="tdcl">11.9</td> + <td class="tdcl"> 5.83</td> + <td class="tdcl"> 4.53</td> + </tr> + <tr> + <td class="tdl">November</td> + <td class="tdcl"> 3.20</td> + <td class="tdcl"> 2.44</td> + <td class="tdcl"> 2.32</td> + <td class="tdcl">11.8</td> + <td class="tdcl">11.4</td> + <td class="tdcl"> 6.50</td> + <td class="tdcl"> 5.98</td> + </tr> + <tr> + <td class="tdl">December</td> + <td class="tdcl"> 2.34</td> + <td class="tdcl"> 1.88</td> + <td class="tdcl"> 1.88</td> + <td class="tdcl"> 9.5</td> + <td class="tdcl">10.6</td> + <td class="tdcl"> 4.06</td> + <td class="tdcl"> 4.51</td> + </tr> + <tr> + <td class="tdl">January</td> + <td class="tdcl"> 2.13</td> + <td class="tdcl"> 1.79</td> + <td class="tdcl"> 1.93</td> + <td class="tdcl"> 7.4</td> + <td class="tdcl"> 8.9</td> + <td class="tdcl"> 2.99</td> + <td class="tdcl"> 3.88</td> + </tr> + <tr> + <td class="tdl">February</td> + <td class="tdclb"> 2.16</td> + <td class="tdclb"> 1.84</td> + <td class="tdclb"> 1.74</td> + <td class="tdclb"> 7.7</td> + <td class="tdclb"> 9.1</td> + <td class="tdclb"> 3.19</td> + <td class="tdclb"> 3.57</td> + </tr> + <tr> + <td class="tdl">March-June</td> + <td class="tdcl"> 9.02</td> + <td class="tdcl"> 3.15</td> + <td class="tdcl"> 3.30</td> + <td class="tdcl"> 8.3</td> + <td class="tdcl"> 9.0</td> + <td class="tdcl"> 5.91</td> + <td class="tdcl"> 6.73</td> + </tr> + <tr> + <td class="tdl">July-September</td> + <td class="tdcl"> 8.24</td> + <td class="tdcl"> 2.49</td> + <td class="tdcl"> 2.20</td> + <td class="tdcl">15.6</td> + <td class="tdcl">13.0</td> + <td class="tdcl"> 8.81</td> + <td class="tdcl"> 6.44</td> + </tr> + <tr> + <td class="tdl">October-Feb.</td> + <td class="tdclb">12.95</td> + <td class="tdclb"> 9.81</td> + <td class="tdclb"> 9.55</td> + <td class="tdclb">10.2</td> + <td class="tdclb">10.4</td> + <td class="tdclb">22.57</td> + <td class="tdclb">22.47</td> + </tr> + <tr> + <td class="tdlb">Whole year</td> + <td class="tdclb">30.21</td> + <td class="tdclb">15.45</td> + <td class="tdclb">15.05</td> + <td class="tdclb">10.7</td> + <td class="tdclb">10.5</td> + <td class="tdclb">37.29</td> + <td class="tdclb">35.64</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_161" id="Page_161">[Pg 161]</a></span> +<br /> +<h2>CHAPTER IV.</h2> + +<h2>NITRIFICATION.</h2> +<br /> + +<p>The most important compound of nitrogen for the plant is <i>nitric acid</i>. +It is as nitrates that most plants absorb the nitrogen they require to +build up their tissue. In nature the nitrogen, present in the soil as +ammonia and different organic forms, is constantly being converted into +nitric acid. This conversion of nitrogen into nitrates, known as +<i>nitrification</i>, is a process of very great importance, and, as has been +already pointed out in the Introductory Chapter, is effected through the +agency of micro-organisms (ferments).<a name="FNanchor_97_97" id="FNanchor_97_97"></a><a href="#Footnote_97_97" class="fnanchor">[97]</a> The process of nitrification, +as well as the nature of the other changes taking place in the soil +between the various compounds of nitrogen, are as yet but most +imperfectly understood, but much light has been thrown on this most +interesting department of agricultural research during the last few +years; and it cannot be doubted that the increased attention which it is +<span class='pagenum'><a name="Page_162" id="Page_162">[Pg 162]</a></span>receiving from different investigators, both on the Continent and in +this country, will be fraught with most important results for practical +agriculture.</p> + +<br /> +<p class="cen"><i>Occurrence of Nitrates in the Soil.</i></p> + +<p>The occurrence of nitre,<a name="FNanchor_98_98" id="FNanchor_98_98"></a><a href="#Footnote_98_98" class="fnanchor">[98]</a> or potassium nitrate, in soils has been +long known, although it is only within the last few years that we have +obtained any precise knowledge with regard to the mode of its +production. While its amount in most soils, especially in this +country,<a name="FNanchor_99_99" id="FNanchor_99_99"></a><a href="#Footnote_99_99" class="fnanchor">[99]</a> is very minute, there are certain parts of the world where +nitrates are found in large quantities. The nitrate fields of Chili and +Peru are the chief natural sources of nitrates, and they are referred to +in the chapter on Nitrate of Soda. We have other parts of the world, +however (in China and India), where soils rich in nitre occur, and which +in the past have formed a source of the commercial article.<a name="FNanchor_100_100" id="FNanchor_100_100"></a><a href="#Footnote_100_100" class="fnanchor">[100]</a></p> + +<br /> +<p class="cen"><i>Nitre Soils of India.</i></p> + +<p>The most important of these nitre soils are those found in the +North-west of India, in the province of Bengal. In these districts the +soil is of a light porous texture, rich in lime, and situated at a +considerable height above water-level. They are the sites of old +<span class='pagenum'><a name="Page_163" id="Page_163">[Pg 163]</a></span>villages, and the nitre is found in the form of an efflorescence on the +surface of different parts of the soil. The occurrence of nitre under +such conditions is due, partly to the natural richness of the soil in +nitrogen, and partly to its artificial enrichment through receiving the +nitrogenous excrements of the inhabitants of the villages and their +cattle. The constant process of evaporation going on in such a warm +climate has the effect of inducing an upward tendency of the soil-water, +the result being a concentration of all the nitre the soil contains in +its surface layer. This goes on until a regular incrustation is formed, +and the soil is covered by a white deposit of nitre. Whenever this +becomes apparent, the surface portion of the soil is scraped off by the +<i>sorawallah</i>, or native manufacturer, and collected and treated for the +purpose of recovering, in a pure state, the saltpetre.</p> + +<br /> +<p class="cen"><i>Saltpetre Plantations.</i></p> + +<p>The large demand for saltpetre, larger than could be supplied by these +nitre soils, soon gave rise to the semi-artificial method of production, +formerly so largely practised in Switzerland, France, Germany, Sweden, +and in many other parts of the Continent, by means of the so-called +"nitre beds," "nitraries," or "saltpetre plantations." Previous to the +introduction of this method of manufacture, the demand for saltpetre for +gunpowder had become so great, that every source of nitre was eagerly +sought for. Thus, when it was <span class='pagenum'><a name="Page_164" id="Page_164">[Pg 164]</a></span>discovered that the earth from the floors +of byres, stables, and farmyards were particularly rich in nitre, and +when mixed with wood-ashes formed an important source of it, the right +to remove these in France was vested in the Government under the +Saltpetre Laws, which obtained till the French Revolution. This great +scarcity soon led, however, to a careful investigation being made into +the conditions under which potassium nitrate was formed in nitre +soils.<a name="FNanchor_101_101" id="FNanchor_101_101"></a><a href="#Footnote_101_101" class="fnanchor">[101]</a> These conditions, which included the presence of rich +nitrogenous matter, warmth, free aeration of the soil, and a certain +proportion of moisture, became, in the course of years, more and more +thoroughly understood, and the result was the institution of numerous +"saltpetre plantations." These generally consisted of heaps of mould, +rich in nitrogen, mixed with decomposing animal matter, rubbish of +various kinds, manurial substances, ashes, road-scrapings, and lime +salts.<a name="FNanchor_102_102" id="FNanchor_102_102"></a><a href="#Footnote_102_102" class="fnanchor">[102]</a> The heap was interlaid with brushwood, and was watered from +time to time with liquid manure from stables, consisting chiefly of +dilute urine. In forming the heap care was taken to keep the mass +porous, so <span class='pagenum'><a name="Page_165" id="Page_165">[Pg 165]</a></span>as to admit of the free access of air. The heap was further +protected from the rain by covering it with a roof. In course of time +considerable quantities of nitrates were developed, and the nitre was +occasionally collected by scraping it from the surface, where it became +concentrated just as in the nitre soils. In all cases, however, the +heaps, when considered rich enough in nitre, were treated from time to +time with water which, by subsequent evaporation, yielded the nitre in a +more or less pure condition.<a name="FNanchor_103_103" id="FNanchor_103_103"></a><a href="#Footnote_103_103" class="fnanchor">[103]</a></p> + +<p>This mode of obtaining nitre is no longer practised to any extent, since +it is now more conveniently obtained from the treatment of nitrate of +soda with potassium chloride.</p> + +<br /> +<p class="cen"><i>Cause of Nitrification.</i></p> + +<p>We have adverted to these nitre plantations as showing how the +conditions most favourable for the development of nitrification were +recognised long before anything was known as to the true nature of the +process. It was only in 1877 that the formation of nitrates in the soil +was proved to be due to the action <span class='pagenum'><a name="Page_166" id="Page_166">[Pg 166]</a></span>of micro-organic life,<a name="FNanchor_104_104" id="FNanchor_104_104"></a><a href="#Footnote_104_104" class="fnanchor">[104]</a> by the +two French chemists, Schloesing and Müntz, who discovered the fact when +carrying out experiments to see if the presence of humic matter was +essential to the purification of sewage by soil. In these experiments +sewage was made to filter slowly through a certain depth of soil (the +time occupied in this filtration being eight days). It was found that +nitrification of the sewage took place. By treating the soil with +chloroform<a name="FNanchor_105_105" id="FNanchor_105_105"></a><a href="#Footnote_105_105" class="fnanchor">[105]</a> it was found that it no longer possessed the power of +inducing the nitrification of the sewage. When, however, a small portion +of a nitrifying soil was added, the power was regained. From this it was +naturally inferred that nitrification was effected by some kind of +ferment. This conclusion was soon confirmed by subsequent experiments by +Warington at Rothamsted, who showed that the power of nitrification +could be communicated to media, which did not nitrify, by <span class='pagenum'><a name="Page_167" id="Page_167">[Pg 167]</a></span>simply +seeding them with a nitrifying substance, and that light was +unfavourable to the process. Since then the question has formed the +subject of a number of researches by Mr Warington at Rothamsted, as well +as by Schloesing and Müntz, Munro, Dehérain, P. F. Frankland, +Winogradsky, Gayon and Dupetit, Kellner, Plath, Pichard, Landolt, Leone, +and others. From these researches we have obtained the following +information with regard to the nature of the organisms concerned in this +process, and the conditions most favourable for their development.</p> + +<br /> +<p class="cen"><i>Ferments effecting Nitrification.</i></p> + +<p>The importance of isolating and studying them microscopically was +recognised at an early period in these researches. Messrs Schloesing and +Müntz were the first to attempt this. They reported that they had +successfully accomplished this, and described the organism as consisting +of very small, round, or slightly elongated corpuscles, occurring either +singly or two together. According, however, to the most recent +researches of Warington, Winogradsky, and P. F. Frankland, nitrification +is not effected by a <i>single</i> micro-organism, but by <i>two</i>, both of +which have been successfully isolated and studied.<a name="FNanchor_106_106" id="FNanchor_106_106"></a><a href="#Footnote_106_106" class="fnanchor">[106]</a> The first of +these to be discovered and isolated was the <i>nitrous</i> organism, which +effects the conversion of ammonia into nitrous <span class='pagenum'><a name="Page_168" id="Page_168">[Pg 168]</a></span>acid; the second, which +has only been lately isolated by Warington and Winogradsky, effects the +conversion of nitrous acid into nitric acid. Each of these ferments thus +has its distinctive function to perform in this most important process, +the nitric ferment being unable to act on ammonia, as the nitrous +ferment is unable to convert nitrites into nitrates. Both ferments occur +in enormous quantities in the soil, and seem to be influenced, so far as +is at present known, by the same conditions. Their action will thus +proceed together. Nearly all we know as yet on the subject of their +nature is with regard to the nitrous ferment.</p> + +<br /> +<p class="cen"><i>Appearance of Nitrous Organism.</i></p> + +<p>Mr Warington<a name="FNanchor_107_107" id="FNanchor_107_107"></a><a href="#Footnote_107_107" class="fnanchor">[107]</a> thus describes the appearance of the nitrous organism: +"As found in suspension in a freshly nitrified solution, it consists +largely of nearly spherical corpuscles, varying extremely in size. The +largest of these corpuscles barely reaches a diameter of 1/1000th of a +millimeter; and some are so minute as to be hardly discernible in +photographs, although shown there with a surface one million times +greater than their own. The larger ones are frequently not strictly +circular. These forms are universally present in nitrifying cultures. +The larger organisms are sometimes seen in the act of dividing."</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_169" id="Page_169">[Pg 169]</a></span><i>Nitric Organism.</i></p> + +<p>So far as at present known, the nitric organism is very similar in +appearance to the nitrous organism, so much so that it is difficult to +distinguish the one from the other. As the same conditions influence +their development, the process may be regarded as a whole.</p> + +<br /> +<p class="cen"><i>Difficulty in isolating them.</i></p> + +<p>A great difficulty has been experienced in the attempt to isolate these +micro-organisms for the purpose of studying their nature. This arises +from the fact that they refuse to grow on the ordinary solid cultivating +media used by bacteriologists. Winogradsky, however, has recently +succeeded in cultivating them in <i>a purely mineral</i> medium—viz., +<i>silica-jelly</i>.<a name="FNanchor_108_108" id="FNanchor_108_108"></a><a href="#Footnote_108_108" class="fnanchor">[108]</a></p> + +<br /> +<p class="cen"><i>Nitrifying Organisms do not require Organic Matter.</i></p> + +<p>The fact that they can develop in media destitute of organic matter, is +one of very great interest and importance to Vegetable Physiology. It +implies that they can derive their carbon from carbonic acid—a power +which it was believed was possessed by green plants alone among living +structures. For organisms destitute of chlorophyll, the source of their +protoplasmic carbon, it has been hitherto commonly believed, <span class='pagenum'><a name="Page_170" id="Page_170">[Pg 170]</a></span>must be +<i>organic matter</i> of some sort. While it would appear that the nitrifying +organisms can, when opportunity affords, feed upon organic matter, yet +it has been proved beyond doubt that they can also freely develop in +media entirely devoid of it, and are capable, under such circumstances, +of deriving their carbon from a purely mineral source.<a name="FNanchor_109_109" id="FNanchor_109_109"></a><a href="#Footnote_109_109" class="fnanchor">[109]</a> This fact, +which is subversive of what was believed to be a fundamental law of +Vegetable Physiology, is one of the most important of the many important +and interesting facts which these nitrification researches have +elicited.<a name="FNanchor_110_110" id="FNanchor_110_110"></a><a href="#Footnote_110_110" class="fnanchor">[110]</a></p> + +<br /> +<p class="cen"><span class="smcap">Conditions favourable for Nitrification.</span></p> + +<p>We may now proceed to discuss the conditions favourable for +nitrification.</p> + +<br /> +<p class="cen"><i>Presence of Food-constituents.</i></p> + +<p>Among these conditions the first is the presence of certain +food-constituents. To both animal and vegetable life alike a certain +amount of mineral food is absolutely necessary. Among these phosphoric +acid is one of the most important, and in the experiments on +nitrification it has been found that the nitrifying organisms will not +develop in any medium destitute <span class='pagenum'><a name="Page_171" id="Page_171">[Pg 171]</a></span>of it. That other mineral +food-constituents are necessary is highly probable, although the +influence of their absence on the development of the process has not +been similarly studied. Probably potash, magnesia, and lime salts are +necessary. In the cultivating solutions used in the experiments on the +subject, the mineral food-constituents added consisted of lime, +magnesia, and potash salts and phosphoric acid.<a name="FNanchor_111_111" id="FNanchor_111_111"></a><a href="#Footnote_111_111" class="fnanchor">[111]</a></p> + +<p>As we have seen above, the presence of organic matter is not necessary +for the process. In this respect these organisms are differentiated from +all other ferments hitherto discovered.</p> + +<br /> +<p class="cen"><i>Presence of a Salifiable Base.</i></p> + +<p>The presence of a sufficient quantity of a base in the soil with which +the nitric acid may combine, when it is formed, is another necessary +condition.<a name="FNanchor_112_112" id="FNanchor_112_112"></a><a href="#Footnote_112_112" class="fnanchor">[112]</a> The process only goes on in a slightly alkaline +solution. The substance which acts as this salifiable base is <i>lime</i>. +The presence of a sufficient quantity of carbonate of lime in the soil +will thus be seen to be of first-rate importance. This furnishes an +explanation of one of the many benefits conferred by <span class='pagenum'><a name="Page_172" id="Page_172">[Pg 172]</a></span>lime on soils. The +activity of nitrification in many soils may be hindered by the absence +of a sufficiency of lime salts, and in such cases most striking results +may follow the application of moderate dressings of chalk. The absence +of the nitrifying organisms in certain soils, such as peaty and forest +soils, may be thus accounted for. In such soils humic acids are present +and the requisite alkalinity is thus awanting.</p> + +<br /> +<p class="cen"><i>Only takes place in slightly Alkaline Solutions.</i></p> + +<p>But while a certain slight amount of alkalinity is necessary, this must +not exceed a certain strength, otherwise the process is retarded. This +is the reason why strong urine solutions do not nitrify. The amount of +carbonate of ammonia generated in them by putrefaction renders the +development of nitrification impossible by rendering the alkalinity of +the solution too great.<a name="FNanchor_113_113" id="FNanchor_113_113"></a><a href="#Footnote_113_113" class="fnanchor">[113]</a> The practical importance of this fact is +considerable, as it shows the importance of diluting urine very +considerably before applying it as a manure. Similarly, when large +quantities of lime, especially burnt lime, are applied to soils, the +result will be to arrest the action of nitrification for the time. The +presence of alkaline carbonates in the soil, unless in minute +quantities, is apt, therefore, to seriously interfere with the +process.<a name="FNanchor_114_114" id="FNanchor_114_114"></a><a href="#Footnote_114_114" class="fnanchor">[114]</a></p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_173" id="Page_173">[Pg 173]</a></span><i>Action of Gypsum on Nitrification.</i></p> + +<p>It has been found by Pichard that the action of certain mineral +sulphates is extremely favourable to the process, and among these +<i>gypsum</i>. Warington has carried out some experiments on the action of +gypsum in promoting nitrification. The reason of its favourable action +is probably because it neutralises the alkalinity of nitrifying +solutions. It thus permits the process to go on in unfavourable +conditions. Where, therefore, too great alkalinity exists for the +maximum development of nitrification, the best specific will be found to +be gypsum.<a name="FNanchor_115_115" id="FNanchor_115_115"></a><a href="#Footnote_115_115" class="fnanchor">[115]</a> The practical value of gypsum as an adjunct to certain +manurial substances, where nitrification is desired to be promoted as +rapidly as possible, such as sewage and farmyard manure, will thus at +once become apparent. So far as there is a proper degree of alkalinity +maintained, the presence of large quantities of saline matter does not +seem to interfere with the process.</p> + +<br /> +<p class="cen"><i>Presence of Oxygen.</i></p> + +<p>The nitrification bacteria belong, it would seem, to the aerobic<a name="FNanchor_116_116" id="FNanchor_116_116"></a><a href="#Footnote_116_116" class="fnanchor">[116]</a> +class of ferment—<i>i.e.</i>, they cannot develop without a free supply of +oxygen. Exclusion of the air <span class='pagenum'><a name="Page_174" id="Page_174">[Pg 174]</a></span>is sufficient to kill them, and in those +portions of the soil where access of air is not freely permitted, +nitrification will be found to be correspondingly feeble. Thus it has +been found in experiments with different portions of soils, that but +little signs of nitrification occur in the lower soil layers. According +to experiments by Schloesing on a moist soil, in atmospheres +respectively containing no oxygen and varying quantities of it, the +action of oxygen in promoting nitrification was strikingly demonstrated. +In an atmosphere of pure nitrogen, entirely devoid of oxygen, the +process no longer took place, but the nitrates already present in the +soil were reduced and free nitrogen was evolved. In an atmosphere, on +the other hand, containing 1.5 per cent of oxygen, a considerable amount +of nitrification took place; while in the presence of 6 per cent, +nitrification took place to double the extent. An addition of 10 to 15 +per cent again doubled the quantity. When the amount of moisture added +was increased, the effect of larger percentages of oxygen was found to +be less marked. The reason of this is that the oxygen probably acts as +dissolved oxygen; the addition of water meaning at the same time an +addition of available oxygen. This condition exemplifies the value of +tillage operations. The more thoroughly a soil is tilled the more +thoroughly will the aeration of its particles take place, and +consequently the more favourable will this necessary condition of +nitrification be rendered. The benefits <span class='pagenum'><a name="Page_175" id="Page_175">[Pg 175]</a></span>conferred on clayey soils by +tillage will in this respect be especially great.</p> + +<br /> +<p class="cen"><i>Temperature.</i></p> + +<p>Another of the conditions determining the rate at which nitrification +takes place, and one which is most important, is <i>Temperature</i>. +According to Schloesing and Müntz the temperature at which maximum +development takes place is 37° C.<a name="FNanchor_117_117" id="FNanchor_117_117"></a><a href="#Footnote_117_117" class="fnanchor">[117]</a> (99° F.), at which temperature it +is ten times as active as at 14° C. (57° F.) Below 5° C. (40° F.) the +action is extremely feeble. It is clearly appreciable at 12° C. (54° +F.), and from there up to 37° C. (99° F.) it rapidly increases. From 37° +C. (99° F.) to 55° C. (131° F.), at which temperature no nitrification +takes place, its activity decreases; at 45° C. (113° F.) it is less +active than at 15° C. (59° F.), and at 50° C. (122° F.) it is very +slight. These results by Schloesing and Müntz have not been exactly +confirmed by Warington. He has found that a considerable amount of +nitrification goes on at a temperature between 3° and 4° C. (37° and 39° +F.), while the highest temperature at which he has found it to take +place is considerably lower than 55° C. (131° F.) Thus he was unable to +start nitrification in a solution maintained at 40° C. (104° F.) It +would thus seem that the nitrifying ferments are able to <span class='pagenum'><a name="Page_176" id="Page_176">[Pg 176]</a></span>develop at +lower temperatures than most organisms; and although nitrification +entirely ceases during frost, yet in a climate such as our own there +must be a considerable proportion of the winter during which +nitrification is moderately active.</p> + +<br /> +<p class="cen"><i>Presence of a sufficient quantity of Moisture.</i></p> + +<p>The presence of moisture in a soil is another of the necessary +conditions of nitrification. It has been shown that it is at once +arrested, and indeed destroyed, by desiccation. Other conditions being +equal, and up to a certain extent, the more moisture a soil contains the +more rapid is the process. Too much water, however, is unfavourable, as +it is apt to exclude the free access of air, which, as we have just +shown, is so necessary, as well as to lower the temperature. During a +period of drought the rate at which nitrification takes place will, +therefore, be apt to be seriously diminished.</p> + +<br /> +<p class="cen"><i>Absence of strong Sunlight.</i></p> + +<p>It has been found that the process goes on much more actively in +darkness; indeed Warington has found in his experiments that +nitrification could be arrested by simply exposing the vessel in which +it was going on to the action of sunshine.</p> + +<br /> +<p class="cen"><i>Nitrifying Organisms destroyed by Poisons.</i></p> + +<p>It has already been pointed out that nitrification is arrested by the +action of antiseptics, such as <span class='pagenum'><a name="Page_177" id="Page_177">[Pg 177]</a></span>chloroform, bisulphide of carbon, and +carbolic acid. Another substance which has been found to have an +injurious action is ferrous sulphate or "copperas," a substance which is +apt to be present in badly drained soils, or soils in which there is +much actively putrefying organic matter. Maercker has found that in moor +soils containing ferrous sulphate, no nitrates, or mere traces of +nitrates, could be found. A substance such as gas-lime, unless submitted +to the action of the atmosphere for some time, would also have a bad +effect in checking nitrification, owing to the poisonous sulphur +compounds it contains. Common salt, it would seem, also arrests the +process; and this antiseptic property which salt exercises on +nitrification throws a certain amount of light on the nature of its +action when applied, as it is often done, along with artificial +nitrogenous manures.</p> + +<br /> +<p class="cen"><i>Denitrification.</i></p> + +<p>In connection with the process of nitrification, it is of interest to +notice that a process of an opposite nature may also take place in +soils—viz., <i>denitrification</i>—a process which consists in reducing the +nitrates to nitrites, nitrous oxide, or free nitrogen. That a reduction +of nitrates takes place in the decomposition of sewage with the +evolution of free nitrogen, was a fact first observed by the late Dr +Angus Smith in 1867; and the reduction of nitrates to nitrites, and +nitric and nitrous oxides in putrefactive changes has been <span class='pagenum'><a name="Page_178" id="Page_178">[Pg 178]</a></span>subsequently +noticed by different experimenters, who have further observed that such +reduction takes place in the case of putrefaction going on in the +presence of large quantities of water or where there is much organic +matter.</p> + +<br /> +<p class="cen"><i>Denitrification also effected by Bacteria.</i></p> + +<p>This change was supposed to be of a purely chemical nature, and it has +only been recently discovered that it is effected, like nitrification, +by means of bacteria. It has been surmised by some that the action of +denitrification may be effected by the same organisms that effect +nitrification, and that it depends on merely external conditions which +process goes on. There is no reason, however, to suppose that this is +so, and several of the denitrifying organisms have been identified.</p> + +<br /> +<p class="cen"><i>Conditions favourable for Denitrification.</i></p> + +<p>That it is a process that goes on to any extent in properly cultivated +soils is not to be supposed. The conditions which favour denitrification +are exactly the opposite of those which favour nitrification. It is only +when oxygen is excluded, or, which practically means the same thing, +when large quantities of organic matter are in active putrefaction, and +the supply of oxygen is therefore deficient, that denitrification takes +place. Schloesing, as we have already seen, found that in the case of a +moist soil, kept in an atmosphere <span class='pagenum'><a name="Page_179" id="Page_179">[Pg 179]</a></span>devoid of oxygen, a reduction of its +nitrates to free nitrogen took place.</p> + +<br /> +<p class="cen"><i>Takes place in water-logged Soils.</i></p> + +<p>The exclusion of oxygen from a soil may be effected by saturating the +soil with water; and Warington has found in experiments carried out in +an arable soil, by no means rich in organic matter, that complete +reduction of nitrates may be effected in this way. It would thus seem +that the process of denitrification will take place in water-logged +soils, or in the putrefaction of sewage matter in the presence of large +quantities of water. Whether this reduction will result in the +production of nitrites, nitrous oxide, or free nitrogen, depends on +different conditions. This process is one of great importance from an +economic point of view, as it reveals to us a source of loss which may +take place in the fermentation of manures. In the rotting of our +farmyard manure it is possible that the denitrifying organisms may be +more active than we have hitherto suspected, and that a considerable +loss of nitrogen may in this way be effected.</p> + +<br /> +<p class="cen"><i>Distribution of the Nitrifying Organisms in the Soil.</i></p> + +<p>The nitrifying organisms are probably chiefly confined to the soil, and +do not usually occur in rain or in the atmosphere. That, however, they +are found in spots which we might be inclined to think extremely +unlikely, is shown by some recent interesting researches <span class='pagenum'><a name="Page_180" id="Page_180">[Pg 180]</a></span>carried out by +Müntz, who discovered that the bare surfaces of felspathic, calcareous, +schistose, and other rocks at the summit of mountains in the Pyrenees, +Alps, and Vosges, yielded large numbers of them, and that they occurred +to a considerable depth in the cracks and fissures of the rocks. The +nitrifying organisms are also found in river-water, in sewage, and +well-waters.</p> + +<br /> +<p class="cen"><i>Depth down at which they occur.</i></p> + +<p>In Warington's earlier experiments, the conclusion he arrived at was +that the occurrence of the nitrifying organisms was almost entirely +limited to the superficial layers of the soil, and that they were seldom +to be met with much below a depth of 18 inches. His subsequent +experiments, however, considerably modified this conclusion, and showed +that nitrification may take place to a depth of at least 6 feet.<a name="FNanchor_118_118" id="FNanchor_118_118"></a><a href="#Footnote_118_118" class="fnanchor">[118]</a> +But although it may take place at this depth, it probably, as a general +rule, is limited to the surface-soil, as it is only there the conditions +for obtaining circulation of air are sufficiently favourable. A great +deal, of course, will depend on the nature of the soil—<i>i.e.</i>, as to +its <span class='pagenum'><a name="Page_181" id="Page_181">[Pg 181]</a></span>texture. In a clayey subsoil the principal hindrance to +nitrification will be the difficulty of obtaining sufficient aeration. +In clay soils it is probable, therefore, that nearly all the +nitrification goes on in the surface layer; in sandy soils it may take +place to a greater depth.<a name="FNanchor_119_119" id="FNanchor_119_119"></a><a href="#Footnote_119_119" class="fnanchor">[119]</a></p> + +<br /> +<p class="cen"><i>Action of Plant-roots in promoting Nitrification.</i></p> + +<p>In this connection the action of plant-roots in permitting a more +abundant access of air to the lower layers of the soil, and thus +promoting nitrification, is worth noticing. This has been observed in +the case of different crops. Thus the action of nitrification has been +found to be more marked in the lower layers of a soil on which a +leguminous crop was growing than on that on which a gramineous. "The +conditions which would favour nitrification in the subsoil are such as +would enable air to penetrate it, as artificial drainage, a dry season, +the growth of a luxuriant crop causing much evaporation of the water in +the soil. Such conditions, by removing the water that fills the pores of +the subsoil, will cause the air to penetrate more or less deeply and +render nitrification possible. Subsoil nitrification will thus be most +active in the drier periods of the year" (Warington).</p> + +<br /> +<p class="cen"><i>Nature of Substances capable of Nitrification.</i></p> + +<p>What kinds of nitrogenous substances are capable <span class='pagenum'><a name="Page_182" id="Page_182">[Pg 182]</a></span>of undergoing this +process of nitrification are not yet well known. The question is, of +course, one of great importance, as the rapidity with which a +nitrogenous body nitrifies will be an important factor in determining +its value as a manure. Unfortunately, on this subject we know, as yet, +very little. We are well aware that the nitrogen present in the humic +matter of the soil is readily nitrifiable. In the experiments on +nitrification the nitrogenous bodies used have been chiefly ammonia +salts, so that it is difficult to say whether, in the case of other +nitrogenous substances, micro-organic life of a different sort has not +also been active and has converted the nitrogen into ammonia, and +thereby prepared the way for the process of nitrification.</p> + +<p>That various manures, such as bones, horn, wool, and rape-cake are +readily nitrifiable, has been shown by experiment. Laboratory +experiments have also been carried out on such different nitrogenous +substances as ethylamine, thiocyanates, gelatin, urea, asparagin, and +albuminoids of milk. But in all these experiments, how far these bodies +have been directly acted upon by the nitrifying organisms, or how far +they have first undergone a preparatory change in which their nitrogen +has been first converted into ammonia, is impossible to say. It is at +least quite probable that all the organic forms of nitrogen have first +to be converted into ammonia ere they are nitrified.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_183" id="Page_183">[Pg 183]</a></span><i>Rate at which Nitrification takes place</i>.</p> + +<p>A question which is practically of no little importance is the rate at +which nitrification takes place. From what has been already said as to +the nature of the conditions favourable for the process, it will be at +once seen that this will depend on how far these conditions are present +in the soil. In point of fact the rate at which nitrification takes +place will vary very much in different soils. A greater difference, +however, in the rate at which it takes place, will be found even in the +same soils at different periods of the year. In this country, where the +most favourable temperature for its development is seldom reached, it +never goes on at the same rate as in tropical climates. One of the +causes of the greater fertility of tropical soils is due, doubtless, to +the very much longer duration of the period of nitrification, as well as +to its greater intensity. As, however, temperature is not the only +condition, and the presence of moisture is quite as necessary, it may be +that its development is seriously retarded in many tropical climates by +the extreme dryness of the soil during long periods.</p> + +<br /> +<p class="cen"><i>Takes place chiefly during the Summer Months</i>.</p> + +<p>Although in this climate, as has already been pointed out, nitrification +probably goes on during most of the winter months, owing to the fact +that the temperature of our soils is only occasionally <span class='pagenum'><a name="Page_184" id="Page_184">[Pg 184]</a></span>below the +minimum temperature at which the process takes place, yet there can be +little doubt that the great bulk of the soil-nitrates are produced +during a few months in summer. A fair conception of this amount is +afforded by the interesting experiments on the composition of +drainage-waters made at Rothamsted, which we shall have occasion to +refer to immediately. It may be pointed out, however, that it is not +always safe to take the amount of nitrates found in drainage-waters as +an infallible indication of this rate, for this amount will depend to a +certain extent on the amount of rainfall, and would be misleading in the +case of a long period of drought. On the whole, however, it furnishes us +with extremely useful data for the elucidation of this important +problem.</p> + +<br /> +<p class="cen"><i>Process goes on most quickly in Fallow Fields.</i></p> + +<p>It has been shown in the Rothamsted experiments that the process goes on +best in fields lying in bare fallow; and in this fact lies the +explanation of one of the many reasons why the practice of leaving +fields in bare fallow, so common in past times, and still practised in +the case of clay soils in some parts of the country, was so beneficial +to the land thus treated. But despite this fact, the practice of leaving +soils in bare fallow can scarcely be justified from this point of view, +as the loss of nitrates through the action of rain is very great in our +moist climate.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_185" id="Page_185">[Pg 185]</a></span><i>Laboratory Experiments on Rate of Nitrification.</i></p> + +<p>Several interesting experiments have been carried out with the object of +affording data for estimating the rate at which the process may go on in +our soils under certain conditions. An old experiment, carried out by +Boussingault, illustrates, in a general way, how rapid the process is +under favourable circumstances. A small portion of rich soil was placed +on a slab protected by a glass roof, and was moistened from time to time +with water. The amount of nitrate of potash formed under these +circumstances was estimated from time to time during a period of two +months. During the first month (August) the percentage was increased +from .01 to .18 (equal to about 5 cwt. of nitrate of potash per acre). +The increase during the second month (September) was very much +less,—indeed only about a seventh of the amount.<a name="FNanchor_120_120" id="FNanchor_120_120"></a><a href="#Footnote_120_120" class="fnanchor">[120]</a> The soil +experimented with was an extremely rich garden soil, and all the +conditions for nitrification were most favourable.</p> + +<p>Of recent experiments on the rate of nitrification, the most striking, +perhaps, are those by Schloesing. He mixed sulphate of ammonia with a +quantity of soil fairly rich in organic matter, and containing 19 per +cent of water. During the twelve days of active nitrification no less +than 56 parts of nitrogen per million of soil were nitrified per day. +Taking the soil to a depth of 9 inches, this would be equal to more +<span class='pagenum'><a name="Page_186" id="Page_186">[Pg 186]</a></span>than 1 cwt. per acre—an amount of nitrogen equal to that contained in +6 cwt. of commercial nitrate of soda. These experiments are interesting +as showing what is probably the maximum rate of nitrification under the +most favourable circumstances, and where there is an abundant supply of +easily nitrifiable nitrogen. That nitrification ever takes place in our +soils to this extent is not to be for a moment supposed.</p> + +<p>Warington, in his Rothamsted experiments, has found that the greatest +rate, working with ordinary arable soil (first 9 inches) from the +Rothamsted farm, was .588 parts per million of air-dried soil per +day—<i>i.e.</i>, 1.3 lb. per acre (equal to about 8 lb. of nitrate of soda). +Similar soil, when supplied with ammonia salts, showed nearly double +this quantity. Higher results were obtained by Lawes and Gilbert with +rich Manitoba soils, the average rate being .7 parts per million per +day.</p> + +<p>The last of these interesting laboratory experiments on the rate of +nitrification we shall refer to, are those by Dehérain. He experimented +with soils containing different amounts of nitrogen and moisture. With a +soil containing .16 per cent of nitrogen he obtained, during a period of +90 days, rates of nitrification varying from .71 to 1.09 per million +parts of soil. The maximum quantity was formed when the soil contained +25 per cent of moisture. On a soil considerably richer—viz.,.261 per +cent of nitrogen—a higher rate of nitrification took place—1.48 parts +per million. <span class='pagenum'><a name="Page_187" id="Page_187">[Pg 187]</a></span>The highest rate obtained in these experiments showed, +when calculated to pounds per acre, about 5-1/2, taking the soil to a +depth of 9 inches. When the soil was alternately dried and moistened the +process was most rapid.</p> + +<br /> +<p class="cen"><i>Portion of Soil-nitrogen more easily Nitrifiable than the rest.</i></p> + +<p>Lastly, it may be noticed that in the above-cited experiments, and +others of a similar kind, the process goes on most rapidly at first, and +steadily diminishes thereafter. This is due to the fact, that there is +generally a certain quantity of nitrogen in most soils in a more easily +nitrifiable condition than the rest, so that when this becomes oxidised +nitrification proceeds more slowly. It would further seem that the +nitrogen of the subsoil is less easily nitrified than that of the +surface-soil.</p> + +<br /> +<p class="cen"><i>Rate of Nitrification deduced from Field Experiments.</i></p> + +<p>While the above experiments throw much light on the question of the rate +at which nitrification may go on under different circumstances, the +results furnished by actual analyses of soils and their drainage-waters +are of still more practical value; and the Rothamsted experiments +fortunately furnish us with a number of these valuable results.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_188" id="Page_188">[Pg 188]</a></span><i>Quantity of Nitrates formed in the soils of Fallow Fields.</i></p> + +<p>These researches had to be carried out on soil taken from fields lying +in bare fallow; for no true estimate of the amount of nitrates formed +could have been obtained from <i>cropped</i> fields. In the first 27 inches +of soil of six separate fields, nitrate-nitrogen was found to vary from +36.3 lb. to 59.9 lb. per acre. In four of these fields the largest +proportion was found in the first 9 inches of soil; in the remaining +two, in the second 9 inches; while the third 9 inches in two fields +showed almost as large a proportion as the first 9 inches.<a name="FNanchor_121_121" id="FNanchor_121_121"></a><a href="#Footnote_121_121" class="fnanchor">[121]</a></p> + +<br /> +<p class="cen"><i>Position of Nitrates depends on Season.</i></p> + +<p>The position of nitrates in the soil depends largely on the season; for, +as has been already pointed out, their production is almost entirely +limited to the surface-soil, and it is only by being washed down in rain +that they find their way to the lower layers. A wet season, therefore, +has the effect of increasing their percentage in the lower soil-layers.</p> + +<br /> +<p class="cen"><i>Nitrates in Drainage-waters.</i></p> + +<p>As there is a certain proportion of nitrates that finds its way even +below the first 27 inches of soil, the above results do not show their +total production. <span class='pagenum'><a name="Page_189" id="Page_189">[Pg 189]</a></span>To accurately estimate this amount we must ascertain +the quantity escaping in drainage-water. Here, again, the Rothamsted +experiments furnish us with valuable data. The amount found in +drainage-waters of course naturally varies very much, and depends +largely on the rainfall; but taking an average of twelve years, this has +been found to amount to between 30 and 40 lb. per acre—an amount not so +very far short of that found in the first 27 inches of the soil itself. +This was from comparatively poor soil, it must be remembered, and a much +larger quantity would undoubtedly be produced in the case of richer +soils. Adding then the results together, we find that in soils like +those at Rothamsted, when in bare fallow, between 80 and 90 lb. of +nitrogen are converted into nitrates in some fourteen months' time—an +amount equal to about 5 cwt. of nitrate of soda. It is a fact of no +little practical significance that nearly one-half of this large +quantity is found in the drainage-water.</p> + +<br /> +<p class="cen"><i>Amount produced at Different Times of the Year.</i></p> + +<p>Some indication of the rate at which nitrification takes place during +the different months of the year is obtained from a study of the results +of the analyses of drainage-waters which we have just referred to. This, +however, it must be remembered, only furnishes us with a very +approximate indication. The month showing the greatest amount of +nitrates in the drainage-water must not necessarily be regarded as <span class='pagenum'><a name="Page_190" id="Page_190">[Pg 190]</a></span>that +during which nitrification has been most active, for the amount chiefly +depends on the rainfall. In illustration of this it will be found that +the drainage-water during the autumn and early winter months contains +most nitrates, not because nitrification is most active then, but +because the rainfall is greatest, and a large proportion of the nitrates +formed during the drier summer months is being only then washed from the +soil. The amount of nitrates in drainage-waters steadily diminishes from +autumn through the winter months, and is least in spring. The total +amount of nitrates found in the drainage-water is, therefore, not a safe +guide. What, however, does furnish us with a more reliable indication is +the <i>percentage</i> of nitrates in the drainage-water. Regarding the +results of the analyses of drainage-water (see Appendix) from this point +of view, it will be seen that this is greatest during the month of +September, and least during April.<a name="FNanchor_122_122" id="FNanchor_122_122"></a><a href="#Footnote_122_122" class="fnanchor">[122]</a></p> + +<br /> +<p class="cen"><i>Nitrification of Manures.</i></p> + +<p>A subject which has not yet been specially referred to, but which is of +great practical importance, is the nitrification of manurial substances. +It is unfortunate <span class='pagenum'><a name="Page_191" id="Page_191">[Pg 191]</a></span>that the amount of research hitherto devoted to this +important question has been slight, and that the knowledge we possess is +therefore very limited.</p> + +<br /> +<p class="cen"><i>Ammonia Salts most easily Nitrifiable.</i></p> + +<p>One fact, however, about which there can be little doubt, is that +nitrogen in the form of ammonia salts is, of all compounds of nitrogen, +the most easily nitrifiable. Indeed, as we have already indicated, it is +highly probable that the conversion of the different forms of organic +nitrogen into ammonia is an intermediate stage in the nitrification of +these bodies. At any rate it seems to be invariably the case that when a +mixture of nitrogen compounds, including ammonia salts, are allowed to +nitrify, the nitrogen in the form of ammonia is the first to become +nitrified.</p> + +<br /> +<p class="cen"><i>Sulphate of Ammonia most easily Nitrifiable Manure.</i></p> + +<p>It follows from this that sulphate of ammonia, the most common of +ammoniacal manures, is one of the most speedily nitrified when applied +to the soil. The rate at which the nitrification of this manure takes +place naturally varies according to the quantity applied, and other +circumstances, such as the nature of the soil and the weather, &c. That, +under favourable circumstances, the conversion of ammonia into nitrates +is very rapid, has been shown by a number of experiments. Dehérain has +found that when sulphate of ammonia was mixed with soil at the rate of 2 +cwt. <span class='pagenum'><a name="Page_192" id="Page_192">[Pg 192]</a></span>per acre, nitrification took place at the rate of 1/100th of its +nitrogen per day.</p> + +<br /> +<p class="cen"><i>Rate of Nitrification of other Manures.</i></p> + +<p>Of other nitrogenous manures, guano, it would seem, comes next to +sulphate of ammonia in the rate at which it becomes nitrified in the +soil; while next to guano stand green manures, dried blood, meat-meal, +&c. As we should expect, such a manure as shoddy is very slowly +nitrified. The rate at which the nitrogen compounds in farmyard manure +become nitrified, when incorporated with the soil, vary very much +according to circumstances. It goes on probably at a greater rate than +the ordinary nitrification of soil-nitrogen. It is a somewhat striking +fact that the effect of adding nitrate of soda to the soil may be at +first to check nitrification. That the addition of common salt, even in +small quantities, has this result, is at any rate certain. The presence +of salt to the extent of one-thousandth of the weight of the soil, has a +prejudicial effect.</p> + +<br /> +<p class="cen"><i>Soils best suited for Nitrification.</i></p> + +<p>To recapitulate, then, nitrification is effected through the agency of +micro-organisms, which are present to a greater or less extent in all +soils. It requires for its favourable development air, warmth, moisture, +absence of strong light, presence of a salifiable base—viz., carbonate +of lime—the presence of certain mineral <span class='pagenum'><a name="Page_193" id="Page_193">[Pg 193]</a></span>food-constituents, such as +phosphates, and a certain amount of alkalinity. It consequently takes +place to the least extent in barren sandy soils. Soils rich, light, well +ventilated, uniformly moist, warm, and chalky, are best suited for its +development. Other things being equal, it develops better in a +fine-grained soil than in a coarse-grained soil, because, in the case of +the former, aeration and uniform moistening of the soil are best +secured.</p> + +<br /> +<p class="cen"><i>Absence of Nitrification in Forest-soils.</i></p> + +<p>A point of considerable interest is the practical absence of the process +in forest-soils. The absence, or occurrence in the most minute traces, +of nitrates in forest-soils has been accounted for by the lowness of the +normal temperature of such soils and their extreme dryness. This latter +condition is accounted for by the enormous transpiration of water which +takes place through the trees, especially in summer-time, which is such +as to render the soil almost air-dry. Lastly, it may be accounted for by +the want of mineral food ingredients.</p> + +<br /> +<p class="cen"><i>Important Bearing of Nitrification on Agricultural Practice.</i></p> + +<p>Before concluding this chapter, it may be well to draw attention to the +important bearing which nitrification has on agricultural practice. The +light which our present knowledge—imperfect as it is—of this <span class='pagenum'><a name="Page_194" id="Page_194">[Pg 194]</a></span>most +interesting process throws on the theory of the rotation of crops is +very striking, for it shows how the adoption of a skilful rotation may +be made to prevent the loss of enormous quantities of the most valuable +of all our soil-constituents,—the one on the presence of which +fertility may be said most to depend—viz., nitrogen.</p> + +<br /> +<p class="cen"><i>Desirable to have Soil covered with Vegetation.</i></p> + +<p>The constant production of nitrates going on in the soil, the inability +of the soil to retain them, and the consequent risk of their being +removed in drainage, furnish a strong argument in favour of keeping our +soils as constantly covered with vegetation as possible.</p> + +<br /> +<p class="cen"><i>Permanent Pasture most Economical Condition of Soil.</i></p> + +<p>From the point of view of conservation of soil-nitrates, permanent +pasture may be said to be the most economical condition for the soil to +be in. In such a case the nitrates are assimilated as they are formed, +and, by being converted in the plant into organic nitrogen, they are at +once removed from all risk of loss. A consideration, therefore, of the +process of nitrification furnishes many arguments in favour of laying +down land in permanent pasture—a practice which of late years has been +increasingly followed in many parts of the country. As, however, it is +not possible or desirable to carry out this practice beyond certain +limits, the rotation which most nearly conforms to the <span class='pagenum'><a name="Page_195" id="Page_195">[Pg 195]</a></span>condition of +keeping the soil covered with vegetation, and most approximates in this +respect to permanent pasture, is most to be recommended.</p> + +<br /> +<p class="cen"><i>Nitrification and Rotation of Crops.</i></p> + +<p>The chief risk of loss of nitrates is in connection with a cereal crop +such as wheat. Where turnips follow wheat, there is a period during +which the soil is left uncovered, and during which most serious loss of +nitrates is apt to ensue. The risk of loss is enhanced by the fact that +the assimilation of nitrates by cereals ceases before the season of +their maximum production in the soil. The soil is then left bare of +vegetation during the autumn, which is the most critical period of all, +and the result must be serious loss. In order to minimise this loss, the +practice of growing catch-crops has been had recourse to. As, however, +this practice will be dealt with elsewhere, nothing further need here be +said.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_97_97" id="Footnote_97_97"></a><a href="#FNanchor_97_97"><span class="label">[97]</span></a> As the formation of nitrites is a stage in the process, +the term <i>nitrification</i> includes the formation of nitrites as well as +nitrates.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_98_98" id="Footnote_98_98"></a><a href="#FNanchor_98_98"><span class="label">[98]</span></a> Nitre seems to have been known as early as the thirteenth +century.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_99_99" id="Footnote_99_99"></a><a href="#FNanchor_99_99"><span class="label">[99]</span></a> Lawes and Gilbert, for example, have shown that in the +Rothamsted soils it only amounts to a few parts per million of soil.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_100_100" id="Footnote_100_100"></a><a href="#FNanchor_100_100"><span class="label">[100]</span></a> See Appendix, Note I., p. 196.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_101_101" id="Footnote_101_101"></a><a href="#FNanchor_101_101"><span class="label">[101]</span></a> The artificial production of nitre seems to have been +first effected by Glauber in the seventeenth century.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_102_102" id="Footnote_102_102"></a><a href="#FNanchor_102_102"><span class="label">[102]</span></a> The lime-rubbish from old buildings, especially those +parts which have come in contact with the earth, or plastering from the +walls of damp cellars, barns, stables, &c., have been found to be rich +in nitrate of lime, and, as has been long well known, constitute by +themselves a valuable manure. The formation of the nitrate of lime can +be accounted for by the contact of the lime with nitrogenous matter of +different kinds.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_103_103" id="Footnote_103_103"></a><a href="#FNanchor_103_103"><span class="label">[103]</span></a> As much of the nitric acid in this solution was present +as nitrate of lime, it was usually treated with a solution of potassium +carbonate, the result being the precipitation of the lime as carbonate, +pure saltpetre being left in solution, according to the following +equation—</p> + +<p class="noin">K<sub>2</sub>CO<sub>3</sub> + Ca(NO<sub>3</sub>)<sub>2</sub> = 2 KNO<sub>3</sub> + CaCO<sub>3</sub>. +</p> + +<p class="noin">Under the French mode of manufacture, the process was considered to have +developed satisfactorily when 1000 lb. of earth, at the expiration of +two years, yielded 5 lb. of nitre.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_104_104" id="Footnote_104_104"></a><a href="#FNanchor_104_104"><span class="label">[104]</span></a> Pasteur had already in 1862 expressed the opinion that +nitrification might probably be in some way connected with ferments. A. +Müller (see 'Journal of Chemical Society,' 1879, p. 249) was the first +to advance the opinion that nitrification was due to the action of a +ferment. This conclusion he was led to by the observation that while the +ammonia in sewage was converted into nitric acid, no change took place +in solutions of ammonia or urine prepared in the laboratory.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_105_105" id="Footnote_105_105"></a><a href="#FNanchor_105_105"><span class="label">[105]</span></a> Bisulphide of carbon and phenol (carbolic acid) have also +been experimented with in connection with their antiseptic action on +nitrification. In these experiments the former had a similar effect to +chloroform; the phenol, however, while hindering it did not entirely +suspend it, due probably to the difficulty of bringing the phenol vapour +into thorough contact with the soil-particles.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_106_106" id="Footnote_106_106"></a><a href="#FNanchor_106_106"><span class="label">[106]</span></a> Winogradsky has named the nitrous organism +<i>nitrosomonas</i>, and the nitric organism <i>nitrobaeter</i>.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_107_107" id="Footnote_107_107"></a><a href="#FNanchor_107_107"><span class="label">[107]</span></a> From a series of Lectures delivered by him in connection +with Lawes Agricultural Trust, in the United States.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_108_108" id="Footnote_108_108"></a><a href="#FNanchor_108_108"><span class="label">[108]</span></a> This silica-jelly consists of dialysed silicic acid, +ammonium sulphate, potassium phosphate, magnesium sulphate, calcium +chloride, and magnesium carbonate.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_109_109" id="Footnote_109_109"></a><a href="#FNanchor_109_109"><span class="label">[109]</span></a> This fact is all the more striking when we remember that +this decomposition of carbonic acid is best effected in the dark, since +light is prejudicial to nitrification.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_110_110" id="Footnote_110_110"></a><a href="#FNanchor_110_110"><span class="label">[110]</span></a> See Appendix, Note II., p. 196, and Note III., p. 197.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_111_111" id="Footnote_111_111"></a><a href="#FNanchor_111_111"><span class="label">[111]</span></a> See Appendix, Note V., p. 198.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_112_112" id="Footnote_112_112"></a><a href="#FNanchor_112_112"><span class="label">[112]</span></a> This is shown by the fact that nitrification will only +continue in a solution of carbonate of ammonia till one-half the ammonia +is nitrified. It then stops. The base, with which the nitrous acid +combines as it is formed, being at that stage entirely used up, +nitrification is no longer possible. With regard to urine solutions the +same is the case. Nitrification thus will only take place where there is +a sufficiency of base.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_113_113" id="Footnote_113_113"></a><a href="#FNanchor_113_113"><span class="label">[113]</span></a> See Appendix, Note IV., p. 197.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_114_114" id="Footnote_114_114"></a><a href="#FNanchor_114_114"><span class="label">[114]</span></a> It would seem that an alkalinity much exceeding four +parts of nitrogen per million is prejudicial to the process.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_115_115" id="Footnote_115_115"></a><a href="#FNanchor_115_115"><span class="label">[115]</span></a> According to Warington, solutions containing 50 per cent +of urine become nitrifiable when sufficient gypsum is added. The gypsum +neutralises the alkalinity of nitrifying solutions by converting the +alkaline ammonium carbonate into neutral ammonium sulphate, the calcium +carbonate being precipitated.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_116_116" id="Footnote_116_116"></a><a href="#FNanchor_116_116"><span class="label">[116]</span></a> See Chapter on Farmyard Manure.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_117_117" id="Footnote_117_117"></a><a href="#FNanchor_117_117"><span class="label">[117]</span></a> As practically illustrating this fact, a solution kept at +10° C. required ten days, while a solution kept at 30° C. required only +eight days for nitrification.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_118_118" id="Footnote_118_118"></a><a href="#FNanchor_118_118"><span class="label">[118]</span></a> In sixty-nine trials no failure to produce nitrification +by seeding with soil from a depth, of 2 feet was experienced. Similarly +in eleven trials only one failure took place with soil from a depth of 3 +feet. With clay soil from a depth of 6 feet success took place to the +extent of 50 per cent. No nitrification was obtained with clay from a +depth of 8 feet. Entire failure was experienced with chalk subsoil. The +process thus diminishes in activity the lower down we go.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_119_119" id="Footnote_119_119"></a><a href="#FNanchor_119_119"><span class="label">[119]</span></a> Koch has found that in soils he has examined few +organisms were found at a depth below 3 feet.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_120_120" id="Footnote_120_120"></a><a href="#FNanchor_120_120"><span class="label">[120]</span></a> See Appendix, Note VI., p. 198.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_121_121" id="Footnote_121_121"></a><a href="#FNanchor_121_121"><span class="label">[121]</span></a> For full analytical results see Appendix, Note VII., p. +198.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_122_122" id="Footnote_122_122"></a><a href="#FNanchor_122_122"><span class="label">[122]</span></a> We find the least amount in the month of April. In the +water, from a 20-and 60-inch gauge respectively, the amounts were 1.35 +lb. and 1.61 lb. per acre (rainfall 2.25 inches). From then on to +November the amount steadily increases. In the latter month it reaches +its maximum—viz., 6.50 lb. (20-inch gauge) and 5.98 lb. (60-inch gauge) +per acre (rainfall 2.30 inches). See Appendix to Chapter III., Note +VIII, p. 160.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_196" id="Page_196">[Pg 196]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER IV.</h2> +<br /> + +<p class="cen">NOTE I. (p. 162).</p> + +<p class="cen"><span class="smcap">Old Theories of Nitrification.</span></p> + +<p>According to the old theories, nitrification was regarded as a simple +case of the oxidation of nitrogen by the oxygen of the air, or by ozone. +The union of nitrogen and oxygen, however, probably takes place only at +very high temperatures, such as are formed during electric discharges. +It is needless to point out that the union of nitrogen and oxygen in +this way is not likely to occur in soils. According to other theories, +nitrification was effected by means of the oxidation of ammonia. +Ammonia, however, can only be oxidised to nitric acid by means of +certain powerful oxidising agents, such as ozone or hydrogen peroxide. +As, however, these substances are not found in the soil, it is much to +be doubted whether nitric acid is ever formed in the soil in this way. +It is possible, however, as held by some, that ferric oxide is capable +of inducing this conversion. On the whole, however, most evidence points +to the conclusion that all nitric acid produced in the soil is formed +through the agency of micro-organic life.</p> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 170).</p> + +<p>The important fact that nitrification can take place in solutions +practically devoid of organic matter, was first shown by Dr J. H. M. +Munro ('Chemical Society Journal,' August 1886, p. 561). It was further +corroborated by Warington and P. F. Frankland. Winogradsky, however, +<span class='pagenum'><a name="Page_197" id="Page_197">[Pg 197]</a></span>has carried out the most conclusive experiments on the subject. "He +prepared vessels and solutions, carefully purified from organic matter, +and these solutions he sowed with the nitrifying organism. Finding that +under these conditions the nitrifying organism increased enormously and +displayed its full vigour, he proceeded further to determine the amount +of carbonaceous organic matter formed in solutions after the +introduction of the organism. By making the nitrification intensive, he +was able to obtain considerable quantities of carbon from the nitrified +solutions by the process of wet combustion. In his third memoir he +publishes figures which apparently show a close relation between the +amount of nitrogen oxidised, and the amount of carbon assimilated; the +ratio is about 35:1."—See Bulletin of U.S. Department of Agriculture, +No. 8, containing Lectures on Rothamsted Experiments by R. Warington, +F.R.S., p. 50.</p> + +<br /> +<br /> +<p class="cen">NOTE III. (p. 170).</p> + +<p>The oxidising power of the micro-organisms of soil is not confined to +the oxidation of ammonia or of organic matter. Müntz has shown that soil +is capable of oxidising iodides to hypo-iodides and iodates, and +bromides to hypo-bromides and bromates. This is a very important result, +and seems to indicate that nitrification is part of a general oxidising +action, and that we must not assume that nitrites or nitrates are +produced because they are in themselves of advantage to the organism.</p> + +<br /> +<br /> +<p class="cen">NOTE IV. (p. 172).</p> + +<p>"When urine in different degrees of dilution was treated with soil, 1 +gram of soil being added to 100 c.c. of diluted urine, nitrification +commenced in the 1-per-cent solution in 11 days, in the 5-per-cent +solution in 20 days, in the 10-per-cent solution in 62 days, in the +12-per-cent solution in 90 days. The alkalinity of the last-named +solution when nitrification commenced was equal to 447 mgs. of <span class='pagenum'><a name="Page_198" id="Page_198">[Pg 198]</a></span>ammonia +per litre. A solution with an alkalinity of 500 mgs. of ammonia per +litre is apparently unnitrifiable."—American Department of Agriculture +Bulletin, Warington's Lectures on Rothamsted Experiments, p. 51.</p> + +<br /> +<br /> +<p class="cen">NOTE V. (p. 171).</p> + +<p>Professor P. F. Frankland in his experiments used the following +solutions:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="grms"> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdc" width="20%">grms.</td> + <td class="tdl" width ="55%">}</td> + </tr> + <tr> + <td class="tdl">NH<sub>4</sub>Cl</td> + <td class="tdc"> .5</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl">H<sub>3</sub>PO<sub>4</sub></td> + <td class="tdc"> .1</td> + <td class="tdl">} In 1000 c.c. of distilled water.</td> + </tr> + <tr> + <td class="tdl">MgSO<sub>4</sub></td> + <td class="tdc"> .02</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl">CaCl<sub>2</sub></td> + <td class="tdc"> .01</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl">CaCO<sub>3</sub></td> + <td class="tdc">5.00</td> + <td class="tdl">}</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE VI. (p. 185).</p> + +<p class="cen">Experiment by Boussingault on Rate of Nitrification.</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Percentage"> + <tr> + <td class="tdl" width="33%"> </td> + <td class="tdc" width="34%">Percentage of</td> + <td class="tdc" width ="33%"> </td> + </tr> + <tr> + <td class="tdl"> 1857.</td> + <td class="tdc">Nitrate of Potash.</td> + <td class="tdc">= lb. per acre.</td> + </tr> + <tr> + <td class="tdl">August 5</td> + <td class="tdc">.01</td> + <td class="tdc"> 34</td> + </tr> + <tr> + <td class="tdl">August 17</td> + <td class="tdc">.06</td> + <td class="tdc">222</td> + </tr> + <tr> + <td class="tdl">September 2</td> + <td class="tdc">.18</td> + <td class="tdc">634</td> + </tr> + <tr> + <td class="tdl">September 17</td> + <td class="tdc">.22</td> + <td class="tdc">760</td> + </tr> + <tr> + <td class="tdl">October 2</td> + <td class="tdc">.21</td> + <td class="tdc">728</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE VII. (p. 188).</p> + +<p class="cen"><span class="smcap">Nitrogen as Nitrates in Rothamsted Soils after bare fallow in Lb. +per Acre.</span></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="rotation"> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;">Alternate</td> + <td class="tdclb" colspan="3" style="border-top: .5pt black solid;">Four-course rotation.</td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Wheat</td> + <td class="tdcl">Super-</td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdc">Depth of</td> + <td class="tdcl">and</td> + <td class="tdcl">phosphate</td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl">Claycroft</td> + <td class="tdcl">Foster's</td> + </tr> + <tr> + <td class="tdc">Soil.</td> + <td class="tdclb">Fallow.</td> + <td class="tdclb">only.</td> + <td class="tdclb" colspan="2">Mixed Manure.</td> + <td class="tdclb">Field.</td> + <td class="tdclb">Field.</td> + </tr> + <tr> + <td class="tdlb" width="16%"> </td> + <td class="tdclb" width="14%">1878.</td> + <td class="tdclb" width="14%">1878.</td> + <td class="tdclb" width="14%">1878.</td> + <td class="tdclb" width="14%">1882.</td> + <td class="tdclb" width="14%">1881.</td> + <td class="tdclb" width="14%">1881.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl">1st 9 ins.</td> + <td class="tdcl">28.5</td> + <td class="tdcl">22.3</td> + <td class="tdcl">30.0</td> + <td class="tdcl">40.1</td> + <td class="tdcl">16.4</td> + <td class="tdcl">14.6</td> + </tr> + <tr> + <td class="tdl">2d 9 ins.</td> + <td class="tdcl"> 5.2</td> + <td class="tdcl">14.0</td> + <td class="tdcl">18.8</td> + <td class="tdcl">14.3</td> + <td class="tdcl">26.5</td> + <td class="tdcl">24.6</td> + </tr> + <tr> + <td class="tdlb">3d 9 ins.</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb"> 5.5</td> + <td class="tdclb">15.9</td> + <td class="tdclb">17.3</td> + </tr> + <tr> + <td class="tdlb">Total</td> + <td class="tdclb">33.7</td> + <td class="tdclb">36.3</td> + <td class="tdclb">48.8</td> + <td class="tdclb">59.9</td> + <td class="tdclb">58.8</td> + <td class="tdclb">56.5</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_199" id="Page_199">[Pg 199]</a></span> +<br /> +<h2>CHAPTER V.</h2> + +<h2>THE POSITION OF PHOSPHORIC ACID.</h2> +<br /> + +<p>We now come to consider the position of phosphoric acid in agriculture. +The question is, however, very much simpler in its nature than that of +nitrogen, and may be consequently discussed in a much shorter space.</p> + +<p>Most soils, as we have already had occasion to point out, are better +supplied with available ash-plant ingredients than available nitrogen +compounds. The quantity of phosphoric acid absorbed by the plant is also +less than that of nitrogen; and lastly, the different chemical compounds +of phosphoric acid occurring in the soil are not nearly so numerous as +those of nitrogen. Phosphoric acid, however, must be regarded as ranking +next to nitrogen in its importance as a soil-constituent.</p> + +<br /> +<p class="cen"><i>Occurrence of Phosphoric Acid in Nature.</i></p> + +<p>That phosphoric acid is of universal occurrence may be assumed from the +fact of the almost universal <span class='pagenum'><a name="Page_200" id="Page_200">[Pg 200]</a></span>occurrence of vegetable life on the +earth's surface; for plants are unable to grow without it. While thus of +practically universal occurrence, its amount in most soils is very +trifling. As the only source of it in the soil is from the +disintegration of the different rocks, a short description of its +occurrence in the mineral kingdom may first be given.</p> + +<br /> +<p class="cen"><i>Mineral Sources of Phosphoric Acid.</i></p> + +<p>It was first discovered in the mineral kingdom towards the close of last +century; but we have only of late years ascertained any exact knowledge +of its percentage in the different rocks out of which soils are formed. +This has been shown in many cases to be very trifling. It most +abundantly occurs as <i>apatite</i>, a mineral consisting of calcium +phosphate, with small quantities of calcium fluoride or calcium +chloride. This apatite, or phosphorite, is found in certain parts of the +world in large masses; but as a rule, it only occurs in small quantities +in most rocks. It may be stated that the older rocks are, as a general +rule, richer in it than those of more recent formation; and Daubeny has +drawn attention to this fact as furnishing a useful guide in estimating +the probable richness of a soil in phosphoric acid. The older, +therefore, a rock is, the richer it is likely to be in phosphoric acid.</p> + +<br /> +<p class="cen"><i>Apatite and Phosphorite.</i></p> + +<p>Of apatite there are a variety of kinds, which differ <span class='pagenum'><a name="Page_201" id="Page_201">[Pg 201]</a></span>in their +appearance as well as in their composition. It occurs chiefly in a +crystalline form, and is found sometimes in regular crystals, but it +also occurs in the amorphous form. In colour it may be white, yellow, +brown, red, green, grey, or blue. Two classes of apatite are found. The +first consists of calcium phosphate along with calcium fluoride; and in +other kinds of apatite the calcium fluoride is replaced by calcium +chloride. Phosphorite is another name for apatite, but is chiefly +applied to impure amorphous apatite. The percentage of phosphate of lime +in different kinds of apatite may be stated at from 70 to 90 per cent. +It occurs in very large quantities in Canada, the Canadian apatite being +very rich in phosphate of lime—80 to 90 per cent. In many parts of the +world it forms portions of mountain-masses, and is quarried, crushed, +and used for artificial manurial purposes. Further details of its +occurrence and chemical composition will be found in the Appendix.<a name="FNanchor_123_123" id="FNanchor_123_123"></a><a href="#Footnote_123_123" class="fnanchor">[123]</a></p> + +<br /> +<p class="cen"><i>Coprolites.</i></p> + +<p>In many parts of the world round nodules, largely consisting of +phosphate of lime, have been found, to which the name "coprolites" has +been given, on the assumption that they consisted of fossilised animal +excrements. These coprolites, or osteolites as they have also been +called, vary in the percentage of phosphate <span class='pagenum'><a name="Page_202" id="Page_202">[Pg 202]</a></span>of lime they contain. +Sometimes this amounts to 80 per cent, but as a rule it is very much +less. They also in the past have formed an important source of manure, +and will be referred to subsequently.</p> + +<br /> +<p class="cen"><i>Guano.</i></p> + +<p>We have, lastly, phosphoric acid occurring in large quantities in +guano-deposits, chiefly found on the west coast of South America. These +deposits, which have been of enormous importance as a source of +artificial manure, are of animal origin, and will be discussed at +considerable length in a chapter specially devoted to the subject; so +that we need do no more than mention them here.</p> + +<p>Phosphoric acid is also found in the form of phosphate of lime in +certain rocks as "layers" and "pockets."</p> + +<br /> +<p class="cen"><i>Universal Occurrence in Common Rocks.</i></p> + +<p>But while it is thus found in considerable quantities in various parts +of the world, and while no anxiety need thus be felt as to its abundance +for artificial manurial purposes, its occurrence in the common rocks, +which, as we have already pointed out, is practically universal, is in +many cases very minute.</p> + +<p>Fownes first identified it in the felspathic rocks in 1844; and since +then its percentage in granite, lava, trachyte, basalt, porphyry, +dolomite, gneiss, syenite, dolerite, diorite, and a number of other +rocks, has <span class='pagenum'><a name="Page_203" id="Page_203">[Pg 203]</a></span>been determined by numerous investigators. For analyses of +these rocks the reader is referred to the Appendix.<a name="FNanchor_124_124" id="FNanchor_124_124"></a><a href="#Footnote_124_124" class="fnanchor">[124]</a></p> + +<br /> +<p class="cen"><i>Occurrence in the Soil.</i></p> + +<p>That no soil is actually without phosphoric acid is highly probable, but +in many soils it is present in the merest traces, and even in fertile +soils it is rarely present in quantities over two-tenths of a per cent; +while half that amount may be taken as an average for most fairly +fertile soils. This would be about 3500 lb. per acre, calculating the +soil to a depth of 9 inches. In exceptional cases it has been found to +the extent of .3 per cent; and in the famous Russian <i>black earth</i> it +has been found to amount to .6 per cent.<a name="FNanchor_125_125" id="FNanchor_125_125"></a><a href="#Footnote_125_125" class="fnanchor">[125]</a> Like nitrogen, it is found +in greatest amount in the surface portion of the soil, but its amount at +different depths does not vary to the same extent as we have found to be +the case with nitrogen.</p> + +<br /> +<p class="cen"><i>Condition in which Phosphoric Acid is present in the Soil.</i></p> + +<p>Unlike nitrogen, phosphoric acid occurs in the soil almost entirely in +an <i>insoluble</i> form; and when applied to the soil in a soluble form, is +speedily converted into an insoluble condition. Its most <span class='pagenum'><a name="Page_204" id="Page_204">[Pg 204]</a></span>commonly +occurring forms are as phosphates of lime, iron, and alumina. These +facts are of importance to remember, as they explain why phosphoric acid +is not found in drainage-water in any quantity. It also shows how little +the risk of loss from drainage is in the application of artificial +phosphatic manure to the soil.</p> + +<br /> +<p class="cen"><i>Occurrence in Plants.</i></p> + +<p>The percentage of phosphoric acid in plants, like other +ash-constituents, is subject to considerable variation, and depends on a +variety of conditions, such as the state of the plant's development, +nature of soil, climate, season, treatment with manures, &c. All these +conditions have a certain influence. The different parts of the plant +have been found to contain it in different quantities. The tendency of +phosphoric acid is to travel up to the higher portions of the plant with +the progress of growth, and to finally accumulate in the seed. As +illustrating this, it may be mentioned that the inner portion of the +stalk of a ripe oat-plant has been found to contain only a seventeenth +of the amount of phosphoric acid found in the same portion of the stalk +of a young oat-plant. Similarly it may be mentioned that, while the ash +of the grain of rye and wheat contains nearly half their weight of +phosphoric acid, the percentage present in the ash of other parts of the +plant amounts only to from 5 to 16 per cent. The percentage of +phosphorus is greater in young plants than in mature plants; it <span class='pagenum'><a name="Page_205" id="Page_205">[Pg 205]</a></span>is +greater also in quickly developed plants than in slowly developed +plants.</p> + +<p>In the plant, phosphorus is present chiefly in the albuminoids; and its +absorption from the soil takes place in greatest quantity during the +period of maximum growth. In beans and peas an oil containing phosphorus +has been found.</p> + +<br /> +<p class="cen"><i>Occurrence in Animals.</i></p> + +<p>That phosphorus in different forms exists in animal tissue is well +known. It is found both in the brain and in the nerves, as well as in +nearly all the fluids of the animal body. It is, however, in the bones +that it is most abundant, the mineral portion of which is almost +entirely made of phosphate of lime,—a fact which renders bones such a +valuable artificial manure. Altogether, phosphoric acid occurs in the +animal body to the extent of 2.3 per cent. There is a point which we +shall have occasion to draw the student's attention to further on in +discussing the nature of farmyard manure—and that is, that the urine of +the common farm animals is practically devoid of phosphoric acid.</p> + +<br /> +<p class="cen"><i>Sources of Loss of Phosphoric Acid in Agriculture.</i></p> + +<p>As we have already done in the case of nitrogen, we may now attempt to +form some conception of the sources of loss and gain of phosphoric acid +in the soil. The sources of loss may be divided into natural and +<span class='pagenum'><a name="Page_206" id="Page_206">[Pg 206]</a></span>artificial. Of natural sources of loss we have only one, and that is +loss by drainage.</p> + +<br /> +<p class="cen"><i>Loss of Phosphoric Acid by Drainage.</i></p> + +<p>We have already seen that the condition in which phosphoric acid is +present in the soil is as insoluble phosphate. In drainage-water it +occurs in mere traces. Minute though the amount seems when stated as +percentage, and small as it appears beside the loss (from the same +source) of nitrogen, it is yet, if considered for large areas, +sufficiently striking. Thus it has been estimated that in the river Elbe +there is carried off by drainage from the fields of Bohemia 2-3/4 +million pounds (1200 tons) of phosphoric acid annually. This, it is +true, is a very trifling amount compared with the annual loss of +nitrogen from an equal area; but then it must be remembered, on the +other hand, the sources of gain to the soil of this ingredient are not +so numerous as are those of nitrogen, the only sources of phosphoric +acid being in the manure applied to the soil, and that coming from the +gradual disintegration of phosphatic minerals.</p> + +<br /> +<p class="cen"><i>Artificial Sources of Loss.</i></p> + +<p>The other sources of loss may be classed under the term artificial, and +are connected with agricultural practice. Just as we have seen that in +the case of nitrogen enormous quantities of that substance are +constantly being removed from the soil in those crops <span class='pagenum'><a name="Page_207" id="Page_207">[Pg 207]</a></span>which are +consumed off the farm, so, too, enormous quantities of phosphoric acid +are being removed in the same way. As illustrating this fact, it may be +mentioned that Professor Grandeau has recently estimated that in the +entire crops grown in France in one year there are about 298,200 tons of +phosphoric acid; while the amount returned in the dung of farm animals +is only 157,200, or only about one-half of what is removed in the crops, +leaving a deficit of 147,000 tons to be made good by the addition of +artificial phosphatic manures, if the fertility of the soil is to be +maintained. The same authority has calculated that in the bones of the +entire farm animals in France there is no less a quantity than 76,820 +tons of phosphoric acid.</p> + +<p>As an example of how, in many cases, the amount of phosphoric acid +removed from the farm is very often much greater than that restored, a +case quoted by Crusius may be cited. This was a farm of 670 acres +(Saxon) which had received only farmyard manure, and from which, during +sixteen years, 985.67 cwt. of phosphoric acid had been sold off in the +crops; while only 408.33 cwt. had been restored in the manure, leaving a +loss of 577.34 cwt.</p> + +<br /> +<p class="cen"><i>Phosphoric Acid removed in Milk.</i></p> + +<p>A further source of loss is the phosphoric acid removed in milk. In the +total annual yield of milk from one cow there may be from 11 to 12 lb. +of phosphoric acid.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_208" id="Page_208">[Pg 208]</a></span><i>Loss in Treatment of Farmyard Manure.</i></p> + +<p>The risks of loss of phosphoric acid in the treatment of farmyard manure +are not so great as in the case of nitrogen. There is, however, a +considerable risk, through want of proper precautions, of the soluble +phosphates being washed away by rain.</p> + +<br /> +<p class="cen"><i>Loss in Sewage.</i></p> + +<p>The loss of phosphoric acid incurred by the present method of sewage +disposal is not so large as the loss of nitrogen, inasmuch as the +quantity of phosphoric acid contained in human excreta is very much +less. Roughly speaking, it may be said to amount to a little less than +one-third of the nitrogen lost in this way.</p> + +<br /> +<p class="cen"><i>Sources of Artificial Gain of Phosphoric Acid.</i></p> + +<p>To balance these losses, we have a practically unlimited supply of +mineral phosphates for application as artificial manure, as well as +large quantities of other manures, many of them already mentioned in +connection with nitrogen, such as bones and guanos of all kinds. Quite +recently, also, a large source of phosphoric acid has been opened up in +the basic slag, a rich phosphatic bye-product obtained in considerable +quantity in steel-works from the basic process of steel manufacture. We +have also large quantities of phosphoric acid in the imported +feeding-stuffs, for statistics regarding which we would refer our +readers <span class='pagenum'><a name="Page_209" id="Page_209">[Pg 209]</a></span>to a previous chapter. The question of the actual amount +contained in these sources is not of the same interest as in the case of +nitrogen, and need not therefore detain us. We have sufficiently +indicated the importance of phosphoric acid in agriculture by the +statements above given. All further consideration of phosphoric acid +must therefore be deferred to future chapters.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_123_123" id="Footnote_123_123"></a><a href="#FNanchor_123_123"><span class="label">[123]</span></a> See Appendix, Note I., p. 210.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_124_124" id="Footnote_124_124"></a><a href="#FNanchor_124_124"><span class="label">[124]</span></a> See Appendix, Note II., p. 211.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_125_125" id="Footnote_125_125"></a><a href="#FNanchor_125_125"><span class="label">[125]</span></a> These results, as indeed all soil percentages, are +calculated on the soil in a dry condition.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_210" id="Page_210">[Pg 210]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER V.</h2> +<br /> + +<p class="cen">NOTE I. (p. 201).</p> + +<p class="cen"><span class="smcap">Composition of Apatite</span> (Voelcker).</p> + +<p class="cen">(<i>Krageröe, Norway.</i>)</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Lime"> + <tr> + <td class="tdl" width="85%">Lime</td> + <td class="tdr" width="15%">52.16</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdr">41.25</td> + </tr> + <tr> + <td class="tdl">Chlorine</td> + <td class="tdr">4.10</td> + </tr> + <tr> + <td class="tdl">Fluorine</td> + <td class="tdr">1.23</td> + </tr> + <tr> + <td class="tdl">Oxide of iron</td> + <td class="tdr">0.29</td> + </tr> + <tr> + <td class="tdl">Alumina</td> + <td class="tdr">0.38</td> + </tr> + <tr> + <td class="tdl">Potash and soda</td> + <td class="tdr">0.17</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdr" style="border-bottom: .5pt black solid">0.42</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr" style="border-bottom: .5pt black solid">100.0</td> + </tr> +</table> +</div> + +<br /> +<p>Apatite is found in considerable quantities in America, Germany, France, +Spain, Hungary, Norway, and Great Britain. According to Rose, apatite is +made up of three molecules of tribasic calcium phosphate (Ca(PO<sub>4</sub>)<sub>2</sub>), +combined with one molecule of calcium fluoride (Ca F<sub>2</sub>) or one molecule +of calcium chloride (CaCl<sub>2</sub>) respectively.</p> + +<p>The composition of the pure mineral should be—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Chlorapatite"> + <tr> + <td class="tdc" colspan="2"><i>Chlorapatite.</i></td> + </tr> + <tr> + <td class="tdl" width="80%"> </td> + <td class="tdr" width="20%">Per cent.</td> + </tr> + <tr> + <td class="tdl">Calcium phosphate</td> + <td class="tdr">89.38</td> + </tr> + <tr> + <td class="tdl">Calcium chloride</td> + <td class="tdr">10.62</td> + </tr> + <tr> + <td class="tdc" colspan="2"><i>Fluorapatite.</i></td> + </tr> + <tr> + <td class="tdl">Calcium phosphate</td> + <td class="tdr">92.31</td> + </tr> + <tr> + <td class="tdl">Calcium fluoride</td> + <td class="tdr"> 7.69</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_211" id="Page_211">[Pg 211]</a></span>NOTE II. (p. 203).</p> + +<p>The following is a list of the commoner rocks in which the percentage of +phosphoric acid has been determined. The results are taken from analyses +by Nesbit, Schramm, Bergemann, Rose, Dehérain, Handtke, Petersen, +Nessler, Muth, Fleischmann, Storer, and others:—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Felspar"> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="4">Per cent.</td> + </tr> + <tr> + <td class="tdl" width="48%">Felspar</td> + <td class="tdl" width="13%">1.7</td> + <td class="tdl" width="13%"> </td> + <td class="tdl" width="13%"> </td> + <td class="tdl" width="13%"> </td> + </tr> + <tr> + <td class="tdl">Granite</td> + <td class="tdl">0.09</td> + <td class="tdl">0.25</td> + <td class="tdl">0.58</td> + <td class="tdl">0.68</td> + </tr> + <tr> + <td class="tdl">Lava</td> + <td class="tdl">1.21</td> + <td class="tdl">1.8</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Trachyte</td> + <td class="tdl">0.30</td> + <td class="tdl">0.66</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Basalt</td> + <td class="tdl">0.50</td> + <td class="tdl">1.11</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Porphyry</td> + <td class="tdl">0.26</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Marl</td> + <td class="tdl">1.45</td> + <td class="tdl">2.31</td> + <td class="tdl">3.8</td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Calcareous stones</td> + <td class="tdl">0.064</td> + <td class="tdl">0.176</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Dolomite</td> + <td class="tdl">1.24</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Lias chalk</td> + <td class="tdl">1.39</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Gneiss</td> + <td class="tdl">0.18</td> + <td class="tdl">0.78</td> + <td class="tdl">1.51</td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Syenite</td> + <td class="tdl">0.10</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Dolerite</td> + <td class="tdl">0.3</td> + <td class="tdl">1.1</td> + <td class="tdl">1.2</td> + <td class="tdl"> </td> + </tr> + <tr> + <td class="tdl">Diorite</td> + <td class="tdl">0.5</td> + <td class="tdl">0.69</td> + <td class="tdl"> </td> + <td class="tdl"> </td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_212" id="Page_212">[Pg 212]</a></span> +<br /> +<h2>CHAPTER VI.</h2> + +<h2>THE POSITION OF POTASH IN AGRICULTURE.</h2> +<br /> + +<p>We may, lastly, consider the position of <i>potash</i> in agriculture, the +only ash ingredient of the plant, in addition to phosphoric acid, which +it is as a rule necessary to add as a manure.</p> + +<br /> +<p class="cen"><i>Potash of less Importance than Phosphoric Acid.</i></p> + +<p>It is of far less importance than phosphoric acid, from the fact of its +much more abundant occurrence in the soil, as well as from the fact that +under the ordinary conditions of agriculture, although removed from the +soil in considerable quantities by crops, it finds its way back again in +the farmyard manure; for it has not the same tendency to accumulate in +large quantities in the grain or seed as we have seen to be the case +with phosphoric acid. On this account straw contains a much greater +proportion of potash than phosphoric acid, and hence farmyard manure may +be regarded as fairly rich in potash.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_213" id="Page_213">[Pg 213]</a></span><i>Occurrence of Potash.</i></p> + +<p>Of all sources of potash the ocean must be regarded as the chief. +Millions and millions of tons are present in a state of solution in the +salt water of the ocean.<a name="FNanchor_126_126" id="FNanchor_126_126"></a><a href="#Footnote_126_126" class="fnanchor">[126]</a> Like phosphoric acid, its occurrence in +the rocks forming the earth's crust may be said to be practically +universal. Many of the commonly occurring rocks and minerals are +extremely rich in it, and by their disintegration furnish large +quantities to the soil. Some of these rocks contain it in such abundance +that they have been tried as potash manures; and were other more +valuable sources less available than they actually are, such a practice +might well be recommended. A volcanic rock known as <i>palagonite</i>, and +that most commonly occurring of all potash minerals—viz., felspar—have +both been experimented with in this way with considerable success.</p> + +<br /> +<p class="cen"><i>Felspar and other Potash Minerals.</i></p> + +<p>That felspar should prove, when finally ground, a valuable source of +potash, is not to be wondered at when we remember that some varieties of +it contain over 16 per cent. It has been calculated that a single cubic +foot of this mineral is sufficient to supply an oak-wood, covering a +surface of 26,910 square feet, <span class='pagenum'><a name="Page_214" id="Page_214">[Pg 214]</a></span>with potash for a period of no less than +five years.<a name="FNanchor_127_127" id="FNanchor_127_127"></a><a href="#Footnote_127_127" class="fnanchor">[127]</a> Some idea of the enormous <i>potential</i> fertility of a +soil containing felspar, so far as potash is concerned, may be obtained +from this statement. It must be remembered, however, that it is only the +orthoclase or potash felspars which contain large quantities of +potash—other felspathic rocks, such as oligoclase and labradorite, +being comparatively poor in it. Another commonly occurring mineral which +is rich in potash is mica, which has been found to contain from 5 to 13 +per cent. From this it follows that rocks which have large amounts of +these minerals in their composition—such as granite, for example, which +often contains 5 or 6 per cent of potash—form by their disintegration +soils rich in this ingredient.</p> + +<br /> +<p class="cen"><i>Stassfurt Salts.</i></p> + +<p>But in addition to the sources of potash already mentioned, it exists in +other forms in the earth's surface. Till within recent years it was +obtained for commercial purposes from the ashes of plants, which, as we +shall immediately see, are extremely rich in this ingredient; from salt +water—this source giving rise to the so-called "salt gardens" on the +coast of France; and from nitre soils in different parts of India, +referred to already at considerable length. Large mineral deposits, +however, have been recently discovered in the neighbourhood of Stassfurt +<span class='pagenum'><a name="Page_215" id="Page_215">[Pg 215]</a></span>in Germany, and have since their discovery supplied all the potash +required for manurial and other purposes. In these deposits (similar +ones have also been found at Kalusz in the Carpathian Mountains) there +are no less than five different minerals which contain potash. The form +in which it is present is as sulphate or chloride, so that it is readily +available for plants, and is of altogether very much greater value than +the form in which it occurs in the minerals already mentioned—viz., as +an insoluble silicate. Of the Stassfurt potash salts, the best known as +a manure is <i>kainit</i>, which contains about 32 per cent of sulphate of +potash. A list of the other potash minerals, with the particulars of +their composition and the percentage of potash they contain, will be +found in the Appendix.<a name="FNanchor_128_128" id="FNanchor_128_128"></a><a href="#Footnote_128_128" class="fnanchor">[128]</a></p> + +<br /> +<p class="cen"><i>Occurrence of Saltpetre.</i></p> + +<p>We have already had occasion, in Chapter IV., when discussing the +question of nitrification, to refer to the occurrence of nitrate of +potash in certain soils in India, which have formed a large source of +saltpetre used in commerce in the past.</p> + +<br /> +<p class="cen"><i>Occurrence of Potash in the Soil.</i></p> + +<p>From what has been said regarding the richness in potash of certain +commonly occurring minerals, such as felspar, it is only natural to +infer that most soils <span class='pagenum'><a name="Page_216" id="Page_216">[Pg 216]</a></span>must contain large quantities of this substance; +and this is so. The wonder is that potash, when applied as an artificial +manure, should have such a marked effect in increasing the fertility of +the soil, as is often the case. We must remember, however, that although +a soil may contain large quantities of potash, there may be a very small +percentage of the whole in an available form for the plant's needs.</p> + +<br /> +<p class="cen"><i>Potash chiefly in insoluble Condition in Soils.</i></p> + +<p>Potash occurs almost entirely in soils in a very insoluble form—viz., +combined with silica as a silicate of potash. It is only by the slow +disintegration of potash rocks that the potash they contain is set free +for plant uses. When it is applied as an artificial manure, on the other +hand, it is in a soluble form. In most soils the amount soluble in water +probably lies between .001 and .009 per cent; that soluble in dilute +acid solutions from .1 to .5 per cent; and that insoluble from .2 to 3.5 +per cent of the soil. It is highly probable that a certain quantity of +potash in the soil may exist in combination with humic and ulmic acids, +forming insoluble potassium humates and ulmates.</p> + +<br /> +<p class="cen"><i>Potash in Plants.</i></p> + +<p>Of all the ash ingredients of plants, potash is the most abundant, as it +forms on an average about 50 per cent of the total ash of plants—about +90 per cent of the alkalies. The ash of plants, indeed, was for long +<span class='pagenum'><a name="Page_217" id="Page_217">[Pg 217]</a></span>the chief source of potash. Certain plants remove very large quantities +from the soil. Of these roots, potatoes, the vine, the tobacco-plant, +and hops may be mentioned as examples. It is present in large quantities +in the grain of cereals, although, as we have already pointed out, not +to the same proportional extent as phosphoric acid. It is found in the +plant's extremities, such as twigs and new leaves, in greatest +abundance.<a name="FNanchor_129_129" id="FNanchor_129_129"></a><a href="#Footnote_129_129" class="fnanchor">[129]</a></p> + +<br /> +<p class="cen"><i>Potash in the Animal Tissue.</i></p> + +<p>It is also found in all parts of the animal body. Especially rich in +potash salts are the blood corpuscles, which contain about ten times the +amount contained in the serum. It is found in especial abundance in the +fleece of sheep, which may contain more potash than that in the whole +body of the sheep. Animal urine also contains potash in considerable +quantities.</p> + +<br /> +<p class="cen"><i>Sources of Loss of Potash.</i></p> + +<p>The capacity of the soil to retain soluble potash compounds, while not +equal to its capacity for retaining phosphoric acid, is yet very much in +excess of its capacity for retaining nitrates. The result is, that +potash is only found in comparatively minute traces in drainage +water.<a name="FNanchor_130_130" id="FNanchor_130_130"></a><a href="#Footnote_130_130" class="fnanchor">[130]</a> Taking the same example as we <span class='pagenum'><a name="Page_218" id="Page_218">[Pg 218]</a></span>already cited in illustration +of the loss of phosphoric acid, we find that the amount carried away in +the course of a year in the waters of the Elbe from Bohemia is +97,000,000 lb. (43,300 tons).</p> + +<br /> +<p class="cen"><i>Potash removed in Crops.</i></p> + +<p>The amount of potash removed by the different crops from the soil will +be considered in a subsequent chapter. We need only say here that the +class of crops which remove the largest quantity are the root crops, +especially mangels. The loss is least in the case of the cereals. The +amount of potash contained in the straw of cereals is about three times +the amount of that removed in the grain.</p> + +<br /> +<p class="cen"><i>Potash removed in Milk.</i></p> + +<p>Lastly, we may refer to the potash removed in milk, which, on an +average, may be taken at 10 lb. per annum for each cow.</p> + +<br /> +<p class="cen"><i>Potash Manures.</i></p> + +<p>Of potash manures the chief are the sulphate and the chloride, or, as it +is commercially known, the "muriate." The chief source of potash manures +are the Stassfurt deposits already referred to. Wood-ashes have also +been used in large quantities in the past (chiefly as a potash manure), +and in some parts <span class='pagenum'><a name="Page_219" id="Page_219">[Pg 219]</a></span>of the world are still used. A considerable source of +artificial potassic manures is the refuse manufacture of sugar-beet, +such a large industry in Germany. Potash occurs as a constituent of +certain other manures, more valuable for nitrogen and phosphoric acid, +such as guano and dried blood.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_126_126" id="Footnote_126_126"></a><a href="#FNanchor_126_126"><span class="label">[126]</span></a> According to Boguslawski and Dittmar, the total amount of +potash calculated as sulphate of potash in salt water equals 1141 × +10<sup>12</sup> tons.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_127_127" id="Footnote_127_127"></a><a href="#FNanchor_127_127"><span class="label">[127]</span></a> See Storer's 'Agricultural Chemistry,' vol. ii. p. 291.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_128_128" id="Footnote_128_128"></a><a href="#FNanchor_128_128"><span class="label">[128]</span></a> See Appendix, Note I., p. 220.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_129_129" id="Footnote_129_129"></a><a href="#FNanchor_129_129"><span class="label">[129]</span></a> See Appendix, Note II., p. 220.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_130_130" id="Footnote_130_130"></a><a href="#FNanchor_130_130"><span class="label">[130]</span></a> According to Way, different samples of drainage waters +were found only to contain from .00003 to .00031 per cent.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_220" id="Page_220">[Pg 220]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER VI.</h2> + +<br /> +<p class="cen">NOTE I. (p. 215).</p> + +<br /> +<p class="cen"><span class="smcap">Amount of Potash in Different Minerals.</span></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Felspars"> + <tr> + <td class="tdl">Felspars—</td> + <td class="tdr" colspan="5"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="5">Percentage of potash.</td> + </tr> + <tr> + <td class="tdl" width="40%"> (<i>a</i>) Orthoclase</td> + <td class="tdr" width="12%">{ 9.11</td> + <td class="tdr" width="12%">10.28</td> + <td class="tdr" width="12%">11.07</td> + <td class="tdr" width="12%">12.12</td> + <td class="tdr" width="12%">12.47</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr">{ 13.49</td> + <td class="tdr">14.35</td> + <td class="tdr">15.21</td> + <td class="tdr">16.7</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> (<i>b</i>)Oligoclase</td> + <td class="tdr">0.50</td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> (<i>c</i>)Labradorite</td> + <td class="tdr">0.33</td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl">Mica</td> + <td class="tdr">{ 5.61</td> + <td class="tdr">6.20</td> + <td class="tdr">7.23</td> + <td class="tdr">8.26</td> + <td class="tdr">8.95</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr">{ 9.00</td> + <td class="tdr">10.25</td> + <td class="tdr">12.40</td> + <td class="tdr">13.15</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl">Amphibole</td> + <td class="tdr">0.25</td> + <td class="tdr">2.96</td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl">Pyroxene</td> + <td class="tdr">0.34</td> + <td class="tdr">2.48</td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl">Leucite</td> + <td class="tdr">13.60</td> + <td class="tdr">18.61</td> + <td class="tdr"> </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl">Zeolites</td> + <td class="tdr">0.30</td> + <td class="tdr">9.35</td> + <td class="tdr">0.98</td> + <td class="tdr">4.93</td> + <td class="tdr"> </td> + </tr> +</table> +</div> + +<br /> +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Stassfurt"> + <tr> + <td class="tdl" width="80%">Stassfurt potash salts—</td> + <td class="tdr" width="20%">Per cent.</td> + </tr> + <tr> + <td class="tdl"> (<i>a</i>) Polyhallite, <i>potassium sulphate</i></td> + <td class="tdr">28</td> + </tr> + <tr> + <td class="tdl"> (<i>b</i>) Karnallite (KCl.MgCl<sub>2</sub>6H<sub>20</sub>), <i>potassium chloride</i></td> + <td class="tdr">24 to 27</td> + </tr> + <tr> + <td class="tdl"> (<i>c</i>) Sylvin, pure <i>potassium chloride</i>.</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> (<i>d</i>) Kainit (K<sub>2</sub>SO<sub>4</sub>MgSO<sub>4</sub>MgCl<sub>2</sub>6H<sub>2</sub>O), <i>potassium + sulphate</i></td> + <td class="tdr">32</td> + </tr> + <tr> + <td class="tdl"> (<i>e</i>) Schoenite (K<sub>2</sub>SO<sub>4</sub>, MgSO<sub>4</sub>, 6H<sub>2</sub>O), pure + <i>potassium</i> + <span style="padding-left: 2.5em;"><i>magnesium sulphate</i>.</span></td> + <td class="tdr"> </td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 217).</p> + +<p>The quantity of potash obtainable from various plants in the manufacture +of potashes on a large scale is illustrated by the following statements. +1000 lb. of the following vegetative products yield the following +quantities of potashes:—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Stassfurt"> + <tr> + <td class="tdl" width="75%"> </td> + <td class="tdl" width="25%"> lb.</td> + </tr> + <tr> + <td class="tdl">Old spruce-wood</td> + <td class="tdl"> 1/2</td> + </tr> + <tr> + <td class="tdl">Old poplar-wood</td> + <td class="tdl"> 3/4</td> + </tr> + <tr> + <td class="tdl">Old oak-wood</td> + <td class="tdl"> 1-1/2</td> + </tr> + <tr> + <td class="tdl">Corn-stalks</td> + <td class="tdl">17-1/2</td> + </tr> + <tr> + <td class="tdl">Bean-stalks</td> + <td class="tdl">20</td> + </tr> + <tr> + <td class="tdl">Grape-vine</td> + <td class="tdl">40</td> + </tr> + <tr> + <td class="tdl" colspan="2">(Storer, 'Agricultural Chemistry,' vol. ii. p. 108.)</td> + <td class="tdl"></td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr style="width: 65%;" /><span class='pagenum'><a name="Page_221" id="Page_221">[Pg 221]</a></span> +<br /> +<h2>PART III.</h2> + +<h2>MANURES</h2> +<br /> +<br /> +<span class='pagenum'><a name="Page_222" id="Page_222">[Pg 222]</a></span> +<br /> +<br /> + +<hr /><span class='pagenum'><a name="Page_223" id="Page_223">[Pg 223]</a></span> +<br /> +<h2>CHAPTER VII.</h2> + +<h2>FARMYARD MANURE</h2> +<br /> + +<p>Farmyard manure is the oldest, and is still undoubtedly the most +popular, of all manures. It has stood the test of long experience, and +has proved its position as one of the most important of all our +fertilisers. It is highly desirable, therefore, to make a somewhat +detailed examination of its composition, and to see on what the +variation in this depends; and, finally, to examine into the mode of its +action as a manure.</p> + +<p>That it should prove a valuable manure is scarcely to be wondered at, as +it is originally formed from vegetable substance, and as it therefore +contains all the elements present in the plant itself.</p> + +<p>Its composition is very variable, and probably no two samples would +yield exactly similar analyses. In this fact lies one of the chief +difficulties of the treatment of the subject, and all statements <span class='pagenum'><a name="Page_224" id="Page_224">[Pg 224]</a></span>made +in the following pages as to its chemical composition must be taken as +only <i>approximate</i>.</p> + +<p>We may divide its constituents into three classes.</p> + +<p>1. That portion due to <i>solid excreta</i>.</p> + +<p>2. The liquid portion, largely made up of dilute <i>urine</i>.</p> + +<p>3. The <i>straw</i>, or other material, which is used as litter.</p> + +<p>The composition of the manure will vary according to the proportion in +which these three substances are present, as well as according to the +composition of the substances themselves. It will consequently tend to a +clearer apprehension of the subject if we first examine briefly the +chemical composition of the solid excreta and urine of the farm animals.</p> + +<br /> +<p class="cen">1. <i>Solid Excreta.</i></p> + +<p>The manurial value of the solid excreta of animals—<i>i.e.</i>, the +proportion they contain of <i>nitrogen</i>, <i>phosphoric acid</i>, and +<i>potash</i>—depends on a variety of conditions.</p> + +<p>The solid excreta of horses, sheep, cows, and pigs, are well known to +possess different properties, as well as to vary in their composition.</p> + +<p>What, however, has a still greater influence is the nature of the food. +This is owing to the fact that the solid excreta are made up of +undigested food. We can scarcely expect the same quality of solid +excreta from an animal fed on poor diet as from an animal fed on very +much richer diet. Again, the <span class='pagenum'><a name="Page_225" id="Page_225">[Pg 225]</a></span>percentage of the food voided in the solid +excreta varies in the case of different animals.<a name="FNanchor_131_131" id="FNanchor_131_131"></a><a href="#Footnote_131_131" class="fnanchor">[131]</a></p> + +<p>Another consideration which enters into the question is the age, as well +as the treatment, of the animal. A young animal, during the period of +its growth, absorbs from its food into its system a larger quantity of +the three fertilising substances, nitrogen, phosphoric acid, and potash, +than is the case with an adult animal whose weight is neither increasing +nor diminishing. A working horse, similarly, will return more of the +nitrogen, phosphates, and potash in its dung than one not at work and +which is permitted to gain in weight. The nature of the composition of +the solid excreta, therefore, will depend on the nature of the <i>food</i>, +<i>age</i>, <i>breed</i>, <i>condition</i>, and <i>treatment</i> of the animal.</p> + +<p>Let us now investigate shortly the influence of the above +considerations. The solid excrements of the common farm animals are +generally distinguished from one another according to the rate at which +they decompose or ferment on keeping. Thus horse-dung is generally known +as a "hot" dung; while cow-dung, on the other hand, is known as "cool." +Why this should be so is not absolutely clear. Probably it is owing to +the fact that the former contains less water, as well as to the fact +(and this probably has more to do with it) that it contains a larger +percentage of fertilising matter, especially nitrogen, thus affording +conditions <span class='pagenum'><a name="Page_226" id="Page_226">[Pg 226]</a></span>more favourable for rapid fermentation than in the case of +the more moist and less rich cow-dung.</p> + +<p>The composition of the solid excreta of various animals, as we have just +said, varies with the nature of their food; so that it is impossible to +take any analyses as absolutely representing its composition. It may be +interesting, however, to compare the analyses of samples of horse-dung +with those of some other of the commoner farm animals, with a view to +obtaining an <i>approximate</i> idea of this difference.</p> + +<p>Stoeckhardt has found that in 1000 lb. of the fresh solid excreta of the +animals below mentioned, there were the following amounts of <i>nitrogen</i>, +<i>phosphoric acid</i>, and <i>alkalies</i>:—</p> + +<br /> +<div class="centered"> +<table border="0" width="90%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"><span class="smcap">Phosphoric</span></td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl" colspan="2"><span class="smcap">Water.</span></td> + <td class="tdclb" colspan="2"><span class="smcap">Nitrogen.</span></td> + <td class="tdclb" colspan="2"><span class="smcap">Acid.</span></td> + <td class="tdclb" colspan="2"><span class="smcap">Alkalies.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Reduced</td> + <td class="tdcl"> </td> + <td class="tdcl">Reduced</td> + <td class="tdcl"> </td> + <td class="tdcl">Reduced</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb" colspan="2"> </td> + <td class="tdclb"> </td> + <td class="tdclb">to</td> + <td class="tdclb"> </td> + <td class="tdclb">to</td> + <td class="tdclb"> </td> + <td class="tdclb">to</td> + </tr> + <tr> + <td class="tdl" width="38%"> </td> + <td class="tdcl" width="5%">lb.</td> + <td class="tdcl" width="12%">per cent.</td> + <td class="tdcl" width="5%">lb.</td> + <td class="tdcl" width="10%">per cent.</td> + <td class="tdcl" width="5%">lb.</td> + <td class="tdcl" width="10%">per cent.</td> + <td class="tdcl" width="5%">lb.</td> + <td class="tdcl" width="10%">per cent.</td> + </tr> + <tr> + <td class="tdl">Horses (winter food)</td> + <td class="tdcl">760</td> + <td class="tdcl">76</td> + <td class="tdcl">5 </td> + <td class="tdcl">.50</td> + <td class="tdcl">3-1/2</td> + <td class="tdcl">.35</td> + <td class="tdcl">3</td> + <td class="tdcl">.30</td> + </tr> + <tr> + <td class="tdl">Cows (winter food)</td> + <td class="tdcl">840</td> + <td class="tdcl">84</td> + <td class="tdcl">3 </td> + <td class="tdcl">.30</td> + <td class="tdcl">2-1/2</td> + <td class="tdcl">.25</td> + <td class="tdcl">1</td> + <td class="tdcl">.10</td> + </tr> + <tr> + <td class="tdl">Swine (winter food)</td> + <td class="tdcl">800</td> + <td class="tdcl">80</td> + <td class="tdcl">6 </td> + <td class="tdcl">.60</td> + <td class="tdcl">4-1/2</td> + <td class="tdcl">.45</td> + <td class="tdcl">5</td> + <td class="tdcl">.50</td> + </tr> + <tr> + <td class="tdlb">Sheep (2 lb. hay per diem)</td> + <td class="tdclb">580</td> + <td class="tdclb">58</td> + <td class="tdclb">7-1/2</td> + <td class="tdclb">.75</td> + <td class="tdclb">6 </td> + <td class="tdclb">.6 </td> + <td class="tdclb">3</td> + <td class="tdclb">.30</td> + </tr> +</table> +</div> + +<br /> +<p>From the above table it will be seen that the sheep's dung contains the +least percentage of <i>water</i>, and is richer in <i>nitrogen</i> and <i>phosphoric +acid</i> than any of the other three. The percentage of alkalies, of which +the most important is potash, is, however, not so large. <span class='pagenum'><a name="Page_227" id="Page_227">[Pg 227]</a></span>This may be +accounted for by the interesting and well-known fact that a large +percentage of potash is to be found in the wool of sheep.<a name="FNanchor_132_132" id="FNanchor_132_132"></a><a href="#Footnote_132_132" class="fnanchor">[132]</a></p> + +<p>The solid excrement of the sheep is, therefore, weight for weight, the +most valuable as a manure, as it contains more nitrogen and phosphates +than the others, and at the same time is much drier.</p> + +<p>If, however, we compare the composition of the solid excreta in a dry +state, we shall find that the following are the results (basing our +calculation on Stoeckhardt's analyses):—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="per cent"> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdc" width="25%"> </td> + <td class="tdc" width="25%">Phosphoric</td> + <td class="tdc" width="25%"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Nitrogen,</td> + <td class="tdc">acid,</td> + <td class="tdc">Alkalies,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + </tr> + <tr> + <td class="tdl">Horse</td> + <td class="tdc">2.08</td> + <td class="tdc">1.45</td> + <td class="tdc">1.25</td> + </tr> + <tr> + <td class="tdl">Cow</td> + <td class="tdc">1.87</td> + <td class="tdc">1.56</td> + <td class="tdc">0.62</td> + </tr> + <tr> + <td class="tdl">Pig</td> + <td class="tdc">3.00</td> + <td class="tdc">2.25</td> + <td class="tdc">2.50</td> + </tr> + <tr> + <td class="tdl">Sheep</td> + <td class="tdc">1.78</td> + <td class="tdc">1.42</td> + <td class="tdc">0.71</td> + </tr> +</table> +</div> + +<p>It will be seen from the above that the dry substance of the solid +excreta of the pig is richest in fertilising substances. Too much +stress, however, as has already been pointed out, must not be put on any +single analysis, as so much depends on various conditions, especially +the food.<a name="FNanchor_133_133" id="FNanchor_133_133"></a><a href="#Footnote_133_133" class="fnanchor">[133]</a> The most reliable method of studying this question, +therefore, is to study it in its relation to the food consumed. Wolff +has calculated from numerous investigations that, <span class='pagenum'><a name="Page_228" id="Page_228">[Pg 228]</a></span>with regard to the +amount of solid excreta produced by the food, the following percentage +of <i>organic matter</i>, <i>nitrogen</i>, and <i>mineral substances</i>, originally +present in the dry matter of the food, is voided in the dung:—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="organic"> + <tr> + <td class="tdl" width="35%"> </td> + <td class="tdc" width="13%">Cow.</td> + <td class="tdc" width="13%">Ox.</td> + <td class="tdc" width="13%">Sheep.</td> + <td class="tdc" width="13%">Horse.</td> + <td class="tdc" width="13%">Average.</td> + </tr> + <tr> + <td class="tdl" width="35%">Organic matter</td> + <td class="tdc" width="13%">39.5</td> + <td class="tdc" width="13%">42.5</td> + <td class="tdc" width="13%">44.0</td> + <td class="tdc" width="13%">44.1</td> + <td class="tdc" width="13%">42.5</td> + </tr> + <tr> + <td class="tdl" width="35%">Nitrogen</td> + <td class="tdc" width="13%">47.5</td> + <td class="tdc" width="13%">33.9</td> + <td class="tdc" width="13%">46.7</td> + <td class="tdc" width="13%">32.4</td> + <td class="tdc" width="13%">40.1</td> + </tr> + <tr> + <td class="tdl" width="35%">Mineral substances</td> + <td class="tdc" width="13%">53.9</td> + <td class="tdc" width="13%">64.6</td> + <td class="tdc" width="13%">57.9</td> + <td class="tdc" width="13%">62.5</td> + <td class="tdc" width="13%">59.7</td> + </tr> +</table> +</div> + +<p>There is one fact to be borne in mind in estimating the manurial value +of the dung of different animals—viz., that the quantity of dung voided +by one animal is much greater than that voided by another. Thus the +amount voided by the cow, for example, is much greater than that voided +by the horse; so that, in this way, the inferior quality of the former +is, to some extent, compensated for by its greater quantity.</p> + +<p class="cen">2. <i>Urine.</i></p> + +<p>The solid excreta possess, however, very much less manurial value than +the urine. The former, as already stated, are undigested +food-substances: any fertilising matters which they contain are such as +have failed to be digested or absorbed into the animal system. The +urine, on the other hand, contains those fertilising substances which +have been digested.</p> + +<p>The amount of nitrogen and mineral matter, however, in the urine, does +not represent necessarily the total amount of these substances. Thus, in +the case of a growing or fattening animal, there is always a <span class='pagenum'><a name="Page_229" id="Page_229">[Pg 229]</a></span>certain +amount of these substances being absorbed to build up the animal tissue +and put on flesh.</p> + +<p>In this respect it will be seen that the composition of urine will vary +in the same way as that of the dung. In the case of the urine, however, +there is a compensating influence to be taken into account. Urine is a +waste product, and there is more waste in a young than in an adult +animal.</p> + +<p>Another very important condition which determines the composition of +urine is the nature of the food, especially the quantity of water drunk. +This, of course, is obvious: the more water drunk, the poorer must the +composition of the urine be. But here again, as in the case of the dung, +this is largely compensated for by the total quantity voided—the more +dilute the urine, the larger will its quantity be; so that the inferior +quality is in this way made up for by its increased quantity.</p> + +<p>Keeping in mind, then, the fact we have just stated—viz., that the +composition of urine will vary according to different conditions—we may +obtain an approximate idea of what its composition is from the following +results of analyses by Stoeckhardt. In 1000 parts the following +quantities of <i>water</i>, <i>nitrogen</i>, <i>phosphoric acid</i>, and <i>alkalies</i> +were found to be present.</p> + +<p>From the following table it will be seen that the urine of swine +(containing 97 per cent of water) is much poorer in nitrogen and +alkalies than is the case with <span class='pagenum'><a name="Page_230" id="Page_230">[Pg 230]</a></span>the urine of the sheep, horse, or +cow.<a name="FNanchor_134_134" id="FNanchor_134_134"></a><a href="#Footnote_134_134" class="fnanchor">[134]</a> While this is the case, the amount of phosphoric acid it +contains is greater than that contained in the sheep's urine.</p> + +<br /> +<div class="centered"> +<table border="0" width="90%" cellpadding="2" cellspacing="0" summary="parts"> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"><span class="smcap">Phosphoric</span></td> + <td class="tdcl" colspan="2" style="border-top: .5pt black solid;"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="2"><span class="smcap">Water.</span></td> + <td class="tdclb" colspan="2"><span class="smcap">Nitrogen.</span></td> + <td class="tdclb" colspan="2"><span class="smcap">Acid.</span></td> + <td class="tdclb" colspan="2"><span class="smcap">Alkalies.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Per</td> + <td class="tdcl"> </td> + <td class="tdcl">Per</td> + <td class="tdcl"> </td> + <td class="tdcl">Per</td> + <td class="tdcl"> </td> + <td class="tdcl">Per</td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">1000</td> + <td class="tdcl">Per</td> + <td class="tdcl">1000</td> + <td class="tdcl">Per</td> + <td class="tdcl">1000</td> + <td class="tdcl">Per</td> + <td class="tdcl">1000</td> + <td class="tdcl">Per</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">parts.</td> + <td class="tdclb">cent.</td> + <td class="tdclb">parts.</td> + <td class="tdclb">cent.</td> + <td class="tdclb">parts</td> + <td class="tdclb">cent.</td> + <td class="tdclb">parts.</td> + <td class="tdclb">cent.</td> + </tr> + <tr> + <td class="tdl" width="30%">Sheep (2 lb. hay per diem)</td> + <td class="tdcl" width="9%">865</td> + <td class="tdcl" width="9%">86.5</td> + <td class="tdcl" width="8%">14</td> + <td class="tdcl" width="9%">1.4</td> + <td class="tdcl" width="9%"> .5</td> + <td class="tdcl" width="9%">.050</td> + <td class="tdcl" width="8%">20</td> + <td class="tdcl" width="9%">2.0</td> + </tr> + <tr> + <td class="tdl">Swine (winter food)</td> + <td class="tdcl">975</td> + <td class="tdcl">97.5</td> + <td class="tdcl"> 3</td> + <td class="tdcl"> .3</td> + <td class="tdcl">1.25</td> + <td class="tdcl">.125</td> + <td class="tdcl"> 2</td> + <td class="tdcl"> .2</td> + </tr> + <tr> + <td class="tdl">Horses (hay and oats)</td> + <td class="tdcl">890</td> + <td class="tdcl">89.0</td> + <td class="tdcl">12</td> + <td class="tdcl">1.2</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + <td class="tdcl">15</td> + <td class="tdcl">1.5</td> + </tr> + <tr> + <td class="tdlb">Cows (hay and potatoes)</td> + <td class="tdclb">920</td> + <td class="tdclb">92.0</td> + <td class="tdclb"> 8</td> + <td class="tdclb"> .8</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">14</td> + <td class="tdclb">1.4</td> + </tr> +</table> +</div> + +<p>Phosphoric acid is present in the urine of the farm animals in the most +minute traces: practically, it may be considered to be wanting in the +urine of the horse and the cow, and is present only in small quantities +in sheep's urine. The pig's urine, indeed, contains it in larger +quantities; but the percentage is still so small as to justify the +statement that the urine of the common farm animals is not a complete +manure, and must be supplemented by phosphates, if it is to be used +alone. The incomplete nature of urine as a manure constitutes a strong +argument in favour of its being applied along with the solid excreta, +which <span class='pagenum'><a name="Page_231" id="Page_231">[Pg 231]</a></span>contain, as we have seen, considerable quantities of phosphoric +acid. It is on this account that the drainings of rotten manure-heaps +are more valuable, from a manurial point of view, than urine itself, +since these contain the soluble portion of the phosphates in the solid +excreta.<a name="FNanchor_135_135" id="FNanchor_135_135"></a><a href="#Footnote_135_135" class="fnanchor">[135]</a> The urine of all animals, however, is not equally poor in +phosphates. In the case of flesh-eating animals, such as the dog, the +urine is found to contain them in considerable quantities.</p> + +<p>The above tables show that the most valuable urine, weight for weight, +is that of the sheep, as it contains the largest amount of alkalies +(including potash) and nitrogen; that the urine of the horse comes next; +then that of the cow; while, as has already been pointed out, that of +the pig is the poorest.</p> + +<p>In order to make our survey of the composition of urine uniform with +that of the dung, let us see how the urine of the common farm animals +compares in the matter of the composition of its dry substance. The +following results (basing our calculations on Stoeckhardt's figures, +previously given) show this:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Pig"> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdc" width="25%">Nitrogen,</td> + <td class="tdc" width="25%">Phosphoric acid,</td> + <td class="tdc" width="25%">Alkalies,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + </tr> + <tr> + <td class="tdl">Pig</td> + <td class="tdc">12.0</td> + <td class="tdc">5 </td> + <td class="tdc">8 </td> + </tr> + <tr> + <td class="tdl">Horse</td> + <td class="tdc">10.9</td> + <td class="tdc">trace</td> + <td class="tdc">13.6</td> + </tr> + <tr> + <td class="tdl">Sheep</td> + <td class="tdc">10.4</td> + <td class="tdc">3.7</td> + <td class="tdc">14.9</td> + </tr> + <tr> + <td class="tdl">Cow</td> + <td class="tdc">10.0</td> + <td class="tdc">trace</td> + <td class="tdc">17.5</td> + </tr> +</table> +</div> + +<p>From these figures we see that the dry substance of the urine of the pig +is richest in nitrogen and <span class='pagenum'><a name="Page_232" id="Page_232">[Pg 232]</a></span>phosphoric acid, but poorest in alkalies, of +the four common farm animals; that of the horse comes next in the amount +of nitrogen it contains, but that, on the whole, there is very little +difference between the horse, cow, and sheep in this respect.<a name="FNanchor_136_136" id="FNanchor_136_136"></a><a href="#Footnote_136_136" class="fnanchor">[136]</a></p> + +<p>As in the case of the dung, this subject is best studied in relation to +the food consumed. We are again indebted to Wolff's investigations for +valuable information on this point. He has found that the following +percentages of <i>organic matter</i>, <i>nitrogen</i>, and <i>mineral substances</i>, +originally present in the dry matter of the food, are voided in the +urine:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Cow"> + <tr> + <td class="tdl" width="30%"> </td> + <td class="tdc" width="14%">Cow.</td> + <td class="tdc" width="14%">Ox.</td> + <td class="tdc" width="14%">Sheep.</td> + <td class="tdc" width="14%">Horse.</td> + <td class="tdc" width="14%">Average.</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdc"> 4.0</td> + <td class="tdc"> 4.4</td> + <td class="tdc"> 2.0</td> + <td class="tdc"> 3.3</td> + <td class="tdc"> 3.4</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc">31.0</td> + <td class="tdc">54.8</td> + <td class="tdc">42.3</td> + <td class="tdc">60.7</td> + <td class="tdc">47.2</td> + </tr> + <tr> + <td class="tdl">Mineral substances</td> + <td class="tdc">43.1</td> + <td class="tdc">34.3</td> + <td class="tdc">41.0</td> + <td class="tdc">37.5</td> + <td class="tdc"> 39.0<a name="FNanchor_137_137" id="FNanchor_137_137"></a><a href="#Footnote_137_137" class="fnanchor">[137]</a></td> + </tr> +</table> +</div> + +<p>We have now considered briefly the composition of the solid excrements +and urine of the common farm animals, and have also enumerated some of +the principal causes of the variation in their composition.</p> + +<p>The solid excreta consist, as we have seen, of <i>undigested</i> food, while +the urine contains the manurial ingredients of the food which have been +<i>digested</i> by the animal system.<a name="FNanchor_138_138" id="FNanchor_138_138"></a><a href="#Footnote_138_138" class="fnanchor">[138]</a> The latter is, weight for weight, +as a rule, very much more valuable as a manure than <span class='pagenum'><a name="Page_233" id="Page_233">[Pg 233]</a></span>the former. From +the table given in the Appendix<a name="FNanchor_139_139" id="FNanchor_139_139"></a><a href="#Footnote_139_139" class="fnanchor">[139]</a> it will be seen that the +proportions of the nitrogen and ash-constituents originally present in +the food consumed, which are voided in the excrements, vary with +different circumstances. Wolff, in summarising his results, points out +that, as a rule, the solid and liquid excrements will contain about 46 +per cent of the organic matter, 87.3 of the nitrogen, and 98.7 of +mineral matter; while the experiments of Lawes and Gilbert at Rothamsted +show that, with fattening oxen and sheep and with horses, more than 95 +per cent of the nitrogen and 96 per cent or more of the ash-constituents +are voided in the manure. The pig retains a larger proportion of the +nitrogen—about 85 per cent appearing in the manure—while in the +milking-cow only about 75 per cent is returned in the excrements. +Generally speaking, we may say that the nitrogen originally present in +the food suffers very little loss in passing through the animal system, +and that, practically speaking, the ash-constituents suffer no loss +whatever.</p> + +<p>As to the distribution of the manurial ingredients, much will depend on +the nature of the food. Almost invariably more than a <i>half</i> of the +total nitrogen excreted will be found in the urine, in many cases very +much more.<a name="FNanchor_140_140" id="FNanchor_140_140"></a><a href="#Footnote_140_140" class="fnanchor">[140]</a> Of the mineral constituents, about a <span class='pagenum'><a name="Page_234" id="Page_234">[Pg 234]</a></span>third on the +average may be said to be excreted in the urine. Of this mineral matter +it may be noted that nearly all the alkalies (potash and soda), or about +98 per cent, are found in the urine. Of phosphoric acid and lime, on the +other hand, there are the merest traces in the urine. Horse-urine, +however, is an exception with regard to lime, as it contains about 60 +per cent of the lime consumed in the food. For information on the +subject of pig-manure the reader is referred to Appendix, Note V.<a name="FNanchor_141_141" id="FNanchor_141_141"></a><a href="#Footnote_141_141" class="fnanchor">[141]</a></p> + +<p>Before passing from this part of the subject, it may be desirable to +place before our readers the composition of the dung and urine taken +together, so that we may be able to form some idea of their relative +value, weight for weight. As the nitrogen constitutes by far the most +valuable portion of the manurial ingredients, it will be sufficient if +we compare them as to their percentage of this ingredient.</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Cow"> + <tr> + <td class="tdl" width="16%"> </td> + <td class="tdc" width="20%"> </td> + <td class="tdc" width="20%"> </td> + <td class="tdc" width="24%">Calculated on</td> + <td class="tdr" width="20%"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Water,</td> + <td class="tdc">Nitrogen,</td> + <td class="tdc">dry substance,</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + <td class="tdr">Analyses by</td> + </tr> + <tr> + <td class="tdl">Sheep</td> + <td class="tdc">67</td> + <td class="tdc">.91</td> + <td class="tdc">2.7</td> + <td class="tdr">Jürgensen.</td> + </tr> + <tr> + <td class="tdl">Horse</td> + <td class="tdc">76</td> + <td class="tdc">.65</td> + <td class="tdc">2.7</td> + <td class="tdr">Boussingault.</td> + </tr> + <tr> + <td class="tdl">Pig</td> + <td class="tdc">82</td> + <td class="tdc">.61</td> + <td class="tdc">3.4</td> + <td class="tdr">Boussingault.</td> + </tr> + <tr> + <td class="tdl">Cow</td> + <td class="tdc">86</td> + <td class="tdc">.36</td> + <td class="tdc">2.6</td> + <td class="tdr">Boussingault.</td> + </tr> +</table> +</div> + +<p>From these figures we see that, in their natural <span class='pagenum'><a name="Page_235" id="Page_235">[Pg 235]</a></span>condition, the excreta +of the sheep are the most valuable; those of the horse and pig coming +next; while those of the cow are the poorest, containing one-third as +much nitrogen as those of the sheep, and one-half as much as those of +the horse and pig. This difference, however, is due almost entirely to +the different percentage of water the excreta of the various animals +contain in their natural state; for in the dry state they are seen to +contain, with the single exception of the pig, practically the same +amount.</p> + +<p>In conclusion, then, the important points to be noticed are—</p> + +<p>1. That in the passage of the food through the system of the common farm +animals, only a very small percentage of the fertilising substances, +nitrogen, phosphoric acid, and potash, is assimilated and retained in +the animal body; and that, therefore, theoretically at least, the +excreta should contain nearly the same amount of fertilising matter as +the food originally did.</p> + +<p>2. That even in the case of a fattening animal, the loss of fertilising +matter sustained by the food in passing through the system is not great.</p> + +<p>3. That with regard to the total amount of solid excreta and urine +voided, the latter contains, as a rule, more nitrogen than the former; +the nitrogen in the urine, further, being more valuable, as it is in a +soluble condition.</p> + +<p>4. That as regards the distribution of the <span class='pagenum'><a name="Page_236" id="Page_236">[Pg 236]</a></span>ash-constituents, <i>lime</i>, +<i>phosphoric acid</i>, and <i>magnesia</i> are almost entirely found in the solid +excrements; while the urine contains nearly all the <i>potash</i>.</p> + +<p>5. That the best results can be expected only when the liquid and solid +excreta are used together as a manure.</p> + +<p>As the composition of the manure depends so largely on the nature of the +food, a table will be found in the Appendix, Note VI.,<a name="FNanchor_142_142" id="FNanchor_142_142"></a><a href="#Footnote_142_142" class="fnanchor">[142]</a> containing +the manurial composition of some of the commoner feeding-stuffs.</p> + +<br /> +<p class="cen">3. <i>Litter.</i></p> + +<p>We have now to consider the third constituent of farmyard manure—viz., +the <i>litter</i>, which generally consists of straw.</p> + +<p>The uses of the litter, in addition to providing a dry and comfortable +bed for the animal, may be briefly summed up as follows:—</p> + +<p>1. To absorb and retain the liquid portion of the excreta.</p> + +<p>2. To increase the quantity of the manure, and thus secure its more +equal distribution when applied to the field than could otherwise be +done.</p> + +<p>3. To add to its value as a manure, both physically and chemically.</p> + +<p>4. To retard and regulate the decomposition of the excreta.</p> + +<p>Of course litter also performs a very useful function <span class='pagenum'><a name="Page_237" id="Page_237">[Pg 237]</a></span>sanitarily, +inasmuch as it serves to keep the stall or byre fresher and cleaner, and +more free from noxious gases, which it absorbs, than would otherwise be +the case.</p> + +<p><i>Straw</i> is almost universally used for this purpose. Besides being one +of the bye-products of the farm, it is admirably suited in many ways, +both owing to its peculiar shape—its tubular structure being +excellently adapted for this purpose—as well as on account of its +composition, being largely composed of cellulose, a very absorptive +substance. Straw thus possesses considerable absorptive power. In +manurial ingredients it is not very rich; for, of the various parts of +the ripened plant, straw contains the least percentage of nitrogen and +phosphates. This is due to the fact that, as the straw ripens, a +considerable proportion of these ingredients passes up from the stalk to +the seeds, where they are retained.</p> + +<p>Generally speaking, straw may be said to contain not more than <i>a half +per cent</i> of nitrogen—<i>i.e.</i>, 11.2 lb. per ton. Its percentage of +nitrogen varies, of course; the recorded analyses<a name="FNanchor_143_143" id="FNanchor_143_143"></a><a href="#Footnote_143_143" class="fnanchor">[143]</a> for wheat-straw +ranging from .22 to .81 per cent, or furnishing an average of .48 per +cent—<i>i.e.</i>, 10.75 lb. per ton. Barley-straw is somewhat richer in +nitrogen, the recorded analyses ranging from .41 to .85 per cent, or +giving an average of .57 per cent—<i>i.e.</i>, 12.76 lb. per ton; while +oat-straw is the richest of the commoner straws, ranging from .32 to +<span class='pagenum'><a name="Page_238" id="Page_238">[Pg 238]</a></span>1.12 per cent, an average of .72 per cent—<i>i.e.</i>, 16.12 lb per ton.</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Composition"> + <tr> + <td class="tdc" colspan="7"><span style="smcap">Composition of Straw.</span><a name="FNanchor_144_144" id="FNanchor_144_144"></a><a href="#Footnote_144_144" class="fnanchor">[144]</a></td> + </tr> + <tr> + <td class="tdl" style="border-top: .5pt black solid;"> </td> + <td class="tdclb" colspan="2" style="border-top: .5pt black solid;"><span class="smcap" style="font-size: 80%;">Ash.</span></td> + <td class="tdclb" colspan="3" style="border-top: .5pt black solid;"><span class="smcap" style="font-size: 80%;">Composition of Ash.</span></td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdclb" colspan="3">Lb. per ton.</td> + <td class="tdcl">Number</td> + </tr> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdcl" width="15%">Per</td> + <td class="tdcl" width="15%">Lb.</td> + <td class="tdcl" width="15%"> </td> + <td class="tdcl" width="15%">Phosphoric</td> + <td class="tdcl" width="15%"> </td> + <td class="tdcl" width="15%">of</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">cent.</td> + <td class="tdclb">per ton.</td> + <td class="tdclb">Potash.</td> + <td class="tdclb">Acid.</td> + <td class="tdclb">Lime.</td> + <td class="tdclb">Analyses.</td> + </tr> + <tr> + <td class="tdl">Wheat (winter)</td> + <td class="tdcl">5.54</td> + <td class="tdcl">124.09</td> + <td class="tdcl">18.61</td> + <td class="tdcl">5.05</td> + <td class="tdcl"> 7.18</td> + <td class="tdcl">8</td> + </tr> + <tr> + <td class="tdl">Wheat (summer)</td> + <td class="tdcl">5.14</td> + <td class="tdcl">115.13</td> + <td class="tdcl">25.76</td> + <td class="tdcl">6.47</td> + <td class="tdcl"> 7.12</td> + <td class="tdcl">6</td> + </tr> + <tr> + <td class="tdl">Rye (winter)</td> + <td class="tdcl">5.33</td> + <td class="tdcl">119.39</td> + <td class="tdcl">20.61</td> + <td class="tdcl">5.89</td> + <td class="tdcl"> 9.73</td> + <td class="tdcl">8</td> + </tr> + <tr> + <td class="tdl">Rtye (summer)</td> + <td class="tdcl">6.14</td> + <td class="tdcl">137.53</td> + <td class="tdcl">42.41</td> + <td class="tdcl">6.73</td> + <td class="tdcl">10.53</td> + <td class="tdcl">1</td> + </tr> + <tr> + <td class="tdl">Barley</td> + <td class="tdcl">4.90</td> + <td class="tdcl">109.76</td> + <td class="tdcl">26.83</td> + <td class="tdcl">5.75</td> + <td class="tdcl"> 8.73</td> + <td class="tdcl">8</td> + </tr> + <tr> + <td class="tdlb">Oats</td> + <td class="tdclb">5.09</td> + <td class="tdclb">114.01</td> + <td class="tdclb">26.22</td> + <td class="tdclb">4.17</td> + <td class="tdclb"> 9.12</td> + <td class="tdclb">4</td> + </tr> +</table> +</div> + +<p>Of mineral matter, however, straw contains a very much larger +percentage, proportionally, than of nitrogen; for, with the exception of +phosphates, there is a considerable quantity of inorganic fertilising +matter, in the shape of potash, lime, &c., present in +it. Of total ash ingredients, on an average, there are generally about 5 +per cent—or 112 lb. per ton. The largest percentage of the fertilising +matter in this 5 per cent is potash, which varies in the ashes of the +straws of the commoner crops from 30 to 15 per cent. The above table +will show the variation in composition of the straws of some of the +commoner farm <span class='pagenum'><a name="Page_239" id="Page_239">[Pg 239]</a></span>crops, and may be valuable for purposes of reference. The +crops are wheat (winter and summer), barley, oats, and rye (winter and +summer), and the amount is also calculated in lb. per ton. The results +represent the average of a number of analyses.<a name="FNanchor_145_145" id="FNanchor_145_145"></a><a href="#Footnote_145_145" class="fnanchor">[145]</a> From the table it +will be seen that the percentage of phosphates is, as has already been +noticed, very small.</p> + +<p>But while straw is well adapted for the purposes for which litter is +used, it is not the only substance. Its almost exclusive use as litter +is largely owing to the fact that it is a bye-product of the farm.</p> + +<p><i>Loam as Litter.</i>—Generally speaking, any substance which has great +absorptive as well as retentive powers for nitrogen and the soluble +fertilising matters present in farmyard manure, and whose price is +nominal, is well suited for acting as litter. Ordinary loamy soil +possesses the above qualifications, and is, besides, a substance to be +had for nothing, and, under certain circumstances and in certain +countries, is actually used for this purpose, often along with straw. A +great objection against loam, however, is that it forms a dirty litter. +Moreover, it possesses a very small percentage of fertilising matter. +The tendency, consequently, <span class='pagenum'><a name="Page_240" id="Page_240">[Pg 240]</a></span>in using ordinary loam, would be to dilute +the manure too much, besides retarding fermentation to an undesirable +extent. Except, therefore, under very exceptional circumstances, loam is +not to be regarded as a good litter.</p> + +<p><i>Peat as Litter.</i>—Some kinds of soil, however, are well suited for this +purpose. Of these, the best are those rich in organic matter, the +so-called peaty soils. Peat, when dried and freed from any earthy +matter, forms an excellent absorbent of the liquid portion of the +manure, surpassing in this respect straw itself. It is, further, +generally very much richer in nitrogen—some peats having been found to +contain between 4 and 5 per cent of nitrogen. In some thirty samples of +peat analysed by Professor S. W. Johnson, the percentage of nitrogen +varied from .4 to 2.9, giving an average of 1.5 per cent.</p> + +<p>While it has a very great capacity for absorbing liquids, it possesses +in an unequalled degree the power of retaining the soluble nitrogen +compounds. This is undoubtedly one of the most important properties +which recommend peat for the purposes of litter.<a name="FNanchor_146_146" id="FNanchor_146_146"></a><a href="#Footnote_146_146" class="fnanchor">[146]</a></p> + +<p>Some interesting experiments on the value of peat-moss as a litter have +been recently carried out by Dr Bernard Dyer.<a name="FNanchor_147_147" id="FNanchor_147_147"></a><a href="#Footnote_147_147" class="fnanchor">[147]</a> From these +experiments Mr Dyer has <span class='pagenum'><a name="Page_241" id="Page_241">[Pg 241]</a></span>found that both its liquid-absorbing and +liquid-retaining powers are very much greater than those of straw. While +straw was only able to absorb three times its weight of water, peat-moss +was found to absorb nearly ten times its weight. With regard to its +water-retaining power, this was also found to be in excess of that of +straw. Both these properties are, it need scarcely be pointed out, of +very great value in a litter. Another point of interest in these +experiments was the respective amounts of nitrogen absorbed and retained +by the peat-moss and the straw. It was found that, in this respect, the +peat-moss had again an advantage over the straw. Lastly, the manure +produced by the peat-moss was shown to be richer in fertilising matter +than that produced by the use of straw.<a name="FNanchor_148_148" id="FNanchor_148_148"></a><a href="#Footnote_148_148" class="fnanchor">[148]</a> These experiments are +interesting as demonstrating the fact that in peat-moss we have a +substance which is capable of acting as an excellent substitute for the +more costly straw, and which might increasingly be used as a fodder with +great benefit to the farmer.</p> + +<p>Another substance which has been suggested as an excellent litter is the +common <i>bracken-fern</i>. According to some analyses made by Mr John +Hughes, the bracken, especially if cut in a young state, is a substance +of considerable manurial value. When dried, it is very much richer in +nitrogen, potash, and lime than straw. Its absorbent properties, +however, are probably not so great. Where it can easily and cheaply <span class='pagenum'><a name="Page_242" id="Page_242">[Pg 242]</a></span>be +had, as in many parts of Scotland and Ireland, it might well be used for +littering purposes.<a name="FNanchor_149_149" id="FNanchor_149_149"></a><a href="#Footnote_149_149" class="fnanchor">[149]</a></p> + +<p><i>Dried leaves</i> have also been used as a litter. Autumn leaves, however, +contain a very small percentage of fertilising matter. This is due to +the fact that the most of their potash, phosphoric acid, and nitrogen +pass into the body of the trees at the approach of winter. According to +Professor Storer, dried leaves only contain from .1 to .5 per cent +potash,.006 to .3 per cent phosphoric acid, and about .75 per cent of +nitrogen. Leaves, however, besides being poor in manurial ingredients, +make a bad litter, as they ferment but slowly. There is in this +fermentation a large quantity of cold sour humic acid formed, which +seriously impairs the value of the manure.<a name="FNanchor_150_150" id="FNanchor_150_150"></a><a href="#Footnote_150_150" class="fnanchor">[150]</a></p> + +<p>Having now considered the composition of the three separate ingredients +of farmyard manure—viz., the <i>dung</i> or <i>solid excreta</i>, the <i>urine</i>, +and the <i>litter</i>—we are in a position to consider the composition of +farmyard manure. In this connection it will be well to consider +separately the manures produced by the different farm animals.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_243" id="Page_243">[Pg 243]</a></span>1. <i>Horse-manure.</i></p> + +<p>The composition of horse-manure is perhaps the most uniform of all the +manures produced by the different farm animals. This is due to the fact +that the food of the horse is generally of the same kind, consisting of +oats, hay, and straw.</p> + +<p>The total excrements voided by a horse in a day have been calculated, +according to the average of experiments by Boussingault and Hofmeister, +at 28.11 lb., of which only 6.37 lb. consisted of dry matter.<a name="FNanchor_151_151" id="FNanchor_151_151"></a><a href="#Footnote_151_151" class="fnanchor">[151]</a> These +28.11 lb. contained .18 lb. of nitrogen and .92 lb. of mineral matter. +The amount of straw necessary to absorb this amount of excrement may be +stated at from 4 to 6 lb. The amounts of nitrogen and mineral matter in +4 lb. of straw are .01 and .23 lb. respectively. The total amount of +nitrogen and ash, therefore, in the farmyard manure produced by a horse +in one day, would be .19 lb. nitrogen and 1.15 lb. mineral matter; or, +if we take the larger quantity of straw, somewhat more.</p> + +<p>Taking these figures, we find that the amount of manure produced by a +horse in a year will be from <span class='pagenum'><a name="Page_244" id="Page_244">[Pg 244]</a></span>11,720 to 12,450 lb. (<i>i.e.</i>, from 5-1/4 +to 5-1/2 tons),<a name="FNanchor_152_152" id="FNanchor_152_152"></a><a href="#Footnote_152_152" class="fnanchor">[152]</a> containing from 69 to 73 lb. nitrogen, and from 420 +to 460 lb. mineral matter.<a name="FNanchor_153_153" id="FNanchor_153_153"></a><a href="#Footnote_153_153" class="fnanchor">[153]</a></p> + +<p>A word or two may be of value regarding the treatment in the stable of +horse-manure. The great object to be aimed at is the prevention of loss +of valuable fertilising constituents. This loss may be due to two +causes. It may be, in the first place, caused by drainage of the soluble +matter of the manure; or secondly, it may be due to volatilisation of +the volatile constituents.</p> + +<p>The first of these two sources of loss depends on the precautions taken +in the way of providing a proper impervious flooring to the stable. This +source of loss is extremely difficult to prevent, inasmuch as nearly all +materials used for flooring absorb a certain percentage of urine. The +judicious use of litter, however, will minimise this loss to within a +trifling extent.</p> + +<p>Dr Heiden states that the amount of straw used as litter for the horse +in Germany is from 4 to 6 lb. per day. The quantity should be regulated +according to the percentage of water the excreta contain; the more +watery excreta requiring naturally a larger quantity of litter. The most +eminent authorities on this subject recommend that the amount of litter +<span class='pagenum'><a name="Page_245" id="Page_245">[Pg 245]</a></span>should equal one-fourth of the food in its natural state, or about +one-third of its dry substance.</p> + +<p>The second source of loss, which is due to volatilisation of the +volatile ingredients, may be largely prevented by the use of certain +preservatives.</p> + +<p>Horse-dung being, comparatively speaking, of a dry nature, it is +extremely difficult to effect its thorough mixture with the litter. For +this reason the manure formed from horse excreta is particularly liable +to rapid fermentation.<a name="FNanchor_154_154" id="FNanchor_154_154"></a><a href="#Footnote_154_154" class="fnanchor">[154]</a> In the process of fermentation, as will be +seen more in detail further on, the nitrogen is converted into carbonate +of ammonia. As nitrogen in this form is of an extremely volatile nature, +the risks of loss from this source are considerable. As illustrating +this fact, it may be mentioned that Boussingault has found by experiment +that the total percentage of nitrogen contained by fresh horse-manure +might be reduced in the process of fermentation to one-half of its +original amount by loss from this source.</p> + +<p>The preservatives used to prevent this volatilisation are technically +known as "fixers." This they do by chemically combining with the +volatile ammonia and forming non-volatile compounds with it.</p> + +<p>Of the acid fixers, hydrochloric and sulphuric acids have been +recommended. The former, however, is not well suited for this purpose. +It is a strongly fuming <span class='pagenum'><a name="Page_246" id="Page_246">[Pg 246]</a></span>acid, and when brought into contact with +ammonia forms dense white fumes. The use of sulphuric acid is not open +to this objection. Sulphate of ammonia, the salt formed in this case, is +one of the most stable (or least volatile) of the compounds of ammonia. +If used, it should be largely diluted with water, and the whole mixed +with sand. Such a mixture, when sprinkled over the stable-floor in even +very small quantities, has been found to effectually prevent any loss of +the volatile carbonate of ammonia.</p> + +<p>It is not, however, on the whole advisable to use an acid substance as a +fixer, since such a substance may act deleteriously on the horses' +hoofs.</p> + +<p>Such substances as <i>gypsum</i>, <i>copperas</i>, and <i>sulphate of magnesia</i>, +while equally efficient, are not open to this objection. The +above-mentioned substances owe their efficacy to the fact that they are +compounds of sulphuric acid, which, by combining with the volatile +ammonia and forming sulphate of ammonia, prevent its escape.</p> + +<p>Gypsum, or sulphate of lime, although, comparatively speaking, an +insoluble substance, when brought in contact with carbonate of ammonia +has been proved to effect the conversion of the ammonia into sulphate of +ammonia. It is also believed to retard the decomposition of the +manure.<a name="FNanchor_155_155" id="FNanchor_155_155"></a><a href="#Footnote_155_155" class="fnanchor">[155]</a> Copperas, or ferrous sulphate, while a soluble salt, and +while thus acting in a more speedy manner in fixing the ammonia, is not +so well <span class='pagenum'><a name="Page_247" id="Page_247">[Pg 247]</a></span>suited, owing to the hurtful influence it is well known to +possess on plant-life. It is only right to remember that there may be +circumstances in which copperas may, in small quantities, act even +beneficially as a manure, as Griffiths' experiments would seem to +indicate. The above objection, however, cannot be urged against sulphate +of magnesia. In addition to fixing the ammonia, sulphate of magnesia may +very probably fix the soluble phosphoric acid. Kainit, which consists of +a mixture of sulphates and chlorides of potassium and magnesium, has +also been suggested for this purpose. By using such a fixer, the value +of the resulting manure would be much enhanced. In conclusion, it must +be remembered that all the above-named fixers act very much in the same +way—viz., by converting the volatile carbonate of ammonia into sulphate +of ammonia.<a name="FNanchor_156_156" id="FNanchor_156_156"></a><a href="#Footnote_156_156" class="fnanchor">[156]</a></p> + +<br /> +<p class="cen">2. <i>Cow-manure.</i></p> + +<p>The composition of the manure formed from the excrementitious matter of +the cow is very much less constant than is the case in the horse-manure. +An average statement of that composition is therefore very much more +difficult to obtain. The number of analyses available for the purpose of +forming this average is, however, very large. The manure produced by +cows contains a large percentage of water. This is due to the large +quantity of water they drink. <span class='pagenum'><a name="Page_248" id="Page_248">[Pg 248]</a></span>It has been estimated that milch-cows +drink along with their winter food, for every pound of dry substance, 4 +lb. of water, and in summer about 6 lb.</p> + +<p>According to some experiments by Boussingault, the excrements of a cow +in a day amounted to 73.23 lb., of which only 9.92 lb. were dry +matter.<a name="FNanchor_157_157" id="FNanchor_157_157"></a><a href="#Footnote_157_157" class="fnanchor">[157]</a> These excrements contained .256 lb. of nitrogen and 1.725 +lb. of mineral matter. The amount of straw necessary to use as litter +for this amount of excrements may be taken at 6 to 10 lb. The manure, +therefore, formed by a cow per day, would contain from .274 to .286 lb. +of nitrogen, and from 2.046 to 2.278 lb. of mineral matter. In a year +this would amount to from 100 to 104.4 lb. of nitrogen, and from 746.8 +lb. to 831.5 lb. of mineral matter; or from 6 cwt. 75 lb. to 7 cwt. 47 +lb.</p> + +<p>Cow-dung is, owing to its more watery nature and poorer quality, very +much slower in its fermentation than horse-dung. When applied alone, +cow-manure is very slow in its action, and makes its influence felt for +at least three or four years. It is difficult to spread it evenly over +the soil, owing to the fact that, when somewhat dried, it has a tendency +to form hard masses, which, when buried in the soil, may resist +decomposition for a very long period. The cause of this is due to the +presence of a considerable amount of mucilaginous and resinous matter in +the solid excreta, which prevents the entrance of moisture and air <span class='pagenum'><a name="Page_249" id="Page_249">[Pg 249]</a></span>into +the centre of the mass. This tendency of cow-manure to resist +decomposition will be greatly lessened in the case of the excrements of +a cow richly fed.</p> + +<p>The risks of loss of volatile ammonia are, therefore, in its case not so +great as we have seen them to be in the case of the "hot" horse-dung. +Notwithstanding this fact, much of what has been said on the use of +preservatives for horse-manure may be also applied to the cow-dung. This +is owing to the fact that the dung is allowed to accumulate in the court +for some time. The amount of straw it is advisable to use as litter +varies, as has been said, from 6 to 10 lb. per day. The best method of +calculating this amount, according to Dr Heiden, is by taking one-third +of the total weight of the dry substance of the food. The above +authority also recommends that the straw is best applied in blocks of +about one foot in length; and this for the following reasons:—</p> + +<p>1. The strewing of it is more convenient.</p> + +<p>2. The absorption of the fluid portion is more complete.</p> + +<p>3. The cleaning out of the manure from the byre is easier.</p> + +<p>4. The manure is more easily distributed when applied to the field.</p> + +<p>Among the advantages incidental to allowing the manure to accumulate in +the court may be mentioned the following:—</p> + +<p>1. The more thorough absorption of the urine by <span class='pagenum'><a name="Page_250" id="Page_250">[Pg 250]</a></span>the straw, and, +consequently, the more uniform mixture which will be thus effected of +the more valuable urine with the less valuable solid excreta.</p> + +<p>2. A certain retardation of decomposition effected by the treading under +foot of the manure.</p> + +<p>3. The protection of the manure from rain and wind, and the securing of +a uniform temperature.</p> + +<p>Against those advantages must be placed the risk of seriously affecting +the health of the animal. Although this is a point of very great +importance, it scarcely falls within the scope of this work. It may be +pointed out, however, that the judicious use of some of the chemical +fixers previously referred to may do much to keep the air of the byre or +court free of noxious gases.<a name="FNanchor_158_158" id="FNanchor_158_158"></a><a href="#Footnote_158_158" class="fnanchor">[158]</a></p> + +<br /> +<p class="cen">3. <i>Pig-manure.</i></p> + +<p>The food of the pig is so very variable in its character that it is +wellnigh impossible to obtain anything like an average analysis of its +excrements. When the food of the pig is rich, then the manure may be +quite equal in quality to the other manures. According to Boussingault, +the total amount of excrements, on an average, voided by a pig in +twenty-four hours is about 8.32 lb., of which 1.5 lb. is dry +matter.<a name="FNanchor_159_159" id="FNanchor_159_159"></a><a href="#Footnote_159_159" class="fnanchor">[159]</a> The amount of nitrogen these excrements contain is only .05 +lb., and of mineral ingredients .313 <span class='pagenum'><a name="Page_251" id="Page_251">[Pg 251]</a></span>lb. If we take the amount of straw +most suitable for absorbing this quantity of excrementitious matter at +from 4 to 8 lb., then we shall find that the manure produced by a pig +will contain from .06 to .074 lb. nitrogen and .545 to .772 lb. mineral +matter. These quantities, calculated for a year, give from 22 to 27 lb. +of nitrogen, and from 1 cwt. 87 lb. to 2 cwt. 57 lb. of mineral matter. +That is about as much nitrogen as would be contained in 1-1/4 to 1-1/2 +cwt. of nitrate of soda (95 per cent purity); or from slightly less than +1 cwt. to slightly over 1 cwt. of sulphate of ammonia (97 per cent +purity).</p> + +<p>As has already been pointed out, the excrements of the pig are, as a +rule, very poor in nitrogen. This accounts for the fact that pig-manure +is a "cold" manure, slow in fermenting.<a name="FNanchor_160_160" id="FNanchor_160_160"></a><a href="#Footnote_160_160" class="fnanchor">[160]</a></p> + +<br /> +<p class="cen">4. <i>Sheep-manure.</i></p> + +<p>The dung and the urine of the sheep, as we have already seen, are, +weight for weight, the most valuable of any of the common farm animals. +The total weight of the excrements voided by a sheep in a day may be +taken, on an average,<a name="FNanchor_161_161" id="FNanchor_161_161"></a><a href="#Footnote_161_161" class="fnanchor">[161]</a> at 3.78 lb., of which .97 lb. is dry matter. +These excrements contain .038 lb. of nitrogen and .223 lb. mineral +matter. <span class='pagenum'><a name="Page_252" id="Page_252">[Pg 252]</a></span>Taking the amount of straw most suitable for absorbing this +quantity of excrementitious matter at three-fifths of a pound, then the +manure produced by a sheep in a day will contain .0429 lb. nitrogen and +.264 lb. mineral matter. That is, in a year the quantities of nitrogen +and mineral matter in the manure produced by a sheep would be 15.66 lb. +of nitrogen and 96.36 lb. of mineral matter.</p> + +<p>From its richness in nitrogen, and from its dry condition, sheep-dung is +peculiarly liable to ferment. While richer in fertilising substances +than horse-manure, it is not so rapid in its fermentation. This is due +to the harder and more compact physical character of the solid excreta. +The risks of loss of volatile ammonia are, in its case, exceptionally +great. The use of artificial "fixers" is therefore to be strongly +recommended.<a name="FNanchor_162_162" id="FNanchor_162_162"></a><a href="#Footnote_162_162" class="fnanchor">[162]</a></p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_253" id="Page_253">[Pg 253]</a></span><i>Fermentation of Farmyard Manure.</i></p> + +<p>Having now considered the nature of the different manures produced by +the four common farm animals separately, it is of importance to consider +the exact nature of the fermentation, decomposition, or putrefaction +which takes place in the manure-heap.</p> + +<p><span class='pagenum'><a name="Page_254" id="Page_254">[Pg 254]</a></span>It is now more than thirty years since Pasteur showed that the +fermentation which ensued on keeping a sample of urine was due to the +action of a minute organism, for the propagation of which a certain +amount of warmth, air, and moisture, as well as <span class='pagenum'><a name="Page_255" id="Page_255">[Pg 255]</a></span>the presence of certain +food-constituents, especially nitrogenous bodies, were necessary.</p> + +<p>Subsequent researches by Pasteur and others have conclusively +demonstrated that the micro-organic life instrumental in effecting the +putrefaction or decay of organic matter of any kind, may be divided into +two great classes:—</p> + +<p>1. Those which require a plentiful supply of oxygen for their +development, and which, when bereft of oxygen, die—known as <i>aerobies</i>.</p> + +<p>2. Those which, on the contrary, develop in the complete absence of +oxygen, and which, when exposed to oxygen, die—known as <i>anaerobies</i>.</p> + +<p>In the fermentation of the manure-heap, therefore, we must conceive of +the two classes of organisms as the active agents. In the interior +portion of the manure-heap, where the supply of oxygen is necessarily +limited, the fermentation going on there is effected by means of the +anaerobic organism—<i>i.e.</i>, the organism which does not require oxygen; +while on the surface portion, which is exposed to the air, the aerobic +(or oxygen-requiring) organism is similarly active. Gradually, as decay +progresses, the aerobic organisms increase in number. It is through +their instrumentality that the final products of decomposition are +largely produced. The functions of the anaerobic organisms may be, on +the contrary, regarded as largely preparatory in their nature. By +breaking up the complex organic substances in the manure into <span class='pagenum'><a name="Page_256" id="Page_256">[Pg 256]</a></span>new and +simpler forms, they advance the process of putrefaction through the +initial stages; and when this is accomplished, they die and give place +to the aerobic, which, as we have just seen, effect the final +transformation of the organic matter into such simple substances as +<i>water</i> and <i>carbonic acid gas</i>.</p> + +<p>The conditions influencing the fermentation of farmyard manure may be +summed up as follows:<a name="FNanchor_163_163" id="FNanchor_163_163"></a><a href="#Footnote_163_163" class="fnanchor">[163]</a>—</p> + +<p>1. <i>Temperature.</i>—The higher the temperature the more rapidly will the +manure decay.</p> + +<p>2. <i>Openness to the Air.</i>—Of course it will be seen that the effect of +exposing the manure to the action of the air is to induce the +development of the aerobic type of organism, and thus to promote more +rapid fermentation. If, on the other hand, the manure be impacted, the +slower but more regular fermentation, due to the anaerobic type of +organism, will be chiefly promoted. It must be remembered that in the +proper rotting of farmyard manure both kinds of fermentation should be +fostered. It is, in fact, on the careful regulation of the two classes +of fermentation that the successful rotting of the manure depends. It +must further be remembered that, even with a certain amount of openness +in a manure-heap, anaerobic fermentation may take place. This is due to +the fact that the evolution of carbonic acid gas, in such a case, is so +<span class='pagenum'><a name="Page_257" id="Page_257">[Pg 257]</a></span>great as to exclude the access of the atmospheric oxygen into the pores +of the heap.</p> + +<p>3. The <i>dampness</i> of the manure-heap is another important influence. +This, of course, will act in two ways. First, by lowering the +temperature. Where the manure-heap is found to be suffering from +"fire-fang," the common method in practice is to lower the temperature +by moistening the heap with water. Secondly, it acts as a retarder of +fermentation by limiting the supply of atmospheric oxygen, and thus +preventing, as we have just seen, aerobic fermentation.</p> + +<p>4. The fourth chief influence in regulating fermentation of the +manure-heap is its <i>composition</i>, and more especially the amount of +nitrogen it contains in a soluble form. The rate at which fermentation +takes place in any organic substance may be said chiefly to depend on +the percentage of soluble nitrogenous matter it contains: the greater +this is in amount, the more quickly does fermentation go on. There are +always a number of soluble nitrogenous bodies in farmyard manure. These +are chiefly found in the urine, such as <i>urea</i>, <i>uric</i> and <i>hippuric +acids</i>, and <i>ammonia</i> salts.</p> + +<br /> +<p class="cen"><i>Products of Decomposition of Farmyard Manure.</i></p> + +<p>The most important of the changes which take place in the rotting of +farmyard manure may be briefly enumerated as follows:—</p> + +<p>1. The gradual conversion into gases of a large portion of the organic +elements in the manure. Of these gaseous <span class='pagenum'><a name="Page_258" id="Page_258">[Pg 258]</a></span>products the most abundant is +<i>carbonic acid gas</i> (CO<sub>2</sub>). It is in this form that the carbonaceous +matter which constitutes the chief portion of the manure escapes into +the air. Carbon also escapes into the air, combined with hydrogen, in +the form of <i>carburetted hydrogen</i> or <i>marsh-gas</i> (CH<sub>4</sub>), a product of +the decomposition of organic matter in the presence of a large quantity +of water. This gas is consequently found bubbling up through stagnant +water. Next to carbonic acid gas, <i>water</i> (H<sub>2O</sub>) is the most abundant +gaseous product of decomposition. The nitrogen present in the manure, in +different forms, is converted by the process of decomposition chiefly +into <i>ammonia</i>, which, combining with the carbonic acid, forms carbonate +of ammonia, a very volatile salt. It is to this fact that one of the +great sources of loss in the decomposition of farmyard manure is due. If +the temperature of the manure-heap be permitted to rise too high, the +carbonate of ammonia volatilises. It is probable, also, that a not +inconsiderable portion of the nitrogen escapes into the air in the free +state. The last of the most important gaseous products of decomposition +are <i>sulphuretted</i> and <i>phosphoretted hydrogen</i>. It is to these gases +that much of the smell of rotting farmyard manure is due.</p> + +<p>2. The second class of substances formed are <i>soluble organic acids</i>, +such as <i>humic</i> and <i>ulmic acids</i>. The function performed by these acids +is a very important <span class='pagenum'><a name="Page_259" id="Page_259">[Pg 259]</a></span>one. They unite with the ammonia and the alkali +substances in the mineral portion of the manure, forming humates and +ulmates of ammonia, potash, &c. It is these ulmates that form the black +liquor which oozes out from the manure-heap.</p> + +<p>In very rotten farmyard manure traces of <i>nitric acid</i> may be found; but +it must be remembered that the formation of nitrates is practically +impossible under the ordinary conditions of active fermentation of +farmyard manure, except perhaps in its very last stages.</p> + +<p>3. The third class of changes taking place have to do with the mineral +portion of the manure. The result of the formation of so much carbonic +and other organic acids is to increase the amount of <i>soluble</i> mineral +matter very considerably.</p> + +<br /> +<p class="cen"><i>Analyses of Farmyard Manure.</i></p> + +<p>It is chiefly to the valuable researches of the late Dr Augustus +Voelcker that we owe our knowledge of the composition of old and fresh +farmyard manure. All interested in this important question should peruse +the original papers on this subject contributed to the 'Journal of the +Royal Agricultural Society' by Dr Voelcker. Typical analyses +illustrating the variation in the composition of farmyard manure at +different stages of decomposition will be found in the Appendix.<a name="FNanchor_164_164" id="FNanchor_164_164"></a><a href="#Footnote_164_164" class="fnanchor">[164]</a> +From what has been already said, it is <span class='pagenum'><a name="Page_260" id="Page_260">[Pg 260]</a></span>obvious chat the composition of +farmyard manure is of a very variable nature.</p> + +<p>The quantity of moisture naturally varies most, and this variation will +depend on the age of the manure, and the conditions under which it is +permitted to decay. It may be taken at from a minimum of 65 per cent in +fresh to 80 per cent in well-rotted manure. The total organic matter may +be taken at from 13 to 14 per cent, containing nitrogen .4 to .65 per +cent. The total mineral matter will range from about 4 to 6.5 per cent, +containing of potash from .4 to .7 per cent, and of phosphoric acid from +.2 to .4 per cent.<a name="FNanchor_165_165" id="FNanchor_165_165"></a><a href="#Footnote_165_165" class="fnanchor">[165]</a></p> + +<p>As Mr Warington<a name="FNanchor_166_166" id="FNanchor_166_166"></a><a href="#Footnote_166_166" class="fnanchor">[166]</a> has pointed out, one ton of farmyard manure would +thus contain 9 to 15 lb. of nitrogen, about the same quantity of potash, +and 4 to 9 lb. of phosphoric acid. These quantities of nitrogen and +phosphoric acid, calculated to (95 per cent) nitrate of soda, and (97 +per cent) sulphate of ammonia, and (25 per cent) superphosphate, give +respectively 57.25 to 96 lb. nitrate of soda, 45 to 75 lb. sulphate of +ammonia, and 35 to 79 lb. superphosphate. That is, in order to apply as +much nitrogen to the soil as is contained in one ton of nitrate of soda, +we should require to use from 23 to 41 tons of farmyard manure: +similarly one ton of sulphate of ammonia contains as much nitrogen as 30 +to 50 tons farmyard manure. In <span class='pagenum'><a name="Page_261" id="Page_261">[Pg 261]</a></span>the same way one ton of superphosphate +of lime contains as much phosphoric acid as 28 to 64 tons farmyard +manure.</p> + +<p>The value of rotten manure is, weight for weight, greater than that of +fresh manure. This is due to the fact that, while the water increases in +amount, the loss of organic matter of a non-nitrogenous nature more than +counterbalances the increase in water. The manure, therefore, becomes +more concentrated in quality. The loss on the total weight, according to +Wolff, in the rotting of farmyard manure, should not exceed in two or +three months' time 16 to 20 per cent—viz., a sixth to a fifth of its +entire weight. Not only, however, does the manure become richer in +manurial ingredients, but the forms in which the manurial ingredients +are present in rotten manure are more valuable, as they are more +soluble. These statements must not be taken as proving that it is more +economical to apply farmyard manure in a rotten condition than in a +fresh one. The distinction must not be lost sight of which exists +between relative increase—increase in the percentage of valuable +constituents—and absolute increase. The increase in the value of the +manure by the changes of the manurial ingredients from the insoluble to +the soluble condition may be effected at the expense of a considerable +amount of absolute loss of these valuable ingredients. This is a point +which is probably too often left out of account in discussing the +relative merits of fresh and rotten <span class='pagenum'><a name="Page_262" id="Page_262">[Pg 262]</a></span>farmyard manure; and it is +important that it should be clearly understood. In the words of the late +Dr Voelcker: "Direct experiments have shown that 100 cwt. of fresh +farmyard manure are reduced to 80 cwt. if allowed to lie till the straw +is half rotten; 100 cwt. of fresh farmyard manure are reduced to 60 cwt. +if allowed to ferment till it becomes 'fat or cheesy'; 100 cwt. of fresh +farmyard manure are reduced to 40-50 cwt. if completely decomposed. This +loss not only affects the water and other less valuable constituents of +farmyard manure, but also its most fertilising ingredients. Chemical +analysis has shown that 100 cwt. of common farmyard manure contain about +40 lb. of nitrogen, and that during fermentation in the first period 5 +lb. of nitrogen are dissipated in the form of volatile ammonia; in the +second, 10 lb.; in the third, 20 lb. Completely decomposed common manure +has thus lost about one-half of its most valuable constituent."<a name="FNanchor_167_167" id="FNanchor_167_167"></a><a href="#Footnote_167_167" class="fnanchor">[167]</a> +While, of course, a very great amount of absolute loss of the valuable +constituents—the nitrogen and ash-constituents—of farmyard manure may +take place through volatilisation and drainage, by taking requisite +precautions this loss may be very much minimised. As regards the total +loss, this, in two or three months' time, should only amount to 16 to 20 +<span class='pagenum'><a name="Page_263" id="Page_263">[Pg 263]</a></span>per cent—or one-sixth to one-fifth of the weight.<a name="FNanchor_168_168" id="FNanchor_168_168"></a><a href="#Footnote_168_168" class="fnanchor">[168]</a> The use of +fixers, to which reference has already been made, will greatly minimise +this loss. The application of fixers is best made to the manure when +still in the stall or byre. The health of the animal benefits by so +doing, while the manure is at once guarded against loss from this +source.</p> + +<p>As to the relative merits of covered and uncovered manure-heaps, much +difference of opinion exists. It is one of those questions which does +not admit of final decision one way or another, as it depends so largely +on the individual circumstances of each case. That manure produced under +cover is more valuable than manure made in the open is readily granted. +The question, however, is as to whether the increase in its value is +sufficiently great to warrant the extra expense involved in building +covered courts. This depends on the individual circumstances of each +case, and cannot be decided in a general way. For experiments on the +relative value of manure made under cover and in the open, see +Appendix.<a name="FNanchor_169_169" id="FNanchor_169_169"></a><a href="#Footnote_169_169" class="fnanchor">[169]</a></p> + +<p>The method of applying farmyard manure to the field is a question which +belongs more to the practical farmer than, to the scientist, and must be +largely decided by economic considerations. There is an aspect, however, +of the question which may well be treated here. The first point in the +production of good manure is in <span class='pagenum'><a name="Page_264" id="Page_264">[Pg 264]</a></span>connection with its even distribution. +It is of great importance that the excrements of the different farm +animals be thoroughly mixed together. By the intimate incorporation of +the "hot" horse-dung with the "cold" cow and pig dung, uniform +fermentation is secured. Fire-fang—or too rapid fermentation—may occur +from this not being properly done, and from the manure becoming too dry. +It is important, also, as we shall see immediately, to have the manure +uniform in quality when applied to the field. The manure ought to be +firmly trodden down, to moderate the rate of fermentation. Where the +manure-heap is exposed to rain, the quantity of water it will naturally +receive will probably be quite sufficient, if indeed not too much, to +ensure a proper rate of fermentation—except, perhaps, in very warm +weather. The great point to be aimed at is to ensure regular +fermentation. What has to be especially avoided is any sudden exposure +of the manure to large quantities of water. The result of such a +washing-out of the soluble nitrogen is to retard fermentation, besides +incurring the risk of great actual loss by drainage.<a name="FNanchor_170_170" id="FNanchor_170_170"></a><a href="#Footnote_170_170" class="fnanchor">[170]</a></p> + +<br /> +<p class="cen"><i>Application of Farmyard Manure to the Field.</i></p> + +<p>In applying the manure to the field, and before ploughing it in, two +methods of procedure may be pursued. First, the manure may be set out in +heaps, <span class='pagenum'><a name="Page_265" id="Page_265">[Pg 265]</a></span>larger or smaller, over the field, and be allowed to remain in +these heaps some time before being spread; and secondly, it may be +directly spread broadcast over the field, and thus allowed to lie for +some time. Lastly, the manure may be ploughed in immediately; and it may +be stated that such a method is, where circumstances permit, the safest +and most economical method.<a name="FNanchor_171_171" id="FNanchor_171_171"></a><a href="#Footnote_171_171" class="fnanchor">[171]</a></p> + +<p>In discussing the merits and demerits of these two methods, Dr Heiden +points out, first, with regard to the distribution of the manure in +small heaps over the field, that this is not to be recommended, on the +following grounds:—</p> + +<p>1. Because the chances of loss by volatilisation are thereby increased. +The manure is distributed several times instead of only once or twice.</p> + +<p>2. It is apt to ensure unequal distribution. The separate heaps run the +risk of losing their soluble nitrogenous matter, which soaks into the +ground beneath the heaps. The other portions of the field not covered by +the manure-heaps are thus manured with washed-out farmyard manure, +bereft of its most valuable constituents. The result is, that while +certain portions of the field are too strongly manured, other portions +are too weakly manured.</p> + +<p><span class='pagenum'><a name="Page_266" id="Page_266">[Pg 266]</a></span>3. The proper fermentation of the manure is apt to be interfered with by +the loss of that which is its most important agent—viz., the soluble +nitrogenous matter—and also by the drying action of the wind.</p> + +<p>The same objections hold good to a large extent with regard to the +setting out in the fields of the manure in large heaps. The risks of +loss, in one respect, may be said to be less, owing to the smaller +surface presented. On the other hand, they may be greater, owing to +fermentation taking place more quickly. Agricultural practice, however, +often renders this custom necessary; and if precautions are taken not to +let the heap lie too long, and to cover it over with earth, the risk of +serious loss may be rendered inconsiderable.</p> + +<p>With regard to the second method of procedure—viz., the spreading of +the manure broadcast over the field, and allowing it thus to lie—Dr +Heiden is of opinion that this should only be done when the field is +level. In the case of uneven ground the risks are, of course, obvious. +It has been affirmed that, by allowing farmyard manure thus to lie +exposed for some time, an important loss of volatile ammonia—carbonate +of ammonia—is apt to take place. This could only take place where the +former treatment of the farmyard manure had been bad. Hellriegel has +shown that in the case of properly prepared farmyard manure there is no +danger of loss in this way. The absorptive power of the soil for +ammonia, it must be <span class='pagenum'><a name="Page_267" id="Page_267">[Pg 267]</a></span>remembered, is very great, and the amount of +volatile ammonia in farmyard manure is relatively so small that it is +scarcely possible that any could escape in this way. Hellriegel's +experiments have demonstrated this in a very striking way. He has found +that in the case of a chalky soil, and during the summer and autumn +months, practically no loss of ammonia takes place. The following +considerations may be further urged in support of this method of +application, as against immediately ploughing in the manure, viz.:—</p> + +<br /> +<p class="cen">1. That fermentation takes place more quickly.</p> + +<p>2. That it results in a more equable distribution of the manurial +constituents in the dung, by gradually and thoroughly incorporating the +liquid portion of the manure with the soil-particles.</p> + +<p>Against, however, these undoubted advantages, one serious disadvantage +may be urged—viz., that the manure, before being ploughed in, becomes +robbed to a large extent of its soluble nitrogenous compounds, which, as +we have repeatedly observed, are so necessary for fermentation; and +that, therefore, when it is ploughed in, it does not so readily ferment. +This being so, it is highly advisable, in the case of light or sandy +soils, not to follow such a practice, but to plough the manure directly +in.</p> + +<p>As to the depth to which it is advisable to plough the manure in, it may +be here noticed that it should not be too deep, so as to permit of the +access of <span class='pagenum'><a name="Page_268" id="Page_268">[Pg 268]</a></span>sufficient moisture to ensure proper fermentation, and to +prevent rapid washing down of nitrates to the drains. Lastly, it need +scarcely be pointed out that it is highly important to have the manure +evenly and thoroughly incorporated with the soil-particles. Where the +manure is permitted to cake together in lumps, it may successfully +resist the action of fermentation for several years.</p> + +<br /> +<p class="cen"><i>Value and Function of Farmyard Manure.</i></p> + +<p>Practical experience has long demonstrated the fact that farmyard manure +is, taking it all round, the most valuable, and admits of the most +universal application, of all manures; and science has done much to +explain the reason of this. The influence of farmyard manure is so +many-sided that it is difficult even to enumerate its different +functions. As has already been pointed out, its indirect value as a +manure is probably as great as, if indeed even not greater than, its +direct value. In concluding our study of farmyard manure, we shall +endeavour to summarise, in as brief a manner as possible, its chief +properties.</p> + +<p>First, as to its value as a supplier of the necessary elements of +plant-food. This, there can be little doubt, has been, and still is, +grossly exaggerated by the ordinary farmer. Much has been claimed for it +as a "general" manure. How far it merits pre-eminence on this score +among other manures will be seen in the <span class='pagenum'><a name="Page_269" id="Page_269">[Pg 269]</a></span>sequel. It is true that, since +it is composed of vegetable matter, it contains all the necessary plant +ingredients.<a name="FNanchor_172_172" id="FNanchor_172_172"></a><a href="#Footnote_172_172" class="fnanchor">[172]</a> As has been shown in the Introduction, there is +practically in the case of most soils no necessity to add to a manure +any more than the three ingredients, <i>nitrogen</i>, <i>phosphoric acid</i>, and +<i>potash</i>. Its value, then, as a direct manure, must depend on the +quantity and proportion in which these three ingredients are present. +These substances, as we have already seen, it contains only in very +small quantities. It is, judged from this point of view, a comparatively +poor manure. Furthermore, only a certain percentage of these substances +is in a soluble or immediately available condition,—in this respect the +rotten manure being very much more valuable than the fresh manure.</p> + +<p>Again, a point of great importance in a universal manure is the +proportion in which the necessary plant-foods are present. If it be +asked, Are the nitrogen, phosphoric acid, and potash in farmyard manure +present in the proportion in which crops require these constituents? the +answer must be in the negative. Heiden<a name="FNanchor_173_173" id="FNanchor_173_173"></a><a href="#Footnote_173_173" class="fnanchor">[173]</a> has very strikingly +illustrated this point, in so far as the relations between the two ash +ingredients are concerned, by some computations as to the amount which +would be removed from the soil in the course of <span class='pagenum'><a name="Page_270" id="Page_270">[Pg 270]</a></span>different +rotations.<a name="FNanchor_174_174" id="FNanchor_174_174"></a><a href="#Footnote_174_174" class="fnanchor">[174]</a> In the case of five different rotations it was found +that the ratio between the potash and phosphoric acid removed was as +follows:<a name="FNanchor_175_175" id="FNanchor_175_175"></a><a href="#Footnote_175_175" class="fnanchor">[175]</a> (1) 2.96 to 1; (2) 2.76 to 1; (3) 2.95 to 1; (4) 4.13 to +1; (5) 3.78 to 1. This would give a mean of 3.32 to 1. This is not the +ratio in which these ingredients are generally present in farmyard +manure. Farmyard manure may be said to be much richer in the mineral +constituents of plants than in nitrogen. Professor Heiden found that in +the case of a farm at Waldau, the crops in the course of ten years +removed from a <i>morgen</i> (.631 of an acre) the following quantities:—</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="Nitrogen"> + <tr> + <td class="tdl" width="80%"> </td> + <td class="tdr" width="20%">lb.</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdr">329</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdr">263</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdr">121</td> + </tr> +</table> +</div> + +<p>In order to supply these amounts the following quantities of manure +would require to be supplied:—</p> + +<p>1. For the nitrogen, 26 or 27 tons (manure containing .606 per cent +nitrogen).</p> + +<p>2. For the potash, 20 to 25 tons (manure containing .672 per cent +potash).</p> + +<p>3. For the phosphoric acid, 13 to 19 tons (manure containing .315 per +cent phosphoric acid).</p> + + +<p>From the above it will be seen that farmyard <span class='pagenum'><a name="Page_271" id="Page_271">[Pg 271]</a></span>manure contains too little +nitrogen in proportion to its ash ingredients.</p> + +<p>It is not merely the amount of fertilising ingredients removed by the +crop we have to take into account in estimating the value of certain +manurial ingredients for the different crops. Two other considerations +have to be remembered—viz., the amount of the constituents already +present in the soil, and the ability of the different crops to obtain +the ingredients from the soil. If we take into account these two +considerations in estimating the value of farmyard manure as a general +manure, we shall find that they accentuate the inadequacy of the ratio +existing between the nitrogen and the mineral ingredients. Messrs Lawes +and Gilbert have found in the Rothamsted experiments with farmyard +manure, that while it restored the mineral ingredients, it was +inadequate as a sufficient source of nitrogen. Nitrogen is, of all +manurial ingredients, in least abundance in soils. It is consequently +found that the ingredient in which farmyard manure requires to be +reinforced is nitrogen. With regard to phosphoric acid and potash, it +has already been shown that the ratio between them is probably greater +than that in a good average manure. We should, arguing from this alone, +be inclined to think that farmyard manure would be best reinforced with +potash. The reverse is the case, however, as every farmer knows. This is +due, first, to the fact that the potash, unlike the phosphoric acid, is +entirely of a soluble nature, and therefore <span class='pagenum'><a name="Page_272" id="Page_272">[Pg 272]</a></span>immediately available for +the plant's needs; and secondly, to the fact that the necessity for the +application of potash as a manure is generally not nearly so great as in +the case of phosphoric acid. The result is, that farmyard manure will +be, as a rule, more valuably supplemented by phosphoric acid than by +potash.</p> + +<p>Another point of great importance, in estimating the value of farmyard +manure as a chemical manure, is the inferior value possessed by much of +the nitrogen it contains, as compared with the nitrogen in such +artificial manures as nitrate of soda and sulphate of ammonia. According +to the Rothamsted experiments, weight for weight, the nitrogen in +farmyard manure is not half so valuable as it is in sulphate of ammonia. +Much of the nitrogen becomes only very slowly available; not a little of +it perhaps actually takes years to be converted into nitrates.<a name="FNanchor_176_176" id="FNanchor_176_176"></a><a href="#Footnote_176_176" class="fnanchor">[176]</a></p> + +<p><span class='pagenum'><a name="Page_273" id="Page_273">[Pg 273]</a></span>Thus, with regard to the direct value of farmyard manure as a manure, we +have seen—</p> + +<p>1. That it contains a very small quantity of the three fertilising +ingredients.</p> + +<p>2. That the proportion in which these three ingredients are present is +not the best proportion for the requirements of crops.</p> + +<p>3. That the form in which a portion of these ingredients—nitrogen and +phosphoric acid—is present is not of the most valuable kind.</p> + +<p>It is consequently not as a direct chemical manure that farmyard manure +is pre-eminently valuable. We must seek for perhaps its most valuable +properties in its indirect influence.</p> + +<p>It adds to the soil a large quantity of organic matter. Most soils are +improved by the addition of <i>humus</i>. The water-absorbing and retaining +powers of a soil are increased by this addition of <i>humus</i>, while it +enables the soil to attract an increased amount of moisture from the +air. This is often of great importance, as in the period of germination +of seed.<a name="FNanchor_177_177" id="FNanchor_177_177"></a><a href="#Footnote_177_177" class="fnanchor">[177]</a> The influence it exerts on the texture of the soil in the +process of <span class='pagenum'><a name="Page_274" id="Page_274">[Pg 274]</a></span>fermentation is also very great. This is especially so in +soils whose texture is too close, such as heavy clayey soils. It opens +up their pores to the air, and renders them more friable. Where such an +influence is most required, as in clayey soils, the manure ought to be +applied in a fresh condition, so that the maximum influence exerted by +the manure in this direction may be experienced. On light soils, on the +contrary, whose friability and openness are already too great, and which +do not require to be increased, the manure will be best applied in a +rotten condition. It adds, further, greatly to the heat of the soils by +its decomposition. Thus on cold damp soils it effects one very marked +benefit. The influence it exerts in its decomposition upon the +fertilising ingredients present in the soil is also by no means +inconsiderable. In the process of its fermentation large quantities of +carbonic acid gas are generated. This carbonic acid probably acts in a +double capacity. It will, in the first place, greatly increase the +solvent power of the soil-water, and thus enable it to set free an +increased amount of mineral plant-food; and secondly, it will help to +conserve a certain quantity of the soil-nitrogen, by preventing its +conversion into nitrates.</p> + +<p>As its indirect and mechanical properties are greatest when in its fresh +condition, it will be better to apply it in that condition to soils most +lacking in these mechanical properties. We may therefore say that +farmyard manure is best applied in a rotted condition <span class='pagenum'><a name="Page_275" id="Page_275">[Pg 275]</a></span>to light sandy +soils, and to soils in a high state of cultivation, where its mechanical +properties are not so much required.</p> + +<p>An important point still remains to be discussed—viz., the rate at +which the farmyard manure should be applied. This, of course, should +naturally depend on a variety of circumstances—the amount of artificial +manures used as supplementary to the farmyard manure, the frequency of +its application, and the nature of the soil.</p> + +<p>These considerations naturally vary so much, that the quantities of +farmyard manure it is advisable to apply in different cases are widely +different. There is a strong probability that the rate at which farmyard +manure has been applied in the past has been grossly in excess of what +could be profitably employed. Opinion is gaining ground among practical +farmers, that smaller and more frequent applications of farmyard manure +to the soil would be fraught with better results than the older custom +of applying a large dressing at a time. This is an opinion in the +support of which science can urge strong arguments. It is only of late +years that we have come to recognise sufficiently the various risks +which all fertilisers are subject to in the soil, and the importance, +therefore, of minimising these risks as much as possible by putting into +the soil at one time only as much manure as it is safely able to retain.</p> + +<p>"The famous old German writer Thaer regarded 17 <span class='pagenum'><a name="Page_276" id="Page_276">[Pg 276]</a></span>or 18 tons as an +abundant dressing; 14 tons he called good, and 8 or 9 tons light. Other +German authorities speak of 7 to 10 tons as light, 12 to 18 tons as +usual, 20 or more tons as heavy, and 30 tons as a very heavy +application."<a name="FNanchor_178_178" id="FNanchor_178_178"></a><a href="#Footnote_178_178" class="fnanchor">[178]</a></p> + +<p>In the new edition of Stephens' 'Book of the Farm,'<a name="FNanchor_179_179" id="FNanchor_179_179"></a><a href="#Footnote_179_179" class="fnanchor">[179]</a> from 8 to 12 +tons per acre for roots, and from 15 to 20 tons for potatoes, along with +artificials, which may cost from 25s. to 60s. per acre additional, are +quoted as general dressings.</p> + +<p>The majority of recent experiments with farmyard manure would seem to +indicate that, even in the case of what are considered small dressings, +the extra return in crop the first year after application is not such as +to cover the expense of the manure. Of course, as is commonly pointed +out, the effect of farmyard manure is of a lasting nature, and is +probably felt throughout the whole rotation, or even longer. This, to a +certain extent, is no doubt true; still it may be strongly doubted +whether farmyard manure is, after all, an economical manure, as compared +with artificial manures. The desirability of manuring the soil and not +the crop is, in this age of keen competition, no longer believed in; and +the Rothamsted experiments have shown that it is highly doubtful whether +even the soil benefits to anything like a commensurate extent by the +application of large quantities of farmyard manure. <span class='pagenum'><a name="Page_277" id="Page_277">[Pg 277]</a></span>This is of course +assuming for farmyard manure the value that it would fetch when sold, +or, to put it rather differently, the price it would cost if the farmer +had to purchase it. Farmyard manure is a necessary bye-product of the +farm, and can scarcely be regarded, therefore, in the same light as the +artificial manures which the farmer buys.<a name="FNanchor_180_180" id="FNanchor_180_180"></a><a href="#Footnote_180_180" class="fnanchor">[180]</a></p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_131_131" id="Footnote_131_131"></a><a href="#FNanchor_131_131"><span class="label">[131]</span></a> See Appendix, Note I., p. 279.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_132_132" id="Footnote_132_132"></a><a href="#FNanchor_132_132"><span class="label">[132]</span></a> "The large amount of potash in unwashed wool is very +remarkable: a fleece must sometimes contain more potash than the whole +body of the shorn sheep."—Warington's 'Chemistry of the Farm,' p. 78.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_133_133" id="Footnote_133_133"></a><a href="#FNanchor_133_133"><span class="label">[133]</span></a> See Appendix, Note II., p. 279.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_134_134" id="Footnote_134_134"></a><a href="#FNanchor_134_134"><span class="label">[134]</span></a> The urine of the pig, from the nature of its food, is, as +a general rule, a very poor nitrogenous manure.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_135_135" id="Footnote_135_135"></a><a href="#FNanchor_135_135"><span class="label">[135]</span></a> See Appendix, Note XV., p. 290.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_136_136" id="Footnote_136_136"></a><a href="#FNanchor_136_136"><span class="label">[136]</span></a> See Appendix, Note III., p. 280.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_137_137" id="Footnote_137_137"></a><a href="#FNanchor_137_137"><span class="label">[137]</span></a> See Appendix, Note XVIII., p. 291.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_138_138" id="Footnote_138_138"></a><a href="#FNanchor_138_138"><span class="label">[138]</span></a> The nitrogen present in the urine, it may be well to +point out, is derived from the waste of nitrogenous tissue as well as +from nitrogenous matter of the food digested.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_139_139" id="Footnote_139_139"></a><a href="#FNanchor_139_139"><span class="label">[139]</span></a> Note IV., p. 281.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_140_140" id="Footnote_140_140"></a><a href="#FNanchor_140_140"><span class="label">[140]</span></a> Warington puts this matter admirably in the following +words: "If the food is nitrogenous and easily digested, the nitrogen in +the urine will greatly preponderate. If, on the other hand, the food is +one imperfectly digested, the nitrogen in the solid excrement may form +the larger quantity. When poor hay is given to horses, the nitrogen in +the solid excrement will exceed that contained in the urine. On the +other hand, corn, cake, and roots yield a large excess of nitrogen in +the urine." ('Chemistry of the Farm,' p. 137).</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_141_141" id="Footnote_141_141"></a><a href="#FNanchor_141_141"><span class="label">[141]</span></a> See p. 281.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_142_142" id="Footnote_142_142"></a><a href="#FNanchor_142_142"><span class="label">[142]</span></a> See p. 282.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_143_143" id="Footnote_143_143"></a><a href="#FNanchor_143_143"><span class="label">[143]</span></a> See Heiden's 'Düngerlehre,' vol. ii. p. 58.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_144_144" id="Footnote_144_144"></a><a href="#FNanchor_144_144"><span class="label">[144]</span></a> Heiden's 'Düngerlehre,' vol. i. p. 404.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_145_145" id="Footnote_145_145"></a><a href="#FNanchor_145_145"><span class="label">[145]</span></a> The following quantities of nitrogen are found in rye, +pea, and bean straw:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Ranging"> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdc" width="25%">Ranging from</td> + <td class="tdc" width="25%">Average</td> + <td class="tdc" width="25%">Lb.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + <td class="tdc">per ton.</td> + </tr> + <tr> + <td class="tdl">Rye-straw</td> + <td class="tdc"> .30 to .73</td> + <td class="tdc"> .57</td> + <td class="tdc">12.76</td> + </tr> + <tr> + <td class="tdl">Pea-straw</td> + <td class="tdc"> .76 to 1.61</td> + <td class="tdc">1.21</td> + <td class="tdc">27.10</td> + </tr> + <tr> + <td class="tdl">Bean-straw</td> + <td class="tdc">1.15 to 2.62</td> + <td class="tdc">1.92</td> + <td class="tdc">43.00</td> + </tr> +</table> +</div> +</div> + + +<div class="footnote"><p class="noin"><a name="Footnote_146_146" id="Footnote_146_146"></a><a href="#FNanchor_146_146"><span class="label">[146]</span></a> Dr J. M. H. Munro recommends the sprinkling of a little +finely sifted peat-powder in addition to straw, as an excellent means of +preventing loss of volatile ammonia in the fermentation of manure.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_147_147" id="Footnote_147_147"></a><a href="#FNanchor_147_147"><span class="label">[147]</span></a> See 'Mark Lane Express,' October 7, 1889, p. 475.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_148_148" id="Footnote_148_148"></a><a href="#FNanchor_148_148"><span class="label">[148]</span></a> See Appendix, Note VII., p. 283.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_149_149" id="Footnote_149_149"></a><a href="#FNanchor_149_149"><span class="label">[149]</span></a> For analyses see Appendix, Note VIII., p. 283.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_150_150" id="Footnote_150_150"></a><a href="#FNanchor_150_150"><span class="label">[150]</span></a> According to Storer, in a ton of autumn leaves of the +best quality there would be 6 lb. of potash, less than 3 lb. of +phosphoric acid, and 10 or 15 lb. of nitrogen. Another substance that +may be used as a litter is sawdust. This substance is a good absorbent, +but is of little value as a manurial substance.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_151_151" id="Footnote_151_151"></a><a href="#FNanchor_151_151"><span class="label">[151]</span></a> Heiden's 'Düngerlehre,' vol. ii. pp. 34, 66. In +Boussingault's experiments the food consisted of 15 lb. <i>hay</i>, 4.54 lb. +<i>oats</i>, and 32 lb. water; the total excrements amounting to 31.16 lb., +containing 7.42 lb. dry matter. In Hofmeister's experiments the food +consisted of 5.23 lb. <i>hay</i>, 6.18 lb. <i>oats</i>, 1 lb. <i>chopped straw</i>, and +25.57 lb. water; the excrements amounting to 25.07 lb., containing 5.32 +lb. dry matter.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_152_152" id="Footnote_152_152"></a><a href="#FNanchor_152_152"><span class="label">[152]</span></a> This is taking no account of the amount of water which +the manure will absorb, and which will probably double the quantity.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_153_153" id="Footnote_153_153"></a><a href="#FNanchor_153_153"><span class="label">[153]</span></a> See Appendix, Note IX., p. 283.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_154_154" id="Footnote_154_154"></a><a href="#FNanchor_154_154"><span class="label">[154]</span></a> The rapid fermentation of horse-manure is due to its +mechanical as well as its chemical nature. The horse does not reduce its +food to such small pieces, and its urine is rich in nitrogen.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_155_155" id="Footnote_155_155"></a><a href="#FNanchor_155_155"><span class="label">[155]</span></a> Schulze recommends one-third of a pound per day of +sulphate of lime for each horse.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_156_156" id="Footnote_156_156"></a><a href="#FNanchor_156_156"><span class="label">[156]</span></a> See Appendix, Note X., p. 284.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_157_157" id="Footnote_157_157"></a><a href="#FNanchor_157_157"><span class="label">[157]</span></a> The food consisted of 30 lb. <i>potatoes</i>, 15 lb. <i>hay</i>, +and 120 lb. <i>water</i>.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_158_158" id="Footnote_158_158"></a><a href="#FNanchor_158_158"><span class="label">[158]</span></a> For further analyses of cow-manure, see Appendix, Note +XI., p. 286.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_159_159" id="Footnote_159_159"></a><a href="#FNanchor_159_159"><span class="label">[159]</span></a> This is for a pig of six to eight months old, and fed on +potatoes.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_160_160" id="Footnote_160_160"></a><a href="#FNanchor_160_160"><span class="label">[160]</span></a> It has been asserted that the use of pig-manure, when +applied alone, is apt to give an unpleasant taste to the produce grown.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_161_161" id="Footnote_161_161"></a><a href="#FNanchor_161_161"><span class="label">[161]</span></a> Taken from a very large number of analyses by a number of +experimenters. See Heiden's 'Düngerlehre,' vol. i. p. 99.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_162_162" id="Footnote_162_162"></a><a href="#FNanchor_162_162"><span class="label">[162]</span></a> See Storer, 'Agricultural Chemistry,' vol. ii. p. 96.</p> + +<p class="noin">A question of great importance is as to the amount of farmyard manure +produced on a farm in a year, and its value. This is a question which is +extremely difficult to satisfactorily deal with. Various methods of +calculating this amount have been resorted to. It may be well to state +these pretty fully. Some practical authorities estimate the amount by +calculating that every ton of straw should produce 4 tons of manure. +Another method consists in estimating the amount from the size of the +farm. Sir John Lawes has calculated the composition of farmyard manure +which should be produced in the case of a farm of 400 acres, farmed on +the four-course system. He assumes that half of the roots and 100 tons +of hay are consumed at the homestead; that the whole of the straw of the +corn crops is retained at home as food and litter; that twelve horses +have corn equal to 10 lb. of oats per head per day; and that about ten +shillings per acre are expended in the purchase of cake for feeding +stock. Under these conditions the amount of farmyard manure should be +855 tons (or an average of 8-1/2 tons for each of the 100 acres of +root-crop) of <i>fresh undecomposed dung</i>. (For composition, see Appendix, +Note XVII., p. 291.) Another method is by taking, as the data of +calculation, the number of cattle, horses, sheep, &c., producing the +manure. Lloyd considers that a fattening animal requires 3 tons of straw +in the year, and makes about 12 tons of manure. A farmer, therefore, +should make 8 tons of manure for every acre of that part of his land +which, in the four-course rotation, is put down to turnips.</p> + +<p class="noin">The last method consists in taking as the data the amount of food +consumed and litter used in the production of the manure. Of these +methods Heiden considers the last as alone satisfactory and trustworthy. +Applying this method to the horse, he shows, from experiments, that a +little over 47 per cent of the dry matter of its food has been proved to +be voided in the solid and liquid excreta. Taking the average percentage +of water in the excreta as about 77.5, the percentage of dry matter in +the excreta will be 22.5. That is, every pound of dry matter in the food +eaten by the horse yields a little over 2 lb. of excrementitious matter. +To this of course must be added the amount of straw used as litter, +which may be taken at 6.5 lb.</p> + +<p class="noin">From these data we may calculate the amount of manure produced in a year +by a horse, making certain assumptions as to the amount of work +performed. This Heiden does by assuming that a horse works 260 days, of +twelve hours each, in the course of a year, or 130 whole days, spending +235 days in the stall. Calculating from the above data, he estimates +that a well-fed working horse will produce about 50 lb. of manure in a +day, or 6.5 tons in a year. Of course this does not necessarily +represent all the manure actually produced by the horse, but how much of +the remaining portion of the manure actually finds its way to the farm +it is impossible to say. According to the 'Book of the Farm,' Division +III. p. 98, a farm-horse makes about 12 tons of manure in a year.</p> + +<p class="noin">It has been calculated that cows void about 48 per cent of the dry +matter of their food in the solid and liquid excreta, which contain of +water, on an average, 87.5 per cent. That is, every pound of dry matter +will furnish 3.84 lb. of total excreta. By adding the necessary amount +of straw for litter (which may be taken at one-third the weight of the +dry matter of the fodder), Heiden calculates that an ox weighing 1000 +lb. should produce 113 lb. of manure in a day, or 20 tons in a year. The +'Book of the Farm,' Division III. p. 98, gives the annual amount at from +10 to 14 tons. According to Wolff, one may assume that on an average the +fresh excrements (both liquid and solid) of the common farm animals +(with the exception of the pig) contain of every 100 lb. of dry matter +in the food consumed about 50 lb., or a half. Estimating the dry matter +in the litter used at equal to about 1/4 of the dry matter of the food, +this would mean that for every 100 lb. of dry matter consumed in food +there would be 75 lb. of dry manure (viz., 50 lb. dry excrements + 25 +lb. dry litter), which would yield 300 lb. of farmyard manure in the wet +state—<i>i.e.</i>, with 75 per cent water. The amount of food daily required +per every 1000 lb. of live-weight of the common farm animals may be +taken, roughly speaking, at 24 lb. dry food material and 6 lb. of straw +as litter. The daily production of manure for 1000 lb. of live-weight +would amount, therefore, to 18 lb. of dry, or 72 lb. wet manure. (See +Appendix, Note XVII., p. 291.) According to J. C. Morton and Evershed, +oxen feeding in boxes require 20 lb. of straw per head per day as +litter. An ox, therefore, will make 8 tons of fresh dung in six months, +using 32 cwt. of litter. This means that each ton of litter gives 5 tons +of fresh dung. It is calculated that nearly twice as much litter must be +used in open yards.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_163_163" id="Footnote_163_163"></a><a href="#FNanchor_163_163"><span class="label">[163]</span></a> It has been calculated that under ordinary circumstances +sheep-dung, when allowed to ferment by itself, should do so in about +four months, horse-dung in six months, and cow-dung in eight months.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_164_164" id="Footnote_164_164"></a><a href="#FNanchor_164_164"><span class="label">[164]</span></a> See Appendix, Note XII., p. 286.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_165_165" id="Footnote_165_165"></a><a href="#FNanchor_165_165"><span class="label">[165]</span></a> See Heiden's 'Düngerlehre,' vol. ii. p. 156.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_166_166" id="Footnote_166_166"></a><a href="#FNanchor_166_166"><span class="label">[166]</span></a> Warington, 'Chemistry of the Farm,' p. 33.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_167_167" id="Footnote_167_167"></a><a href="#FNanchor_167_167"><span class="label">[167]</span></a> Recent experiments by Müntz and Girard in France have +shown that the loss in sheep excreta from volatilisation of the +carbonate of ammonia amounted to over 50 per cent. By the use of straw +litter this was reduced to about a half less, and with earth litter one +quarter less.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_168_168" id="Footnote_168_168"></a><a href="#FNanchor_168_168"><span class="label">[168]</span></a> See Appendix, Note XIII., p. 288.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_169_169" id="Footnote_169_169"></a><a href="#FNanchor_169_169"><span class="label">[169]</span></a> See Appendix, Note XIV., p. 289.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_170_170" id="Footnote_170_170"></a><a href="#FNanchor_170_170"><span class="label">[170]</span></a> See Appendix, Note XV., p. 290.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_171_171" id="Footnote_171_171"></a><a href="#FNanchor_171_171"><span class="label">[171]</span></a> For spring application rotten farmyard manure is +generally used, because in this condition its fertilising matter is more +quickly available. On light land it is best to apply it in the rotten +condition shortly before it is likely to be used. (See p. 261.)</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_172_172" id="Footnote_172_172"></a><a href="#FNanchor_172_172"><span class="label">[172]</span></a> The total amount of plant-food in a ton of farmyard +manure is together less than 1/20th of its total weight.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_173_173" id="Footnote_173_173"></a><a href="#FNanchor_173_173"><span class="label">[173]</span></a> See Heiden's 'Düngerlehre,' vol. ii. p. 171.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_174_174" id="Footnote_174_174"></a><a href="#FNanchor_174_174"><span class="label">[174]</span></a> For full details see Appendix, Note XVI., p. 290.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_175_175" id="Footnote_175_175"></a><a href="#FNanchor_175_175"><span class="label">[175]</span></a> Storer reproduces these results in his 'Agricultural +Chemistry,' vol. ii. p. 21.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_176_176" id="Footnote_176_176"></a><a href="#FNanchor_176_176"><span class="label">[176]</span></a> This aspect of farmyard manure has been ably stated by Mr +F. J. Cooke, a well-known Norfolk farmer. In commenting on the results +of the Rothamsted experiments, he says: "It is clear enough that the +faith of the farmer in the soil-enriching character of his home-made +manure is amply justified; the only question being, indeed, if this +quality be not too highly appreciated. It is not, after all, so much by +the fattening of our land as by the bounty of the crop grown upon it +that we reap the fruit of our exertions. The man of scientific mind +keeps his purpose fixed on the <i>production of good crops</i> mainly, and +the cheapest way to grow them. The experiments under consideration show +that richness of land may be purchased much too dearly, and that +richness of crop by no means bears the necessary relation to richness of +soil which has sometimes been imagined. We may boast of the 'lasting +qualities' of our dung, but the answer of science by these experiments +is, that so great is the last that the life of one man may not be long +enough to exhaust it. In the extravagant use of dung, therefore, such +considerations, amongst many others, as length of purse, as well as +length and character of tenure, must clearly be taken into account."</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_177_177" id="Footnote_177_177"></a><a href="#FNanchor_177_177"><span class="label">[177]</span></a> See paper on "Manurial Experiments with Turnips" by +author, in 'Transactions of the Highland and Agricultural Society of +Scotland;' 1891.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_178_178" id="Footnote_178_178"></a><a href="#FNanchor_178_178"><span class="label">[178]</span></a> Storer's 'Agricultural Chemistry,' vol. i. p. 498.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_179_179" id="Footnote_179_179"></a><a href="#FNanchor_179_179"><span class="label">[179]</span></a> Division III. p. 130.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_180_180" id="Footnote_180_180"></a><a href="#FNanchor_180_180"><span class="label">[180]</span></a> Mr F. J. Cooke, who has already been quoted, has kindly +furnished the author with his views on the peculiar functions of +farmyard manure as a manure. He says: "I look upon it, broadly speaking, +as chiefly of value in restoring to good land, after cropping, those +particular advantages which good land alone can give, and in helping +better than any other manure, when applied to poor land, to bring it up +to the level of good land in those particular merits which belong alone +to fine soils. I speak now of an inherent value in good soils, beyond +that attaching to them as mere reservoirs of abundant plant-food. For +instance, one may supply a poor soil by artificial manure with much more +food—and in a highly soluble condition—than is needed by the crop to +be grown upon it, and yet not get so good a crop as upon a naturally +richer but otherwise similar soil less abundantly filled with +immediately available food. This may arise from a more perfect +distribution of the plant-food in the rich soil, or from the steady way +in which it becomes available to the crop, as well as for other reasons. +But whatever the cause, there, I think, is the broad fact of the power +of farmyard manure to enrich poor soils, so to speak, more +naturally—that is, in a way which makes them more nearly correspond to +better soils than artificial manures can."</p> + +<p class="noin">Hence the indirect benefit to the farmer from farmyard manure is +probably greater than its direct value as a mere manure. And the usual +provision and use of it amongst all straw-growing farmers is +sufficiently justified. The extent, however, to which that course may be +beneficially carried, is one of the most important of the many difficult +economic and scientific problems which the farmer has to face.</p> + +<p class="noin">On the economic side must of course be considered the cost of +manufacture in individual instances, as ruled by the market value of the +straw, and the different circumstances and conditions under which the +various farm animals are kept and fed (I have the figures by me of one +well-known farmer, which show the cost to him of every ton of home-made +manure to be 20s. or more); the price the resultant crops may be +expected to command; the cost at the moment of artificial manures, &c., +&c. Whilst on the scientific side must be considered the nature of the +soil, the particular rotation of crops, &c.</p> + +<span class='pagenum'><a name="Page_278" id="Page_278">[Pg 278]</a></span> +<p class="noin">It was, amongst others, just these scientific and yet very definite and +practical problems we have tried to throw light on in the series of +field experiments conducted for several years by the Norfolk Chamber of +Agriculture. (See reprint of summary of same in last year's Report of +the Board of Agriculture.)</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_279" id="Page_279">[Pg 279]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER VII.</h2> +<br /> + +<p class="cen">NOTE I. (p. 225).</p> + +<p class="cen"><span class="smcap">Difference in Amount of Excreta voided for Food consumed</span>.</p> + +<p>With regard to the difference in the composition of the solid excreta +voided by different fattening animals fed on the same amount of food, +see Warington's 'Chemistry of the Farm,' p. 125, where it is shown that +for equal amount of live-weight, the sheep produces on the same weight +of dry food very much more manure than the pig, while the ox produces +even more than the sheep. Of course this does not refer to the total +amount of manure produced by the different animals, but only to the +amount of manure produced from the consumption of equal quantities of +food. This would seem to be owing to the greater capacity the pig has +for assimilating its food.</p> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 227).</p> + +<p class="cen"><span class="smcap">Solid Excreta voided by Sheep, Oxen, and Cows</span>.</p> + +<p>To contrast with the analyses given by Stoeckhardt, it may be well to +cite those based on Lawes and Gilbert's experiments, and quoted by +Warington ('Chemistry of the Farm,' p. 138):—</p> + +<p><span class='pagenum'><a name="Page_280" id="Page_280">[Pg 280]</a></span>I.—<span class="smcap">Sheep</span> (fed on <i>meadow-hay</i>).</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Solid"> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="2"><span class="smcap" style="font-size: 80%;">Solid Excrement. </span></td> + </tr> + <tr> + <td class="tdl" width="45%"> </td> + <td class="tdc" width="25%">Fresh.</td> + <td class="tdc" width="30%">Dry.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc">66.2</td> + <td class="tdc">—</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdc">30.3</td> + <td class="tdc">89.6</td> + </tr> + <tr> + <td class="tdl">Ash</td> + <td class="tdc" style="text-decoration: underline;"> 3.5</td> + <td class="tdc" style="text-decoration: underline;">10.4</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc"> .7</td> + <td class="tdc"> 2.0</td> + </tr> +</table> +</div> + +<p>II.—<span class="smcap">Oxen</span> (fed on <i>clover-hay</i> and <i>oat-straw</i>, with 8 lb. +<i>beans</i> per day).</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Oxen"> + <tr> + <td class="tdl" width="45%"> </td> + <td class="tdc" width="25%">Fresh.</td> + <td class="tdc" width="30%">Dry.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc">86.3</td> + <td class="tdc">—</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdc">12.3</td> + <td class="tdc">89.7</td> + </tr> + <tr> + <td class="tdl">Ash</td> + <td class="tdc" style="text-decoration: underline;"> 1.4</td> + <td class="tdc" style="text-decoration: underline;">10.3</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc"> .3</td> + <td class="tdc"> 1.9</td> + </tr> +</table> +</div> + +<p>III.—<span class="smcap">Cows</span> (fed on <i>mangels</i> and <i>lucerne hay</i>).</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Oxen"> + <tr> + <td class="tdl" width="45%"> </td> + <td class="tdc" width="25%">Mangels.</td> + <td class="tdc" width="30%">Lucerne hay.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc">83.00</td> + <td class="tdc">79.70</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc"> .33</td> + <td class="tdc"> .34</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdc"> .24</td> + <td class="tdc"> .16</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc"> .14</td> + <td class="tdc"> .23</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE III. (p. 232).</p> + +<p class="cen"><span class="smcap">Urine voided by Sheep, Oxen, and Cows.</span></p> + +<p>The following are the results for urine, the animals being fed as in +Note II.:—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Sheep"> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="2"><span class="smcap">Sheep.</span></td> + <td class="tdc" colspan="2"><span class="smcap">Oxen.</span></td> + </tr> + <tr> + <td class="tdl" width="28%"> </td> + <td class="tdc" width="18%">Fresh.</td> + <td class="tdc" width="18%">Dry.</td> + <td class="tdc" width="18%">Fresh.</td> + <td class="tdc" width="18%">Dry</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc">85.7</td> + <td class="tdc">—</td> + <td class="tdc">94.1</td> + <td class="tdc">—</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdc"> 8.7</td> + <td class="tdc">61.0</td> + <td class="tdc"> 3.7</td> + <td class="tdc">63.0</td> + </tr> + <tr> + <td class="tdl">Ash</td> + <td class="tdc"><span style="text-decoration: underline;"> 5.6</span></td> + <td class="tdc"><span style="text-decoration: underline;">39.0</span></td> + <td class="tdc"><span style="text-decoration: underline;"> 2.2</span></td> + <td class="tdc"><span style="text-decoration: underline;">37.0</span></td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc"> 1.4</td> + <td class="tdc"> 9.6</td> + <td class="tdc"> 1.2</td> + <td class="tdc">20.6</td> + </tr> +</table> +</div> + +<br /> +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Cows"> + <tr> + <td class="tdc" colspan="3"><span class="smcap">Cows.</span></td> + </tr> + <tr> + <td class="tdl" width="45%"> </td> + <td class="tdc" width="25%">Mangels.</td> + <td class="tdc" width="30%">Lucerne hay.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdc">95.94</td> + <td class="tdc">88.25</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc"> .12</td> + <td class="tdc"> 1.54</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdc"> .01</td> + <td class="tdc"> .006</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc"> .59</td> + <td class="tdc"> 1.69</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_281" id="Page_281">[Pg 281]</a></span>NOTE IV. (p. 233).</p> + +<p class="cen"><span class="smcap">Percentage of Food voided in the Solid and Liquid Excrements</span>.</p> + +<p>According to Wolff, the following table shows the percentage of the dry +substance of the food which is voided in the solid and liquid excrements +of the cow, ox, sheep, and horse:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="excreta"> + <tr> + <td class="tdl" width="25%"> </td> + <td class="tdc" width="15%">Cow.</td> + <td class="tdc" width="15%">Ox.</td> + <td class="tdc" width="15%">Sheep.</td> + <td class="tdc" width="15%">Horse.</td> + <td class="tdc" width="15%">Average.</td> + </tr> + <tr> + <td class="tdl">Solid excreta</td> + <td class="tdc">38.0</td> + <td class="tdc">44.0</td> + <td class="tdc">42.6</td> + <td class="tdc">46.7</td> + <td class="tdc">42.8</td> + </tr> + <tr> + <td class="tdl">Urine</td> + <td class="tdc"><span style="text-decoration: underline;"> 5.8</span></td> + <td class="tdc"><span style="text-decoration: underline;"> 6.3</span></td> + <td class="tdc"><span style="text-decoration: underline;"> 6.8</span></td> + <td class="tdc"><span style="text-decoration: underline;"> 5.7</span></td> + <td class="tdc"><span style="text-decoration: underline;"> 6.2</span></td> + </tr> + <tr> + <td class="tdl">Total</td> + <td class="tdc">43.8</td> + <td class="tdc">50.3</td> + <td class="tdc">49.4</td> + <td class="tdc">52.4</td> + <td class="tdc">49.0</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE V. (p. 234).</p> + +<p class="cen"><span class="smcap">Pig Excrements</span>.</p> + +<p>The excrements voided by pigs are poor in manurial constituents, because +the food on which they are fed is generally of a very poor nature. In +their case the urine is always very much richer in manurial ingredients +than the solid excreta. The relative composition of the solid excreta +and the urine will be best illustrated by quoting some experiments +carried out by Wolff on this subject. The experiments were carried out +with two pigs nine and a half months old, and each 121.9 kilogrammes (a +kilogramme is equal to about 2-1/4 lb.) in weight. The first consumed +daily 1000 grammes of barley, 5000 grammes of potatoes, and 2572 grammes +of sour-milk. The second one consumed the same quantities of potatoes +and sour-milk as the first, and 1000 grammes of peas. The following +table gives the results of excreta and urine daily voided, in grammes:—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Dry"> + <tr> + <td class="tdl" colspan="2"> </td> + <td class="tdc">Dry</td> + <td class="tdc" colspan="5"> </td> + <td class="tdc">Phosphoric</td> + </tr> + <tr> + <td class="tdl" width="10%"> </td> + <td class="tdl" width="10%"> </td> + <td class="tdc" width="15%">substance.</td> + <td class="tdc" width="15%">Nitrogen.</td> + <td class="tdc" width="5%">Ash.</td> + <td class="tdc" width="10%">Potash.</td> + <td class="tdc" width="10%">Lime.</td> + <td class="tdc" width="10%">Magnesia.</td> + <td class="tdc" width="15%">acid.</td> + </tr> + <tr> + <td class="tdl">Solid</td> + <td class="tdr">I.</td> + <td class="tdc">217.7</td> + <td class="tdc"> 8.7</td> + <td class="tdc">28.6</td> + <td class="tdc"> 7.3</td> + <td class="tdc">4.4</td> + <td class="tdc">3.0</td> + <td class="tdc">10.3</td> + </tr> + <tr> + <td class="tdl">excreta</td> + <td class="tdr">II.</td> + <td class="tdc">161.1</td> + <td class="tdc"> 9.1</td> + <td class="tdc">31.1</td> + <td class="tdc"> 5.9</td> + <td class="tdc">4.9</td> + <td class="tdc">2.8</td> + <td class="tdc">11.1</td> + </tr> + <tr> + <td class="tdl">Urine</td> + <td class="tdr">I.</td> + <td class="tdc">112.8</td> + <td class="tdc">19.3</td> + <td class="tdc">56.2</td> + <td class="tdc">33.0</td> + <td class="tdc">0.4</td> + <td class="tdc">0.9</td> + <td class="tdc"> 6.7</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr">II.</td> + <td class="tdc">137.7</td> + <td class="tdc">30.6</td> + <td class="tdc">62.2</td> + <td class="tdc">37.1</td> + <td class="tdc">0.2</td> + <td class="tdc">1.1</td> + <td class="tdc"> 7.1</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_282" id="Page_282">[Pg 282]</a></span>NOTE VI.(p. 236).</p> + +<p class="cen"><span class="smcap">Manurial Constituents in 1000 Parts of Ordinary Foods</span>.</p> + +<p class="cen">Based on Lawes and Gilbert's Analyses.</p> + +<p class="cen">(Warington's 'Chemistry of the Farm,' p. 139.)</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Dry"> + <tr> + <td class="tdl" width="44%" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" width="13%" style="border-top: .5pt black solid;">Dry</td> + <td class="tdcl" width="15%" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" width="13%" style="border-top: .5pt black solid;"> </td> + <td class="tdcl" width="15%" style="border-top: .5pt black solid;">Phosphoric</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">matter.</td> + <td class="tdclb">Nitrogen.</td> + <td class="tdclb">Potash.</td> + <td class="tdclb">acid.</td> + </tr> + <tr> + <td class="tdl">Cotton-cake, decorticated</td> + <td class="tdcl">918</td> + <td class="tdcl">70.4</td> + <td class="tdcl">15.8</td> + <td class="tdcl">30.5</td> + </tr> + <tr> + <td class="tdl">Rape-cake</td> + <td class="tdcl">887</td> + <td class="tdcl">50.5</td> + <td class="tdcl">13.0</td> + <td class="tdcl">20.0</td> + </tr> + <tr> + <td class="tdl">Linseed-cake</td> + <td class="tdcl">883</td> + <td class="tdcl">43.2</td> + <td class="tdcl">12.5</td> + <td class="tdcl">16.2</td> + </tr> + <tr> + <td class="tdl">Cotton-cake, undecorticated</td> + <td class="tdcl">878</td> + <td class="tdcl">33.3</td> + <td class="tdcl">20.0</td> + <td class="tdcl">22.7</td> + </tr> + <tr> + <td class="tdl">Linseed</td> + <td class="tdcl">882</td> + <td class="tdcl">32.8</td> + <td class="tdcl">10.0</td> + <td class="tdcl">13.5</td> + </tr> + <tr> + <td class="tdl">Palm-kernel meal, English</td> + <td class="tdcl">930</td> + <td class="tdcl">25.0</td> + <td class="tdcl"> 5.5</td> + <td class="tdcl">12.2</td> + </tr> + <tr> + <td class="tdl">Beans</td> + <td class="tdcl">855</td> + <td class="tdcl">40.8</td> + <td class="tdcl">12.9</td> + <td class="tdcl">12.1</td> + </tr> + <tr> + <td class="tdl">Peas</td> + <td class="tdcl">857</td> + <td class="tdcl">35.8</td> + <td class="tdcl">10.1</td> + <td class="tdcl"> 8.4</td> + </tr> + <tr> + <td class="tdl">Malt-dust</td> + <td class="tdcl">905</td> + <td class="tdcl">37.9</td> + <td class="tdcl">20.8</td> + <td class="tdcl">18.2</td> + </tr> + <tr> + <td class="tdl">Bran</td> + <td class="tdcl">860</td> + <td class="tdcl">23.2</td> + <td class="tdcl">15.3</td> + <td class="tdcl">26.9</td> + </tr> + <tr> + <td class="tdl">Oats</td> + <td class="tdcl">870</td> + <td class="tdcl">20.6</td> + <td class="tdcl"> 4.8</td> + <td class="tdcl"> 6.8</td> + </tr> + <tr> + <td class="tdl">Rice-meal</td> + <td class="tdcl">900</td> + <td class="tdcl">19.1</td> + <td class="tdcl"> 6.1</td> + <td class="tdcl">23.8</td> + </tr> + <tr> + <td class="tdl">Wheat</td> + <td class="tdcl">877</td> + <td class="tdcl">18.7</td> + <td class="tdcl"> 5.2</td> + <td class="tdcl"> 7.9</td> + </tr> + <tr> + <td class="tdl">Rye</td> + <td class="tdcl">857</td> + <td class="tdcl">17.6</td> + <td class="tdcl"> 5.8</td> + <td class="tdcl"> 8.5</td> + </tr> + <tr> + <td class="tdl">Barley</td> + <td class="tdcl">860</td> + <td class="tdcl">17.0</td> + <td class="tdcl"> 4.7</td> + <td class="tdcl"> 7.8</td> + </tr> + <tr> + <td class="tdl">Maize</td> + <td class="tdcl">890</td> + <td class="tdcl">16.6</td> + <td class="tdcl"> 3.7</td> + <td class="tdcl"> 5.7</td> + </tr> + <tr> + <td class="tdl">Brewers' grains</td> + <td class="tdcl">234</td> + <td class="tdcl"> 7.8</td> + <td class="tdcl"> 0.4</td> + <td class="tdcl"> 3.9</td> + </tr> + <tr> + <td class="tdl">Clover-hay</td> + <td class="tdcl">840</td> + <td class="tdcl">19.7</td> + <td class="tdcl">18.6</td> + <td class="tdcl"> 5.6</td> + </tr> + <tr> + <td class="tdl">Meadow-hay</td> + <td class="tdcl">857</td> + <td class="tdcl">15.5</td> + <td class="tdcl">16.0</td> + <td class="tdcl"> 4.3</td> + </tr> + <tr> + <td class="tdl">Bean-straw</td> + <td class="tdcl">840</td> + <td class="tdcl">13.0</td> + <td class="tdcl">19.4</td> + <td class="tdcl"> 2.9</td> + </tr> + <tr> + <td class="tdl">Oat-straw</td> + <td class="tdcl">857</td> + <td class="tdcl"> 6.4</td> + <td class="tdcl">16.3</td> + <td class="tdcl"> 2.8</td> + </tr> + <tr> + <td class="tdl">Barley-straw</td> + <td class="tdcl">857</td> + <td class="tdcl"> 5.6</td> + <td class="tdcl">10.7</td> + <td class="tdcl"> 1.9</td> + </tr> + <tr> + <td class="tdl">Wheat-straw</td> + <td class="tdcl">857</td> + <td class="tdcl"> 4.8</td> + <td class="tdcl"> 6.3</td> + <td class="tdcl"> 2.2</td> + </tr> + <tr> + <td class="tdl">Potatoes</td> + <td class="tdcl">250</td> + <td class="tdcl"> 3.4</td> + <td class="tdcl"> 5.8</td> + <td class="tdcl"> 1.6</td> + </tr> + <tr> + <td class="tdl">Swedes</td> + <td class="tdcl">107</td> + <td class="tdcl"> 2.2</td> + <td class="tdcl"> 2.0</td> + <td class="tdcl"> 0.6</td> + </tr> + <tr> + <td class="tdl">Carrots</td> + <td class="tdcl">140</td> + <td class="tdcl"> 2.1</td> + <td class="tdcl"> 3.0</td> + <td class="tdcl"> 1.1</td> + </tr> + <tr> + <td class="tdl">Mangels</td> + <td class="tdcl">120</td> + <td class="tdcl"> 1.8</td> + <td class="tdcl"> 4.6</td> + <td class="tdcl"> 0.7</td> + </tr> + <tr> + <td class="tdlb">Turnips</td> + <td class="tdclb"> 80</td> + <td class="tdclb"> 1.6</td> + <td class="tdclb"> 2.9</td> + <td class="tdclb"> 0.8</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_283" id="Page_283">[Pg 283]</a></span>NOTE VII. (p. 241).</p> + +<p class="cen"><span class="smcap">Analyses of Stable-Manure, made respectively with Peat-moss Litter +and Wheat-straw</span> (by <span class="smcap">Bernard Dyer</span>, B.Sc.)</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Peat-moss"> + <tr> + <td class="tdl" width="50%"> </td> + <td class="tdc" width="25%">Peat-moss litter.</td> + <td class="tdc" width="25%">Wheat-straw.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Per cent.</td> + <td class="tdc">Per cent.</td> + </tr> + <tr> + <td class="tdl">Total nitrogen</td> + <td class="tdc">0.88</td> + <td class="tdc">0.61</td> + </tr> + <tr> + <td class="tdl">Equal to ammonia</td> + <td class="tdc">1.07</td> + <td class="tdc">0.74</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdc">0.37</td> + <td class="tdc">0.43</td> + </tr> + <tr> + <td class="tdl">Equal to Tribasic phosphate of lime (or Tricalcic phosphate)</td> + <td class="tdc" style="vertical-align: bottom;">0.80</td> + <td class="tdc" style="vertical-align: bottom;">0.94</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc">1.02</td> + <td class="tdc">0.59</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE VIII. (p. 242).</p> + +<p class="cen"><span class="smcap">Analyses of Bracken</span> (by <span class="smcap">J. Hughes</span>, F.C.S.)</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Young"> + <tr> + <td class="tdl" width="50%"> </td> + <td class="tdc" width="25%">Peat-moss litter.</td> + <td class="tdc" width="25%">Wheat-straw.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">No. 1</td> + <td class="tdc">No. 2</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Young fern.</td> + <td class="tdc">Old fern.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Per cent.</td> + <td class="tdc">Per cent.</td> + </tr> + <tr> + <td class="tdl"> Water</td> + <td class="tdc">11.66</td> + <td class="tdc">14.90</td> + </tr> + <tr> + <td class="tdl">*Organic matter</td> + <td class="tdc">83.38</td> + <td class="tdc">80.54</td> + </tr> + <tr> + <td class="tdl">+Mineral matter</td> + <td class="tdc"><span style="text-decoration: underline;"> 4.96</span></td> + <td class="tdc"><span style="text-decoration: underline;"> 4.56</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"><span style="text-decoration: underline;">100.0</span></td> + <td class="tdc"><span style="text-decoration: underline;">100.0</span></td> + </tr> + <tr> + <td class="tdl" colspan="3">Containing—</td> + </tr> + <tr> + <td class="tdl">*Nitrogen</td> + <td class="tdc"> 2.42</td> + <td class="tdc"> 0.90</td> + </tr> + <tr> + <td class="tdl">+Silica</td> + <td class="tdc"> 1.60</td> + <td class="tdc"> 2.81</td> + </tr> + <tr> + <td class="tdl"> Potash</td> + <td class="tdc"> 1.15</td> + <td class="tdc"> 0.10</td> + </tr> + <tr> + <td class="tdl"> Soda</td> + <td class="tdc"> 0.64</td> + <td class="tdc"> 0.26</td> + </tr> + <tr> + <td class="tdl"> Lime</td> + <td class="tdc"> 0.44</td> + <td class="tdc"> 0.62</td> + </tr> + <tr> + <td class="tdl"> Magnesia</td> + <td class="tdc"> 0.13</td> + <td class="tdc"> 0.47</td> + </tr> + <tr> + <td class="tdl"> Phosphoric acid</td> + <td class="tdc"> 0.60</td> + <td class="tdc"> 0.30</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE IX. (p. 244).</p> + +<p class="cen"><span class="smcap">Analyses of Horse-Manure</span>.</p> + +<p>For a fuller discussion of this question, the reader is referred to +Heiden's 'Düngerlehre,' vol. ii. p. 185, and also to Storer's +'Agricultural Chemistry,' vol. i. p. 575. <span class='pagenum'><a name="Page_284" id="Page_284">[Pg 284]</a></span>The statements in the +different text-books as to the quantity of manure produced by the horse +are such as naturally to perplex the student. This discrepancy is due, +however, to the different methods adopted by different writers of +calculating this amount. The subject is further discussed in the +footnote to p. 252. The following analyses of horse-manure may be +valuable for reference. They are taken from Storer's 'Agricultural +Chemistry,' vol. i. p. 496:—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdlb" width="22%" style="border-top: .5pt solid black;"> </td> + <td class="tdclb" width="13%" style="border-top: .5pt solid black;">1.</td> + <td class="tdclb" width="13%" style="border-top: .5pt solid black;">2.</td> + <td class="tdclb" width="13%" style="border-top: .5pt solid black;">3.</td> + <td class="tdclb" width="13%" style="border-top: .5pt solid black;">4.</td> + <td class="tdclb" width="13%" style="border-top: .5pt solid black;">5.</td> + <td class="tdclb" width="13%" style="border-top: .5pt solid black;">Average.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdcl">75.76</td> + <td class="tdcl">69.30</td> + <td class="tdcl">67.23</td> + <td class="tdcl">72.13</td> + <td class="tdcl">71.30</td> + <td class="tdcl">71.15</td> + </tr> + <tr> + <td class="tdl">Dry matter</td> + <td class="tdcl">24.24</td> + <td class="tdcl">24.82</td> + <td class="tdcl">32.72</td> + <td class="tdcl">27.87</td> + <td class="tdcl">28.70</td> + <td class="tdcl">27.67</td> + </tr> + <tr> + <td class="tdl">Ash ingredients</td> + <td class="tdcl"> 5.07</td> + <td class="tdcl"> 5.05</td> + <td class="tdcl"> 6.49</td> + <td class="tdcl"> 3.37</td> + <td class="tdcl"> 3.30</td> + <td class="tdcl"> 4.65</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdcl"> 0.51</td> + <td class="tdcl"> 0.63</td> + <td class="tdcl"> 0.22</td> + <td class="tdcl"> 0.59</td> + <td class="tdcl"> 0.53</td> + <td class="tdcl"> 0.49</td> + </tr> + <tr> + <td class="tdl">Lime></td> + <td class="tdcl"> 0.30</td> + <td class="tdcl"> 0.74</td> + <td class="tdcl"> 0.17</td> + <td class="tdcl"> 0.41</td> + <td class="tdcl"> 0.21</td> + <td class="tdcl"> 0.36</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdcl"> 0.19</td> + <td class="tdcl"> 0.29</td> + <td class="tdcl"> 0.20</td> + <td class="tdcl"> 0.17</td> + <td class="tdcl"> 0.14</td> + <td class="tdcl"> 0.20</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdcl"> 0.41</td> + <td class="tdcl"> 0.67</td> + <td class="tdcl"> 0.35</td> + <td class="tdcl"> 0.12</td> + <td class="tdcl"> 0.28</td> + <td class="tdcl"> 0.36</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl"> 0.26</td> + <td class="tdcl"> 0.12</td> + <td class="tdcl"> 0.15</td> + <td class="tdcl"> 0.44</td> + <td class="tdcl">—</td> + <td class="tdcl"> 0.24</td> + </tr> + <tr> + <td class="tdlb">Total nitrogen</td> + <td class="tdclb"> 0.53</td> + <td class="tdclb"> 0.69</td> + <td class="tdclb"> 0.47</td> + <td class="tdclb"> 0.67</td> + <td class="tdclb"> 0.58</td> + <td class="tdclb"> 0.59</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE X. (p. 247).</p> + +<p class="cen"><span class="smcap">The Nature of the Chemical Reactions of Ammonia "Fixers."</span></p> + +<p>For the student, the exact nature of the chemical reactions taking place +may be of interest.</p> + +<p>In the first place, it must be distinctly understood that the form in +which ammonia escapes from the manure-heap is not, as is so commonly +erroneously stated in agricultural text-books, as "free" ammonia. +Whenever ammonia is brought into contact with carbonic acid, carbonate +of ammonia is formed. When it is remembered that carbonic acid is by far +the most abundant of the gaseous products of the decomposition of +organic matter, it will be at once seen that free ammonia could not +exist under such circumstances.</p> + +<p><span class='pagenum'><a name="Page_285" id="Page_285">[Pg 285]</a></span>1. In the case of <i>hydrochloric acid</i>, the following chemical equation +will represent the nature of the reaction—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" width="23%">2HCl</td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">(NH<sub>4</sub>)<sub>2</sub>CO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">2NH<sub>4</sub>Cl</td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="22%">H<sub>2</sub>O+CO<sub>2</sub></td> + </tr> + <tr> + <td class="tdl">(Hydrochloric</td> + <td class="tdc">+</td> + <td class="tdc">(carbonate of</td> + <td class="tdc">=</td> + <td class="tdc">(sal-ammoniac,)</td> + <td class="tdc">+</td> + <td class="tdc">(carbonic acid.)</td> + </tr> + <tr> + <td class="tdl">acid,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia,)</td> + <td class="tdc"> </td> + <td class="tdc"> </td> + <td class="tdc"> </td> + <td class="tdc"> </td> + </tr> +</table> +</div> + +<p>2. In the case of <i>sulphuric acid</i>, the equation will be—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" width="23%">H<sub>2</sub>SO<sub>4</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">(NH<sub>4</sub>)<sub>2</sub>CO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">(NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="22%">H<sub>2</sub>O+CO<sub>2</sub></td> + </tr> + <tr> + <td class="tdl">(Sulphuric acid,)</td> + <td class="tdc">+</td> + <td class="tdc">(carbonate of</td> + <td class="tdc">=</td> + <td class="tdc">(sulphate of</td> + <td class="tdc">+</td> + <td class="tdc">(carbonic acid.)</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"> </td> + <td class="tdc">ammonia,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia,)</td> + <td class="tdc"> </td> + <td class="tdc"> </td> + </tr> + +</table> +</div> + +<p>3. With <i>gypsum</i> (CaSO<sub>4</sub>)—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" width="23%">CaSO<sub>4</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">(NH<sub>4</sub>)<sub>2</sub>CO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">CaCO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="22%">(NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub></td> + </tr> + <tr> + <td class="tdl">(Gypsum,)</td> + <td class="tdc">+</td> + <td class="tdc">(carbonate of</td> + <td class="tdc">=</td> + <td class="tdc">(calcium</td> + <td class="tdc">+</td> + <td class="tdc">(sulphate of</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"> </td> + <td class="tdc">ammonia,)</td> + <td class="tdc"> </td> + <td class="tdc">carbonate,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia.)</td> + </tr> +</table> +</div> + +<p>4. With <i>copperas</i> (FeSO<sub>4</sub>)—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" width="23%">FeSO<sub>4</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">(NH<sub>4</sub>)<sub>2</sub>CO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">FeCO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="22%">(NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub></td> + </tr> + <tr> + <td class="tdl">(Sulphate of</td> + <td class="tdc">+</td> + <td class="tdc">(carbonate of</td> + <td class="tdc">=</td> + <td class="tdc">(ferrous</td> + <td class="tdc">+</td> + <td class="tdc">(sulphate of</td> + </tr> + <tr> + <td class="tdl">iron,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia,)</td> + <td class="tdc"> </td> + <td class="tdc">carbonate,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia.)</td> + </tr> +</table> +</div> + +<p>5. With <i>sulphate of magnesia</i> (MgSO<sub>4</sub>)—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" width="23%">MgSO<sub>4</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">(NH<sub>4</sub>)<sub>2</sub>CO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="23%">MgCO<sub>3</sub></td> + <td class="tdc" width="3%"> </td> + <td class="tdc" width="22%">(NH<sub>4</sub>)<sub>2</sub>SO<sub>4</sub></td> + </tr> + <tr> + <td class="tdl">(Sulphate of</td> + <td class="tdc">+</td> + <td class="tdc">(carbonate of</td> + <td class="tdc">=</td> + <td class="tdc">(carbonate of</td> + <td class="tdc">+</td> + <td class="tdc">(sulphate of</td> + </tr> + <tr> + <td class="tdl">magnesia,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia,)</td> + <td class="tdc"> </td> + <td class="tdc">magnesia,)</td> + <td class="tdc"> </td> + <td class="tdc">ammonia.)</td> + </tr> +</table> +</div> + +<p>Reference has been made to the fact that magnesium sulphate may probably +not only fix the ammonia, but the phosphoric acid. When magnesium +sulphate, soluble phosphoric acid, and ammonia are brought in contact +with one another, the double insoluble phosphate of ammonium and +magnesium (MgNH<sub>4</sub>PO<sub>4</sub>6Aq) is formed. While such a reaction is +possible, it is highly improbable that it takes place to any extent. The +double phosphate is a crystalline salt which only separates after a +considerable time, and in the presence of a large excess of ammonia.</p> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_286" id="Page_286">[Pg 286]</a></span>NOTE XI. (p. 250).</p> + +<p class="cen"><span class="smcap">Analyses of Cow-Manure</span>.<a name="FNanchor_181_181" id="FNanchor_181_181"></a><a href="#Footnote_181_181" class="fnanchor">[181]</a></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Average"> + <tr> + <td class="tdlb" width="23%" style="border-top: .5pt black solid;"> </td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">1.</td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">2.</td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">3.</td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">4.</td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">5.</td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">6.</td> + <td class="tdclb" width="11%" style="border-top: .5pt black solid;">Average.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdcl">85.30</td> + <td class="tdcl">77.71</td> + <td class="tdcl">74.02</td> + <td class="tdcl">72.87</td> + <td class="tdcl">75.00</td> + <td class="tdcl">77.50</td> + <td class="tdcl">77.06</td> + </tr> + <tr> + <td class="tdl">Dry matter</td> + <td class="tdcl">14.70</td> + <td class="tdcl">22.30</td> + <td class="tdcl">25.98</td> + <td class="tdcl">27.13</td> + <td class="tdcl">25.00</td> + <td class="tdcl">22.50</td> + <td class="tdcl">22.93</td> + </tr> + <tr> + <td class="tdl">Ash ingredients</td> + <td class="tdcl"> 2.04</td> + <td class="tdcl"> 4.71</td> + <td class="tdcl"> 3.94</td> + <td class="tdcl"> 6.70</td> + <td class="tdcl"> 6.22</td> + <td class="tdcl"> 2.20</td> + <td class="tdcl"> 4.30</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdcl"> 0.36</td> + <td class="tdcl"> 0.46</td> + <td class="tdcl"> 0.56</td> + <td class="tdcl"> 1.69</td> + <td class="tdcl"> 0.39</td> + <td class="tdcl"> 0.40</td> + <td class="tdcl"> 0.64</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdcl"> 0.29</td> + <td class="tdcl"> 0.37</td> + <td class="tdcl"> 0.58</td> + <td class="tdcl"> 0.41</td> + <td class="tdcl"> 0.24</td> + <td class="tdcl"> 0.31</td> + <td class="tdcl"> 0.48</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdcl"> 0.19</td> + <td class="tdcl"> 0.11</td> + <td class="tdcl"> 0.13</td> + <td class="tdcl">—</td> + <td class="tdcl"> 0.18</td> + <td class="tdcl"> 0.11</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdcl"> 0.16</td> + <td class="tdcl"> 0.13</td> + <td class="tdcl"> 0.07</td> + <td class="tdcl"> 0.20</td> + <td class="tdcl"> 0.14</td> + <td class="tdcl"> 0.16</td> + <td class="tdcl"> 0.14</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl"> 0.06</td> + <td class="tdcl"> 0.16</td> + <td class="tdcl"> 0.07</td> + <td class="tdcl">—</td> + <td class="tdcl"> 0.27</td> + <td class="tdcl">—</td> + <td class="tdcl"> 0.14</td> + </tr> + <tr> + <td class="tdlb">Total nitrogen</td> + <td class="tdclb"> 0.38</td> + <td class="tdclb"> 0.54</td> + <td class="tdclb"> 0.41</td> + <td class="tdclb"> 0.79</td> + <td class="tdclb"> 0.46</td> + <td class="tdclb"> 0.34</td> + <td class="tdclb"> 0.48</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE XII. (p. 259).</p> + +<p class="cen"><span class="smcap">Composition of Fresh and Rotten Farmyard +Manure (Voelcker)</span>.</p> + +Composition of fresh manure, composed of horse, cow, +and pig dung, about fourteen days old:— + +<br /> +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Soluble"> + <tr> + <td class="tdc" width="3%"> </td> + <td class="tdl" width="85%">Water</td> + <td class="tdr" width="15%">66.17 </td> + </tr> + <tr> + <td class="tdc">*</td> + <td class="tdl">Soluble organic matter</td> + <td class="tdr">2.48 </td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Solumble inorganic matter</td> + <td class="tdr">1.54 </td> + </tr> + <tr> + <td class="tdc">+</td> + <td class="tdl">Insoluble organic matter</td> + <td class="tdr">25.76 </td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Insoluble inorganic matter</td> + <td class="tdr"><span style="text-decoration: underline;"> 4.05</span> </td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span> </td> + </tr> + <tr> + <td class="tdc">*</td> + <td class="tdl">Containing nitrogen</td> + <td class="tdr">.149</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Equal to ammonia</td> + <td class="tdr">.181</td> + </tr> + <tr> + <td class="tdc">+</td> + <td class="tdl">Containing nitrogen</td> + <td class="tdr">.494</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Equal to ammonia</td> + <td class="tdr">.599</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl"> Total percentage of nitrogen</td> + <td class="tdr">.643</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl"> Equal to ammonia</td> + <td class="tdr">.780</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl"> Ammonia in a volatile state</td> + <td class="tdr">.034</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl"> Ammonia in form of salts</td> + <td class="tdr">.088</td> + </tr> +</table> +</div> + +<span class='pagenum'><a name="Page_287" id="Page_287">[Pg 287]</a></span>Composition of the whole ash:— + +<br /> +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="silica"> + <tr> + <td class="tdl" colspan="3">Soluble in water, 27.55 per cent;—</td> + </tr> + <tr> + <td class="tdl" width="3%"> </td> + <td class="tdl" width="85%">Soluble silica</td> + <td class="tdr" width="15%">4.25 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Phosphate of lime</td> + <td class="tdr">4.25 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Lime</td> + <td class="tdr">1.10 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Magnesia</td> + <td class="tdr">0.20 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Potash</td> + <td class="tdr">10.26 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soda</td> + <td class="tdr">0.92 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Chloride of sodium</td> + <td class="tdr">0.54 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Sulphuric acid</td> + <td class="tdr">0.22 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Carbonic acid and loss</td> + <td class="tdr">4.71 </td> + </tr> + <tr> + <td class="tdl" colspan="3">Insoluble in water. 72.45 per cent:—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soluble silica</td> + <td class="tdr">17.34 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Insoluble silicious matter</td> + <td class="tdr">10.04 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Oxide of iron and alumina with phosphates</td> + <td class="tdr">8.47 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> (Containing phosphoric acid, 3.18 per cnet.)</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> (Equal to bone-earath, 6.88 percnet.)</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Lime</td> + <td class="tdr">20.21 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Magnesia</td> + <td class="tdr">2.56 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Potash</td> + <td class="tdr">1.78 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soda</td> + <td class="tdr">0.38 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Sulphuric acid</td> + <td class="tdr">1.27 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Carbonic acid and loss</td> + <td class="tdr"><span style="text-decoration: underline;">10.40</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span> </td> + </tr> +</table> +</div> + +Composition of rotten dung, six months old, is as +follows:— + +<br /> +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="organic"> + <tr> + <td class="tdl" width="3%"> </td> + <td class="tdl" width="85%">Water</td> + <td class="tdr" width="15%">75.42 </td> + </tr> + <tr> + <td class="tdl">*</td> + <td class="tdl">Soluble organic matter</td> + <td class="tdr">3.71 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soluble inorganic matter</td> + <td class="tdr">1.47 </td> + </tr> + <tr> + <td class="tdl">+</td> + <td class="tdl">Insoluble organic matter</td> + <td class="tdr">12.82 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Insoluble inorganic matter</td> + <td class="tdr"><span style="text-decoration: underline;"> 6.58</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span> </td> + </tr> + <tr> + <td class="tdl">*</td> + <td class="tdl">Containing nitrogen</td> + <td class="tdr">.297</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Equal to ammonia</td> + <td class="tdr">.360</td> + </tr> + <tr> + <td class="tdl">+</td> + <td class="tdl">Containing nitrogen</td> + <td class="tdr">.309</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Equal to ammonia</td> + <td class="tdr">.375</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total amount of nitrogen</td> + <td class="tdr">.606</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Equal to ammonia</td> + <td class="tdr">.735</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Ammonia in a volatile state</td> + <td class="tdr">.046</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Ammonia in form of salts</td> + <td class="tdr">.057</td> + </tr> +</table> +</div> + +<p><span class='pagenum'><a name="Page_288" id="Page_288">[Pg 288]</a></span>Composition of the whole ash:—</p> + +<br /> +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="lime"> + <tr> + <td class="tdl" colspan="3">Soluble in water, 18.27 per cent:—</td> + </tr> + <tr> + <td class="tdl" width="3%"> </td> + <td class="tdl" width="85%">Soluble silica</td> + <td class="tdr" width="15%">3.16 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Phosphate of lime</td> + <td class="tdr">4.75 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Lime</td> + <td class="tdr">1.44 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Magnesia</td> + <td class="tdr">0.59 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Potash</td> + <td class="tdr">5.58 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soda</td> + <td class="tdr">0.29 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Chloride of sodium</td> + <td class="tdr">0.46 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Sulphuric acid</td> + <td class="tdr">0.72 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Carbonic acid and loss</td> + <td class="tdr">1.28 </td> + </tr> + <tr> + <td class="tdl" colspan="3">Insoluble in water, 81.7 per cent:—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soluble silica</td> + <td class="tdr">17.69 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Insoluble silica</td> + <td class="tdr">12.54 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Phosphate of lime</td> + <td class="tdr">— </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Oxides of iron alumina with phosphates</td> + <td class="tdr">11.76 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> (Containing phosphoric acid, 3.40 per cent.)</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> (Equal to bone-earth, 7.36 per cent.)</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Lime</td> + <td class="tdr">20.70 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Magnesia</td> + <td class="tdr">1.17 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Potash</td> + <td class="tdr">0.56 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Soda</td> + <td class="tdr">0.47 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Chloride of sodium</td> + <td class="tdr">— </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Sulphuric acid</td> + <td class="tdr">0.79 </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Carbonic acid and loss</td> + <td class="tdr"><span style="text-decoration: underline;">16.05</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span> </td> + </tr> +</table> +</div> + +<br /> +<p class="cen">NOTE XIII. (p. 263).</p> + +<p class="cen"><span class="smcap">Comparison of Fresh and Rotten Manure (Wolff).</span></p> + +<br /> +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="moderately"> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdc" width="30%">Fresh.</td> + <td class="tdc" width="30%">Moderately rotten</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="2">(Taking the quantity of dry matter as the same.)</td> + </tr> + <tr> + <td class="tdl">Dry matter</td> + <td class="tdc">25.00</td> + <td class="tdc">25.00</td> + </tr> + <tr> + <td class="tdl">Ash</td> + <td class="tdc"> 3.81</td> + <td class="tdc"> 4.76</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdc"> 0.39</td> + <td class="tdc"> 0.49</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc"> 0.45</td> + <td class="tdc"> 0.56</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdc"> 0.49</td> + <td class="tdc"> 0.61</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdc"> 0.12</td> + <td class="tdc"> 0.15</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdc"> 0.18</td> + <td class="tdc"> 0.23</td> + </tr> + <tr> + <td class="tdl">Sulphuric acid</td> + <td class="tdc"> 0.10</td> + <td class="tdc"> 0.13</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdc"> 0.86</td> + <td class="tdc"> 1.08</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_289" id="Page_289">[Pg 289]</a></span>NOTE XIV. (p. 263).</p> + +<p class="cen"><span class="smcap">Lord Kinnaird's Experiments.<a name="FNanchor_182_182" id="FNanchor_182_182"></a><a href="#Footnote_182_182" class="fnanchor">[182]</a></span></p> + +<p>"Lord Kinnaird has given the particulars of a very careful experiment. +He tried to test the comparative value of manure kept in an open court +with that kept under cover. He selected the same kind of cattle, gave +them the same kind and quantity of food, and bedded them with the same +kind of straw. A field of 20 acres of uniform land was selected. This +having been equally divided, 2 acres out of each 10 gave the following +results:—</p> + +<br /> +<p class="cen"><i>Potatoes grown with Uncovered Manure.</i></p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="first"> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdc" width="15%">Tons.</td> + <td class="tdc" width="15%">cwt.</td> + <td class="tdc" width="15%">lb.</td> + </tr> + <tr> + <td class="tdl">First measurement—1 acre produced</td> + <td class="tdc"> 7</td> + <td class="tdc"> 6</td> + <td class="tdc"> 8</td> + </tr> + <tr> + <td class="tdl">Second measurement—1 acre produced</td> + <td class="tdc"> 7</td> + <td class="tdc">18</td> + <td class="tdc">99</td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><i>Potatoes grown with Covered Manure.</i></p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="measurement"> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdc" width="15%">Tons.</td> + <td class="tdc" width="15%">cwt.</td> + <td class="tdc" width="15%">lb.</td> + </tr> + <tr> + <td class="tdl">First measurement—1 acre produced</td> + <td class="tdc">11</td> + <td class="tdc">17</td> + <td class="tdc">56</td> + </tr> + <tr> + <td class="tdl">Second measurement—1 acre produced</td> + <td class="tdc">11</td> + <td class="tdc">12</td> + <td class="tdc">26</td> + </tr> +</table> +</div> + +<p class="noin">This shows an increase of about 4 tons of potatoes per acre with the +covered manure.</p> + +<p>"The next year the weather was wet, grain soft and not in very good +order, but the following was the amount of produce:—</p> + +<p class="cen"><i>Wheat grown with Uncovered Manure.</i></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="acre"> + <tr> + <td class="tdl"> </td> + <td class="tdc"> </td> + <td class="tdc"> </td> + <td class="tdc">Weight per</td> + <td class="tdc"> </td> + <td class="tdc"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="2">Produce in grain.</td> + <td class="tdc">bushel.</td> + <td class="tdc" colspan="3">Produce in straw.</td> + </tr> + <tr> + <td class="tdl" width="14%">Acre.</td> + <td class="tdc" width="14%">bushels.</td> + <td class="tdc" width="14%">lb.</td> + <td class="tdc" width="24%">lb.</td> + <td class="tdc" width="14%">stones.</td> + <td class="tdc" width="6%"> </td> + <td class="tdc" width="14%">lb.</td> + </tr> + <tr> + <td class="tdl">First</td> + <td class="tdc">41</td> + <td class="tdc">19</td> + <td class="tdc">61-1/2</td> + <td class="tdc">152</td> + <td class="tdc">of</td> + <td class="tdc">22</td> + </tr> + <tr> + <td class="tdl">Second</td> + <td class="tdc">42</td> + <td class="tdc">38</td> + <td class="tdc">61-1/2</td> + <td class="tdc">160</td> + <td class="tdc">of</td> + <td class="tdc">22</td> + </tr> +</table> +</div> + +<p class="cen"><i>Wheat grown with Covered Manure.</i></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="weight"> + <tr> + <td class="tdl" width="14%">First</td> + <td class="tdc" width="14%">53</td> + <td class="tdc" width="14%"> 5</td> + <td class="tdc" width="24%">61</td> + <td class="tdc" width="14%">220</td> + <td class="tdc" width="6%">of</td> + <td class="tdc" width="14%">22 </td> + </tr> + <tr> + <td class="tdl">Second</td> + <td class="tdc">53</td> + <td class="tdc">47</td> + <td class="tdc">61</td> + <td class="tdc">210</td> + <td class="tdc">of</td> + <td class="tdc">22"</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_290" id="Page_290">[Pg 290]</a></span>NOTE XV. (pp. 231, 264).</p> + +<p class="cen"><span class="smcap">Drainings of Manure-heaps</span>.</p> + +<p>The importance of not separating the liquid portion from the solid +portion has already been pointed out in dealing with the composition of +the solid excreta and the urine. These two constituents of the manure +are complementary to one another, and the value of farmyard manure as a +general manure is very much impaired if the liquid portion is not +applied along with the solid. In one important respect do the drainings +of manure-heaps differ from urine—that is, in the percentage of +phosphates they contain, the latter being practically devoid of +phosphoric acid.</p> + +<p>The following is an analysis of drainings from a manure-heap (Wolff):—</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="substance"> + <tr> + <td class="tdl" width="60%">Dry substance</td> + <td class="tdr" width="40%">18.0</td> + </tr> + <tr> + <td class="tdl">Ash</td> + <td class="tdr">10.7</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdr"> 1.5</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdr"> 4.9</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdr"> 0.3</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdr"> 0.4</td> + </tr> + <tr> + <td class="tdl"><i>Phosphoric acid</i></td> + <td class="tdr"> 0.1</td> + </tr> + <tr> + <td class="tdl">Sulphuric acid</td> + <td class="tdr"> 0.7</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdr"> 0.2</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE XVI. (p. 270).</p> + +<p class="cen"><span class="smcap">Amounts of Potash and Phosphoric Acid removed by the following +Rotations from a Prussian Morgen (.631 Acre</span>).</p> + +<div class="centered"> +<table border="0" width="55%" cellpadding="2" cellspacing="0" summary="lb"> + <tr> + <td class="tdl" width="50%"> </td> + <td class="tdc" width="25%"> </td> + <td class="tdr" width="25%">Phosphoric</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Potash.</td> + <td class="tdr">acid. </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">lb.</td> + <td class="tdr">lb. </td> + </tr> + <tr> + <td class="tdl">1. Wheat</td> + <td class="tdc"> 16.40</td> + <td class="tdr">10.67 </td> + </tr> + <tr> + <td class="tdl"> Oats</td> + <td class="tdc"> 10.47</td> + <td class="tdr"> 4.59 </td> + </tr> + <tr> + <td class="tdl"> Potatoes</td> + <td class="tdc"> 66.41</td> + <td class="tdr">18.33 </td> + </tr> + <tr> + <td class="tdl"> Hay</td> + <td class="tdc"><span style="text-decoration: underline;"> 39.54</span></td> + <td class="tdr"><span style="text-decoration: underline;">11.32</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"><span style="text-decoration: underline;">132.82</span></td> + <td class="tdr"><span style="text-decoration: underline;">44.91</span> </td> + </tr> + <tr> + <td class="tdc" colspan="3">The ratio of potash to phosphoric acid is 2.96 to 1.</td> + </tr> + <tr> + <td class="tdc" colspan="3"> </td> + </tr> + <tr> + <td class="tdl">2. Wheat</td> + <td class="tdc"> 16.90</td> + <td class="tdr">10.67 </td> + </tr> + <tr> + <td class="tdl"> Barley</td> + <td class="tdc"> 17.44</td> + <td class="tdr">10.65 </td> + </tr> + <tr> + <td class="tdl"> Potatoes</td> + <td class="tdc"> 66.41</td> + <td class="tdr">18.33 </td> + </tr> + <tr> + <td class="tdl"> Hay</td> + <td class="tdc"><span style="text-decoration: underline;"> 39.54</span></td> + <td class="tdr"><span style="text-decoration: underline;">11.32</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"><span style="text-decoration: underline;">140.29</span></td> + <td class="tdr"><span style="text-decoration: underline;">50.97</span> </td> + </tr> + <tr> + <td class="tdc" colspan="3">The ratio of potash to phosphoric acid is 2.76 to 1</td> + </tr> + <tr> + <td class="tdc" colspan="3"> </td> + </tr> + <tr> + <td class="tdl">3. Rye<span class='pagenum'><a name="Page_291" id="Page_291">[Pg 291]</a></span></td> + <td class="tdc"> 20.03</td> + <td class="tdr">12.15 </td> + </tr> + <tr> + <td class="tdl"> Oats</td> + <td class="tdc"> 10.97</td> + <td class="tdr"> 4.59 </td> + </tr> + <tr> + <td class="tdl"> Potatoes</td> + <td class="tdc"> 66.41</td> + <td class="tdr">18.33 </td> + </tr> + <tr> + <td class="tdl"> Hay</td> + <td class="tdc"><span style="text-decoration: underline;"> 39.54</span></td> + <td class="tdr"><span style="text-decoration: underline;">11.32</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"><span style="text-decoration: underline;">136.95</span></td> + <td class="tdr"><span style="text-decoration: underline;">46.39</span> </td> + </tr> + <tr> + <td class="tdc" colspan="3">The ratio of potash to phosphoric acid is 2.95 to 1.</td> + </tr> + <tr> + <td class="tdc" colspan="3"> </td> + </tr> + <tr> + <td class="tdl">4. Wheat</td> + <td class="tdc"> 16.90</td> + <td class="tdr">10.67 </td> + </tr> + <tr> + <td class="tdl"> Oats</td> + <td class="tdc"> 10.97</td> + <td class="tdr"> 4.59 </td> + </tr> + <tr> + <td class="tdl"> Mangels</td> + <td class="tdc">148.54</td> + <td class="tdr">25.62 </td> + </tr> + <tr> + <td class="tdl"> Hay</td> + <td class="tdc"><span style="text-decoration: underline;"> 39.54</span></td> + <td class="tdr"><span style="text-decoration: underline;">11.32</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"><span style="text-decoration: underline;">215.95</span></td> + <td class="tdr"><span style="text-decoration: underline;">52.20</span> </td> + </tr> + <tr> + <td class="tdc" colspan="3">The ration of potash to phosphoric acid is 4.13 to 1.</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdl">5. Rye</td> + <td class="tdc"> 20.03</td> + <td class="tdr">12.15 </td> + </tr> + <tr> + <td class="tdl"> Barley</td> + <td class="tdc"> 17.44</td> + <td class="tdr">10.65 </td> + </tr> + <tr> + <td class="tdl"> Mangels</td> + <td class="tdc">148.54</td> + <td class="tdr">25.62 </td> + </tr> + <tr> + <td class="tdl"> Hay</td> + <td class="tdc"><span style="text-decoration: underline;"> 39.54</span></td> + <td class="tdr"><span style="text-decoration: underline;">11.32</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc"><span style="text-decoration: underline;">225.55</span></td> + <td class="tdr"><span style="text-decoration: underline;">59.74</span> </td> + </tr> + <tr> + <td class="tdc" colspan="3">The ratio of potash to phosphoric acid is 3.78 to 1.</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE XVII. (pp. 253, 254).</p> + +<p class="cen"><span class="smcap">Composition of Farmyard Manure (Fresh),</span> (calculated by <span class="smcap">Sir +John Lawes</span>).</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="matter"> + <tr> + <td class="tdl" width="26%"> </td> + <td class="tdc" width="12%"> </td> + <td class="tdc" width="12%"> </td> + <td class="tdc" width="24%">Phosphoric acid</td> + <td class="tdc" width="12%"> </td> + <td class="tdc" width="12%"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Total</td> + <td class="tdc">Total</td> + <td class="tdc">calculated as</td> + <td class="tdc"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">dry</td> + <td class="tdc">mineral</td> + <td class="tdc">phosphate of</td> + <td class="tdc"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">matter.</td> + <td class="tdc">matter.</td> + <td class="tdc">lime.</td> + <td class="tdc">Potash.</td> + <td class="tdc">Nitrogen.</td> + </tr> + <tr> + <td class="tdl">Percent</td> + <td class="tdc">30.0</td> + <td class="tdc"> 2.77</td> + <td class="tdc"> .50</td> + <td class="tdc"> .53</td> + <td class="tdc"> .64</td> + </tr> + <tr> + <td class="tdl">Per ton (in lb.)</td> + <td class="tdc">67.2</td> + <td class="tdc">62.0</td> + <td class="tdc">11.1</td> + <td class="tdc">12.0</td> + <td class="tdc">14.3</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE XVIII. (p. 232).</p> + +<p class="cen"><span class="smcap">The Urine.</span></p> + +<p>An important consideration we have omitted to take note of in the text +is the quantity of the urine voided. It is this consideration that +renders the urine so much more <span class='pagenum'><a name="Page_292" id="Page_292">[Pg 292]</a></span>valuable than the solid excreta. In the +case of a man it has been estimated that the urine voided is fifteen +times as much, is twelve times as rich in nitrogen, three times in +potash, and two in phosphoric acid, as the solid excreta (Munro). The +relation of solid matter in the case of the farm animals is not exactly +similar. The urine of the ox is about twice the weight of its solid +excreta. Both the horse and the sheep, however, void as a rule more +solid excreta than urine. Munro, in his work on 'Soils and Manures,' +contrasts the composition of the urine and solid excreta of the +different farm animals by the following statement:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="ton"> + <tr> + <td class="tdl"> </td> + <td class="tdc" colspan="2" style="vertical-align: bottom;">1 ton of urine contains in lb.:</td> + <td class="tdc">1 ton of solid excreta contains in lb.:</td> + </tr> + <tr> + <td class="tdl" width="20%"> </td> + <td class="tdc" width="25%">Nitrogen.</td> + <td class="tdc" width="25%">Potash.</td> + <td class="tdc" width="30%">Nitrogen.</td> + </tr> + <tr> + <td class="tdl">Cow</td> + <td class="tdc">30</td> + <td class="tdc">20</td> + <td class="tdc"> 9</td> + </tr> + <tr> + <td class="tdl">Horse</td> + <td class="tdc">36</td> + <td class="tdc">22</td> + <td class="tdc">12</td> + </tr> + <tr> + <td class="tdl">Sheep</td> + <td class="tdc">38</td> + <td class="tdc">30</td> + <td class="tdc">16</td> + </tr> +</table> +</div> +<br /> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_181_181" id="Footnote_181_181"></a><a href="#FNanchor_181_181"><span class="label">[181]</span></a> Storer's 'Agricultural Chemistry,' vol. I. p. 496.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_182_182" id="Footnote_182_182"></a><a href="#FNanchor_182_182"><span class="label">[182]</span></a> Scott's 'Manures and Manuring,' p. 19.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_293" id="Page_293">[Pg 293]</a></span> +<br /> +<h2>CHAPTER VIII.</h2> + +<h2>GUANO.</h2> +<br /> + +<p class="cen"><i>Importance in Agriculture.</i></p> + +<p>In the consideration of <i>artificial</i> manures, guano deserves the first +place. This it does mainly on historical grounds, as it is now largely a +manure of the past. Not merely has it been used in agriculture to an +extent to which no other artificial manure has as yet ever approximated, +but its influence on agricultural practice has been enormous. Introduced +into this country about the middle of the present century, it was the +first of artificial manures to be used in large quantities.<a name="FNanchor_183_183" id="FNanchor_183_183"></a><a href="#Footnote_183_183" class="fnanchor">[183]</a> It may +be thus described as having introduced the modern system of <i>intensive</i> +cultivation, and given rise to the now almost universal practice of +artificial manuring.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_294" id="Page_294">[Pg 294]</a></span><i>Influence on British Farming.</i></p> + +<p>It is, indeed, difficult to over-estimate the important influence which +the introduction of this most valuable fertiliser has exercised on +British as well as, to a large extent, on European husbandry. Before its +introduction the farmer was almost completely dependent on his farmyard +manure. He was tied down to a great extent, by the exigencies of the +then prevailing agricultural customs, to certain rotations of crops. He +could do little in the way of enriching barren soils or of ensuring a +heavy yield of crop. By the use of this very potent fertiliser, he +quickly discovered that the most wonderful results ensued—results which +must have seemed to him at first little short of miraculous. He found +that by the application of a few hundredweights per acre, poor soils +could be made to yield large returns, and that barren patches in a field +could be brought up to the average of the surrounding portions by +sprinkling merely a few handfuls of it; that by its means a good start +could be ensured to every crop, and one slow of coming away could be +hastened on. In short, in this wonderful brown powder, with such a +characteristic odour, the astonished farmer discovered a manure which, +for the speed of its action, and for the increase of crop it gave, +completely threw into the shade both farmyard manure and bones. What +wonder, then, that its fame as a manure should have become so quickly +known and its use <span class='pagenum'><a name="Page_295" id="Page_295">[Pg 295]</a></span>so extensive! It thus gave a most powerful impetus to +intelligent farming by bringing home to the minds of those who used it +the important position nitrogen and phosphates occupied as constituents +of the soil, and the influence they exercised on plant-growth. It +furnished, in fact, on an enormously large scale, a practical +demonstration of the principles of manuring. The educational value which +the use of guano thus exercised may be said to have been very great. It +also led the way to the use of the various artificial manures so much +used during the last fifty years. Impressed by the value of guano, +farmers were favourably disposed towards the use of other fertilisers; +and, largely owing to its widespread popularity, the new practice +speedily gained ground.</p> + +<br /> +<p class="cen"><i>Influence not wholly for Good.</i></p> + +<p>But its influence, it must be admitted, was not wholly for good. In its +very popularity lay the danger of its abuse. Had its value and the +method of its action been more widely understood, and had the principles +upon which the practice of artificial manuring depends been better +realised, agriculturists would have been spared much of the needless +pecuniary losses they sustained by being imposed upon by unscrupulous +manure-dealers. Among the farming community the word guano soon became a +name to conjure with, and under this title many spurious and worthless +manures were attempted to be palmed off on the <span class='pagenum'><a name="Page_296" id="Page_296">[Pg 296]</a></span>unwary farmer. Even the +genuine article, there can be little doubt, was at one time largely +adulterated; and as the farmer was almost invariably content to purchase +the article not on any guaranteed chemical analysis, but simply on the +ground of its appearance, colour, and more especially smell, every +facility was given for the successful perpetration of such fraudulent +imposition. Guano, it was very soon found, varied in its composition, +but this variation in quality the farmer did not recognise. In the early +days of its use all guano was in his eyes of the same value. Too often, +as we have just pointed out, provided it had a good colour and a strong +odour, it was all right. Under such conditions, it can scarcely be +wondered at that its introduction should have proved not an unmixed +blessing to agriculture.</p> + +<br /> +<p class="cen"><i>Its Value as a Manure.</i></p> + +<p>Guano derives its value as a manure from the nitrogen, phosphates, and +the small amount of potash it contains. This at any rate is true of the +great bulk of guano which has been used in the past. There are, as we +shall immediately see, certain kinds of guano, known as phosphatic +guanos, which only contain phosphates. The amount of such purely +phosphatic guano directly used as a manure in this country is, however, +inconsiderable, and guano may truly be described as owing its value +chiefly to its nitrogen. Not a little of its value and popularity as a +manure may <span class='pagenum'><a name="Page_297" id="Page_297">[Pg 297]</a></span>be said to be due to the fact that it contains all of the +three important manurial constituents, and that in this respect it may +be regarded in a sense as a <i>general</i> manure, thus resembling most +nearly, of all artificial manures, farmyard manure. Although its sources +are now, to a very large extent, exhausted, and its total annual imports +into this country are at present considerably less than what they were +thirty or forty years ago,<a name="FNanchor_184_184" id="FNanchor_184_184"></a><a href="#Footnote_184_184" class="fnanchor">[184]</a> it may be well, on account of its +historical importance, to give a somewhat detailed account of its +origin, occurrence, and value as a manure.</p> + +<br /> +<p class="cen"><i>Origin and Occurrence.</i></p> + +<p>Guano (which means <i>dung</i>)—or huano, as it is spelt in the Spanish +language—was first used in Peru. It seems to have been used there long +before that country was discovered by the Spaniards—probably as early +as the twelfth century. Regarding its origin there can be little doubt. +It is almost entirely derived from the excrements of sea-birds, such as +pelicans, penguins, and gulls, as well as from the remains of the birds +themselves, and of seals, walruses, and various other animals.<a name="FNanchor_185_185" id="FNanchor_185_185"></a><a href="#Footnote_185_185" class="fnanchor">[185]</a> +Under the influence of a tropical <span class='pagenum'><a name="Page_298" id="Page_298">[Pg 298]</a></span>sun, and in a region in which rain +scarcely ever falls, these excrements are soon dried, and remain little +changed in their composition through centuries. Many of the Peruvian +deposits must be extremely old, as they are covered up with sand and +other <i>débris</i>, and are of considerable depth. Especially is this the +case with deposits occurring on the mainland, such as those at Pabellon +de Pica, where the layer of sand or conglomerate covering up the deposit +varies in depth from a few feet to over a hundred. The effect of this +superficial covering has been to protect the guano, to a certain extent, +from loss of nitrogen.</p> + +<p>Although guano of the best class has been derived from the neighbourhood +of Peru, deposits have also been found in many other parts of the +world—viz., in North America, West Indies, Australia, Asia, Africa, and +among the islands of the Pacific.<a name="FNanchor_186_186" id="FNanchor_186_186"></a><a href="#Footnote_186_186" class="fnanchor">[186]</a></p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_299" id="Page_299">[Pg 299]</a></span><i>Variation in the Composition of different Guanos.</i></p> + +<p>The guano found in these different deposits varies very considerably in +composition. This is due to the difference in the nature of the +prevailing climate of the places where these deposits occur. Where the +climate is dry and warm, as is the case in Chili and Peru, the +excrements dry quickly and remain very little changed, as one very +important condition of fermentation—viz., moisture—is absent.<a name="FNanchor_187_187" id="FNanchor_187_187"></a><a href="#Footnote_187_187" class="fnanchor">[187]</a> In +a damp climate, on the other hand, speedy fermentation ensues, resulting +in the loss of nearly all the organic matter, including nitrogen, in +such volatile forms as carbonate of ammonia, carbonic acid gas, water, +&c. The soluble alkalies, the most important of which is potash, as well +as the soluble phosphates, are also, under such conditions, lost to the +guano by being washed out by the rain. We have thus a wide difference in +the quality of the different deposits, depending on the extent to which +decomposition has taken place. Guano thus ranges from the rich +nitrogenous Peruvian kind, which has undergone little or no change from +the time of its deposit, to the purely phosphatic kind (such as those of +Malden and Baker islands), in which everything of manurial value has +been lost except the insoluble phosphate of lime. Even among the +nitrogenous guanos we find a considerable difference in quality, some +deposits being partially impoverished <span class='pagenum'><a name="Page_300" id="Page_300">[Pg 300]</a></span>by the action of the atmospheric +moisture, dew, spray or sea-water, but still containing a considerable +proportion of their nitrogen. Other deposits, again, are largely admixed +with sand, which has been blown in upon them to such an extent as to +make them unsaleable. We can divide guano, therefore, into two great +classes—viz., <i>nitrogenous</i> and <i>phosphatic</i>.</p> + +<br /> +<p class="cen">I.—<span class="smcap">Nitrogenous Guanos.</span></p> + +<p class="cen">(<i>a</i>) <span class="smcap">Peruvian.</span></p> + +<p>By far the most valuable and abundant deposits as yet discovered have +been those on the Peruvian and Chilian coasts. As already pointed out, +guano seems to have been used in this country from a very early period; +and so impressed were the Incas with its importance as a manure, that +the penalty of death was imposed on any one guilty of killing the +sea-fowl during the breeding season in the vicinity of the deposits.</p> + +<p>The occurrence of guano in Peru seems first to have been made known in +Europe in the beginning of the eighteenth century. It was not, however, +till the beginning of the present century—viz., 1804—that A. Humboldt, +the great German traveller, brought some of the wonderful fertiliser +home with him, and that its composition was able to be investigated by +chemical analysis. Shortly afterwards, its practical value was +demonstrated by experiments carried out on potatoes <span class='pagenum'><a name="Page_301" id="Page_301">[Pg 301]</a></span>by General Beatson +in St Helena. To Lord Derby is due the credit of having first introduced +it into this country, the earliest importation into Liverpool being in +1840. Experiments were shortly afterwards instituted in different parts +of the country, prominent among which were those by Sir John Lawes and +Sir James Caird; and so striking were the results obtained, that the +manure rapidly found favour with the farming community—so much so, that +ten years later the importations into this country amounted to no less +than 200,000 tons, while in 1855 the total exports from the west coast +of South America reached the enormous amount of 400,000 tons. In all, it +has been estimated that since the year 1840 over 5,000,000 tons of +Peruvian guano have been imported into this country.</p> + +<br /> +<p class="cen"><i>Different Deposits.</i></p> + +<p>Peruvian guano has been derived from various deposits occurring in +different parts of the coast, and from a number of small adjacent +islands. The richest of these was that found on Angamos, a rocky +promontory on the coast of Bolivia. Samples of this guano contained as +high as 20 per cent of nitrogen (equal to 24 per cent ammonia).<a name="FNanchor_188_188" id="FNanchor_188_188"></a><a href="#Footnote_188_188" class="fnanchor">[188]</a> +Unfortunately, however, the quantity of this deposit was extremely +limited, and became rapidly exhausted. Next to this <span class='pagenum'><a name="Page_302" id="Page_302">[Pg 302]</a></span>deposit in quality +was the guano found on the Chincha islands, three little islands off the +coast of Peru. These deposits were the largest which have ever been +discovered, and for a period of nearly thirty years were almost the sole +source of the Peruvian guano sold in commerce, over 10,000,000 tons +having been exported from them alone. Some of this guano contained 14 +per cent of nitrogen (equal to 17 per cent ammonia); and although part +of the guano shipped from these islands was not quite so rich, yet it +was all of a high-class order. The deposits on these islands were in +many cases 100 to 200 feet in depth, and rested on rocks of granite. The +lower layers were consequently found to be poorer in quality, and mixed +with pieces of granite. The Chincha island deposits have been long +exhausted,<a name="FNanchor_189_189" id="FNanchor_189_189"></a><a href="#Footnote_189_189" class="fnanchor">[189]</a> and the chief deposits of Peruvian guano since worked +have been those on Guanape and Macabi islands—a considerably inferior +guano, containing only 9 to 11 per cent of nitrogen (equal to 11 to 13 +per cent of ammonia)—which in their turn have become exhausted; from +Ballestas, almost as rich as the Chincha island guano, also now +exhausted; and from Pabellon de Pica, Punta de Lobos, Huanillos, +Independence Bay, and Lobos de Afuera. Quite recently a deposit of very +high-class guano was discovered in Corcovado, and a good many cargoes +have already been shipped to this country. It is found to contain +<span class='pagenum'><a name="Page_303" id="Page_303">[Pg 303]</a></span>nitrogen equal to from 10 to 13 per cent ammonia, 30 to 35 per cent +phosphates, and some potash, being thus a most valuable guano.</p> + +<br /> +<p class="cen"><i>Appearance, Colour, and Nature.</i></p> + +<p>In colour it varies from a very light to a very dark brown, the richer +samples being generally lighter. Samples taken from even the same +deposit have been found to differ very considerably in appearance, those +taken from the lower and older layers being usually darker than those +taken from the more recent upper layers. It was soon found also to vary +very much in composition. After a deposit had been worked for some time, +the quality of guano it yielded was found to be inferior and coarser, +and in many cases mixed with pebbles or pieces of granite, porphyry, &c. +This led to the custom of screening it on arrival in this country, +before it was used as a manure. In the richer qualities—<i>e.g.</i>, in the +Chincha guano—little round concretionary nodules, varying in colour +from pure white to dark brown, were occasionally found. Analysis showed +these nodules<a name="FNanchor_190_190" id="FNanchor_190_190"></a><a href="#Footnote_190_190" class="fnanchor">[190]</a> to be composed chiefly of potash salts. Sometimes, +also, little crystals of almost pure ammonia salts were found. It soon +became customary, therefore, to prepare guano for the market by +separating the stones and reducing the whole to a fine uniform powder. +One of its most characteristic <span class='pagenum'><a name="Page_304" id="Page_304">[Pg 304]</a></span>properties, and the one which seems to +have impressed the public most, was its pungent odour. Undue importance +was attached to this property, in the belief that it was caused by the +ammonia it contained. It may be doubted, however, whether the +characteristic smell of guano is due so much to its ammonia as to +certain fatty acids.</p> + +<br /> +<p class="cen"><i>Composition.</i></p> + +<p>In composition it is of a most complex nature. It contains its nitrogen +in a great variety of forms, the chief of these being urate, oxalate, +ulmate, humate, sulphate, phosphate, carbonate, and muriate of ammonia; +and also in a rare form of organic nitrogen peculiar to guano, called +guanine. According to Boussingault, some guanos contain small quantities +of nitrates. Its phosphoric acid is present both in the soluble +state—viz., as phosphates of the alkalies (ammonia and potash)—and in +the insoluble state as phosphate of lime; and lastly, its potash is +present as sulphate and phosphate. The proportion in which these +different forms of nitrogen and phosphoric acid are present varies +considerably in different samples. The richer a sample, as a rule, the +more nitrogen in the form of uric acid it contains. The most of the +nitrogen is present as uric acid and ammonia. Damp guanos contain more +of their nitrogen as ammonia than dry ones, this being due to the +fermentation which goes on in the former. On an average, about <span class='pagenum'><a name="Page_305" id="Page_305">[Pg 305]</a></span>a third +of its total nitrogen is soluble in water. Of its phosphates, on the +other hand, only about a fourth are soluble in water.</p> + +<p>The following analyses of a sample of Chincha island guano by +Karmrodt<a name="FNanchor_191_191" id="FNanchor_191_191"></a><a href="#Footnote_191_191" class="fnanchor">[191]</a> will illustrate this. (Sample dried at 212° Fahr.):—</p> + +<p class="cen">1. <i>Constituents easily soluble in Water.</i></p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="urate"> + <tr> + <td class="tdl" width="80%">Urate of ammonium</td> + <td class="tdr" width="20%">12.74</td> + </tr> + <tr> + <td class="tdl">Oxalate of ammonium</td> + <td class="tdr">13.60</td> + </tr> + <tr> + <td class="tdl">Nitrogenous and sulphurous organic substances</td> + <td class="tdr">3.61</td> + </tr> + <tr> + <td class="tdl">Ammonium-magnesium phosphate</td> + <td class="tdr">4.00</td> + </tr> + <tr> + <td class="tdl">Ammonium phosphate</td> + <td class="tdr">.90</td> + </tr> + <tr> + <td class="tdl">Ammonium sulphate</td> + <td class="tdr">1.82</td> + </tr> + <tr> + <td class="tdl">Ammonium chloride</td> + <td class="tdr">1.55</td> + </tr> + <tr> + <td class="tdl">Potassium sulphate</td> + <td class="tdr">3.30</td> + </tr> + <tr> + <td class="tdl">Sodium chloride</td> + <td class="tdr"><span style="text-decoration: underline;"> 2.44</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">43.96</span></td> + </tr> +</table> +</div> + +<br /> +<p class="cen">2. <i>Difficultly soluble in Water, soluble in Acids, +Alcohol, and Ether.</i></p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="uric"> + <tr> + <td class="tdl" width="80%">Uric acid</td> + <td class="tdr" width="20%">21.14</td> + </tr> + <tr> + <td class="tdl">Resin</td> + <td class="tdr">1.11</td> + </tr> + <tr> + <td class="tdl">Fatty acids</td> + <td class="tdr">1.60</td> + </tr> + <tr> + <td class="tdl">Nitrogenous and sulphurous organic substances</td> + <td class="tdr">2.29</td> + </tr> + <tr> + <td class="tdl">Calcium phosphate</td> + <td class="tdr">18.22</td> + </tr> + <tr> + <td class="tdl">Phosphate of iron</td> + <td class="tdr">1.04</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdr"><span style="text-decoration: underline;"> .64</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">46.04</span></td> + </tr> +</table> +</div> + +<p>In the above analysis it will be noticed that none of the ammonia is +present as carbonate. In most samples, however, of Peruvian guano, the +ammonia in <span class='pagenum'><a name="Page_306" id="Page_306">[Pg 306]</a></span>this form amounted to from 1 to 2 per cent. In the inferior +qualities, chiefly those which had been subjected to the action of +water, and consequently of fermentation, to a certain extent, this form +of ammonia was found to be most abundant. Such guanos were most liable +to loss of nitrogen by volatilisation.</p> + +<p>The older Peruvian guano contained as high as 14 per cent of nitrogen +(equal to 17 per cent of ammonia), and of phosphoric acid 12 to 14 per +cent (equal to 26 to 28 per cent of phosphate of lime). It, however, +gradually deteriorated in quality as the deposits became worked out, the +percentage of nitrogen becoming year by year less, until latterly +Peruvian guano, as imported, contains only from 3 to 4 per cent of +nitrogen (equal to 4 to 5 per cent of ammonia). This guano is, however, +richer in phosphates, containing often 50 to 60 per cent of phosphate of +lime, and 3 to 4 per cent of potash.<a name="FNanchor_192_192" id="FNanchor_192_192"></a><a href="#Footnote_192_192" class="fnanchor">[192]</a></p> + +<br /> +<p class="cen">(<i>b</i>) <span class="smcap">Other Nitrogenous Guanos.</span></p> + +<p>The guanos, other than those which come from Peru, are chiefly purely +phosphatic guanos, so that the term Peruvian has not unfrequently in the +past been used as a generic term synonymous with the term nitrogenous, +and consequently applied to all nitrogenous guanos independent of their +source. There are, however, a few deposits other than the <span class='pagenum'><a name="Page_307" id="Page_307">[Pg 307]</a></span>Peruvian +which have yielded considerable quantities of valuable nitrogenous +guano. Of those, the richest in quality—in fact, the richest of any +deposits hitherto discovered—was the Angamos guano, which came from a +rocky promontory on the coast of Bolivia. The few samples of this which +have been analysed showed over 20 per cent of nitrogen. Unfortunately, +the deposit proved to be comparatively insignificant in amount, and has +long been exhausted.</p> + +<p>Poorer in quality, but more abundant in quantity, were the deposits +found on the Ichaboe and other islands off the south-west coast of +Africa. These deposits were discovered shortly after the introduction of +Peruvian guano, and for a few years supplied considerable quantities of +valuable manure. The deposits first discovered were soon exhausted, so +that for a number of years Ichaboe guano ceased to be procurable. Fresh +deposits, however, were subsequently found, and considerable quantities +have of late years been used in agriculture.<a name="FNanchor_193_193" id="FNanchor_193_193"></a><a href="#Footnote_193_193" class="fnanchor">[193]</a> Ichaboe guano is +inferior in value to Peruvian. It exemplifies the influence of small +quantities of rain on guano deposits in impoverishing them in their +nitrogen. In much of the Ichaboe guano imported into this country a +large amount of feathers is found. It also contains an abnormally large +quantity of insoluble matter.</p> + +<p>Among the other nitrogenous guanos may be <span class='pagenum'><a name="Page_308" id="Page_308">[Pg 308]</a></span>mentioned the Patagonian, +Falkland, and Saldanha Bay. They are, like the Ichaboa, of comparatively +recent origin, and are collected in small quantities after the breeding +season every year.</p> + +<br /> +<p class="cen">II.—<span class="smcap">Phosphatic Guanos.</span></p> + +<p>Phosphatic guanos, as already pointed out, are similar in origin to +nitrogenous guanos. In their case, however, the nitrogen, alkalies, and +soluble phosphates which they originally contained have been almost +entirely lost by the decomposition of their organic matter and the +action of water.<a name="FNanchor_194_194" id="FNanchor_194_194"></a><a href="#Footnote_194_194" class="fnanchor">[194]</a> Most of them still contain very small quantities +of nitrogen, amounting to a fraction of a per cent. Of these deposits +there are very many occurring on islands in different parts of the +world. In appearance the guano obtained from them is very different from +nitrogenous guano, being much lighter in colour, and of a fine powdery +nature. It forms a very rich phosphatic guano, containing in many cases +between 70 and 80 per cent of insoluble phosphate of lime. Such guanos +are largely used in the manufacture of high-class superphosphates, by +treating them with sulphuric <span class='pagenum'><a name="Page_309" id="Page_309">[Pg 309]</a></span>acid. Being of an insoluble nature, they +are not very suitable for direct application to the soil. Of these +phosphatic guanos the following are the chief—those marked in italics +being still unexhausted:—</p> + +<p>1. <i>Baker</i>, Jarvis, Howland, Starbuck, Flint, <i>Enderbury</i>, <i>Malden</i>, +Lacepede, <i>Browse</i>, <i>Huon</i>, <i>Chesterfield</i>, <i>Sydney</i>, <i>Phœnix</i>, +<i>Arbrohlos</i>, <i>Shark's Bay</i>, and <i>Timor</i>—all found on islands in the +Pacific Ocean.</p> + +<p>2. <i>Mejillones</i>, on the coast of Bolivia.</p> + +<p>3. Aves, <i>Tortola</i>, <i>Mona</i>, and other deposits in the West Indies.</p> + +<p>4. <i>Kuria Muria</i> islands, in the Arabian Gulf.</p> + +<p>For further particulars as to the composition of these different guanos, +the reader is referred to the Appendix, Note V., p. 329.</p> + +<br /> +<p class="cen"><i>Inequality in Composition.</i></p> + +<p>That guano was a substance of by no means uniform composition was a fact +early recognised in the history of the trade. Not only did guano from +different deposits show on analysis different percentages of the +manurial ingredients, but different samples of guano from the same +deposit were often found to differ very considerably from one another. +It soon became the custom, therefore, to sell it on chemical analysis, +each separate cargo being carefully analysed. But this custom did not +wholly obviate the difficulty, as the guano in even one cargo might +differ. In the case of the older and richer guanos, there was certainly +more <span class='pagenum'><a name="Page_310" id="Page_310">[Pg 310]</a></span>uniformity in quality, but they were liable to differ in their +percentage of nitrogen.<a name="FNanchor_195_195" id="FNanchor_195_195"></a><a href="#Footnote_195_195" class="fnanchor">[195]</a> As, however, the deposits became gradually +worked out, their lower layers were found more or less largely admixed +with stony and earthy matter, and their composition was naturally +rendered very variable. This state of matters was unsatisfactory to +buyers and sellers, and led to much friction between the two, as it was +found wellnigh impossible on the part of the seller to guarantee the +composition of his manure. The custom of preparing the material by +reducing it to a fine powder before sending it into the market, and the +custom, subsequently introduced, of treating it with sulphuric acid, +have done away with this difficulty to a large extent.</p> + +<br /> +<p class="cen"><i>"Dissolved" Guano.</i></p> + +<p>The treatment of guano with sulphuric acid was first had recourse to in +the case of cargoes damaged with water. In such guano, as has been +already pointed out, fermentation has been permitted to take place, with +the result of the formation of volatile carbonate of ammonia in greater +or less quantity. By the addition of sulphuric acid the ammonia was +fixed, and the guano was prevented from losing its most valuable +constituent. It was soon found, however, that guano so treated possessed +greater activity as a manure. The result of the sulphuric acid was to +<span class='pagenum'><a name="Page_311" id="Page_311">[Pg 311]</a></span>increase very materially the amount of its soluble phosphates, and also +its soluble nitrogen compounds.<a name="FNanchor_196_196" id="FNanchor_196_196"></a><a href="#Footnote_196_196" class="fnanchor">[196]</a> It had, moreover, the effect of +producing a guano of uniform composition. The custom, first introduced +in 1864 by Messrs Ohlendorff & Co., was soon largely practised. The +guano is treated with 25 to 30 per cent sulphuric acid (sp. gr. 1.73). +After a short time the resulting hard mass is, by means of +disintegrators, reduced to a uniform powder.</p> + +<br /> +<p class="cen"><i>"Equalised" or "Rectified" Guano.</i></p> + +<p>As guano decreased in its quality the demand for a high-class article +became more and more difficult to meet. This led to the custom of +"fortifying" or "rectifying"—as it is variously called—the natural +material with sulphate of ammonia. A manure closely resembling in the +percentage of its manurial constituents the older rich guanos is thus +obtained. Of these so-called "equalised" guanos, two qualities are at +present sold, the first being guaranteed to contain nitrogen equal to 8 +to 9 per cent ammonia, 30 to 35 per cent phosphates, and 2 to 3 per cent +of potash; the second quality containing only about half as much +nitrogen, but more phosphates.</p> + +<p>However valuable this fortified guano may be—and it is, undoubtedly, a +most valuable manure—its action cannot be supposed to be exactly +similar to the old <span class='pagenum'><a name="Page_312" id="Page_312">[Pg 312]</a></span>Peruvian guano, which it resembles in the percentage +of its nitrogen, phosphates, and potash. Much of the distinctive value +of guano as a manure, as will be pointed out immediately, lies in the +fact that it contains its manurial ingredients in a variety of +differently soluble compounds, which are gradually rendered available in +the soil for the plant's needs. This undoubtedly is one of the reasons +why the action of guano among manures is quite unique; and there are +other reasons which we probably do not clearly understand. However +skilfully the composition of the guano may be artificially simulated, it +still remains an undoubted fact that the "equalised" guano is not +exactly similar in its action to the genuine article. Nevertheless, that +it is superior in its results to the poorer classes of guano at present +available, and to ordinary compound manures, there can be little doubt. +A great merit of the equalised guano is, however, that it is sold at a +lower price than guano as imported; and as the guano is sold on a +guaranteed analysis, the practice has done much to advance the true +interests of agriculture.</p> + +<br /> +<p class="cen"><i>Its Action as a Manure.</i></p> + +<p>Next to farmyard manure, guano may be regarded as the most "general" of +all the commonly used manures; for in addition to nitrogen, phosphoric +acid, and potash, it contains nearly all the other plant ingredients, +such as lime, magnesia, &c. Its special value as a manure, however, does +not merely consist <span class='pagenum'><a name="Page_313" id="Page_313">[Pg 313]</a></span>in the amount of valuable plant-food it contains. +Like farmyard manure, it owes much of its characteristic action to the +state of the intimate mixture of its manurial constituents, and also, as +has already been pointed out, to the fact that it contains those +constituents in a great variety of chemical forms, each of which differs +in its solubility, and consequently availability for the plant's needs. +Take, for example, the great number of different forms of nitrogen it +contains. Some are in the condition in which plants can immediately +absorb them, while the rest are in a series of less and less available +forms, which, however, are gradually converted into available forms as +the plant requires them. Like farmyard manure, again, it may be applied +with almost equally good results to all kinds of crops and on all kinds +of soils. We have in guano, in short, an admirable example of the value +of applying our manurial ingredients in different forms. That this is no +mere theory is abundantly proved by the large number of different +experiments which have in the past been carried out with guano, more +especially the well-known experiments made by Grouven, the German +chemist. In those well-known experiments, guano was tested against a +large variety of different fertilisers, and the tests were so arranged +that in most cases the amounts of nitrogen, phosphoric acid, and potash +were the same in the other manures used. In short, these experiments +prove in a very striking manner that a manure artificially made up out +<span class='pagenum'><a name="Page_314" id="Page_314">[Pg 314]</a></span>of most valuable fertilisers, such as nitrate of soda, sulphate of +ammonia, superphosphate, &c., so as to closely resemble in its +composition guano, is by no means similar in its effects to the genuine +article. As in farmyard manure, so in guano: we must look to the +complexity of the composition of both these fertilisers in order to +fully estimate their worth. There is in the action of both manures much +that we cannot explain, or even, as yet, understand. The action of guano +is merely one of many problems in the science of manuring which +illustrate how unsatisfactory, despite the great amount of research +already carried out, is our knowledge of this most important department +of agriculture.<a name="FNanchor_197_197" id="FNanchor_197_197"></a><a href="#Footnote_197_197" class="fnanchor">[197]</a></p> + +<br /> +<p class="cen"><i>Proportion of fertilising Constituents in Guano.</i></p> + +<p>Guano must be regarded as a nitrogenous and phosphatic manure, as the +quantity of potash it generally contains is small. In many soils, more +especially in such a country as Scotland, this deficiency in potash is +not of so much importance, as the value of potash as an artificial +manure is less than is the case with the other two ingredients. In +soils, however, lacking potash, guano ought to be supplemented with some +potash manure. With regard to the nitrogen and phosphoric acid, we may +ask if these two constituents are in the best proportions. This question +does not admit of a direct answer. In the first place, the <span class='pagenum'><a name="Page_315" id="Page_315">[Pg 315]</a></span>proportion +in which these two ingredients are present is variable. In the old rich +Peruvian guanos, as we have above shown, the nitrogen was more abundant +than is the case at present. Such guanos, it was found, were best +supplemented with phosphatic manure when applied to the field. In the +"equalised" and "dissolved" guanos, which are now so largely sold, +manufacturers attempt to adjust the percentage of nitrogen and +phosphoric acid to what is considered the best proportion in most cases. +As, however, we have again and again to point out, regard must be had +both to the soil and the crop in determining what is the best proportion +of the manurial ingredients in a manure. For cereals it may be well +supplemented by nitrogenous manures, while for roots it may be well +supplemented by phosphatic manures.</p> + +<br /> +<p class="cen"><i>Mode of Application.</i></p> + +<p>Like all manures, it is desirable to apply it in as fine a condition as +possible, so as to ensure as thorough a mixture with the soil-particles +as practicable. In order, furthermore, to prevent any risk of loss +through volatilisation of the ammonia, as well as to ensure even +distribution, it is best applied mixed with dry earth, ashes, sand, or +some other substance,—not lime, however. The custom of applying along +with the guano common salt, has been proved by numerous experiments to +be highly beneficial to the action of the guano as a manure. The exact +nature <span class='pagenum'><a name="Page_316" id="Page_316">[Pg 316]</a></span>of the action of salt as an adjunct to manures is a point which +has elicited much discussion. Its action is probably to be ascribed to a +number of causes. For one thing, it probably acts as an antiseptic in +retarding the fermentative action which has a tendency to go on so +rapidly in such manures as guano. It further increases the power of the +manure to attract moisture from the air—a most important property in +the case of drought. Some experiments by Dr Voelcker illustrate this in +a striking manner. Two lots of guano—one pure and one mixed with +salt—were exposed to the action of the air for a month, and were then +tested as to the amount of water they contained, when it was found that +the lot containing the salt had absorbed 2 per cent more water than the +other.</p> + +<p>Much stress has been laid on the importance of having the guano buried a +certain depth in the soil; and many experiments have been carried out to +prove how much better it acts when so applied. This is probably due to +the prevention of any loss of volatile ammonia, and the mixture of the +manure with the soil-particles before it comes in contact with the +plant-roots. This last precaution is an important one, for it has been +found that the raw material is apt to have a bad effect on the seed or +the plant's roots. This has been found to be especially the case in +regard to potatoes, the quality of which has been found to suffer when +the guano is brought <span class='pagenum'><a name="Page_317" id="Page_317">[Pg 317]</a></span>into direct contact with the tubers. As guano is a +manure which is speedily available, it is desirable to apply it as +shortly before it is required by the plant as possible. It is therefore +generally best applied in spring, shortly before seed-time, or indeed at +the same time. Where farmyard manure is used, the guano has been +recommended to be used as a top-dressing in small quantities. In the +majority of cases it will be advisable, however, not to apply it as a +top-dressing, for the various reasons above-mentioned.</p> + +<br /> +<p class="cen"><i>Quantity to be used.</i></p> + +<p>As to the quantity to be used, this of course will depend on the soil, +the crop, and the amount and nature of the other manures employed: 1 to +4 cwt. per acre have been the usual limits, but even heavier dressings +have been commonly resorted to, especially in Scotland, where 6 to 8 or +even 9 cwt. for turnips are often used. Sir J. B. Lawes and Sir James +Caird long ago, shortly after the introduction of guano, estimated, from +the experiments they carried out, that the application of 2 cwt. per +acre to the wheat crop gave an increase of 8 to 9 bushels in grain, and +added a fourth to the quantity of straw. The former authority recommends +2 to 3 cwt. per acre for wheat, to be sown broadcast and harrowed into +the land before sowing the seed. We have already stated that it may be +used in all soils and for all kinds of <span class='pagenum'><a name="Page_318" id="Page_318">[Pg 318]</a></span>crops. While this is so, it has +been found to have specially favourable results when applied to the +turnip crop, when it may be used in larger quantities than in the case +of cereals. When applied to the turnip crop, it is well to use the more +phosphatic guanos or to supplement it with superphosphates. By applying +it in two lots, the larger portion before seed-time and the rest between +the drills after the turnips are up, excellent results have been +obtained. It has also proved an admirable manure for mangels. On the +whole, it gives best results on heavy soils and in a dampish climate.</p> + +<br /> +<p class="cen"><i>Adulteration of Guano.</i></p> + +<p>Probably no artificial manure has been subjected to greater adulteration +in the past than guano. This has been due to the fact that the practice +of selling guano on analysis—especially among retail buyers—did not +largely obtain in the early years of the trade. A good deal of this +adulteration was probably caused by ignorant prejudice on the part of +the farmer, to whom the pungency of its smell and its colour were too +apt to be ranked as its most important properties. The variation in the +quality of different kinds of guano was too often not sufficiently +realised by the buyer, who not unfrequently was made to pay as high a +price for guano of an inferior quality as he ought to have paid for that +of the best quality. Indeed no manure illustrates the importance of +<span class='pagenum'><a name="Page_319" id="Page_319">[Pg 319]</a></span>chemical analysis more than guano. Among the different forms of +adulteration practised may be mentioned the addition of such substances +as sawdust, rice-meal, chalk, sulphates of lime and magnesia, common +salt, sand, earth, peat, ashes of various kinds, and water. There can be +no doubt, however, that such adulteration has now long ceased to be +practised to any extent. Nevertheless, it may be of use to draw +attention to one or two of the tests by means of which some of the +commoner forms of adulteration may be detected. One or two are extremely +easily detected—as, for example, adulteration with sand or other +mineral substances. In such a case, the percentage of ash left on +burning a small portion of the guano will be found to be excessive. The +percentage of ash in a sample of genuine Peruvian guano should not +exceed from 50 to 60 per cent. The colour of the ash is another +important point, and may serve as a further indication of adulteration. +In the case of genuine guano, this should be whitish or greyish. +Red-coloured ash generally points to the adulteration of the guano with +some mineral substance containing iron—such, <i>e.g.</i>, as Redonda +phosphate, a mineral phosphate of iron and alumina. Where the ash is +white, but excessive in quantity, adulteration with common salt, +sulphate of magnesia, gypsum, or chalk, may be suspected. The last-named +substance is easily detected by treating it with any of the common +acids, when brisk effervescence, due <span class='pagenum'><a name="Page_320" id="Page_320">[Pg 320]</a></span>to the liberation of the carbonic +acid, will ensue.<a name="FNanchor_198_198" id="FNanchor_198_198"></a><a href="#Footnote_198_198" class="fnanchor">[198]</a> A further point of importance with regard to the +ash is its solubility in water and in acids. A large insoluble residue +may be taken as indicating adulteration with sand. Adulteration with +water is also easily detected by heating a sample to the boiling +temperature and determining the loss it sustains. Of course the amount +of water varies in different samples. The appearance of the guano will +serve fairly well to detect whether it is abnormally moist. It may be +added, in conclusion, that Peruvian guano is extremely light; and while +this by itself is not a sufficient test of genuineness, it may serve to +confirm other tests.</p> + +<br /> +<p class="cen">III.—<span class="smcap">So-called Guanos.</span></p> + +<p>Before concluding this chapter, reference may be made to certain manures +which are commonly known under the name of guanos—such as "fish-guano," +"flesh-guano," "meat-meal-guano," and "bat-guano,"—as well as to +manures which may more conveniently be described here—viz., "fowl and +pigeon dung."</p> + +<br /> +<p class="cen"><i>Fish-Guano.</i></p> + +<p>The application of fish, not suited for other <span class='pagenum'><a name="Page_321" id="Page_321">[Pg 321]</a></span>purposes, to the fields +as a manure is a practice which has obtained in certain parts of the +country for a number of years. In many districts on the sea-coast, where +fishing is the chief industry, the only way in the past of disposing of +a superabundant catch of herrings, for example, has been to utilise them +as a manure. From such a practice has sprung up what is now an important +and ever-increasing trade—viz., the manufacture of fish-guano.</p> + +<p>This manufacture was first started, and is still most largely practised, +in Norway. The guano obtained varies very considerably in quality +according to the nature of the process employed, and as to whether the +guano is made from whole fish or merely from fish-offal. The latter +source is the common one. The manufacture is carried on at the +fish-curing stations, and the quality of the guano made from this source +is somewhat different from that made from whole fish, as a large +proportion of the fish-offal is made up of bones and heads. Large +quantities of Norwegian fish-guano are exported to various parts of +Europe.</p> + +<p>The best quality of this guano may contain as much as 10 per cent of +nitrogen, but as a rule it is nearer 8 per cent. A very considerable +variation in the amount of phosphoric acid occurs for the reason above +stated, the guano made from fish-scrap being naturally much richer in +this ingredient than whole-fish guano. The phosphoric acid may be said +to range from 4 to <span class='pagenum'><a name="Page_322" id="Page_322">[Pg 322]</a></span>15 per cent, and there is also a small quantity of +potash present.</p> + +<p>Guano is also manufactured in Norway from the carcasses of whales. Such +guano contains from 7-1/2 to 8-1/2 per cent of nitrogen, and about +13-1/2 per cent of phosphoric acid.</p> + +<p>In America fish-guano is manufactured to a considerable extent—one +important source being the menhaddo, a coarse sort of herring. This fish +is caught for the sake of its oil, which is extracted by boiling, the +residue being manufactured, after pressing and drying, into guano.</p> + +<p>In this country the manufacture of fish-guano is carried out to a +considerable and increasing extent. Formerly it was imported from Norway +to a larger extent than is now the case, the present annual imports +amounting only to 1000 or 2000 tons. The total annual production in the +United Kingdom is probably 7000 or 8000 tons.</p> + +<br /> +<p class="cen"><i>Value of "Fish-Guano."</i></p> + +<p>That fish-guano is a valuable manure there can be no doubt. What, +however, impairs its value is the fact that, as a rule, it contains a +certain amount of oil. The effect of this oil is to retard fermentation +and decomposition when the guano is applied to the soil, and thus render +its action slower than would otherwise be the case.</p> + +<p>When applied to the soil, therefore, every <span class='pagenum'><a name="Page_323" id="Page_323">[Pg 323]</a></span>opportunity ought to be +given to promote its fermentation. It is best applied some time before +it is likely to be used. It ought to be well mixed with the +soil-particles, and not allowed to lie on the top of the soil. Its best +effect will be on light well-cultivated soils, which permit of the +access both of sufficient moisture and of sufficient air for rapid +fermentation. Its value as a manure for hops, vines, grass, and +strawberries has been found to be considerable. It has been recommended +to be applied along with farmyard manure; and such a mode of application +is no doubt well suited to promote its decomposition. It has also been +used for mixing with superphosphate of lime. Professor Storer has +advocated a more general use of fish as a manure than is at present the +case. He suggests that even fish not suitable for edible purposes might +be caught for the purpose of conversion into manure. The difficulty of +preserving fish, however, is considerable; and he suggests the use of +potash salts, such as muriate of potash, or lime for this purpose. The +benefit of using potash would be twofold. In addition to acting as a +preservative, it would considerably enhance the value of the resulting +guano as a manure. There is much truth in Professor Storer's views; and +no doubt, as our sources of artificial nitrogenous manures grow more +limited, the manufacture of fish-guano will be carried on in the future +on a larger and more systematic scale than hitherto.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_324" id="Page_324">[Pg 324]</a></span><i>Meat-meal Guano.</i></p> + +<p>What is called "meat-meal guano" is generally that made from the refuse +of the carcasses of cattle after they have been treated for their +meat-extract according to Liebig's process. The meat-meal is used both +for feeding and manurial purposes. Considerable quantities<a name="FNanchor_199_199" id="FNanchor_199_199"></a><a href="#Footnote_199_199" class="fnanchor">[199]</a> of this +guano are imported annually into this country from South America, +Queensland, and New Zealand,—that coming from Frey Bentos, in Uruguay, +being best known. It is a valuable manure, especially so for its +nitrogen, which varies from 4 to 8 per cent, while it contains of +phosphoric acid from 13 to 20 per cent. Some meat-meal guanos contain as +much nitrogen as 11 per cent.</p> + +<p>In some parts of the world, more especially in Germany, the carcasses of +horses, as well as cattle, dogs, pigs, &c., which have died of disease, +are converted into a guano. They are subjected to treatment by steam in +digestors, by which means the fat and gelatine are separated and +utilised, while the remaining portion of the animal is converted into +guano. Other processes are also employed. The resulting manure contains +from 6 to 10 per cent of nitrogen, and from 6 to 14 per cent of +phosphoric acid.</p> + +<br /> +<p class="cen"><i>Value of Meat-meal Guano.</i></p> + +<p>Meat-meal guano is a valuable nitrogenous manure. <span class='pagenum'><a name="Page_325" id="Page_325">[Pg 325]</a></span>The same remarks +apply to it as to fish-guano, although it ferments probably very much +more quickly than the latter, and is undoubtedly a more valuable manure.</p> + +<br /> +<p class="cen"><i>Bat Guano.</i></p> + +<p>In conclusion, we may consider bat guano. Bat guano, which is really a +very rare curiosity, has been found accumulated in hot climates in +caves.</p> + +<p>The samples which have been analysed have differed very much in quality, +some containing as much as 9 per cent of nitrogen and 25 per cent of +phosphoric acid. Provided it could be obtained in any quantity, and of a +quality even approximating to the above analysis, it need scarcely be +pointed out that bat guano would be a most valuable manure.</p> + +<p>A singular point about its composition is, that it has been found to +contain a considerable proportion of its nitrogen (as much as 3 per +cent) in the form of nitrates.</p> + +<br /> +<p class="cen"><i>Pigeon and Fowl Dung.</i></p> + +<p>Pigeon dung is a manure which historically is of great importance. The +dung of pigeons was used as a manure by the ancient Romans; and even in +modern times, more especially in France, it was considered a most +important fertiliser. Despite these facts, pigeon dung is by no means a +rich manure, and its composition compares most unfavourably with that of +the guanos we have just been considering. According to <span class='pagenum'><a name="Page_326" id="Page_326">[Pg 326]</a></span>Storer,<a name="FNanchor_200_200" id="FNanchor_200_200"></a><a href="#Footnote_200_200" class="fnanchor">[200]</a> it +only contains from 1-1/4 to 2-1/2 per cent of nitrogen, and from 1-1/2 +to 2 per cent of phosphoric acid, and a little over 1 per cent of +potash.</p> + +<p>The dung of poultry is just about as poor, fowl dung containing from .8 +to 2 per cent of nitrogen, 1-1/2 to 2 per cent of phosphoric acid, and a +little under 1 per cent of potash; while that of ducks and geese is even +poorer.<a name="FNanchor_201_201" id="FNanchor_201_201"></a><a href="#Footnote_201_201" class="fnanchor">[201]</a></p> + +<p>From these statements it will be seen that the excrements of pigeons, +hens, and ducks do not form a rich manure. One thing about pigeon dung +which is to be noticed, is the fact that it ferments very quickly.</p> + +<p>None of the pseudo-guanos, however rich they may be in manurial +ingredients, can be regarded as equal in their action to the genuine +article, for reasons which we have gone into already when considering +the action of guano.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_183_183" id="Footnote_183_183"></a><a href="#FNanchor_183_183"><span class="label">[183]</span></a> Bones, it is true, were in use long before guano; but +popular as they deservedly were, they had not been used, at the time of +the importation of guano, to any very considerable extent.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_184_184" id="Footnote_184_184"></a><a href="#FNanchor_184_184"><span class="label">[184]</span></a> The total annual imports at present may be taken at under +30,000 tons, whereas in 1855 they amounted to over 200,000 tons. For +statistics on this point the reader is referred to the Appendix, Note +I., p. 327.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_185_185" id="Footnote_185_185"></a><a href="#FNanchor_185_185"><span class="label">[185]</span></a> With regard to the origin of certain guano deposits, +which are of very recent date—<i>e.g.</i>, <i>Angamos</i> and <i>Ichaboe</i>—there +can be no doubt whatever, because we can witness the process of +formation still taking place. It is not so, however, with regard to +older deposits, for which some have been inclined to claim mineral +origin. The best proof that such deposits owe their origin mainly to +bird excrements is the comparatively large quantity of <i>uric acid</i> they +contain. On the other hand, the evidence in support of the belief that +they are also formed from the remains of the birds themselves and other +animals, is to be found in the large proportion of phosphates they +contain, and the presence in the deposits of feathers and the fossilised +skeletons of the animals above mentioned.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_186_186" id="Footnote_186_186"></a><a href="#FNanchor_186_186"><span class="label">[186]</span></a> A complete list of the various deposits will be found in +the Appendix, Note II., p. 327. It may be noticed that nearly all the +deposits lie within 10° to 20° north and south of the Equator.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_187_187" id="Footnote_187_187"></a><a href="#FNanchor_187_187"><span class="label">[187]</span></a> See Chapter on Farmyard Manure, p. 257.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_188_188" id="Footnote_188_188"></a><a href="#FNanchor_188_188"><span class="label">[188]</span></a> According to Nesbit, some of the cargoes of this guano +contained hard saline lumps of very little manurial value—over 50 per +cent being common salt.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_189_189" id="Footnote_189_189"></a><a href="#FNanchor_189_189"><span class="label">[189]</span></a> The salt exports were made in 1868.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_190_190" id="Footnote_190_190"></a><a href="#FNanchor_190_190"><span class="label">[190]</span></a> For analyses of these nodules and crystals, see Appendix, +Note III., p. 328.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_191_191" id="Footnote_191_191"></a><a href="#FNanchor_191_191"><span class="label">[191]</span></a> See Heiden, vol. ii. p. 356.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_192_192" id="Footnote_192_192"></a><a href="#FNanchor_192_192"><span class="label">[192]</span></a> See Appendix, Note IV., p. 329.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_193_193" id="Footnote_193_193"></a><a href="#FNanchor_193_193"><span class="label">[193]</span></a> The Ichaboe guano at present exported is a fresh deposit, +and is annually collected for shipment.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_194_194" id="Footnote_194_194"></a><a href="#FNanchor_194_194"><span class="label">[194]</span></a> Further chemical changes have occurred in certain cases +between the guano and the limestone rock beneath, resulting in the +formation of what is called a "crust" guano. Such guanos form a soft +phosphatic rock, and are extremely rich in phosphates. As examples of +these "crust" guanos may be mentioned Sombrero, Curaçao, Aruba, Mexico, +and Navassa phosphates.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_195_195" id="Footnote_195_195"></a><a href="#FNanchor_195_195"><span class="label">[195]</span></a> The presence in the old Peruvian guano of concretionary +nodules has already been referred to.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_196_196" id="Footnote_196_196"></a><a href="#FNanchor_196_196"><span class="label">[196]</span></a> According to Vogel the nitrogen as urates is converted by +the sulphuric acid into ammonia salts.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_197_197" id="Footnote_197_197"></a><a href="#FNanchor_197_197"><span class="label">[197]</span></a> See Appendix, Note VI. p. 330.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_198_198" id="Footnote_198_198"></a><a href="#FNanchor_198_198"><span class="label">[198]</span></a> It must be remembered, however, that even genuine guano +contains a certain quantity of carbonate of lime, and will give a slight +amount of effervescence when so treated.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_199_199" id="Footnote_199_199"></a><a href="#FNanchor_199_199"><span class="label">[199]</span></a> The annual imports may be stated at from 3000 to 4000 +tons.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_200_200" id="Footnote_200_200"></a><a href="#FNanchor_200_200"><span class="label">[200]</span></a> Agricultural Chemistry, vol. i. p. 367.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_201_201" id="Footnote_201_201"></a><a href="#FNanchor_201_201"><span class="label">[201]</span></a> See Appendix, Note VII., p. 331.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_327" id="Page_327">[Pg 327]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER VIII.</h2> +<br /> + +<p class="cen">NOTE I. (p. 297).</p> + +<p class="cen"><span class="smcap">Peruvian Guano Imported into the United Kingdom, 1865-1893.</span></p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="urate"> + <tr> + <td class="tdl" width="50%">Year.</td> + <td class="tdr" width="50%">Tons. </td> + </tr> + <tr> + <td class="tdl">1865</td> + <td class="tdr">213,024</td> + </tr> + <tr> + <td class="tdl">1870</td> + <td class="tdr">247,028</td> + </tr> + <tr> + <td class="tdl">1871</td> + <td class="tdr">144,735</td> + </tr> + <tr> + <td class="tdl">1872</td> + <td class="tdr">74,964</td> + </tr> + <tr> + <td class="tdl">1873</td> + <td class="tdr">135,895</td> + </tr> + <tr> + <td class="tdl">1874</td> + <td class="tdr">94,346</td> + </tr> + <tr> + <td class="tdl">1875</td> + <td class="tdr">86,042</td> + </tr> + <tr> + <td class="tdl">1876</td> + <td class="tdr">158,674</td> + </tr> + <tr> + <td class="tdl">1877</td> + <td class="tdr">111,835</td> + </tr> + <tr> + <td class="tdl">1878</td> + <td class="tdr">127,813</td> + </tr> + <tr> + <td class="tdl">1879</td> + <td class="tdr">45,475</td> + </tr> + <tr> + <td class="tdl">1880</td> + <td class="tdr">58,631</td> + </tr> + <tr> + <td class="tdl">1881</td> + <td class="tdr">33,393</td> + </tr> + <tr> + <td class="tdl">1882</td> + <td class="tdr">27,382</td> + </tr> + <tr> + <td class="tdl">1883</td> + <td class="tdr">36,713</td> + </tr> + <tr> + <td class="tdl">1884</td> + <td class="tdr">15,802</td> + </tr> + <tr> + <td class="tdl">1885</td> + <td class="tdr">— </td> + </tr> + <tr> + <td class="tdl">1886</td> + <td class="tdr">28,733</td> + </tr> + <tr> + <td class="tdl">1887</td> + <td class="tdr">5,784</td> + </tr> + <tr> + <td class="tdl">1888</td> + <td class="tdr">16,446</td> + </tr> + <tr> + <td class="tdl">1889</td> + <td class="tdr">17,000</td> + </tr> + <tr> + <td class="tdl">1890</td> + <td class="tdr">19,000</td> + </tr> + <tr> + <td class="tdl">1891</td> + <td class="tdr">11,000</td> + </tr> + <tr> + <td class="tdl">1892</td> + <td class="tdr">14,000</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 298).</p> + +<p class="cen"><span class="smcap">Guano Deposits of the World.</span></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="hanging indent"> + <tr> + <td class="tdlh" width="100%"><span class="smcap">South America</span>—<br /> + <i>Peru.</i>—In various islands off the coast—viz., + Chincha, Guanape, Ballestas, Macabi, Lobos, and Patillos; and on different parts of the + coast—viz., Pabellon de Pica, Chipana, Huanillos, Punta de Patillos, Indiependence Bay, + and Lobos de fuera.<br /> + <i>Columbia.</i>—In different parts of the States of Venezuela, + New Granada, and Ecuador. Guano coming from these parts is often known as Columbian + guano, or according to the name of the State in which it is found. Maracaïbo and Monks + guanos come from the coast of Venezuela. Deposits are also found on the Galapagos Islands, + to the west of Ecuador.<br /> + <i>Bolivia.</i>—Mejillones, Patagonia, Leon's.</td> + </tr> + <tr> + <td class="tdlh"><span class='pagenum'><a name="Page_328" id="Page_328">[Pg 328]</a></span><span class="smcap">North + America</span>—Deposits have been found on the coasts of Mexico and + California; on the Raza and Patos Islands; and on the coasts of + Labrador. They have also been found on the Islands of Curaçao, Aruba, + and Navassa in the Gulf of Mexico.</td> + </tr> + <tr> + <td class="tdlh"><span class="smcap">Africa</span>—On the west coast deposits have been found at Algoa + Bay, Saldanha Bay, and on the Island of Ichaboe.</td> + </tr> + <tr> + <td class="tdlh"><span class="smcap">Australia</span>—Shark's Bay and Swan Island.</td> + </tr> + <tr> + <td class="tdlh"><span class="smcap">West Indies</span>—Sombrero, Aves, and Cuba.</td> + </tr> + <tr> + <td class="tdlh"><span class="smcap">Pacific Ocean</span>—On the Islands of Baker, Jarvis, Howland, + Malden, Starbuck, Fanning, Enderbury, Lacepede, Browse, Huon, and Surprise.</td> + </tr> + <tr> + <td class="tdlh"><span class="smcap">Asia</span>—Deposits at Kuria Muria on the Arabian coast, and on the + Sandwich Islands. (See Heiden's 'Düngerlehre,' vol. ii. p. 349.)</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE III. (p. 303).</p> + +<p class="cen"><span class="smcap">Composition of Concretionary Nodules.</span></p> + +<p class="cen">(<i>Analyses by Karmrodt.</i>)</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="calcium"> + <tr> + <td class="tdc" colspan="2">No. 1</td> + </tr> + <tr> + <td class="tdl" width="80%">Potassium sulphate</td> + <td class="tdr" width="20%">7.49</td> + </tr> + <tr> + <td class="tdl">Potassium phosphate</td> + <td class="tdr">9.52</td> + </tr> + <tr> + <td class="tdl">Sodium phosphate</td> + <td class="tdr">9.08</td> + </tr> + <tr> + <td class="tdl">Ammonium phosphate</td> + <td class="tdr">7.57</td> + </tr> + <tr> + <td class="tdl">Calcium sulphate</td> + <td class="tdr">3.40</td> + </tr> + <tr> + <td class="tdl">Ammonium urate</td> + <td class="tdr">4.09</td> + </tr> + <tr> + <td class="tdl">Ammonium oxalate</td> + <td class="tdr">41.28</td> + </tr> + <tr> + <td class="tdl">Nitrogenous organic matter</td> + <td class="tdr">10.17</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdr"><span style="text-decoration: underline;"> 7.40</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span></td> + </tr> + <tr> + <td class="tdc" colspan="2">Nitrogen - 14.84</td> + </tr> +</table> +</div> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="sulphate"> + <tr> + <td class="tdc" colspan="2">No. 2</td> + </tr> + <tr> + <td class="tdl" width="80%">Potassium sulphate</td> + <td class="tdr" width="20%">45.64</td> + </tr> + <tr> + <td class="tdl">Sodium sulphate</td> + <td class="tdr">13.22</td> + </tr> + <tr> + <td class="tdl">Ammonium sulphate</td> + <td class="tdr">10.23</td> + </tr> + <tr> + <td class="tdl">Ammonium oxalate</td> + <td class="tdr">9.14</td> + </tr> + <tr> + <td class="tdl">Basic ammonium phosphate</td> + <td class="tdr">12.09</td> + </tr> + <tr> + <td class="tdl">Precipitated ammonium phosphate</td> + <td class="tdr">4.78</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdr">.94</td> + </tr> + <tr> + <td class="tdl"> Insoluble</td> + <td class="tdr">1.90</td> + </tr> + <tr> + <td class="tdl"> Water</td> + <td class="tdr"><span style="text-decoration: underline;"> 2.06</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span></td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_329" id="Page_329">[Pg 329]</a></span>NOTE IV. (p. 306).</p> + +<p>The following analyses, being the average of a large number of different +samples analysed from time to time in the chemical laboratory of the +Pommritz Agricultural Experimental Station, show the gradual +deterioration of Peruvian guano, as regards its percentage of nitrogen, +during the years 1867-81:—</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="1867"> + <tr> + <td class="tdl"> </td> + <td class="tdr">Nitrogen.</td> + </tr> + <tr> + <td class="tdl" width="80%">1867</td> + <td class="tdr" width="20%">13.16 </td> + </tr> + <tr> + <td class="tdl">1868</td> + <td class="tdr">11.98 </td> + </tr> + <tr> + <td class="tdl">1869</td> + <td class="tdr">13.66 </td> + </tr> + <tr> + <td class="tdl">1870</td> + <td class="tdr">12.37 </td> + </tr> + <tr> + <td class="tdl">1871</td> + <td class="tdr">10.04 </td> + </tr> + <tr> + <td class="tdl">1872</td> + <td class="tdr">10.72 </td> + </tr> + <tr> + <td class="tdl">1873</td> + <td class="tdr">9.16 </td> + </tr> + <tr> + <td class="tdl">1874</td> + <td class="tdr">9.83 </td> + </tr> + <tr> + <td class="tdl">1878</td> + <td class="tdr">7.10 </td> + </tr> + <tr> + <td class="tdl">1879</td> + <td class="tdr">6.95 </td> + </tr> + <tr> + <td class="tdl">1880</td> + <td class="tdr">7.07 </td> + </tr> + <tr> + <td class="tdl">1881</td> + <td class="tdr">6.93 </td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE V. (p. 309).</p> + +<p class="cen"><span class="smcap">Composition of Different Guanos.</span></p> + +<p>The following is a list of the more common nitrogenous and phosphatic +guanos which have been used in the past or are at present in use. Those +printed in italics are still being worked. As their value depends on +their nitrogen and phosphoric acid, these alone have been given. The +percentages must be taken as mere approximations, as the quality of +different cargoes from the same deposits varies very much. The table may +be found useful for reference.</p> + +<p class="cen"><i>Nitrogenous Guanos.</i></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Angamos"> + <tr> + <td class="tdl" width="24%"> </td> + <td class="tdc" width="14%"> </td> + <td class="tdc" width="5%"> </td> + <td class="tdc" width="14%"> </td> + <td class="tdc" width="17%">Phosphoric</td> + <td class="tdc" width="14%">} {</td> + <td class="tdc" width="17%">Tricalcic</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Nitrogen</td> + <td class="tdc">=</td> + <td class="tdc">Ammonia.</td> + <td class="tdc">acid</td> + <td class="tdc">} = {</td> + <td class="tdc">phosphate.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">per cent.</td> + <td class="tdc"> </td> + <td class="tdc">per cent.</td> + <td class="tdc">per cent.</td> + <td class="tdc"> </td> + <td class="tdc">per cent.</td> + </tr> + <tr> + <td class="tdl">Angamos</td> + <td class="tdc">20</td> + <td class="tdc"> </td> + <td class="tdc">24</td> + <td class="tdc"> 5</td> + <td class="tdc"> </td> + <td class="tdc">11</td> + </tr> + <tr> + <td class="tdl">Chincha</td> + <td class="tdc">14</td> + <td class="tdc"> </td> + <td class="tdc">17</td> + <td class="tdc">13</td> + <td class="tdc"> </td> + <td class="tdc">28</td> + </tr> + <tr> + <td class="tdl">Ballestas</td> + <td class="tdc">12</td> + <td class="tdc"> </td> + <td class="tdc">15</td> + <td class="tdc">12</td> + <td class="tdc"> </td> + <td class="tdc">26</td> + </tr> + <tr> + <td class="tdl">Egyptian</td> + <td class="tdc">11</td> + <td class="tdc"> </td> + <td class="tdc">13</td> + <td class="tdc">19</td> + <td class="tdc"> </td> + <td class="tdc">41</td> + </tr> + <tr> + <td class="tdl">Guanape</td> + <td class="tdc">11</td> + <td class="tdc"> </td> + <td class="tdc">13</td> + <td class="tdc">—</td> + <td class="tdc"> </td> + <td class="tdc">—</td> + </tr> + <tr> + <td class="tdl">Macabi</td> + <td class="tdc">11</td> + <td class="tdc"> </td> + <td class="tdc">13</td> + <td class="tdc">12</td> + <td class="tdc"> </td> + <td class="tdc">26</td> + </tr> + <tr> + <td class="tdl">Corcovado</td> + <td class="tdc">11</td> + <td class="tdc"> </td> + <td class="tdc">13</td> + <td class="tdc">15</td> + <td class="tdc"> </td> + <td class="tdc">33</td> + </tr> + <tr> + <td class="tdl"><i>Saldanha Bay</i></td> + <td class="tdc"> 9</td> + <td class="tdc"> </td> + <td class="tdc">11</td> + <td class="tdc"> 9</td> + <td class="tdc"> </td> + <td class="tdc">20</td> + </tr> + <tr> + <td class="tdl"><i>Ichaboe</i></td> + <td class="tdc"> 8</td> + <td class="tdc"> </td> + <td class="tdc">10</td> + <td class="tdc"> 9</td> + <td class="tdc"> </td> + <td class="tdc">20</td> + </tr> + <tr> + <td class="tdl">Independence Bay</td> + <td class="tdc"> 7</td> + <td class="tdc"> </td> + <td class="tdc"> 9</td> + <td class="tdc">12</td> + <td class="tdc"> </td> + <td class="tdc">26</td> + </tr> + <tr> + <td class="tdl"><i>Pabellon de Pica</i><span class='pagenum'><a name="Page_330" id="Page_330">[Pg 330]</a></span></td> + <td class="tdc"> 7</td> + <td class="tdc"> </td> + <td class="tdc"> 9</td> + <td class="tdc">14</td> + <td class="tdc"> </td> + <td class="tdc">31</td> + </tr> + <tr> + <td class="tdl"><i>Punta de Lobos</i></td> + <td class="tdc"> 4</td> + <td class="tdc"> </td> + <td class="tdc"> 5</td> + <td class="tdc">15</td> + <td class="tdc"> </td> + <td class="tdc">33</td> + </tr> + <tr> + <td class="tdl">Huanillos</td> + <td class="tdc"> 6</td> + <td class="tdc"> </td> + <td class="tdc"> 7</td> + <td class="tdc">18</td> + <td class="tdc"> </td> + <td class="tdc">28</td> + </tr> + <tr> + <td class="tdl">Penguin</td> + <td class="tdc"> 5</td> + <td class="tdc"> </td> + <td class="tdc"> 6</td> + <td class="tdc">11</td> + <td class="tdc"> </td> + <td class="tdc">24</td> + </tr> + <tr> + <td class="tdl">Patagonian</td> + <td class="tdc"> 4</td> + <td class="tdc"> </td> + <td class="tdc"> 5</td> + <td class="tdc">18</td> + <td class="tdc"> </td> + <td class="tdc">39</td> + </tr> + <tr> + <td class="tdl">Falkland Islands</td> + <td class="tdc"> 4</td> + <td class="tdc"> </td> + <td class="tdc"> 5</td> + <td class="tdc">14</td> + <td class="tdc"> </td> + <td class="tdc">31</td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><i>Phosphatic Guanos.</i></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Angamos"> + <tr> + <td class="tdl" width="57%"> </td> + <td class="tdc" width="17%">Phosphoric</td> + <td class="tdc" width="14">} {</td> + <td class="tdc" width="17%">Tricalcic</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">acid</td> + <td class="tdc">} = {</td> + <td class="tdc">phosphate.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">per cent.</td> + <td class="tdc"> </td> + <td class="tdc">per cent.</td> + </tr> + <tr> + <td class="tdl">Maracaïbo, or Monks</td> + <td class="tdc">42</td> + <td class="tdc"> </td> + <td class="tdc">92</td> + </tr> + <tr> + <td class="tdl">Raza Island</td> + <td class="tdc">40</td> + <td class="tdc"> </td> + <td class="tdc">87</td> + </tr> + <tr> + <td class="tdl">Curaçao</td> + <td class="tdc">40</td> + <td class="tdc"> </td> + <td class="tdc">87</td> + </tr> + <tr> + <td class="tdl"><i>Baker Island</i></td> + <td class="tdc">39</td> + <td class="tdc"> </td> + <td class="tdc">85</td> + </tr> + <tr> + <td class="tdl">Starbuck</td> + <td class="tdc">38</td> + <td class="tdc"> </td> + <td class="tdc">83</td> + </tr> + <tr> + <td class="tdl"><i>Enderbury</i></td> + <td class="tdc">37</td> + <td class="tdc"> </td> + <td class="tdc">81</td> + </tr> + <tr> + <td class="tdl">Californian</td> + <td class="tdc">35</td> + <td class="tdc"> </td> + <td class="tdc">76</td> + </tr> + <tr> + <td class="tdl"><i>Aves</i></td> + <td class="tdc">34</td> + <td class="tdc"> </td> + <td class="tdc">74</td> + </tr> + <tr> + <td class="tdl">Fanning Island</td> + <td class="tdc">34</td> + <td class="tdc"> </td> + <td class="tdc">74</td> + </tr> + <tr> + <td class="tdl">Howland</td> + <td class="tdc">34</td> + <td class="tdc"> </td> + <td class="tdc">74</td> + </tr> + <tr> + <td class="tdl"><i>Sidney Island</i></td> + <td class="tdc">34</td> + <td class="tdc"> </td> + <td class="tdc">74</td> + </tr> + <tr> + <td class="tdl">Mejillones</td> + <td class="tdc">33</td> + <td class="tdc"> </td> + <td class="tdc">72</td> + </tr> + <tr> + <td class="tdl">Lacepede Island</td> + <td class="tdc">33</td> + <td class="tdc"> </td> + <td class="tdc">72</td> + </tr> + <tr> + <td class="tdl"><i>Malden Island</i></td> + <td class="tdc">32</td> + <td class="tdc"> </td> + <td class="tdc">70</td> + </tr> + <tr> + <td class="tdl">Sombrero</td> + <td class="tdc">32</td> + <td class="tdc"> </td> + <td class="tdc">70</td> + </tr> + <tr> + <td class="tdl"><i>Browse Island</i></td> + <td class="tdc">31</td> + <td class="tdc"> </td> + <td class="tdc">68</td> + </tr> + <tr> + <td class="tdl"><i>Huon Island</i></td> + <td class="tdc">28</td> + <td class="tdc"> </td> + <td class="tdc">61</td> + </tr> + <tr> + <td class="tdl">Patos Island</td> + <td class="tdc">24</td> + <td class="tdc"> </td> + <td class="tdc">52</td> + </tr> + <tr> + <td class="tdl">Jarvis Island</td> + <td class="tdc">20</td> + <td class="tdc"> </td> + <td class="tdc">44</td> + </tr> + <tr> + <td class="tdl">Cape Vert</td> + <td class="tdc">11</td> + <td class="tdc"> </td> + <td class="tdc">24</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE VI. (p. 314).</p> + +<p>It may be of interest to refer to a theory put forward by Liebig as to +the action of oxalic acid in guano. This, he considered, had the effect +of gradually rendering the insoluble calcium phosphate soluble, and +giving rise to the formation of ammonium phosphate and calcium oxalate. +Such an action would probably take place were the guano allowed to +ferment by itself. We know, however, that when it is brought in contact +with the soil-particles, all its soluble phosphate is converted into +precipitated phosphate.</p> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_331" id="Page_331">[Pg 331]</a></span>NOTE VII. (p. 326).</p> + +<p class="cen"><span class="smcap">Analyses of Dung of Fowls, Pigeons, Ducks, and Geese.</span> <br />(Storer's +'Agricultural Chemistry,' vol. i. p. 367.)</p> +<br /> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Angamos"> + <tr> + <td class="tdl" width="20%"> </td> + <td class="tdr" width="20%">Fowls.</td> + <td class="tdr" width="20%">Pigeons.</td> + <td class="tdr" width="20%">Ducks.</td> + <td class="tdr" width="20%">Geese.</td> + </tr> + <tr> + <td class="tdl">Water</td> + <td class="tdr">56.00</td> + <td class="tdr">52.00</td> + <td class="tdr">56.60</td> + <td class="tdr">77.10</td> + </tr> + <tr> + <td class="tdl">Organic matter</td> + <td class="tdr">25.50</td> + <td class="tdr">31.00</td> + <td class="tdr">26.20</td> + <td class="tdr">13.40</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdr">1.60</td> + <td class="tdr">1.75</td> + <td class="tdr">1.00</td> + <td class="tdr">.55</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdr">1.5-2.00</td> + <td class="tdr">1.5-2.00</td> + <td class="tdr">1.40</td> + <td class="tdr">.54</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdr">.80-.90</td> + <td class="tdr">1.0-1.25</td> + <td class="tdr">.62</td> + <td class="tdr">.95</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdr">2.00-2.50</td> + <td class="tdr">1.50-2.00</td> + <td class="tdr">1.70</td> + <td class="tdr">.84</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdr">.75</td> + <td class="tdr">.50</td> + <td class="tdr">.35</td> + <td class="tdr">.20</td> + </tr> +</table> +</div> + +<p>According to a computation by a Belgian farmer, a pigeon yields about 6 +lb. of dung in a year, a hen about 12 lb., a turkey or goose about 25 +lb., and a duck 18 lb.</p> + +<br /> +<br /> +<br/> +<br /> +<hr /><span class='pagenum'><a name="Page_332" id="Page_332">[Pg 332]</a></span> +<br /> +<h2>CHAPTER IX.</h2> + +<h2>NITRATE OF SODA.</h2> +<br /> + +<p>Nitrate of soda,<a name="FNanchor_202_202" id="FNanchor_202_202"></a><a href="#Footnote_202_202" class="fnanchor">[202]</a> or, as it is more correctly designated from a +chemical point of view, sodium nitrate, now forms the chief artificial +nitrogenous manure in use. Along with sulphate of ammonia, it has taken +the place once held in the manure markets by the older Peruvian guano, +and may without doubt be reckoned, at present prices, one of the +cheapest and most valuable of the artificial sources of nitrogen for the +plant. It is some sixty-two years ago since it was first exported from +South America into this country. The total exports in that year amounted +to about 800 tons, and some indication of the enormous extent to which +the use of this valuable fertiliser has been developed since then will +be obtained from the statement that the total exports at present amount +to little less than 1,000,000 tons per annum, representing a monetary +value of 6 to 7 millions sterling. Of this <span class='pagenum'><a name="Page_333" id="Page_333">[Pg 333]</a></span>quantity about 120,000 tons +are imported into Britain.<a name="FNanchor_203_203" id="FNanchor_203_203"></a><a href="#Footnote_203_203" class="fnanchor">[203]</a> While its chief use is for manurial +purposes, it must not be imagined that it is only used for this purpose. +A certain amount is used in connection with various chemical +manufactures—for instance, that of nitric and sulphuric acid—and also +in the manufacture of saltpetre, the chief constituent of gunpowder.</p> + +<br /> +<p class="cen"><i>Date of Discovery of Nitrate Deposits.</i></p> + +<p>The exact date of the discovery of the nitrate deposits seems to be a +point of considerable dubiety. The earliest published description of +them was written by Bollaert about the year 1820, in which year, it is +stated, the first shipment was made to England. It was not, however, +till some ten or twelve years later that the Peruvian Government, to +whom they then belonged,<a name="FNanchor_204_204" id="FNanchor_204_204"></a><a href="#Footnote_204_204" class="fnanchor">[204]</a> seems to have recognised their value. The +most important deposits are found in the vicinity of the town of +Iquique, which is the chief nitrate port of South America. It is a +somewhat striking fact that this substance, which has conclusively +proved itself to be the most potent of all known artificial agents in +the promotion of vegetable growth, should be found in a district utterly +lacking the slightest traces of vegetation of any kind. Lest such a +statement should seem <span class='pagenum'><a name="Page_334" id="Page_334">[Pg 334]</a></span>to savour of irony, we hasten to explain that the +singular barrenness of this part of the country is largely due to the +character of its climate, the deposits occurring in the midst of sandy +deserts,<a name="FNanchor_205_205" id="FNanchor_205_205"></a><a href="#Footnote_205_205" class="fnanchor">[205]</a> on which rain never falls.</p> + +<br /> +<p class="cen"><i>Their Origin.</i></p> + +<p>The origin of these nitrate-fields is a geological problem of very +considerable interest, the difficulty of which is greatly enhanced by +their altitude—3000 to 4000 feet above the sea-level—and their +distance inland, which amounts in some cases to eighty or ninety miles +from the sea-coast. The nitrate deposits are not the only saline +deposits found in Chili. According to the late David Forbes,<a name="FNanchor_206_206" id="FNanchor_206_206"></a><a href="#Footnote_206_206" class="fnanchor">[206]</a> they +are not to be confused with other saline formations, which appear at +intervals scattered over the whole of that portion of the western coast, +on which no rain falls. The latter stretch from north to south for a +distance of more than 550 miles—their greatest development being +between latitudes 19° and 25° south. The depth to which they extend +downwards varies considerably. Most of them, however, are of a very +superficial character, and "they always show signs of their existence by +the saline <span class='pagenum'><a name="Page_335" id="Page_335">[Pg 335]</a></span>efflorescence seen on the surface of the ground, which often +covers vast plains as a white crystalline incrustation, the dust from +which, entering the nostrils and mouth of the traveller, causes much +annoyance, whilst at the same time the eyes are equally suffering from +the intensely brilliant reflection of the rays of a tropical sun." These +saline incrustations, or <i>salinas</i>, as they are generally called, are +chiefly composed of salts of lime, soda, magnesia, alumina, and of +boracic acid. Their composition would lead one to attribute their origin +to the evaporation of salt water; for, with the single exception of +boracic acid,<a name="FNanchor_207_207" id="FNanchor_207_207"></a><a href="#Footnote_207_207" class="fnanchor">[207]</a> all the mineral substances are such as would be +obtained by the evaporation of sea-water, or by the mutual reactions of +its salts with the constituents of the adjacent rocks. As there is +"indisputable evidence of the recent elevation of the whole of this +coast," volcanic upheaval might be reasonably held to explain their +altitude. Their comparative proximity to the coast would seem further to +favour this theory. On these grounds, therefore, Forbes is inclined to +think that they owe their origin to the evaporation, under the influence +of a tropical sun, of lagoons of salt water, the communication of which +with the sea had been cut off by the rising of the land.</p> + +<br /> +<p class="cen"><i>Forbes and Darwin on the Theory of their Origin.</i></p> + +<p>The obvious difficulty of accounting for the formation of the larger +deposits by such a theory he meets <span class='pagenum'><a name="Page_336" id="Page_336">[Pg 336]</a></span>by saying that it is only necessary +to suppose that, even after the partial isolation of the lagoons by the +elevations of the coast, they might still have maintained tidal or +occasional communication with the sea by means of lateral openings in +the chain of hills separating them from the ocean. In such cases there +would be a gradual accumulation of salts, very much greater in amount +than that due simply to the evaporation of the water originally +contained in the lagoons. The above theory of the origin of the lower +saline deposits may go to explain the mode of formation of the +nitrate-fields; but in this case several difficulties present +themselves. One is the much greater altitude of the latter, as well as +their greater distance inland. This difficulty, however, may be met by +assuming that they are of older origin than the lower deposits, and have +been subjected to a correspondingly greater amount of volcanic upheaval. +There is abundance of proof that this part of the continent has been the +scene in the past of such volcanic upheaval. Forbes is of opinion that +there is the fullest evidence to prove that, even since the arrival of +the Spaniards, a very considerable elevation of the land has taken place +over the greater part, if not the whole extent, of the line of coast; +while Darwin states that he has convincing proof that this part of the +continent has been elevated from 400 to 1200 feet since the epoch of +existing shells. Furthermore, elevations of the coast-line, amounting in +many cases to several feet, are known to have <span class='pagenum'><a name="Page_337" id="Page_337">[Pg 337]</a></span>happened within recent +times, while earthquakes and volcanic disturbances of a less striking +nature are still of common occurrence. Successive lines, indicative of +old sea-beaches, can be distinctly traced stretching inland, one behind +the other; and patches of sea-sand and water-worn stone, found at a +great distance from the coast, both in valleys and at altitudes much +greater even than 4000 feet, point to the same conclusion.<a name="FNanchor_208_208" id="FNanchor_208_208"></a><a href="#Footnote_208_208" class="fnanchor">[208]</a> The +difficulty, therefore, of altitude and distance from the coast cannot be +regarded as insuperable.</p> + +<br /> +<p class="cen"><i>Source of Nitric Acid.</i></p> + +<p>A difficulty, however, which is not so easily met, is afforded by the +presence of the nitric acid which, in combination with the soda, forms +the nitrate of soda. It is scarcely necessary to inform our readers that +nitrogen—except, of course, in small quantities in the free state—is +not a normal constituent of salt water. The question, therefore, of +greatest interest in connection with the formation of these nitrate-beds +is, Whence has the nitric acid been derived? Several theories have been +put forward to account for it.</p> + +<br /> +<p class="cen"><i>Guano Theory.</i></p> + +<p>One is to the effect that it owes its origin to huge <span class='pagenum'><a name="Page_338" id="Page_338">[Pg 338]</a></span>guano deposits, +originally covering the shores of the large salt lakes which, by the +subsequent overflowing of their shores, effected the mixture of the +guano with the salts. In this way, by a slow process of decomposition, +nitrate of soda would be ultimately formed.<a name="FNanchor_209_209" id="FNanchor_209_209"></a><a href="#Footnote_209_209" class="fnanchor">[209]</a> This theory, apart from +other considerations, seems at first sight extremely plausible, more +especially when we remember that it is on this very coast that the +greatest guano deposits have been found, and that the famous Chincha +Islands, which alone have yielded over 10 million tons of this valuable +fertiliser, are comparatively near the scene of the nitrate deposits. +What seems further to support this theory, is the actual occurrence in +the nitrate-fields themselves of small quantities of guano. But however +plausible it may appear at first sight, it does not bear closer +criticism. One very serious objection is the absence in these deposits +of phosphate of lime, which is the largest constituent of guano. If they +were really due to guano, how does it happen that the insoluble +phosphate of lime should have disappeared, while the easily soluble +nitrate of soda should alone be preserved? Again, assuming this theory +to be correct, we should naturally expect to be still able to find +evidence of the chemical changes which would under such <span class='pagenum'><a name="Page_339" id="Page_339">[Pg 339]</a></span>circumstances +have taken place, in the shape of portions of the guano in the +transition stage. Such evidence, however, the most careful +investigations have failed to detect. Apart, however, from the above +objections, there seems to be little doubt, from evidence afforded by +traces of birds' nests, &c., that the guano found in the nitrate-beds +was deposited subsequent to the formation of the nitrate of soda.</p> + +<br /> +<p class="cen"><i>Nitric Acid derived from Sea-weed.</i></p> + +<p>The most probable theory seems to be that put forward by Nöllner. The +origin of the nitric acid is, according to him, to be ascribed to the +decay of great masses of sea-weed, which, by means of hurricanes such as +are still prevalent in these districts, were driven into the lagoons. +The chief difficulty in the way of accepting this theory is the enormous +quantity of sea-weed required to produce the millions of tons of nitric +acid these deposits contain. It must be remembered, however, as bearing +upon this point, that the occurrence of gigantic masses of sea-weed in +the Pacific Ocean<a name="FNanchor_210_210" id="FNanchor_210_210"></a><a href="#Footnote_210_210" class="fnanchor">[210]</a> is by no means uncommon even at the present time. +If, to understand the formation of coal, we must suppose the +Carboniferous period to be one during which exceptionally luxuriant +growth of vegetation took place, we may be <span class='pagenum'><a name="Page_340" id="Page_340">[Pg 340]</a></span>permitted to suppose a +similar luxuriant growth of sea-weed during the formation of the nitrate +deposits. Very strong confirmation of the truth of this theory is +further afforded by the presence in large quantities, in the raw nitrate +of soda, of iodine, a substance characteristic of sea-weed; while pieces +of sea-weed still undecomposed are met with here and there. On the +whole, therefore, this theory, while not free from difficulties, seems +to be the most worthy of acceptance as regards the origin of the nitrate +deposits.<a name="FNanchor_211_211" id="FNanchor_211_211"></a><a href="#Footnote_211_211" class="fnanchor">[211]</a></p> + +<br /> +<p class="cen"><i>Appearance of Nitrate-fields.</i></p> + +<p>Having thus discussed the origin of the nitrate-fields, we may now give +a more detailed description of their appearance. The chief deposits at +present being worked are those lying in the Pampa de Tamarugal, in the +province of Tarapaca. They stretch to a distance of thirty or forty +miles inland, from Pisagua southwards to somewhat beyond the town of +Iquique. This huge desert, as has been already indicated, seems to be +entirely destitute of all vegetation and animal life. Even in the +immediately <span class='pagenum'><a name="Page_341" id="Page_341">[Pg 341]</a></span>adjoining country the only kind of vegetation that seems to +grow is a species of <i>acacia</i>. The few streams that are found in this +neighbourhood are entirely fed by the melting snow from the Cordilleras. +Darwin describes the appearance presented by these pampas as resembling +"a country after snow, before the last dirty patches are thawed." The +<i>caliche</i>, or raw nitrate of soda, is not equally distributed over the +pampas. The most abundant deposits are situated on the slopes of the +hills which probably formed the shores of the old lagoons. An expert can +tell from the external appearance of the ground where the richest +deposits are likely to be found. The <i>caliche</i> itself is not found on +the surface of the plain, but is covered up by two layers. The +uppermost, known technically as <i>chuca</i>, is of a friable nature, and +consists of sand and gypsum; while the lower, the <i>costra</i>, is a rocky +conglomerate of clay, gravel, and fragments of felspar. The <i>caliche</i> +varies in thickness from a few inches to 10 or 12 feet, and rests on a +soft stratum of earth called <i>cova</i>.</p> + +<br /> +<p class="cen"><i>The Method of mining the Nitrate.</i></p> + +<p>The mode in which the <i>caliche</i> is excavated is as follows: A hole is +bored through the <i>chuca</i>, <i>costra</i>, and <i>caliche</i> layers till the +<i>cova</i> or soft earth is reached below. It is then enlarged until it is +wide enough to admit of a small boy being let down, who scrapes away the +earth below the <i>caliche</i> so as to form a little hollow cup. Into this a +charge of gunpowder <span class='pagenum'><a name="Page_342" id="Page_342">[Pg 342]</a></span>is introduced, and subsequently exploded. The +<i>caliche</i> is then separated by means of picks from the overlying +<i>costra</i> and carried to the refinery.</p> + +<br /> +<p class="cen"><i>Composition of Caliche.</i></p> + +<p>Both in appearance and composition it varies very much. In colour it may +be snow-white, sulphur, lemon, orange, violet, blue, and sometimes brown +like raw sugar.</p> + +<p>The <i>caliche</i> found in the Pampa de Tamarugal contains generally about +30 to 50 per cent pure nitrate of soda; that in the province of Atacama +contains from 25 to 40 per cent. The subsequent refining processes, +which consist in crushing it by means of rollers and then dissolving it, +need not here be described. It may be sufficient to mention that the +process used is that known as systematic lixiviation, and is analogous +to the method introduced by Shanks in the manufacture of soda. The chief +impurity in the raw material is common salt: gypsum, sulphates of +potassium, sodium, and magnesium, along with insoluble matters, are the +other impurities. The manufacture of iodine, which, as has been already +noticed, is found in the nitrate-beds, is also carried on at these +<i>oficinas</i>.</p> + +<br /> +<p class="cen"><i>Extent of the Nitrate Deposits.</i></p> + +<p>The question of the extent of the nitrate of soda deposits is naturally +one of very great interest, <span class='pagenum'><a name="Page_343" id="Page_343">[Pg 343]</a></span>especially from the agricultural point of +view. M. Charles Legrange, a French writer, estimated a few years ago +that they still contained about 100,000,000 tons of pure nitrate of +soda. Opinions on this point differ very considerably, and it seems +wellnigh impossible to arrive at any very accurate estimate.</p> + +<p>The number of years they will last will depend, of course, on the amount +of annual exportation. This, at present, falls little short of 1,000,000 +tons. If this amount is maintained, they should last, according to +experts, some twenty or thirty years at least. A consideration which has +an important influence on this question, is the price obtained for the +article. If this should be increased, it may be possible to treat the +larger quantities of the inferior raw material (which at present prices +are allowed to accumulate) at a profit. Undoubtedly this is what will +ultimately take place, when the richer quality of the <i>caliche</i> has been +exhausted.</p> + +<br /> +<p class="cen"><i>Composition and Properties of Nitrate of Soda.</i></p> + +<p>As has already been pointed out, commercial nitrate of soda contains +about 95 per cent of pure nitrate of soda, or about 15-1/2 per cent of +nitrogen, which, if calculated as ammonia, would equal 19 per cent. It +is, next to sulphate of ammonia (which contains 24-1/2 per cent of +ammonia), the most concentrated nitrogenous manure, and further, +contains its nitrogen in the form most readily available for the plant's +use. Its most <span class='pagenum'><a name="Page_344" id="Page_344">[Pg 344]</a></span>characteristic property is its great solubility, and +consequent speedy diffusion in the soil, and the inability of the +soil-particles to fix its nitrogen. In the latter respect it differs +very considerably from other forms of nitrogen. Ammonia salts, though +practically quite as soluble, do not diffuse in the soil so rapidly as +nitrate of soda does; for the ammonia is more or less tenaciously fixed +by the soil-particles, and retained till converted by the process of +<i>nitrification</i> into nitrates.</p> + +<br /> +<p class="cen"><i>Nitrate of Soda applied as a Top-dressing.</i></p> + +<p>On this account nitrate of soda is chiefly employed—and rightly so—as +a top-dressing. The risk of loss by drainage is thus minimised, and the +valuable nitrogen finds its rightful destination—viz., in the plant's +roots.</p> + +<br /> +<p class="cen"><i>Encourages deep Roots.</i></p> + +<p>A special benefit which the diffusibility of nitrate of soda has been +held to confer on the plant, is to encourage the growth of deep roots, +by inducing the growing plant to send down its roots into the lower +layers of the soil after the nitrate of soda. The benefit of deep roots +is, of course, very great. They enable the plant to withstand the action +of drought, and at the same time increase the area whence the plant may +derive its nourishment. Although the value of the manure is practically +entirely due to the <span class='pagenum'><a name="Page_345" id="Page_345">[Pg 345]</a></span>nitrogen it contains, it has been urged that the +soda exercises a beneficial effect on the mechanical properties of the +soil, by increasing its power of absorbing moisture, and in also +rendering it more compact. This would partly explain how its results in +dry seasons are so much better than those obtained from sulphate of +ammonia. This mechanical action of nitrate can scarcely be very great +when we remember the comparatively small quantity applied. Even in the +driest of seasons there will always be sufficient moisture to secure the +diffusion of the nitrate of soda, while the risk of loss by drainage +will be reduced to a minimum. Much ignorance, as well as prejudice, has +existed in the past as to the true nature of the action of nitrate of +soda. Nor is this prejudice even yet entirely dispelled.</p> + +<br /> +<p class="cen"><i>Is Nitrate an exhausting Manure?</i></p> + +<p>The common charge brought against it is, that it is what has been termed +an exhausting manure. This objection, to have any weight, must mean that +nitrate of soda produces a crop which takes out of the soil an +<i>abnormal</i> quantity of fertilising matter. But, so far as the writer is +aware, no scientific evidence has ever been brought forward to support +this contention. That the indiscriminate use of a manure may produce a +crop in which the stem and leaves are unduly developed at the expense of +the grain, or in which the quality of the crop may suffer from too rapid +growth, <span class='pagenum'><a name="Page_346" id="Page_346">[Pg 346]</a></span>is, of course, a well-known fact. But as this could also be +produced by an overdose of soluble phosphoric acid as well as ammonia +salts, it is not a property that belongs exclusively to nitrate of soda. +Probably nitrate of soda has in the past been often used in this +indiscriminate way so as to produce such results. The fault, therefore, +lies not in the manure, but in the mode of its application. A few +remarks, therefore, on this most important subject may prove +serviceable.</p> + +<br /> +<p class="cen"><i>Crops for which it is suited.</i></p> + +<p>Opinions will naturally differ as to the crops to which it is profitable +to apply nitrate of soda. Its value as a manure for cereals is pretty +generally admitted. Its value as a manure for roots is not, however, so +universally admitted. Experiments would seem to show that such a crop as +the mangold derives just as much benefit as do the cereals; while in +Germany practical experience on a very large scale has demonstrated its +value as a manure for beetroots. It may be generally recommended as a +manure for all crops, except, perhaps, the so-called leguminous crops, +such as clover, beans, peas, &c., whose ability to obtain nitrogen for +themselves renders the application of expensive artificial nitrogenous +manures unadvisable.</p> + +<p>An interesting point with regard to nitrate of soda is the curious +effect it seems to have on the colour of the leaves of plants. This +interesting fact has been <span class='pagenum'><a name="Page_347" id="Page_347">[Pg 347]</a></span>strikingly demonstrated at the Rothamsted +Experimental Station, in the contrast in the colour of the leaves of +different experimental grass-plots, manured with nitrate of soda and +sulphate of ammonia respectively—the plots manured with nitrate of soda +being distinctly darker in hue, obviously owing to the greater +production of chlorophyll or green matter. Such a depth of colour would +seem to indicate a more healthy development.</p> + +<br /> +<p class="cen"><i>Method of Application.</i></p> + +<p>While opinions, therefore, will naturally differ as to the crops to +which nitrate of soda will be most profitably applied, little difference +of opinion exists as to the method of its application. The inability of +the soil-particles to retain it, the frequency of rain, the costly +nature of the manure itself, and its immediate availability as a +plant-food, all point to the extreme advisability of using it as a +top-dressing. Even when used as a top-dressing, it may be advisable not +to apply the entire quantity all at one time. By applying it in +instalments, little risk is run that, through inclemency of weather, the +manure will be lost. Another point of importance in applying nitrate of +soda is to secure uniform distribution. This of course is applicable to +all artificial manures, but in a very special degree to nitrate of soda, +because of its great value and the comparatively small quantity +applied.</p> + +<p><span class='pagenum'><a name="Page_348" id="Page_348">[Pg 348]</a></span>As the uniform distribution of one cwt. of any material over an acre of +soil is by no means an easy task, the mixing of nitrate of soda with +some diluent, such as dry loam, is consequently highly advisable. Common +salt is often applied along with nitrate of soda. The indirect value of +salt as a manure is considerable, and when applied along with nitrate, +ensures its more speedy diffusion in the soil, by increasing the soil's +capacity for absorbing moisture from the air.</p> + +<br /> +<p class="cen"><i>Must be a Sufficiency of other Fertilising Constituents.</i></p> + +<p>A third point of importance in applying nitrate of soda, is to see that +the soil is sufficiently supplied with the other plant-foods—phosphates +and potash. This is a <i>sine qua non</i>, if the nitrate is to get a fair +chance. If it is desired to apply nitrate of soda along with +superphosphate of lime, a word of caution is necessary against making +the mixture long before it is used. The reason of this is, that a +chemical action is apt to ensue, resulting in the loss of the nitric +acid in the nitrate of soda. The nature of the soil is another important +consideration to be taken into account. In the case of extremely loose +and sandy soils, it is scarcely to be recommended as the most suitable +form in which to apply nitrogen. If applied to such soils, especial care +ought to be taken to minimise risk of loss. No hard-and-fast rules can +be laid down as to the quantity in which it ought to be applied. This +<span class='pagenum'><a name="Page_349" id="Page_349">[Pg 349]</a></span>must be regulated very much by the crop, the nature of the soil, and +the quantity of other manures employed. From 1 to 1-1/4 cwt. may be +recommended as a suitable quantity for corn crops which are otherwise +liberally manured. On strong clay soils this quantity may be judiciously +increased up to 2 cwt. Dr Bernard Dyer, who has experimented largely on +its use as a manure for mangolds, is of opinion that an application of +from 3 to 4 cwt. an acre is likely to prove thoroughly profitable; and +the present writer has found in his experiments with turnips that a +top-dressing of 1 cwt. amply repaid itself.</p> + +<br /> +<p class="cen"><i>Conclusions drawn.</i></p> + +<p>In conclusion, the nature and characteristics of nitrate of soda as a +manure may be briefly summed up as follows:—</p> + +<p>1. It is a whitish, crystalline salt, extremely soluble, and is quickly +diffused in the soil. It should contain 95 per cent of pure nitrate of +soda—<i>i.e.</i>, 15-1/2 per cent of nitrogen, equal to about 19 per cent of +ammonia.</p> + +<p>2. Next to sulphate of ammonia, it is the most concentrated nitrogenous +manure; the relative quantities of nitrogen these two manures contain +being as three is to four.</p> + +<p>3. It contains its nitrogen in the most valuable and readily assimilable +form—<i>i.e.</i>, as <i>nitric acid</i>, the form into which all other forms of +nitrogen have first to be <span class='pagenum'><a name="Page_350" id="Page_350">[Pg 350]</a></span>converted before they become available for +the plant's uses.</p> + +<p>4. That, at present market prices, nitrate of soda may be safely +affirmed to be the cheapest form of nitrogenous manure.</p> + +<p>5. That nitrate of soda, in addition to its direct value as a manure, +probably exercises a slight influence on the mechanical properties of +the soil, by increasing its compactness and water-absorbing capacities; +that it further tends to promote deep roots, and thus to increase the +soil area whence the plant may derive its nourishment, at the same time +rendering the plant more able to withstand the injurious influence of +drought.</p> + +<p>6. That a plentiful supply of the other manurial constituents should be +present in the soil, if nitrate of soda is to exercise its full value.</p> + +<p>7. That it may be profitably applied in the case of nearly all kinds of +crops, but that great care should be taken as to the mode of its +application. That this should be almost invariably as a top-dressing, +and that it should be applied in several doses if possible.</p> + +<p>8. That its effects can be regarded as lasting only during the first +year after application.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_202_202" id="Footnote_202_202"></a><a href="#FNanchor_202_202"><span class="label">[202]</span></a> This substance is also largely known under the name Chili +saltpetre, to distinguish it from potassium nitrate or common +saltpetre.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_203_203" id="Footnote_203_203"></a><a href="#FNanchor_203_203"><span class="label">[203]</span></a> See Appendix, p. 351.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_204_204" id="Footnote_204_204"></a><a href="#FNanchor_204_204"><span class="label">[204]</span></a> We may remind our readers that these nitrate deposits +were largely the cause of the late war between Chili and Peru, which +resulted in the cession to Chili by Peru of the province of Tarapaca, +where the most important deposits are situated.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_205_205" id="Footnote_205_205"></a><a href="#FNanchor_205_205"><span class="label">[205]</span></a> The other nitrate deposits are found in the provinces of +Antofagasta and Atacama, and a certain amount of the refined article is +exported from these places. The amount, however, is inconsiderable as +compared with that which comes from the province of Tarapaca.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_206_206" id="Footnote_206_206"></a><a href="#FNanchor_206_206"><span class="label">[206]</span></a> See his elaborate article on the Geology of Bolivia and +Peru, published in the 'Quarterly Journal of the Geological Society' for +November 1860.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_207_207" id="Footnote_207_207"></a><a href="#FNanchor_207_207"><span class="label">[207]</span></a> The source of the boracic acid is probably volcanic.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_208_208" id="Footnote_208_208"></a><a href="#FNanchor_208_208"><span class="label">[208]</span></a> A friend of the present writer, who has visited this part +of the west coast of South America, informs him that at one point of the +coast at Mejillones (in Bolivia) he could trace the remains of no fewer +than twelve distinct sea-beaches, situated at different distances from +the sea, and rising to an altitude of 2500 feet.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_209_209" id="Footnote_209_209"></a><a href="#FNanchor_209_209"><span class="label">[209]</span></a> In this change, lime derived from the sea-shells would +play an important part. Modern researches have shown, as we have already +said in a previous chapter, that, in the conversion of organic nitrogen +into nitrates, the presence of carbonate of lime is a necessary +condition.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_210_210" id="Footnote_210_210"></a><a href="#FNanchor_210_210"><span class="label">[210]</span></a> The Gulf weed is an instance in point. Huge masses of +floating sea-weed are sometimes found, 500 to 600 miles in length, +forming the so-called Saragossa Sea.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_211_211" id="Footnote_211_211"></a><a href="#FNanchor_211_211"><span class="label">[211]</span></a> A difficulty which has not been referred to is the belief +entertained by geologists that "there has been a change of climate in +Northern Chili, and that there must have been more rain there formerly +than there is at present. Traces of human habitations are found high up +in the Cordilleras to-day. Cobs of Indian corn, axes and knives of +copper tempered to exceeding sharpness, arrow-heads of agate, even +pieces of cloth, are dug up in arid plains now without any trace of +water for many leagues in or around them" (Russell, 'The Nitrate-Fields +of Chili,' p. 290).</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_351" id="Page_351">[Pg 351]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER IX.</h2> +<br /> + +<p class="cen"><span class="smcap">Nitrate of Soda</span>.</p> + +<p class="cen"><i>Total Shipments from South America, 1830-1892.</i></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="shipments"> + <tr> + <td class="tdl" width="7%">Year.</td> + <td class="tdrr" width="26%">Tons. </td> + <td class="tdr" width="7%"> Year.</td> + <td class="tdrr" width="26%">Tons. </td> + <td class="tdr" width="7%"> Year.</td> + <td class="tdr" width="27%">Tons. </td> + </tr> + <tr> + <td class="tdl">1830</td> + <td class="tdrr">800 </td> + <td class="tdr"> 1870</td> + <td class="tdrr">131,400 </td> + <td class="tdr"> 1886</td> + <td class="tdr">437,500</td> + </tr> + <tr> + <td class="tdl">1835</td> + <td class="tdrr">6,200 </td> + <td class="tdr"> 1875</td> + <td class="tdrr">321,000 </td> + <td class="tdr"> 1887</td> + <td class="tdr">680,600</td> + </tr> + <tr> + <td class="tdl">1840</td> + <td class="tdrr">10,100 </td> + <td class="tdr"> 1880</td> + <td class="tdrr">217,300 </td> + <td class="tdr"> 1888</td> + <td class="tdr">745,700</td> + </tr> + <tr> + <td class="tdl">1845</td> + <td class="tdrr">16,800 </td> + <td class="tdr"> 1881</td> + <td class="tdrr">344,600 </td> + <td class="tdr"> 1889</td> + <td class="tdr">930,000</td> + </tr> + <tr> + <td class="tdl">1850</td> + <td class="tdrr">22,800 </td> + <td class="tdr"> 1882</td> + <td class="tdrr">477,800 </td> + <td class="tdr"> 1890</td> + <td class="tdr">1,030,000</td> + </tr> + <tr> + <td class="tdl">1855</td> + <td class="tdrr">41,800 </td> + <td class="tdr"> 1883</td> + <td class="tdrr">572,400 </td> + <td class="tdr"> 1891</td> + <td class="tdr">790,000</td> + </tr> + <tr> + <td class="tdl">1860</td> + <td class="tdrr">55,200 </td> + <td class="tdr"> 1884</td> + <td class="tdrr">540,900 </td> + <td class="tdr"> 1892</td> + <td class="tdr">790,000</td> + </tr> + <tr> + <td class="tdl">1865</td> + <td class="tdrr">109,000 </td> + <td class="tdr"> 1885</td> + <td class="tdrr">423,100 </td> + <td class="tdr"> </td> + <td class="tdr"> </td> + </tr> +</table> +</div> + +<br /> +<p>The following tables exhibit the total imports into Europe, and into the +United Kingdom from the years 1873-92:—</p> + +<p class="cen"><span class="smcap">Nitrate of Soda</span>, 1873-1892.</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="iimports"> + <tr> + <td class="tdc" colspan="2"><i>Imports into Europe.</i></td> + <td class="tdc" colspan="2"><i>Imports into United Kingdom.</i></td> + </tr> + <tr> + <td class="tdl" width="25%">Year.</td> + <td class="tdrr" width="25%">Tons. </td> + <td class="tdl" width="25%"> Year.</td> + <td class="tdr" width="25%">Tons. </td> + </tr> + <tr> + <td class="tdl">1873</td> + <td class="tdrr">225,000 </td> + <td class="tdl"> 1873</td> + <td class="tdr">124,000</td> + </tr> + <tr> + <td class="tdl">1874</td> + <td class="tdrr">230,000 </td> + <td class="tdl"> 1874</td> + <td class="tdr">108,200</td> + </tr> + <tr> + <td class="tdl">1875</td> + <td class="tdrr">280,000 </td> + <td class="tdl"> 1875</td> + <td class="tdr">164,900</td> + </tr> + <tr> + <td class="tdl">1876</td> + <td class="tdrr">300,000 </td> + <td class="tdl"> 1876</td> + <td class="tdr">166,800</td> + </tr> + <tr> + <td class="tdl">1877</td> + <td class="tdrr">208,000 </td> + <td class="tdl"> 1877</td> + <td class="tdr">69,600</td> + </tr> + <tr> + <td class="tdl">1878</td> + <td class="tdrr">250,000 </td> + <td class="tdl"> 1878</td> + <td class="tdr">104,400</td> + </tr> + <tr> + <td class="tdl">1879</td> + <td class="tdrr">205,000 </td> + <td class="tdl"> 1879</td> + <td class="tdr">55,300</td> + </tr> + <tr> + <td class="tdl">1880</td> + <td class="tdrr">140,000 </td> + <td class="tdl"> 1880</td> + <td class="tdr">48,300</td> + </tr> + <tr> + <td class="tdl">1881</td> + <td class="tdrr">230,000 </td> + <td class="tdl"> 1881</td> + <td class="tdr">54,800</td> + </tr> + <tr> + <td class="tdl">1882</td> + <td class="tdrr">335,000 </td> + <td class="tdl"> 1882</td> + <td class="tdr">96,000</td> + </tr> + <tr> + <td class="tdl">1883</td> + <td class="tdrr">440,000 </td> + <td class="tdl"> 1883</td> + <td class="tdr">103,700</td> + </tr> + <tr> + <td class="tdl">1884</td> + <td class="tdrr">505,000 </td> + <td class="tdl"> 1884</td> + <td class="tdr">103,700</td> + </tr> + <tr> + <td class="tdl">1885</td> + <td class="tdrr">380,000 </td> + <td class="tdl"> 1885</td> + <td class="tdr">109,400</td> + </tr> + <tr> + <td class="tdl">1886</td> + <td class="tdrr">330,000 </td> + <td class="tdl"> 1886</td> + <td class="tdr">75,100</td> + </tr> + <tr> + <td class="tdl">1887</td> + <td class="tdrr">440,000 </td> + <td class="tdl"> 1887</td> + <td class="tdr">83,100</td> + </tr> + <tr> + <td class="tdl">1888</td> + <td class="tdrr">640,000 </td> + <td class="tdl"> 1888</td> + <td class="tdr">103,100</td> + </tr> + <tr> + <td class="tdl">1889</td> + <td class="tdrr">760,000 </td> + <td class="tdl"> 1889</td> + <td class="tdr">120,000</td> + </tr> + <tr> + <td class="tdl">1890</td> + <td class="tdrr">784,000 </td> + <td class="tdl"> 1890</td> + <td class="tdr">114,000</td> + </tr> + <tr> + <td class="tdl">1891</td> + <td class="tdrr">851,000 </td> + <td class="tdl"> 1891</td> + <td class="tdr">121,000</td> + </tr> + <tr> + <td class="tdl">1892</td> + <td class="tdrr">795,000 </td> + <td class="tdl"> 1892</td> + <td class="tdr">115,000</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_352" id="Page_352">[Pg 352]</a></span> +<br /> +<h2>CHAPTER X.</h2> + +<h2>SULPHATE OF AMMONIA.</h2> + +<br /> +<p class="cen"><i>Value of Ammonia as a Manure.</i></p> + +<p>The value of ammonia salts as a manure has been long recognised; indeed +till recently ammonia was thought to be the most valuable form in which +nitrogen could be applied as a plant-food—a view, we may mention, held +by Liebig. While the plant, no doubt, can absorb its nitrogen in the +form of ammonia,<a name="FNanchor_212_212" id="FNanchor_212_212"></a><a href="#Footnote_212_212" class="fnanchor">[212]</a> as well as in other forms, as we have already +pointed out in previous chapters, it is now fully recognised that +ammonia salts, when applied to the soil, are converted into nitrates. +Nitric acid, then, must be regarded as the most valuable, inasmuch as it +is the most rapidly <span class='pagenum'><a name="Page_353" id="Page_353">[Pg 353]</a></span>assimilated form of nitrogen for the plant; but +next to nitric acid in value comes ammonia. Of the different forms of +ammonia available for manurial purposes, the only one used to a large +extent is sulphate.</p> + +<br /> +<p class="cen"><i>Sources of Sulphate of Ammonia.</i></p> + +<p>The oldest, and what is still the chief source of this valuable salt, is +the gas-works, where it is obtained as one of the bye-products in the +manufacture of gas. It is also obtained to a lesser extent from shale, +iron, coke, and carbonising works. Bones, horn, leather, and certain +other animal substances rich in nitrogen, when subjected to dry +distillation, as is the case in certain manufactures, such as the +manufacture of bone-charcoal for use in sugar-refineries, and the +distillation of horn, &c., in the manufacture of prussiate of potash, +also constitute less abundant sources.</p> + +<br /> +<p class="cen"><i>Ammonia from Gas-works.</i></p> + +<p>Coal contains on an average from a half to one and a half per cent of +nitrogen. When it is subjected to dry distillation, as is done in the +gas-works, the nitrogen which it contains is chiefly converted into +ammonia, and, in the process of purification of the gas, is removed in +the "gas-liquor,"<a name="FNanchor_213_213" id="FNanchor_213_213"></a><a href="#Footnote_213_213" class="fnanchor">[213]</a> which contains about <span class='pagenum'><a name="Page_354" id="Page_354">[Pg 354]</a></span>one per cent of ammonia. +The ammonia recovered from this liquor by distillation is then absorbed +in sulphuric acid. It may be pointed out that nothing like all the +nitrogen contained in the coal is recovered as sulphate of ammonia. It +has been calculated that only from a fifth to a tenth is actually +recovered, and many processes have been patented with a view to +increasing the yield of ammonia in gas manufacture. The total production +of ammonia from gas-works may be placed at little over 100,000 tons per +annum for Great Britain. Mr L. Mond, F.R.S., recently drew attention to +the possibility of largely increasing our supply of sulphate of ammonia +from coal. As indicating what an enormous source of sulphate of ammonia +we have in coal, Mr Mond calculated that its annual consumption in this +country (estimated at 150,000,000 tons) would yield as much as 5,000,000 +tons of sulphate of ammonia.</p> + +<br /> +<p class="cen"><i>Other Sources.</i></p> + +<p>While the ammonia produced in the manufacture of gas has long been +collected, it is only of recent years that the other sources of ammonia +have been developed. Next to the gas-works, the shale-works of Scotland +form in this country the chief source of this valuable manure. In these +works the ammonia is obtained in distilling the paraffin shale by a +method somewhat similar to that in use in the gas-works. The amount of +sulphate of ammonia obtained from this source is between 20,000 and +30,000 tons per <span class='pagenum'><a name="Page_355" id="Page_355">[Pg 355]</a></span>annum. Recently the ammonia has been recovered from the +blast-furnace gases in iron-works—some 6000 tons being annually +obtained in this way; while from coke and carbonising works the annual +production is about half that amount. The combined annual production +from all these sources may be put down at 140,000 tons, the total +production in Europe being probably little more than 200,000 tons. In +the Appendix further statistics will be found.<a name="FNanchor_214_214" id="FNanchor_214_214"></a><a href="#Footnote_214_214" class="fnanchor">[214]</a></p> + +<br /> +<p class="cen"><i>Composition, &c., of Sulphate of Ammonia.</i></p> + +<p>Pure sulphate of ammonia is a whitish crystalline salt, extremely +soluble in water. The commercial article, however, is generally greyish +or brownish in colour, owing to the presence of slight quantities of +impurities. The pure salt should contain 25.75 per cent of ammonia; but +the commercial article is generally sold on a basis of 24.5 per cent. A +useful test of its purity is the fact that when subjected to a red-heat +it should almost entirely volatilise, leaving very little residue. The +chief impurities which it is likely to contain are an excess of +moisture, free acid, or the presence of insoluble matter. Certain +samples contain small quantities of ammonium sulphocyanate, an extremely +poisonous substance for plants. The presence of this dangerous impurity +is easily detected by adding ferric chloride, which, in presence of the +sulphocyanate, produces a blood-red colour. Sulphate of ammonia is <span class='pagenum'><a name="Page_356" id="Page_356">[Pg 356]</a></span>thus +the most concentrated of all nitrogenous manures in common use, and is +for that reason the most expensive.</p> + +<br /> +<p class="cen"><i>Application.</i></p> + +<p>For this reason, as well as from the fact that it contains a speedily +available form of nitrogen, sulphate of ammonia should only as a rule be +applied in comparatively small quantities—100 to 125 lb. per acre.<a name="FNanchor_215_215" id="FNanchor_215_215"></a><a href="#Footnote_215_215" class="fnanchor">[215]</a> +It should also be applied before, but not too long before, the crop is +likely to require it. The reason of this is to give it time to be +converted into nitrates. The ability of the soil to retain ammonia has +already been pointed out. It is not safe, however, to rely too much on +the retentive power of the soil for ammonia, the conversion of ammonia +into nitrates going on very quickly under favourable circumstances. It +is most profitably used as a manure for cereals, and it has been found +by Lawes and Gilbert in their experiments, that an increase of one +bushel of wheat and a corresponding increase of straw have been obtained +for every 5 lb. of ammonia added to the soil. As has been pointed out in +the previous chapter, the respective merits of sulphate of ammonia and +nitrate of soda depend largely on the nature of the season during which +they are used. In wet seasons the sulphate is rather more favourable +than the nitrate, but, on an average, nitrate of soda is probably the +more valuable <span class='pagenum'><a name="Page_357" id="Page_357">[Pg 357]</a></span>manure—<i>i.e.</i>, due regard being had to the quantity of +nitrogen the two manures respectively contain. In one respect sulphate +of ammonia is a much more useful manure than nitrate of soda, as the +nature of its action when applied to the soil permits of it being used +as an ingredient of mixed manures.</p> + +<p>Like nitrate of soda, but even to a greater extent, its most favourable +action is obtained when it is applied along with other manurial +ingredients. It should be applied at least a month earlier than nitrate. +It has been shown that in the case of chalky soils a certain loss of +ammonia in sulphate of ammonia is apt to take place, due to the action +of the lime; and this leads us to point out that, in preparing mixed +manures, care ought to be taken that it is not mixed with any compound +containing free lime or caustic alkali, as otherwise loss of ammonia +will ensue. It should never, for example, be used along with basic slag.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_212_212" id="Footnote_212_212"></a><a href="#FNanchor_212_212"><span class="label">[212]</span></a> From experiments by Lehmann and others with buckwheat and +maize, it would seem that certain plants may prefer, at certain stages +of their growth, ammonia to nitrates. In the case of maize, ammonia may +be preferred in the early stages of growth, while nitrates are preferred +as it becomes more mature. In view, however, of our present knowledge of +nitrification, it may well be doubted whether the conclusions arrived at +from Lehmann's experiments can be accepted.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_213_213" id="Footnote_213_213"></a><a href="#FNanchor_213_213"><span class="label">[213]</span></a> As the expense of converting the ammonia present in the +ammoniacal liquor is considerable, the practice of using the liquor +itself as a manure has been advocated; but as an objection to this it +must be urged that, besides being so bulky a manure, the liquor contains +various substances poisonous to plant-life.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_214_214" id="Footnote_214_214"></a><a href="#FNanchor_214_214"><span class="label">[214]</span></a> See Appendix, p. 358.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_215_215" id="Footnote_215_215"></a><a href="#FNanchor_215_215"><span class="label">[215]</span></a> Some crops, however, may with advantage be treated with +larger quantities of sulphate of ammonia, such as mangels and +potatoes.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_358" id="Page_358">[Pg 358]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER X.</h2> + +<br /> +<p class="cen">NOTE (p. 355).</p> + +<p>The following table will exhibit the production of sulphate of ammonia +in this country from 1870 to 1892:—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="following"> + <tr> + <td class="tdl" width="25%">Year.</td> + <td class="tdrr" width="25%">Tons. </td> + <td class="tdl" width="25%"> Year.</td> + <td class="tdr" width="25%">Tons. </td> + </tr> + <tr> + <td class="tdl">1870</td> + <td class="tdrr">40,000 </td> + <td class="tdl"> 1882</td> + <td class="tdr">72,000</td> + </tr> + <tr> + <td class="tdl">1871</td> + <td class="tdrr">41,000 </td> + <td class="tdl"> 1883</td> + <td class="tdr">75,000</td> + </tr> + <tr> + <td class="tdl">1872</td> + <td class="tdrr">42,000 </td> + <td class="tdl"> 1884</td> + <td class="tdr">87,000</td> + </tr> + <tr> + <td class="tdl">1873</td> + <td class="tdrr">43,000 </td> + <td class="tdl"> 1885</td> + <td class="tdr">97,000</td> + </tr> + <tr> + <td class="tdl">1874</td> + <td class="tdrr">45,000 </td> + <td class="tdl"> 1886</td> + <td class="tdr">106,500</td> + </tr> + <tr> + <td class="tdl">1875</td> + <td class="tdrr">46,000 </td> + <td class="tdl"> 1887</td> + <td class="tdr">113,700</td> + </tr> + <tr> + <td class="tdl">1876</td> + <td class="tdrr">48,000 </td> + <td class="tdl"> 1888</td> + <td class="tdr">122,800</td> + </tr> + <tr> + <td class="tdl">1877</td> + <td class="tdrr">52,000 </td> + <td class="tdl"> 1889</td> + <td class="tdr">132,000</td> + </tr> + <tr> + <td class="tdl">1878</td> + <td class="tdrr">55,000 </td> + <td class="tdl"> 1890</td> + <td class="tdr">140,000</td> + </tr> + <tr> + <td class="tdl">1879</td> + <td class="tdrr">57,000 </td> + <td class="tdl"> 1891</td> + <td class="tdr">143,500</td> + </tr> + <tr> + <td class="tdl">1880</td> + <td class="tdrr">60,000 </td> + <td class="tdl"> 1892</td> + <td class="tdr">157,000</td> + </tr> + <tr> + <td class="tdl">1881</td> + <td class="tdrr">65,000 </td> + <td class="tdl"> </td> + <td class="tdr"> </td> + </tr> +</table> +</div> + +<p>The following table exhibits the sources, and the respective quantities +from each source, of the last seven years' production:—</p> + +<div class="centered"> +<table border="0" width="95%" cellpadding="2" cellspacing="0" summary="sources"> + <tr> + <td class="tdlb" style="border-top: .5pt black solid;" width="31%"> </td> + <td class="tdctlb" width="9%">1886.</td> + <td class="tdctlb" width="10%">1887.</td> + <td class="tdctlb" width="10%">1888.</td> + <td class="tdctlb" width="10%">1889.</td> + <td class="tdctlb" width="10%">1890.</td> + <td class="tdctlb" width="10%">1891.</td> + <td class="tdctlb" width="10%">1892.</td> + </tr> + <tr> + <td class="tdl">Gas-works</td> + <td class="tdrl">82,500</td> + <td class="tdrl">85,000</td> + <td class="tdrl">93,000</td> + <td class="tdrl">100,000</td> + <td class="tdrl">102,150</td> + <td class="tdrl">107,950</td> + <td class="tdrl">112,000</td> + </tr> + <tr> + <td class="tdl">Iron-works</td> + <td class="tdrl">4,000</td> + <td class="tdrl">5,000</td> + <td class="tdrl">5,,300</td> + <td class="tdrl">6,000</td> + <td class="tdrl">5,050</td> + <td class="tdrl">6,300</td> + <td class="tdrl">12,000</td> + </tr> + <tr> + <td class="tdl">Shale-works</td> + <td class="tdrl">18,000</td> + <td class="tdrl">21,000</td> + <td class="tdrl">22,000</td> + <td class="tdrl">23,000</td> + <td class="tdrl">24,750</td> + <td class="tdrl">26,600</td> + <td class="tdrl">28,000</td> + </tr> + <tr> + <td class="tdl" style="border-bottom: .5pt black solid;">Coke and carbonising works</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">2,000</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">2,700</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">2,500</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">3,000</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">2,300</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">2,800</td> + <td class="tdrl" style="border-bottom: .5pt black solid;">5,000</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_359" id="Page_359">[Pg 359]</a></span> +<br /> +<h2>CHAPTER XI.</h2> + +<h2>BONES</h2> +<br /> + +<p class="cen"><i>Early Use of Bones.</i></p> + +<p>A most important manure, and one to the history of which very peculiar +interest attaches, is Bones. Employed first in 1774, their use has +steadily increased ever since, and their popularity as a phosphatic +manure is among farmers in this country quite unrivalled. Like guano, +although to a less extent, the early practice of using bones has done +much to arouse interest in the problems of manuring, and to bring home +to farmers the principles underlying that practice. It was from bones +that Liebig first made superphosphate of lime, and the distinguished +veteran experimenter, Sir John Bennet Lawes, has told us that the +benefit accruing from the use of bones on the turnip crop first drew his +attention to the interesting problem connected with the application of +artificial manures. Bones were first used in Yorkshire. Shortly +<span class='pagenum'><a name="Page_360" id="Page_360">[Pg 360]</a></span>afterwards they were applied to exhausted pastures in Cheshire. Soon +their use became so popular that the home supply was found inadequate; +and they were imported from Germany and Northern Europe, Hull being the +port of disembarkation. So largely were they used by English farmers, +that Baron Liebig considered it necessary to raise a warning protest +against their lavish application. "England is robbing all other +countries of the condition of their fertility. Already, in her eagerness +for bones, she has turned up the battle-fields of Leipzig, of Waterloo, +and of the Crimea; already from the catacombs of Sicily she has carried +away the skeletons of many successive generations. Annually she removes +from the shores of other countries to her own the manurial equivalent of +three millions and a half of men, whom she takes from us the means of +supporting, and squanders down her sewers to the sea. Like a vampire, +she hangs upon the neck of Europe—nay, of the entire world!—and sucks +the heart-blood from nations without a thought of justice towards them, +without a shadow of lasting advantage to herself."<a name="FNanchor_216_216" id="FNanchor_216_216"></a><a href="#Footnote_216_216" class="fnanchor">[216]</a></p> + +<br /> +<p class="cen"><i>Different Forms in which Bones are used.</i></p> + +<p>It may be pointed out that bones have done much to alter our system of +farming, by helping to develop <span class='pagenum'><a name="Page_361" id="Page_361">[Pg 361]</a></span>turnip culture. Used at first in +comparatively large pieces, experience gradually showed that a finer +state of division facilitated their action. Yet it was long before the +prejudice in favour of rough bones disappeared; and it was not till 1829 +that Mr Anderson of Dundee introduced machinery for preparing 1/2-inch +and 1/4-inch bones and bone-dust. In the early days of their use, bones +were fermented before being used, in order to render their action more +speedy when applied to the soil; and this practice still obtains to the +present day in some parts of the country among farmers. This +fermentation was often effected simply by mixing the bones with water, +and allowing the heap to lie for a week or two. In other cases the bones +were mixed with urine or other refuse matter. The most important step, +however, in the history of the treatment of bones for manure was the +discovery in 1840, by Liebig, of the action of sulphuric acid on them—a +discovery which led to the institution of the manufacture of +superphosphate of lime by Sir John Lawes. The nature of this action will +be explained in the following chapter, so that we need only say here +that the efficacy of the manure by treatment with sulphuric acid is more +than doubled. Bones have thus been used, and still are used, in a +variety of conditions, such as in the raw or green state, bruised, +boiled, steamed, fermented, burned, dissolved, and broken or ground into +various states of fineness, to which the names of 1/2-inch, 1/4-inch +bones, bone-meal, <span class='pagenum'><a name="Page_362" id="Page_362">[Pg 362]</a></span>bone-dust, and floated bones are given. We shall now +proceed to discuss the composition of bones, and investigate more +exactly the nature of their action.</p> + +<br /> +<p class="cen"><i>Composition of Bones.</i></p> + +<p>The composition of bone-tissue varies considerably, and depends on the +age and kind of animal to which it belongs, as well as to the part of +the animal frame from which it is taken. Bones are made up of an organic +and an inorganic part. By steeping a piece of bone in a dilute acid +solution, the inorganic portion of the bone is dissolved out, and the +organic portion, which forms the framework of the bone, is alone left. +On the other hand, by submitting a bone to the action of great heat, the +organic portion of the bone is driven off, and all that remains is a +quantity of ash. The proportion of the organic to the inorganic matter +varies considerably in different bones. The bones of young animals +contain more organic matter than those of old animals. In compact bones, +also, the organic matter is greater than in spongy bones. The +thigh-bone, of all the bones, contains most inorganic matter. In short, +bones which have to bear the greatest strain are richest in inorganic +matter. Of the bones of animals, fish-bones exhibit the greatest variety +of composition, some being almost entirely made up of organic matter, +while others are similar in their composition to the bones of +quadrupeds.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_363" id="Page_363">[Pg 363]</a></span><i>The Organic Matter of Bones.</i></p> + +<p>The organic portion of bones is almost entirely made up of a substance +to which the name <i>ossein</i> has been given, and which, when boiled for a +long time, is converted into gelatine. This ossein, which forms on an +average from 25 to 30 per cent of the weight of bones, is extremely rich +in nitrogen, containing over 18 per cent.</p> + +<br /> +<p class="cen"><i>Inorganic Portion of Bones.</i></p> + +<p>The inorganic portion, which forms about 70 per cent, is made up chiefly +of phosphate of lime. The dry leg-bones of oxen and sheep, according to +Heintz, have the following percentage composition:—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="phosphate"> + <tr> + <td class="tdl" width="50%"> </td> + <td class="tdr" width="50%">Per cent.</td> + </tr> + <tr> + <td class="tdl" width="50%">Phosphate of lime</td> + <td class="tdr" width="50%">58 to 63</td> + </tr> + <tr> + <td class="tdl" width="50%">Carbonate of lime</td> + <td class="tdr" width="50%"> 6 to 7</td> + </tr> + <tr> + <td class="tdl" width="50%">Phosphate of magnesia</td> + <td class="tdr" width="50%"> 1 to 2</td> + </tr> + <tr> + <td class="tdl" width="50%">Fluoride of calcium</td> + <td class="tdr" width="50%">2</td> + </tr> + <tr> + <td class="tdl" width="50%">Organic matter</td> + <td class="tdr" width="50%">25 to 30</td> + </tr> +</table> +</div> + +<p>According to Payen and Boussingault, raw bones contain 6-1/4 per cent of +nitrogen and 8 per cent of water. Pure bones are thus seen to contain +about 29 per cent of phosphoric acid and 6-1/4 per cent of nitrogen. The +composition of the commercial article, however, differs very widely. +This is due to the fact that bones collected from India and America, +where they have been long exposed to atmospheric influences, have lost +much of their organic matter. The amount of sand and earthy impurities +also varies very considerably.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_364" id="Page_364">[Pg 364]</a></span><i>Treatment of Bones.</i></p> + +<p>Bones are used for the manufacture of glue and gelatine. These are +extracted from them by steaming the bones. The bones after treatment are +used as a manure. The improvement noted in the action of the bones thus +treated led to the introduction of the use of steamed bones as a manure. +Raw bones are now rarely used. The fat present in raw bones retards +their decomposition in the soil. Probably, as has been suggested, it +forms along with lime an insoluble soap which prevents the mineral +matter in the bone being dissolved by the carbonic acid of the soil. In +the process of boiling or steaming a certain loss of nitrogen takes +place, greater or less, according to the length of time they are boiled +or steamed, and in the latter case the pressure applied. A more +economical method for extracting the fat has been introduced by using +benzine, but this process is not used to any extent. The loss of +nitrogen in the former case is more than compensated for by their more +speedy action as a manure when applied to the soil. Bone-meal of good +quality contains from 45 to 55<a name="FNanchor_217_217" id="FNanchor_217_217"></a><a href="#Footnote_217_217" class="fnanchor">[217]</a> per cent of phosphate of lime, and +3-1/2 per cent of nitrogen. Our present total consumption of bones is +probably little less than 100,000 tons per annum, of which about half is +obtained from home collections, over 20,000 tons being annually +collected in and around London alone.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_365" id="Page_365">[Pg 365]</a></span><i>Action of Bones.</i></p> + +<p>It is well known that bones are a slow-acting manure. They may be said +to possess both a mechanical and chemical action when applied to the +soil. When they putrefy, their nitrogen is slowly converted into +ammonia, and carbonic acid as well as various organic acids are formed, +which, acting upon the insoluble mineral matter in the bones, renders it +available for plant uses. Bones thus, when applied in large quantities, +may not merely act directly as suppliers of plant-food, but in the +course of their putrefaction may act upon a certain amount of the inert +fertilising matter of the soil and render it available. The more +readily, then, bones putrefy, the more speedy will be their effect. As +we have already pointed out, bones, in order to increase their +efficiency, are often fermented before application. The removal of the +fat is another means of increasing the rate of their action, but the +fineness to which they are ground determines this more than anything +else. Much ingenuity has been expended in perfecting machinery for +grinding bones. At one time in Germany they were pounded in stamps +similar to those used for ore. In America what has been called "floated +bone" has been prepared. This bone is so fine that it actually floats in +the air like flour-dust, and is made by whirling the bones against one +another. The action of bones prepared in this way is of course very +speedy, but the difficulty of applying a manure <span class='pagenum'><a name="Page_366" id="Page_366">[Pg 366]</a></span>in such a fine state of +division to the soil is great. The expense of the process also is +considerable.</p> + +<p>The ease with which bones when ground into a fine state of division +putrefy, is evidenced by the fact that bone-flour has to be salted in +order to enable it to keep. Another condition which determines the rate +at which the fertilising matters in bones become available is the nature +of the soil. Fermentation, as we have already seen, requires a plentiful +supply of air, and a certain amount, but not too much, of moisture. +Consequently bones act best in medium soils—soils which are "neither +too light and dry, nor too close and wet." There can be no doubt that +what gives to bones a peculiar value in the eyes of the farmer is the +fact that they form a manure of a lasting character. They give what has +been termed backbone to a soil. But the tendency of modern agricultural +practice is to use quick-acting manures rather than slow. This has been +admirably put by Professor Storer in the following words: "The old +notion, that those manures are best which make themselves felt through a +long series of years, is now recognised to be an error. The adage, that +'one cannot eat the cake and have the cake' is conspicuously true in +agriculture; and just as it is the part of prudence in household or +maritime economy to abstain from laying in at any one time more +provisions than can be properly disposed of in a year or during a +voyage, so should the farmer refrain from bringing to the land an +unnecessary excess of plant-food. Such <span class='pagenum'><a name="Page_367" id="Page_367">[Pg 367]</a></span>food is liable to spoil withal +in the soil, as well as other kinds of provisions that are kept too long +in store. A just proportion of food, properly prepared, is the point to +be aimed at always."</p> + +<p>In view, therefore, of what has just been said, it might seem best to +use bones in the form in which they are most speedily available—viz., +as dissolved bones. This would be so if bones were the only source we +possessed for the manufacture of superphosphate of lime; but we now +have, in the various mineral phosphates, abundant and cheaper sources of +this valuable manure. The opinion of leading agriculturists and +agricultural chemists is rather in favour of applying bones in the +undissolved condition. For one thing, it seems far from economical to +utilise an expensive material such as bones for manufacturing an article +which can be equally well manufactured from cheaper materials; for once +the phosphate of lime is dissolved, it is equally valuable from whatever +source it may be derived. Of course this is not tantamount to saying +that dissolved bones as a manure are no more valuable than +superphosphate. In dissolved bones we have, in addition to soluble +phosphate, a considerable proportion of undissolved bone-tissue, +containing a certain quantity of nitrogen and organic matter; but so far +as the soluble phosphate is concerned, it seems only rational to +conclude that its efficacy is equally great, whether it be derived from +bone or mineral phosphate. Another reason is, that <span class='pagenum'><a name="Page_368" id="Page_368">[Pg 368]</a></span>much of the +characteristic action of bones is lost by treating them with sulphuric +acid. As Dr Aitken has pointed out, the germ life in the soil and in the +bones gradually converts them into a form available for the nourishment +of plants; but to dissolve bones with sulphuric acid is to kill out the +germ life and retard the decay of any nucleus of bone in the dissolved +manure.</p> + +<br /> +<p class="cen"><i>Dissolved Bones.</i></p> + +<p>Dissolved bones, however, are still manufactured. Formerly the manure +called dissolved bones was often a mixture of mineral superphosphate +along with undissolved bone-meal, but recent legislation has stopped the +continuance of this practice. The composition of dissolved bones varies +somewhat, the percentage of soluble phosphate being about 20 to 23 per +cent, the insoluble amounting to from 9 to 10 per cent, and the nitrogen +from 2-1/2 to 3-1/2 per cent.<a name="FNanchor_218_218" id="FNanchor_218_218"></a><a href="#Footnote_218_218" class="fnanchor">[218]</a> Another reason against dissolving +bones is to be found in the difficulty experienced in dissolving their +phosphate. Bones, especially when raw, are not easily acted upon by +acids.</p> + +<br /> +<p class="cen"><i>Crops suited for Bones.</i></p> + +<p>Bones are commonly regarded as being specially beneficial to +pasture-land, to which they are applied as a top-dressing. Turnips, +tobacco, potatoes, vines, and hops are also much benefited by the +application <span class='pagenum'><a name="Page_369" id="Page_369">[Pg 369]</a></span>of bones. In America, mixed with wood-ashes (the chief +manurial constituent of which is potash), they have been extensively +used as a substitute for farmyard manure, and have been applied at the +rate of 5 to 6 cwt. per acre. In Saxony, according to Professor Storer, +1 cwt. of fine bone-meal is worth as much as 25 to 30 cwt. of farmyard +manure.</p> + +<br /> +<p class="cen"><i>Bone-ash.</i></p> + +<p>The ash which is left on burning bones used to be an article of +considerable manurial importance. It is still imported from South +America in some quantity, and is used chiefly in the pottery industry. +It is occasionally still used to a limited extent for the manufacture of +high-class superphosphates. It is extremely rich in phosphate of lime, +of which it contains between 70 and 80 per cent; but of course it is +devoid of nitrogen.<a name="FNanchor_219_219" id="FNanchor_219_219"></a><a href="#Footnote_219_219" class="fnanchor">[219]</a> Bone-ash is best used in the dissolved form, as +it possesses no characteristic action such as is possessed by bones.</p> + +<br /> +<p class="cen"><i>Bone-char or Bone-black.</i></p> + +<p>When heated in a closed retort, bones are not converted into bone-ash, +but into a body called bone-char. This body is similar in composition to +bone-ash, except for a certain percentage of charcoal—amounting, on an +average, to 10 per cent. It contains but little nitrogen and other +organic matter. Bone-black or <span class='pagenum'><a name="Page_370" id="Page_370">[Pg 370]</a></span>bone-char is an article which is prepared +in enormous quantities for use in sugar-refineries, where it is used in +the purification of sugar. After use it may be renovated by submitting +it to heat; but as this process gradually lessens the percentage of +carbon it contains, after a certain period it becomes too poor in this +substance for efficiently acting as a filter. When this takes place it +is technically known as spent char, and is used for the manufacture of +superphosphates. Spent char is a highly phosphatic substance, being very +little poorer than bone-ash, and containing about 70 per cent of +phosphate of lime.<a name="FNanchor_220_220" id="FNanchor_220_220"></a><a href="#Footnote_220_220" class="fnanchor">[220]</a></p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_216_216" id="Footnote_216_216"></a><a href="#FNanchor_216_216"><span class="label">[216]</span></a> It is only fair to Liebig to say that when he wrote these +words the practically boundless supply of mineral phosphates which we +now know to exist in many parts of the world was little dreamt of.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_217_217" id="Footnote_217_217"></a><a href="#FNanchor_217_217"><span class="label">[217]</span></a> See Appendix, Note I., p. 371.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_218_218" id="Footnote_218_218"></a><a href="#FNanchor_218_218"><span class="label">[218]</span></a> See Appendix, Note II., p. 371.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_219_219" id="Footnote_219_219"></a><a href="#FNanchor_219_219"><span class="label">[219]</span></a> See Appendix, Note III., p. 372.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_220_220" id="Footnote_220_220"></a><a href="#FNanchor_220_220"><span class="label">[220]</span></a> See Appendix, Note IV., p. 372.</p></div> + +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_371" id="Page_371">[Pg 371]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER XI.</h2> +<br /> + +<p class="cen">NOTE I. (p. 364).</p> + +<p>The following analysis will serve to show the composition of +bone-meal:—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="moisture"> + <tr> + <td class="tdl" width="80%"> Moisture</td> + <td class="tdr" width="20%">10.43</td> + </tr> + <tr> + <td class="tdl">* Organic matter</td> + <td class="tdr">32.30</td> + </tr> + <tr> + <td class="tdl"> Phosphate of lime</td> + <td class="tdr">48.40</td> + </tr> + <tr> + <td class="tdl"> Carbonate of lime, magnesia, &c.</td> + <td class="tdr">7.20</td> + </tr> + <tr> + <td class="tdl"> Insoluble siliceous matter</td> + <td class="tdr"><span style="text-decoration: underline;"> 1.67</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span></td> + </tr> + <tr> + <td class="tdl">* Containing:—</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> Nitrogen</td> + <td class="tdr">3.71</td> + </tr> + <tr> + <td class="tdl"> Equal to ammonia</td> + <td class="tdr">4.51</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 368).</p> + +<p class="cen"><span class="smcap">Composition of Dissolved Bones.</span></p> + +<p>The accompanying analysis may be taken as representing the average +composition of dissolved bones:—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="organic"> + <tr> + <td class="tdl" width="85%"> Moisture</td> + <td class="tdr" width="15%">10.10 </td> + </tr> + <tr> + <td class="tdl">* Organic matter and water of combination</td> + <td class="tdr">29.34 </td> + </tr> + <tr> + <td class="tdl"> Monobasic phosphate of lime</td> + <td class="tdr">11.23 </td> + </tr> + <tr> + <td class="tdl"> (Equal to tricalcic phosphate rendered "soluble"</td> + <td class="tdr">17.58)</td> + </tr> + <tr> + <td class="tdl"> Phosphate soluble in ammonium citrate</td> + <td class="tdr">14.02 </td> + </tr> + <tr> + <td class="tdl"> Insoluble phosphate of lime</td> + <td class="tdr">1.88 </td> + </tr> + <tr> + <td class="tdl"> Calcium sulphate, magnesia, alkalies, &c.</td> + <td class="tdr">30.23 </td> + </tr> + <tr> + <td class="tdl"> Sand</td> + <td class="tdr"><span style="text-decoration: underline;"> 3.20</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span> </td> + </tr> + <tr> + <td class="tdl">* Containing:—</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> Nitrogen</td> + <td class="tdr">2.62 </td> + </tr> + <tr> + <td class="tdl"> Equal to ammonia</td> + <td class="tdr">3.18 </td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_372" id="Page_372">[Pg 372]</a></span><span class="smcap">Composition of Compound Bones.</span></p> + +<p>The following analysis illustrates the composition of compound bones:—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="matter"> + <tr> + <td class="tdl" width="85%"> Moisture</td> + <td class="tdr" width="15%">8.10 </td> + </tr> + <tr> + <td class="tdl">* Organic matter and water of combination</td> + <td class="tdr">37.22 </td> + </tr> + <tr> + <td class="tdl"> Monobasic phosphate of lime</td> + <td class="tdr">13.68 </td> + </tr> + <tr> + <td class="tdl"> (Equal to tricalcic phosphate rendered "soluble"</td> + <td class="tdr">21.42)</td> + </tr> + <tr> + <td class="tdl"> Insoluble phosphate of lime</td> + <td class="tdr">10.48 </td> + </tr> + <tr> + <td class="tdl"> Calcium sulphate, magnesia, alkalies, &c.</td> + <td class="tdr">26.02 </td> + </tr> + <tr> + <td class="tdl"> Sand</td> + <td class="tdr"><span style="text-decoration: underline;"> 4.50</span> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span> </td> + </tr> + <tr> + <td class="tdl">* Containing:—</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> Nitrogen</td> + <td class="tdr">1.90 </td> + </tr> + <tr> + <td class="tdl"> Equal to ammonia</td> + <td class="tdr">2.30 </td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE III. (p. 369).</p> + +<p>As showing the composition of bone-ash, the following analysis may be +quoted:—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="acid"> + <tr> + <td class="tdl" width="80%"> Moisture</td> + <td class="tdr" width="20%">.25</td> + </tr> + <tr> + <td class="tdl"> Organic matter</td> + <td class="tdr">.85</td> + </tr> + <tr> + <td class="tdl">* Phosphoric acid</td> + <td class="tdr">.25</td> + </tr> + <tr> + <td class="tdl"> Lime</td> + <td class="tdr">47.09</td> + </tr> + <tr> + <td class="tdl"> Magnesia, alkalies, &c.</td> + <td class="tdr">9.80</td> + </tr> + <tr> + <td class="tdl"> Sand</td> + <td class="tdr"><span style="text-decoration: underline;"> 6.45</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span></td> + </tr> + <tr> + <td class="tdl">* Equal to tricalcic phosphate</td> + <td class="tdr">77.63</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE IV. (p. 370).</p> + +<p>Composition of bone-char (on dry sample):—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="carbon"> + <tr> + <td class="tdl" width="80%">Carbon</td> + <td class="tdr" width="20%">10.51</td> + </tr> + <tr> + <td class="tdl">Calcium and magnesium phosphates, calcium fluoride, &c.</td> + <td class="tdr" style="vertical-align: bottom;">80.21</td> + </tr> + <tr> + <td class="tdl">Calcium carbonate</td> + <td class="tdr">8.30</td> + </tr> + <tr> + <td class="tdl">Calcium sulphate</td> + <td class="tdr">.17</td> + </tr> + <tr> + <td class="tdl">Ferric oxide</td> + <td class="tdr">.12</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdr">.34</td> + </tr> + <tr> + <td class="tdl">Alkaline salts</td> + <td class="tdr"><span style="text-decoration: underline;"> .35</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr"><span style="text-decoration: underline;">100.00</span></td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_373" id="Page_373">[Pg 373]</a></span> +<br /> +<h2>CHAPTER XII.</h2> + +<h2>MINERAL PHOSPHATES.</h2> +<br /> + +<p>In this chapter we shall give an account of the more commonly occurring +mineral phosphates. In Chapter V., where we discussed the position of +phosphoric acid in agriculture, it was pointed out that mineral +phosphates were very abundant, and that large deposits of them were +found in many parts of the world.</p> + +<br /> +<p class="cen"><i>Coprolites.</i></p> + +<p>Reference may first be made to the so-called coprolites or phosphatic +nodules which have been found in great abundance in the greensand +formation, in the crag of the eastern counties, and in the chalk +formation of the southern counties. These coprolites are rounded +nodules, and are composed of the fossil excrements and remains of +ancient animals. They are found in large quantities in Cambridgeshire, +and were discovered by Dr Buckland many years ago. The history of their +discovery is not a little curious. <span class='pagenum'><a name="Page_374" id="Page_374">[Pg 374]</a></span>The manurial properties of +road-scrapings in parts of Cambridgeshire were noticed, and on being +examined were found to be in part composed of phosphate of lime, derived +from phosphatic nodules dug out of the underlying greensand, and used +for the purpose of repairing roads. Professor Henslow first drew +attention to them at a meeting of the British Association held in +Cambridge in 1845, and pointed out that they contained about 60 per cent +of phosphate of lime. They were also found in enormous quantities in +Suffolk, Norfolk, Bedfordshire, and Essex, and were for a long time +largely used in the manufacture of superphosphate, but of late years +have not been used to anything like the same extent, owing to the fact +that there are richer and cheaper sources of phosphate of lime +available. In 1887 about 20,000 tons of coprolites were raised. The +richest were those obtained in Cambridge, while those got from +Bedfordshire were about the poorest. Deposits have also been found in +France and other countries. The average amount of phosphate of lime in +English coprolites is between 50 and 60 per cent, while the French +contain about 45 per cent.</p> + +<br /> +<p class="cen"><i>Canadian Apatite or Phosphorite.</i></p> + +<p>We have already referred in Chapter V. to large deposits of apatite or +phosphorite found in Canada. The Canadian mines commenced to be worked +about <span class='pagenum'><a name="Page_375" id="Page_375">[Pg 375]</a></span>fifteen years ago, and the output now amounts to nearly 25,000 +tons per annum.<a name="FNanchor_221_221" id="FNanchor_221_221"></a><a href="#Footnote_221_221" class="fnanchor">[221]</a> A portion of this goes to the United States; the +rest, amounting to about 20,000 tons, being shipped to England, whence +it is again exported to Hamburg and other places.<a name="FNanchor_222_222" id="FNanchor_222_222"></a><a href="#Footnote_222_222" class="fnanchor">[222]</a> It contains from +70 to 80 per cent of phosphate. Deposits are also found at Estremadura +in Spain, and in Norway.</p> + +<br /> +<p class="cen"><i>Estremadura or Spanish Phosphates.</i></p> + +<p>Large deposits of phosphate have long been known to exist at Estremadura +in Spain, and the mines at Caceres have been worked on a large scale for +seventeen years, and about half a million tons have been raised. In 1882 +the imports into this country amounted to over 56,000 tons; but latterly +they have only been about a fourth of this amount. Dr Dauberry visited +the deposits in 1843, and wrote a most interesting account of them. They +do not seem, however, to have been imported for purposes of +superphosphate manufacture till a number of years afterwards. Of +Estremadura phosphate there are three classes, containing respectively +50, 60, and 70 per cent of phosphate of lime, the lowest quality being +the commonest.<a name="FNanchor_223_223" id="FNanchor_223_223"></a><a href="#Footnote_223_223" class="fnanchor">[223]</a></p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_376" id="Page_376">[Pg 376]</a></span><i>Norwegian Apatite.</i></p> + +<p>This apatite has ceased to be imported of late years, owing to a duty on +exportation.</p> + +<br /> +<p class="cen"><i>Charleston or South Carolina Phosphate.</i></p> + +<p>For a number of years these deposits have formed the chief source of +phosphate of lime used in the manufacture of mineral superphosphates in +this country (in fact they have furnished two-thirds of our phosphate +supply during recent years). Discovered twenty-five years ago, some four +to five million tons have already been shipped. About half a million +tons were raised in 1886 from these mines, which are the most abundant +in the world. There are two kinds—the so-called "land" and "river" +phosphates. The former contains more oxide of iron and alumina, and is +therefore less pure than the latter, in which the iron and alumina do +not exceed 2 per cent. The river phosphate is dredged from the Bull, +Coosaw, and Beaufort rivers. Of phosphate of lime it contains from 50 to +60 per cent. It is generally sold in three grades—50 to 52 per cent, 55 +to 56 per cent, and 58 to 60 per cent of phosphate of lime. It will thus +be seen to be incapable of producing very high-class superphosphates +—<i>i.e.</i>, containing more than 30 per cent "soluble" phosphate. +This point will be more intelligible when we describe the manufacture of +superphosphate. The demand for these phosphates <span class='pagenum'><a name="Page_377" id="Page_377">[Pg 377]</a></span>in the United States has +increased enormously in recent years, owing to the increase in the +quantity of manure used.</p> + +<br /> +<p class="cen"><i>Belgian Phosphate.</i></p> + +<p>Another very important source of mineral phosphates are deposits +discovered some years ago in Belgium near Mons. These phosphates are of +different qualities, and are found, some in layers near the surface in +pockets forming the richest class, and containing from 45 to 65 per cent +of phosphate, and some in the form of a friable phosphatic rock, the +so-called <i>craie-grise</i> (phosphatic chalk), containing from 25 to 35 per +cent of phosphate of lime. The higher quality of Belgian phosphate is +pretty well exhausted, and it is the second class that forms the bulk of +the ordinary Belgian phosphate at present exported. The commercial +article contains about 35 to 40 per cent of phosphate, and about 45 per +cent of carbonate of lime. The fact of its poor quality, together with +the large percentage of carbonate of lime it contains, renders its +adoption alone in the manufacture of superphosphate unsuitable. Attempts +have been made to get rid of a portion of this carbonate of lime and to +raise the percentage of phosphate. For this purpose the phosphate has +been calcined, but this was soon found to be a great mistake. Other +means have been adopted, with the result that the percentage has been +increased to 50 <span class='pagenum'><a name="Page_378" id="Page_378">[Pg 378]</a></span>per cent. It is consequently used in small quantities +as a drier, for which it is peculiarly suited on account of its +carbonaceous nature, along with the higher-class phosphates. In the year +1886 about 145,000 tons of this phosphate were raised, of which about +45,000 tons were imported into the United Kingdom.</p> + +<br /> +<p class="cen"><i>Somme Phosphate.</i></p> + +<p>Still more recently a discovery of phosphate deposits has been made in +the Somme and Pas de Calais departments in the north of France, +adjoining, and similar in character to, the Belgian deposits. The only +difference between Belgian and French phosphates is, that the latter is +of a higher quality, and contains from 50 to 80 per cent of phosphate of +lime. A very large demand for these phosphates sprang up, and in 1888, +although they had only been worked for some two years, no less than +150,000 tons had been raised, of which about one-half contained from 70 +to upwards of 75 per cent. There are four grades in the market, +containing 55 to 60, 60 to 65, 70 to 75, and 75 to 80 per cent of +phosphate of lime. The highest quality furnishes the chief material for +the manufacture of high-grade superphosphates.</p> + +<br /> +<p class="cen"><i>Florida Phosphate.</i><a name="FNanchor_224_224" id="FNanchor_224_224"></a><a href="#Footnote_224_224" class="fnanchor">[224]</a></p> + +<p>During the last few years large quantities of <span class='pagenum'><a name="Page_379" id="Page_379">[Pg 379]</a></span>phosphates have been +imported from Florida. These are of different qualities, the land rocks +now imported containing from 70 to 80 per cent of phosphate of lime, and +the river phosphate about 60 per cent. The latter class are similar in +composition to the best South Carolina river-phosphates, which they much +resemble.</p> + +<br /> +<p class="cen"><i>Lahn Phosphate.</i></p> + +<p>Phosphate deposits were found at Nassau in Germany in 1864; but as the +phosphate contained a considerable proportion of iron and alumina, they +are not used in this country now, although they are in Germany for +double superphosphate manufacture.</p> + +<br /> +<p class="cen"><i>Bordeaux or French Phosphate.</i></p> + +<p>Similar in quality to Lahn phosphate is that obtained in the +neighbourhood of Bordeaux.</p> + +<br /> +<p class="cen"><i>Algerian Phosphate.</i></p> + +<p>Excellent phosphates are now being sent from Algeria—some cargoes being +as rich as 70 per cent.</p> + +<br /> +<p class="cen"><i>Crust Guanos.</i></p> + +<p>We have already referred to the guanos in the chapter on Guano. They are +also known under the name of Caribbean phosphates, and come from the +West India Islands. The chief kinds are Aruba, Curaçao, Sombrero, and +Navassa, the Great Cayman, <span class='pagenum'><a name="Page_380" id="Page_380">[Pg 380]</a></span>Redonda, and Alta Vela. Most of them are of +high quality, containing from 60 to 80 per cent of phosphate, and are +thus suited for the manufacture of high-class superphosphates. Some of +them, however, contain a considerable proportion of iron and alumina, +and are not suitable for this purpose. The Redonda and Alta Vela +phosphates consist chiefly of phosphate of alumina.</p> + +<br /> +<p class="cen"><i>Value of Mineral Phosphates as a Manure.</i></p> + +<p>While it is commonly regarded as unadvisable to use mineral phosphates +directly as phosphatic manures, it may well be questioned how far such +an opinion is warranted by actual experience. Professor Jamieson of +Aberdeen, in his interesting and valuable experiments, has drawn +attention to the fact that coprolites in a fine state of division are an +extremely valuable source of phosphoric acid for crops, and are a more +quickly available source than is commonly supposed. Experiments +conducted elsewhere with ground coprolites and other mineral phosphates +corroborate Professor Jamieson's conclusions. The successful use of +Thomas-phosphate has drawn attention to the possibility of profitably +applying undissolved mineral phosphate to the soil; and no doubt the +practice may in future years be increased. At present, however, with the +exception of Thomas-phosphate, mineral phosphates alone are used for +conversion into superphosphate.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_221_221" id="Footnote_221_221"></a><a href="#FNanchor_221_221"><span class="label">[221]</span></a> Since the discovery of the Florida deposits of phosphate, +the working of the Canadian mines has been practically abandoned.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_222_222" id="Footnote_222_222"></a><a href="#FNanchor_222_222"><span class="label">[222]</span></a> See Appendix, p. 381.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_223_223" id="Footnote_223_223"></a><a href="#FNanchor_223_223"><span class="label">[223]</span></a> These phosphates are now no longer worked.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_224_224" id="Footnote_224_224"></a><a href="#FNanchor_224_224"><span class="label">[224]</span></a> These deposits were discovered a few years ago; and as +they are of considerable extent and high quality, have entirely +revolutionised the phosphate market. About 300,000 tons are now annually +raised in Florida.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_381" id="Page_381">[Pg 381]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER XII.</h2> +<br /> + +<p class="cen">NOTE (p. 375).</p> + +<p class="cen"><span class="smcap">The following Table shows the Imports of Phosphates into the United +Kingdom,<br /> and the Countries of Production, during the Years 1885-92.</span></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="United"> + <tr> + <td class="tdltb"> </td> + <td class="tdctlb">1885.</td> + <td class="tdctlb">1886.</td> + <td class="tdctlb">1887.</td> + <td class="tdctlb">1888.</td> + <td class="tdctlb">1889.</td> + <td class="tdctlb">1890.</td> + <td class="tdctlb">1891.</td> + <td class="tdctlb">1892.</td> + </tr> + <tr> + <td class="tdl" width="36%"> </td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdcl" width="8%">Tons.</td> + </tr> + <tr> + <td class="tdl">United States</td> + <td class="tdcl">138,844</td> + <td class="tdcl">144,623</td> + <td class="tdcl">165,275</td> + <td class="tdcl">111,369</td> + <td class="tdcl">122,554</td> + <td class="tdcl">177,283</td> + <td class="tdcl">*131,084</td> + <td class="tdcl">*201,465</td> + </tr> + <tr> + <td class="tdl">Canada</td> + <td class="tdcl"> 21,484</td> + <td class="tdcl"> 18,069</td> + <td class="tdcl"> 19,194</td> + <td class="tdcl"> 12,423</td> + <td class="tdcl"> 23,297</td> + <td class="tdcl"> 21,089</td> + <td class="tdcl"> 15,918</td> + <td class="tdcl"> 7,814</td> + </tr> + <tr> + <td class="tdl">Dutch West Indies (Curaçao, Aruba)</td> + <td class="tdcl" style="vertical-align: bottom;"> 11,588</td> + <td class="tdcl" style="vertical-align: bottom;"> 12,581</td> + <td class="tdcl" style="vertical-align: bottom;"> 9,505</td> + <td class="tdcl" style="vertical-align: bottom;"> 10,736</td> + <td class="tdcl" style="vertical-align: bottom;"> 14,730</td> + <td class="tdcl" style="vertical-align: bottom;"> 14,763</td> + <td class="tdcl" style="vertical-align: bottom;"> 8,851</td> + <td class="tdcl" style="vertical-align: bottom;"> 6,648</td> + </tr> + <tr> + <td class="tdl">British West Indies (Sombrero, &c)</td> + <td class="tdcl" style="vertical-align: bottom;"> 7,727</td> + <td class="tdcl" style="vertical-align: bottom;"> 3,351</td> + <td class="tdcl" style="vertical-align: bottom;"> 6,451</td> + <td class="tdcl" style="vertical-align: bottom;"> 11,010</td> + <td class="tdcl" style="vertical-align: bottom;"> 1,880</td> + <td class="tdcl" style="vertical-align: bottom;"> 3,970</td> + <td class="tdcl" style="vertical-align: bottom;"> 1,960</td> + <td class="tdcl" style="vertical-align: bottom;"> 2,473</td> + </tr> + <tr> + <td class="tdl">Spain and Portugal</td> + <td class="tdcl"> 19,282</td> + <td class="tdcl"> 5,825</td> + <td class="tdcl"> 15,612</td> + <td class="tdcl"> 6,978</td> + <td class="tdcl"> 1,326</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 320</td> + <td class="tdcl"> 971</td> + </tr> + <tr> + <td class="tdl">Belgium</td> + <td class="tdcl"> 35,405</td> + <td class="tdcl"> 31,551</td> + <td class="tdcl"> 45,322</td> + <td class="tdcl"> 54,261</td> + <td class="tdcl"> 64,643</td> + <td class="tdcl"> 82,096</td> + <td class="tdcl"> 70,723</td> + <td class="tdcl"> 65,079</td> + </tr> + <tr> + <td class="tdl">Holland</td> + <td class="tdcl"> 865</td> + <td class="tdcl"> 2,194</td> + <td class="tdcl"> 4,778</td> + <td class="tdcl"> 4,137</td> + <td class="tdcl"> 2,270</td> + <td class="tdcl"> 2,428</td> + <td class="tdcl"> 3,434</td> + <td class="tdcl"> 6,627</td> + </tr> + <tr> + <td class="tdl">France</td> + <td class="tdcl"> 2,276</td> + <td class="tdcl"> 1,503</td> + <td class="tdcl"> 11,140</td> + <td class="tdcl"> 39,059</td> + <td class="tdcl"> 65,490</td> + <td class="tdcl"> 35,659</td> + <td class="tdcl"> 18,325</td> + <td class="tdcl"> 18,239</td> + </tr> + <tr> + <td class="tdl">Australia</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 200</td> + <td class="tdcl"> 350</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 1,250</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + </tr> + <tr> + <td class="tdl">Germany</td> + <td class="tdcl"> 704</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + </tr> + <tr> + <td class="tdl">Hayti (San Domingo)</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 2,175</td> + <td class="tdcl"> 3,044</td> + <td class="tdcl"> 6,238</td> + <td class="tdcl"> 4,094</td> + <td class="tdcl"> 992</td> + <td class="tdcl"> 1,639</td> + <td class="tdcl"> 2,965</td> + </tr> + <tr> + <td class="tdl">Brazil</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 1,200</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + </tr> + <tr> + <td class="tdl">Venezuela and Guiana</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 405</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 540</td> + <td class="tdcl"> —</td> + </tr> + <tr> + <td class="tdl">Norway</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 4,151</td> + <td class="tdcl"> 1,495</td> + <td class="tdcl"> 305</td> + </tr> + <tr> + <td class="tdl">Other countries</td> + <td class="tdcl"> 397</td> + <td class="tdcl"> 1,039</td> + <td class="tdcl"> 1,139</td> + <td class="tdcl"> 1,675</td> + <td class="tdcl"> 390</td> + <td class="tdcl"> 1,070</td> + <td class="tdcl"> 1,483</td> + <td class="tdcl"> 1,594</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> *Florida phosphate</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> —</td> + <td class="tdcl"> 35,203</td> + <td class="tdcl"> 66,327</td> + </tr> + <tr> + <td class="tdlb"> Carolina phosphate</td> + <td class="tdclb"> —</td> + <td class="tdclb"> —</td> + <td class="tdclb"> —</td> + <td class="tdclb"> —</td> + <td class="tdclb"> —</td> + <td class="tdclb"> —</td> + <td class="tdclb"> 96,881</td> + <td class="tdclb">135,138</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_382" id="Page_382">[Pg 382]</a></span> +<br /> +<h2>CHAPTER XIII.</h2> + +<h2>SUPERPHOSPHATES.</h2> +<br /> + +<p>As was mentioned in the chapter on Bones, Liebig in the year 1840 +discovered that the effect of adding oil of vitriol, or sulphuric acid, +to bones was to render the phosphate they contain soluble. This +discovery marked an epoch in the history of artificial manures, and laid +the foundation of the now enormous manufacture of superphosphate. In +1862 the juries of the London International Exhibition published an +elaborate report containing an interesting article on the manure trade +of Great Britain, in which it was stated that the annual quantity of +superphosphate then made amounted to from 150,000 to 200,000 tons. Now +it may be placed not far short of a million tons. Probably that made in +the United States is considerably more. In the first instance, +superphosphate was manufactured by Sir John Lawes from spent bone-char. +This was superseded by coprolites and Estremadura phosphorite, <span class='pagenum'><a name="Page_383" id="Page_383">[Pg 383]</a></span>Suffolk +coprolites being for many years the chief material employed. This in +turn was succeeded by the richer Cambridge coprolites, but of late years +coprolites have practically ceased to be a source of superphosphate, the +other mineral phosphates mentioned in the previous chapter—such as the +South Carolina, Belgian, Somme, &c., phosphates—taking their place.</p> + +<br /> +<p class="cen"><i>Manufacture of Superphosphate.</i></p> + +<p>The manufacture of superphosphate is of too technical a nature to permit +of discussion in a work of this kind. It is important, however, that the +general principles underlying the process of manufacture and the +chemical changes in the phosphate taking place during the process be +clearly understood. In the first place, great importance attaches in the +manufacture of the superphosphate to the fineness of division of the raw +material, and much ingenuity has been spent on apparatus designed for +this purpose. The difficulty of grinding the phosphate varies, of +course, with the nature of the material used—apatite, for example, +being much more difficult to reduce to the necessary fineness than +phosphatic guano. The finer the state of division, the more complete +will be the decomposition of the phosphate by the acid. Mr Warington +recommends that for first-class work the powder should be so fine as to +admit of it passing through a sieve of eighty wires to the inch. After +the phosphate is reduced to <span class='pagenum'><a name="Page_384" id="Page_384">[Pg 384]</a></span>powder, it is mixed with acid. This takes +place in the mixer, which is generally in the form of an iron cylinder +furnished in the centre with a revolving shaft, the sulphuric acid used +being the ordinary chamber acid (sp. gr. 1.57). Whatever strength of +acid is used, there must be a certain quantity of water present to form +gypsum. It is to the formation of gypsum in the resulting product that +the dryness of the superphosphate is due. The proportion of sulphuric +acid used depends on the composition of the phosphate; and here it may +be pointed out that the presence of much carbonate of lime is a most +important factor in determining the quantity of acid required. The +reason of this is, that where carbonate and phosphate of lime are +present together, sulphuric acid first acts upon the carbonate, and it +is not till this is wholly decomposed that the phosphate can be acted +upon. Hence mineral phosphates with a large percentage of carbonate of +lime do not constitute such an economical material for the manufacture +of superphosphate as those in which the percentage of carbonate is +small.<a name="FNanchor_225_225" id="FNanchor_225_225"></a><a href="#Footnote_225_225" class="fnanchor">[225]</a> A certain amount of heat is necessary for the purpose <span class='pagenum'><a name="Page_385" id="Page_385">[Pg 385]</a></span>of +enabling a quick decomposition to take place. For this purpose the +sulphuric acid added has been previously heated. In the ordinary +manufacture of superphosphate, however, this is not considered +necessary, as the heat developed by the chemical action between the +phosphate and the acid is sufficiently great. The phosphate, after being +thoroughly mixed with the acid, is discharged into what is technically +known as the pit, a chamber built of brick or concrete. The mixture, +which is in a fluid state when it enters the pit, very soon hardens, and +is dug out in a day or two. It is next reduced to powder in a +disintegrator, and is then ready for use as a manure.</p> + +<br /> +<p class="cen"><i>Nature of the Reaction taking place.</i></p> + +<p>In order to clearly understand the nature of the reaction which takes +place when sulphuric acid is added to a phosphatic material, it may be +well to say a word or two on the composition of the different compounds +of lime and phosphoric acid.</p> + +<br /> +<p class="cen"><i>Phosphates of Lime.</i></p> + +<p>In the various phosphatic manures used in agriculture there are four +different kinds of phosphates. In the commonest form, popularly called +bone-phosphate, which is the form in which lime and phosphoric acid are +combined in bones, guano, and the ordinary mineral phosphates, the lime +and phosphoric acid are combined in the form of what is known as +<span class='pagenum'><a name="Page_386" id="Page_386">[Pg 386]</a></span>tribasic phosphate of lime, or tricalcic phosphate—that is to say, for +every equivalent of phosphoric acid there are three equivalents of lime. +This may be represented as follows:—</p> + + +<p class="noin"> <span style="padding-left: 10em;">Lime }</span><br /> +<span style="padding-left: 10em;">Lime } Phosphoric acid.</span><br /> +<span style="padding-left: 10em;">Lime }</span></p> + + +<p>Or we may also say that for every 142 parts by weight of phosphoric acid +there are 168 parts by weight of lime in this form of phosphate. This is +the least soluble form of phosphoric acid,<a name="FNanchor_226_226" id="FNanchor_226_226"></a><a href="#Footnote_226_226" class="fnanchor">[226]</a> and is the form +generally referred to in commercial analyses as insoluble phosphate. +When this phosphate is acted upon with sulphuric acid, a soluble +phosphate is formed, as Liebig first showed, to which the name +superphosphate has been given, and which is also known as monobasic +phosphate of lime, or monocalcic phosphate. This compound may be +represented as containing, instead of three equivalents of lime, only +one, the other two equivalents being replaced by water. This compound +may be represented as follows:—</p> + + +<p class="noin"><span style="padding-left: 10em;">Lime }</span><br /> +<span style="padding-left: 10em;">Water } Phosphoric acid.</span><br /> +<span style="padding-left: 10em;">Water }</span><br /></p> + + + +<p><span class='pagenum'><a name="Page_387" id="Page_387">[Pg 387]</a></span>In it, for every 142 parts of phosphoric acid, there are only 56 parts +of lime. It is soluble in water, and gives to the commercial article +known as superphosphate of lime its value. Intermediate in composition +between these two phosphates there is another known as precipitated +phosphate of lime, or dicalcic phosphate (the same as reverted +phosphate), which contains two equivalents of lime and one equivalent of +water as follows:—</p> + + +<p class="noin"><span style="padding-left: 10em;">Lime }</span><br /> +<span style="padding-left: 10em;">Lime } Phosphoric acid.</span><br /> +<span style="padding-left: 10em;">Water }</span><br /></p> + +<p>This compound contains, for every 142 parts of phosphoric acid, 112 +parts of lime; and in solubility occupies an intermediate position. +Lastly, there is a fourth compound of lime and phosphoric acid, which +only occurs in one phosphatic manure—viz., phosphatic slag, in which +indeed it was first discovered—which consists of four equivalents of +lime to one of phosphoric acid, to which the name tetrabasic phosphate +of lime or tetracalcic phosphate has been given. Its composition may be +illustrated as follows:—</p> + + +<p class="noin"><span style="padding-left: 10em;">Lime }</span><br /> +<span style="padding-left: 10em;">Lime } Phosphoric acid.</span><br /> +<span style="padding-left: 10em;">Lime }</span><br /> +<span style="padding-left: 10em;">Lime }</span><br /></p> + +<p>Or, for every 142 parts of phosphoric acid, there are 224 parts of lime. +Contrary to what we might expect, this phosphate is less insoluble than +the ordinary tribasic or bone phosphate. This may be owing to <span class='pagenum'><a name="Page_388" id="Page_388">[Pg 388]</a></span>the fact +that, in the tetrabasic phosphate, there is more lime present than that +which the phosphoric acid can retain with strong chemical affinity.<a name="FNanchor_227_227" id="FNanchor_227_227"></a><a href="#Footnote_227_227" class="fnanchor">[227]</a> +In the manufacture of superphosphate the tribasic phosphate is converted +into the soluble phosphate—the lime, which was formerly in combination +with the phosphoric acid, uniting with the sulphuric acid, and forming +gypsum.<a name="FNanchor_228_228" id="FNanchor_228_228"></a><a href="#Footnote_228_228" class="fnanchor">[228]</a> It was till recently supposed that soluble phosphate and +gypsum were the only two resulting products of this decomposition. It +has been recently shown, however, by Ruffle and others, that this is +not, strictly speaking, the case, and that probably a large proportion +of free phosphoric acid is formed; in fact, it seems probable that in +the first stage of the reaction, only phosphoric acid is produced, and +that this subsequently acts upon the undecomposed phosphate, with the +production of monocalcic phosphate.<a name="FNanchor_229_229" id="FNanchor_229_229"></a><a href="#Footnote_229_229" class="fnanchor">[229]</a> The amount of sulphuric acid +which experience has shown it is necessary to add for the successful and +economical manufacture of superphosphate, depends on the composition of +the raw material employed. The larger the percentage of tribasic +phosphate, the larger the quantity <span class='pagenum'><a name="Page_389" id="Page_389">[Pg 389]</a></span>of sulphuric acid required for its +decomposition; but sometimes even a poor phosphate consumes a large +amount of sulphuric acid. This is the case where much calcium carbonate +or fluoride is present in the raw phosphate, as both of these compounds +require a quantity of acid for their decomposition, which takes place +before the decomposition of the phosphate. Hence phosphates rich in +carbonate of lime are not well suited as economical materials from which +to manufacture superphosphate.</p> + +<br /> +<p class="cen"><i>Reverted Phosphates.</i></p> + +<p>A change which is apt to take place in superphosphate after its +manufacture is what is known as reversion of the soluble phosphate. Thus +it is found that on keeping superphosphate for a long time the +percentage of soluble phosphate becomes less than it was at first. The +rate at which this deterioration of the superphosphate goes on varies in +different samples. In a well-made article it is practically +inappreciable, whereas in some superphosphates, made from unsuitable +materials, it may amount to a considerable percentage. The causes of +this reversion are twofold. For one thing, the presence of undecomposed +phosphate of lime may cause it. This source of reversion, however, is +very much less important than the other, which is the presence of iron +and alumina in the raw material. When a soluble phosphate reverts, what +takes place is the conversion of the monocalcic <span class='pagenum'><a name="Page_390" id="Page_390">[Pg 390]</a></span>phosphate into the +dicalcic. Now in the first case, where reversion is due to the presence +of undecomposed phosphate, the action taking place may be represented as +follows:—</p> + +<div class="centered"> +<table border="0" width="95%" cellpadding="2" cellspacing="0" summary="Lime"> + <tr> + <td class="tdl" width="11%"> Lime</td> + <td class="tdl" width="32%">}</td> + <td class="tdl" width="9%">} {</td> + <td class="tdl" width="9%">lime</td> + <td class="tdl" width="32%">}</td> + <td class="tdl" width="7%">}</td> + </tr> + <tr> + <td class="tdl"> Lime</td> + <td class="tdl">} phosphoric acid</td> + <td class="tdl">} {</td> + <td class="tdl">water</td> + <td class="tdl">} phosphoric acid</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl"> Lime</td> + <td class="tdl">}</td> + <td class="tdl">} + {</td> + <td class="tdl">water</td> + <td class="tdl">}</td> + <td class="tdl">} =</td> + </tr> + <tr> + <td class="tdl" colspan="2"> (One molecule of insoluble phosphate)</td> + <td class="tdl">} {</td> + <td class="tdl" colspan="2">(One molecule of soluble phosphate)</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl" colspan="6"> </td> + </tr> + <tr> + <td class="tdl"> Lime</td> + <td class="tdl">}</td> + <td class="tdl">} {</td> + <td class="tdl">lime</td> + <td class="tdl">}</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl"> Lime</td> + <td class="tdl">} phosphoric acid</td> + <td class="tdl">} {</td> + <td class="tdl">lime</td> + <td class="tdl">} phosphoric acid</td> + <td class="tdl">}</td> + </tr> + <tr> + <td class="tdl"> Water</td> + <td class="tdl">}</td> + <td class="tdl">} + {</td> + <td class="tdl">water</td> + <td class="tdl">}</td> + <td class="tdl">} =</td> + </tr> + <tr> + <td class="tdl" colspan="2"> (One molecule of reverted phosphate)</td> + <td class="tdl">} {</td> + <td class="tdl" colspan="2">(One molecule of reverted phosphate)</td> + <td class="tdl">}</td> + </tr> +</table> +</div> + +<p>It may be mentioned, however, that reversion from this cause probably +takes place to a very slight extent in practice.<a name="FNanchor_230_230" id="FNanchor_230_230"></a><a href="#Footnote_230_230" class="fnanchor">[230]</a> Where reversion is +due to the presence of iron and alumina in the raw material, the nature +of the reaction is not well understood, and is consequently not so +easily demonstrated as in the former case. Where iron is present in the +form of pyrites, or ferrous silicate, it does not seem to cause +reversion. It is only when it is present in the form of oxide—and in +most raw phosphatic materials it is generally in this latter +form<a name="FNanchor_231_231" id="FNanchor_231_231"></a><a href="#Footnote_231_231" class="fnanchor">[231]</a>—that it causes reversion in the phosphate.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_391" id="Page_391">[Pg 391]</a></span><i>Value of reverted Phosphate.</i></p> + +<p>The value of reverted phosphate is a subject which has given rise to +much dispute among chemists. That it has a higher value than the +ordinary insoluble phosphate is now admitted; but in this country, in +the manure trade, this is not as yet recognised. At first it was thought +that it was impossible to estimate its quantity by chemical analysis. +This difficulty, however, has been overcome, and it is generally +admitted that the ammonium citrate process furnishes an accurate means +of determining its amount. Both on the Continent and in the United +States reverted phosphate is recognised as possessing a monetary value +in excess of that possessed by the ordinary insoluble phosphate. The +result is, that raw phosphates containing iron and alumina to any +appreciable extent are not used in this country, although they do find a +limited application in America and on the Continent.</p> + +<br /> +<p class="cen"><i>Composition of Superphosphates.</i></p> + +<p>Superphosphates as manufactured may be divided, generally speaking, into +three classes—viz., low class, medium, and high class. The ordinary or +medium class contains from 25 to 27 per cent of soluble phosphate; and +here it may be pointed out that by soluble phosphate is meant the +percentage of tribasic phosphate which has been dissolved—not, as might +at first sight be supposed, the percentage of monocalcic <span class='pagenum'><a name="Page_392" id="Page_392">[Pg 392]</a></span>phosphate. The +lower-class superphosphates are those containing less than 25 per cent, +generally 23 to 25 per cent, of soluble phosphate; while the high-class +superphosphate may contain from 30 to 45 per cent. For the manufacture +of high-class superphosphate only a certain number of raw phosphates are +available, such as Curaçao and Somme phosphates, phosphatic guanos, +bone-char, &c. Certain processes have been patented for the manufacture +of even more concentrated superphosphates, and by them phosphates +containing as much as 40 per cent of soluble phosphoric acid—<i>i.e.</i>, +equal to 87 per cent of soluble phosphate—have been prepared. To this +class belongs the so-called double superphosphate, manufactured at +Wetzlar in Germany. Such a concentrated form of manure is naturally very +expensive to manufacture, and is hardly to be recommended for home +consumption. Where, however, manures have to be conveyed long distances, +and the freight is consequently very high, such a concentrated article +may be found most economical.</p> + +<br /> +<p class="cen"><i>Action of Superphosphates.</i></p> + +<p>When superphosphate is applied to the soil it is converted into an +insoluble state. In short, the process of reversion is carried on on a +wholesale scale. This is due to the lime, iron, and alumina salts which +the soil contains. In all probability the phosphate is finally converted +into a hydrated ferric or aluminic <span class='pagenum'><a name="Page_393" id="Page_393">[Pg 393]</a></span>phosphate, in which form it is +gradually acted upon by the sap of the plant-roots as required. This +being the case, it may be asked, Why is superphosphate so much more +rapid in its action than insoluble phosphate; or why should we be at the +trouble and expense of dissolving the phosphate if it has to become +insoluble again in the soil? This question is one of very great +importance, for the answer to it furnishes, in our opinion, the key to +the whole phosphate question. When superphosphate is added to the soil, +being soluble in water, it is soon dissolved and carried down by the +rain into its pores, and becomes thoroughly mixed with the +soil-particles. It is thus soon fixed in the soil, beyond the risk of +being washed away. The result is, that the phosphate is obtained in a +state of division infinitely more minute than could ever be obtained by +mechanical grinding, and is, further, most intimately mixed with the +particles of the soil. It is this intimate mixture of the phosphate with +the particles of the soil, and its minute state of division, that +constitute the only reason for rendering superphosphate superior in its +action to even the most finely ground insoluble phosphates. This opinion +is supported by the fact, that although the chemist has imitated nature +in this matter so far as to manufacture precipitated phosphate, he has +failed, as a rule, in getting as favourable results with it as with +superphosphate. Although the mechanical state of division of the +<span class='pagenum'><a name="Page_394" id="Page_394">[Pg 394]</a></span>manufactured precipitated phosphate is probably as fine as that +obtained by nature from the superphosphate, it is impossible to obtain +so intimate a mixture with the soil-particles, and hence the results +obtained are different. For these reasons it will be easily seen that +the rate of action of the superphosphate must always be quicker than +that of any other form of phosphatic manure. The phosphate is everywhere +distributed in the soil. The plant-roots are thus furnished with a +continuous supply throughout their growth, and micro-organisms, which +require for their development a supply of this necessary plant-food, are +propagated. A regularity in the plant's growth is thus secured, which is +of great importance. But while admitting this, there are many cases in +which this greater quickness of action does not render soluble phosphate +the most economical form. The nature of the crop, as well as the nature +of the soil, may in many cases be such as to render the application of +the cheaper insoluble phosphate more economical. It is imperative that +the early growth of some crops be hastened as much as possible by a +ready supply of easily assimilable plant-food, in order to enable them +to successfully sustain the attack of certain pests to which they are +liable to succumb. This, for example, is notably the case with turnips. +In such a case there can be no doubt that the value of soluble phosphate +to the young plants is very great, as it enables them to survive this +critical period.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_395" id="Page_395">[Pg 395]</a></span><i>Action of Superphosphate sometimes unfavourable.</i></p> + +<p>But even in this case there may be other conditions which render +insoluble phosphate a preferable manure. Such a case is where the soil +is of a very light nature and is deficient in lime. In this case the +acid superphosphate, not having the necessary base to combine with, may +prove even hurtful to the young plants. According to the late Dr +Voelcker, a concentrated superphosphate may produce a smaller crop than +a fertiliser containing only a quarter as much soluble phosphoric acid, +when applied to root-crops on sandy soils, greatly deficient in lime. +Cases such as the above, however, are extremely rare; and we may say +that, in the case of root-crops generally, superphosphate must be +regarded as of special value.</p> + +<br /> +<p class="cen"><i>Application of Superphosphate.</i></p> + +<p>In any case, superphosphate ought to be applied to a soil some time +before it is likely to be assimilated by the plant, in order to allow +neutralisation of its acid character to be fully effected before the +plant's roots come in contact with it. Thus Professor S. W. Johnson, one +of the greatest living American authorities, states it as his opinion +that recent investigations tend to show that soluble and reverted (or +precipitated) phosphates are, upon the whole, about equally valuable as +plant-food, and of nearly equal commercial value. But as Sir John Lawes, +in quoting Professor Johnson <span class='pagenum'><a name="Page_396" id="Page_396">[Pg 396]</a></span>to the above effect, remarks, this opinion +is based on an experience of American agriculture, in which country +soluble phosphate is chiefly applied to cereal crops, while in this +country it is chiefly applied to turnips. In the case of cereal crops, +the importance of a speedy early growth is not so great, as we have +already pointed out, as it is in turnips, where the danger to the young +plants from the ravages of the turnip-fly is such that the growth of +even a day or two may make a very considerable difference.</p> + +<br /> +<p class="cen"><i>Value of Insoluble Phosphate.</i></p> + +<p>A consideration of the action of superphosphate, then, throws a good +deal of light on the conditions which determine the value of insoluble +phosphates when applied to the soil, and shows that the state of +division, intimacy of mixture with soil-particles, and the nature of the +soil, are the determining factors. Insoluble phosphates, as we shall +have occasion to see when discussing basic slag, have their best action +on soils poor in lime and rich in organic matter. Tables have been drawn +up with a view to furnishing a guide for the value of phosphoric acid in +different manures. In the Appendix<a name="FNanchor_232_232" id="FNanchor_232_232"></a><a href="#Footnote_232_232" class="fnanchor">[232]</a> we give those of Wolff for 1893, +and an American table, drawn up for 1892. The comparative values of +mineral phosphates, as well as Peruvian guano and bone-dust, will be +further referred to in the following chapter.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_397" id="Page_397">[Pg 397]</a></span><i>Rate at which Superphosphate is applied.</i></p> + +<p>The rate at which superphosphate is applied to the soil varies in +different parts of the country. In England 2 to 3 cwt. per acre is +considered an average dressing; whereas in many parts of Scotland it is +applied in as large quantities as 6 to 8 cwt. per acre to the turnip +crop. The reason why so much heavier dressings can be advantageously +given in northern parts of this country is owing to the much longer +period of unchecked growth. In the more southern districts, where the +rainfall is less, mildew is almost certain to appear when the sowing is +as early as required for a maximum crop. With it, as with other manures, +the quantity must be determined by the conditions of its application, +and the amount of other manure applied.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_225_225" id="Footnote_225_225"></a><a href="#FNanchor_225_225"><span class="label">[225]</span></a> This holds true, it may be mentioned, with regard to the +application of certain manures, such as bone-char, to the soil. +Bone-char was for a long time used in France as a manure without being +dissolved. The action of such a manure, containing a considerable +percentage of carbonate of lime, is slower than its action would be were +it pure phosphate of lime, as the carbonate of lime is first acted upon +(as in the case of superphosphate manufacture) by the soil acids.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_226_226" id="Footnote_226_226"></a><a href="#FNanchor_226_226"><span class="label">[226]</span></a> The solubility of tribasic phosphate, of course, is not +always equal in different manures. For example, the phosphate in +apatite, owing to the crystalline structure of that mineral, is not +nearly so soluble as the phosphate in phosphatic guanos, although in +both cases its chemical composition is practically the same.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_227_227" id="Footnote_227_227"></a><a href="#FNanchor_227_227"><span class="label">[227]</span></a> For formulæ of the different phosphates, see Appendix, +Note I., p. 398.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_228_228" id="Footnote_228_228"></a><a href="#FNanchor_228_228"><span class="label">[228]</span></a> For chemical formulæ, showing reaction, see Appendix, +Note II., p. 398.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_229_229" id="Footnote_229_229"></a><a href="#FNanchor_229_229"><span class="label">[229]</span></a> Of course it is well known that free phosphoric acid is +obtained by acting upon phosphate of lime with an excess of sulphuric +acid; but the point above referred to as having been recently discovered +is, that when phosphate of lime is acted upon, even by a small quantity +of sulphuric acid, free phosphoric acid is formed.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_230_230" id="Footnote_230_230"></a><a href="#FNanchor_230_230"><span class="label">[230]</span></a> For chemical formulæ showing this reversion, see +Appendix, Note III., p. 399.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_231_231" id="Footnote_231_231"></a><a href="#FNanchor_231_231"><span class="label">[231]</span></a> For chemical theories on reversion of soluble phosphate +by iron and alumina, see Appendix, Note IV., p. 399.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_232_232" id="Footnote_232_232"></a><a href="#FNanchor_232_232"><span class="label">[232]</span></a> See Appendix, Note V., p. 400.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_398" id="Page_398">[Pg 398]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER XIII.</h2> + +<br /> +<p class="cen">NOTE I. (p. 388).</p> + +<p>The formulæ, and molecular and percentage composition, of the different +phosphates, are given in the following table:—</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Name"> + <tr> + <td class="tdltb" rowspan="2" colspan="2"> </td> + <td class="tdctlb" colspan="7">Composition in terms of—</td> + </tr> + <tr> + <td class="tdcl" colspan="4">Molecular weight.</td> + <td class="tdcl" colspan="3">Per cent.</td> + </tr> + <tr> + <td class="tdc" style="border-bottom: .5pt black solid;" width="20%">Name.</td> + <td class="tdclb" width="25%">Symbol.</td> + <td class="tdctlb" width="7%">Lime.</td> + <td class="tdctlb" width="7%">Water.</td> + <td class="tdctlb" width="10%">Phosphoric acid.</td> + <td class="tdctlb" width="7%">Total.</td> + <td class="tdctlb" width="7%">Lime.</td> + <td class="tdctlb" width="7%">Water.</td> + <td class="tdctlb" width="10%">Phosphoric acid.</td> + </tr> + <tr> + <td class="tdl">Tri- or bone-phosphate.</td> + <td class="tdll" style="vertical-align: bottom;">3CaO, P<sub>2</sub>O<sub>5</sub></td> + <td class="tdcly">168</td> + <td class="tdcly"> 0</td> + <td class="tdcly">142</td> + <td class="tdcly">310</td> + <td class="tdcly">54.19</td> + <td class="tdcly"> 0.00</td> + <td class="tdcly">45.81</td> + </tr> + <tr> + <td class="tdl">Bi- or di-phosphate.</td> + <td class="tdll" style="vertical-align: bottom;">2CaO, H<sub>2</sub>O<sub>5</sub></td> + <td class="tdcly">112</td> + <td class="tdcly">18</td> + <td class="tdcly">142</td> + <td class="tdcly">272</td> + <td class="tdcly">41.18</td> + <td class="tdcly"> 6.61</td> + <td class="tdcly">52.21</td> + </tr> + <tr> + <td class="tdlb">Mono- or super-phosphate.</td> + <td class="tdllb" style="vertical-align: bottom;">CaO, 2H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub></td> + <td class="tdcly" style="border-bottom: .5pt black solid;"> 56</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">36</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">142</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">234</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">23.93</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">15.39</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">60.68</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE II. (p. 388).</p> + +<p>When sulphuric acid is added to tricalcic phosphate, the following +reaction takes place:—</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Water"> + <tr> + <td class="tdl" width="10%">(1.)</td> + <td class="tdc" width="40%">3CaO, P<sub>2</sub>O<sub>5</sub></td> + <td class="tdc" width="10%">+</td> + <td class="tdc" width="40%">2(H<sub>2</sub>O, SO<sub>3</sub>)</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">(Tricalcic phosphate),</td> + <td class="tdc"> </td> + <td class="tdc">(Sulphuric acid),</td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl">=</td> + <td class="tdc">2(CaO, SO<sub>3</sub>)</td> + <td class="tdc">+</td> + <td class="tdc">CaO, 2H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">(Gypsum)</td> + <td class="tdc"> </td> + <td class="tdc">(Monocalcic phosphate).</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">(2.) 3CaO, P<sub>2</sub>O<sub>5</sub> + 3(H<sub>2</sub>O, SO<sub>3</sub>) = 3CaO, SO<sub>3</sub> + + 3H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub>, or 2H<sub>3</sub>PO<sub>4</sub>.</p> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_399" id="Page_399">[Pg 399]</a></span>NOTE III. (p. 390).</p> + +<p>This equation gives the chemical reaction taking place when soluble +phosphate is reverted, owing to the presence of undissolved +phosphate:——</p> + +<div class="centered"> +<table border="0" width="60%" cellpadding="2" cellspacing="0" summary="Tricalcic"> + <tr> + <td class="tdl" width="10%"> </td> + <td class="tdc" width="40%">3CaO, P<sub>2</sub>O<sub>5</sub></td> + <td class="tdc" width="10%">+</td> + <td class="tdc" width="40%">CaO,2H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">(Tricalcic phosphate),</td> + <td class="tdc"> </td> + <td class="tdc">Monocalcic phosphate,</td> + </tr> + <tr> + <td class="tdl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl">=</td> + <td class="tdc">2CaO, H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub></td> + <td class="tdc">+</td> + <td class="tdc">2CaO, H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">(Dicalcic phosphate),</td> + <td class="tdc"> </td> + <td class="tdc">(Dicalcic phosphate).</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen">NOTE IV. (p. 390).</p> + +<p>"Just what the reactions are which are produced by the iron and alumina +compounds has never been made out very clearly. But some idea of them +may be gained from the following suggestions, which were thrown out by +the English chemist Patterson. Suppose the sulphuric acid has dissolved +a quantity of iron or alumina, then we may have the reaction:——</p> + +<p class="cen">Fe<sub>2</sub>O<sub>3</sub>, 3SO<sub>3</sub> + CaO, 2H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub> = Fe<sub>2</sub>O<sub>3</sub>, +P<sub>2</sub>O<sub>5</sub> + CaO, SO<sub>3</sub> + 2(H<sub>2</sub>O, SO<sub>3</sub>),</p> + +<p>and the free acid thus formed would proceed to dissolve more iron or +alumina from the rock that had previously escaped decomposition, and the +reaction here formulated would occur again and again. Here we have a +cumulative process continually increasing the quantity of insoluble +Fe<sub>2</sub>O<sub>3</sub>, P<sub>2</sub>O<sub>5</sub>, and diminishing in the same proportion the +soluble P<sub>2</sub>O<sub>5</sub>. Again, we may have simply——</p> + +<p class="cen">2Fe<sub>2</sub>O<sub>3</sub> + 3(CaO, 2H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub>) = 2(Fe<sub>2</sub>O<sub>3</sub>, P<sub>2</sub>O<sub>5</sub>) ++ 3CaO, P<sub>2</sub>O<sub>5</sub>;</p> + +<p>where three molecules of the soluble phosphoric acid are made to revert +to the insoluble state at one blow.</p> + +<p>"In case the iron in the original rock were in the state <span class='pagenum'><a name="Page_400" id="Page_400">[Pg 400]</a></span>of ferrous +oxide, perhaps the following reaction might occur:——</p> + +<p class="cen">4(FeO, SO<sub>3</sub>) + 2O + CaO, 2H<sub>2</sub>O, P<sub>2</sub>O<sub>5</sub> + 3CaO, P<sub>2</sub>O<sub>5</sub> = +2(Fe<sub>2</sub>O<sub>3</sub>, P<sub>2</sub>O<sub>5</sub>) + 4(CaO, SO<sub>3</sub>).</p> + +<p>In all these equations, except the last, alumina would serve as well as +oxide of iron."—(<i>Vide</i> Storer's 'Agricultural Chemistry,' vol. i. pp. +276, 277.)</p> + +<br /> +<br /> +<p class="cen">NOTE V. (p. 396).</p> + +<p>The following table shows the relative trade values of phosphoric acid +in different manures:—</p> +<br /> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Precipitated"> + <tr> + <td class="tdc" colspan="2">I.—<span class="smcap">Wolff</span>, 1893.</td> + </tr> + <tr> + <td class="tdl" width="90%">Phosphate soluble in water (as in super)</td> + <td class="tdr" width="10%">100</td> + </tr> + <tr> + <td class="tdl">Precipitated phosphate, Peruvian guano</td> + <td class="tdr">92</td> + </tr> + <tr> + <td class="tdl">Reverted phosphate, finest steamed bone-dust fish-guano, poudrette</td> + <td class="tdr">83</td> + </tr> + <tr> + <td class="tdl">Phosphatic guanos (Baker Island), wood-ashes</td> + <td class="tdr">75</td> + </tr> + <tr> + <td class="tdl">Coarser bone-dust, powdered animal charcoal, bone-ash</td> + <td class="tdr">67</td> + </tr> + <tr> + <td class="tdl">Coarse fragments of bone, powdered phosphorite and coprolite, Thomas-slag, + farmyard manure</td> + <td class="tdrb">33</td> + </tr> + <tr> + <td class="tdl" colspan="2"> </td> + </tr> + <tr> + <td class="tdc" colspan="2">II.—<span class="smcap">American</span>, 1892.</td> + </tr> + <tr> + <td class="tdl">Phosphate soluble in water</td> + <td class="tdr">100</td> + </tr> + <tr> + <td class="tdl">Phosphate soluble in ammonium citrate</td> + <td class="tdr">94</td> + </tr> + <tr> + <td class="tdl">Fine bone-dust, powdered fish</td> + <td class="tdr">94</td> + </tr> + <tr> + <td class="tdl">Fine medium bone</td> + <td class="tdr">74</td> + </tr> + <tr> + <td class="tdl">Medium bone</td> + <td class="tdr">60</td> + </tr> + <tr> + <td class="tdl">Coarse bone</td> + <td class="tdr">40</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_401" id="Page_401">[Pg 401]</a></span> +<br /> +<h2>CHAPTER XIV.</h2> + +<h2>THOMAS-PHOSPHATE OR BASIC SLAG.</h2> +<br /> + +<p>In this substance we have a most important addition to our phosphatic +manures. It has been in the market since 1886, and the consumption alone +in Germany in 1887 amounted to nearly 300,000 tons. In this country it +is only now beginning to be used to any extent.</p> + +<br /> +<p class="cen"><i>Its Manufacture.</i></p> + +<p><i>Thomas-slag</i> is a bye-product obtained in the manufacture of steel by +what is known as the "basic" process. In the year 1879 an improvement in +the well-known "Bessemer" process was patented by Messrs Gilchrist & +Thomas. It must be explained that in the manufacture of steel from +pig-iron certain impurities in the raw material have to be got rid of in +order to produce a good steel. Among these impurities one of the most +important is <i>phosphorus</i>. This is owing to the fact that even a very +small percentage of phosphoric acid in steel has the effect of +<span class='pagenum'><a name="Page_402" id="Page_402">[Pg 402]</a></span>rendering it brittle. The extraction of the phosphorus from the raw +material was formerly, however, attended with very serious difficulties, +and had the effect naturally of rendering steel a costly article, +inasmuch as only the purer kinds of pig-iron could be used for the +purpose.</p> + +<p>By the introduction in 1879, however, of the "Thomas-Gilchrist" or +"basic" process, these difficulties were very largely overcome, and the +employment of even such impure irons as the Cleveland (containing +comparatively a large percentage of phosphorus) was rendered possible, +and the price of steel consequently generally very much reduced. The +process consists of submitting the molten pig-iron to a very great heat +in a pear-shaped vessel (known technically as the "converter"). This is +open at the top, and is supported on hinges, which permit of its being +moved so as to pour off the scum which rises to the surface at the end +of the operation, and which, we may explain, consists of "basic slag." +In the original process the sides of the "converter" were lined with +fire-bricks, consisting largely of silica. This process was known as the +"acid" process. In the "Thomas-Gilchrist" process, however, the sides of +the "converter" are lined with <i>lime</i> (dolomitic limestone being largely +used), lime being also added to the pig-iron. An air-blast is injected +through the molten mass, and the impurities are burnt, or oxidised as it +is chemically termed. The phosphorus in the <span class='pagenum'><a name="Page_403" id="Page_403">[Pg 403]</a></span>iron is thus converted into +phosphoric acid, and, uniting with the lime, forms phosphate of lime, +which rises, as we have already said, to the surface in the form of a +scum, and is separated from the steel by being poured off.</p> + +<br /> +<p class="cen"><i>Not at first used.</i></p> + +<p>This, then, is how the <i>Thomas-slag</i> is obtained. It did not seem, +however, for some years after the introduction of this ingenious +process, to have struck any one that this rich phosphatic bye-product +might prove a valuable addition to our artificial fertilisers. The +result was, that the Thomas-slag was treated as another of the only too +numerous valueless bye-products which seem to be necessarily incidental +to most of our chemical and other manufactures, and was allowed to +accumulate in large quantities without being used for any purpose.</p> + +<br /> +<p class="cen"><i>Discovery of its Value.</i></p> + +<p>In 1883 some short articles published in Germany on the subject were the +means of first drawing the attention of the public to its importance as +a manure. During the years 1884 and 1885 numerous experiments were +carried out on the subject in the same country; and from then up till +the present hour it has become more and more extensively used in +Germany, till in 1887, as already stated, its consumption amounted to +nearly 300,000 tons.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_404" id="Page_404">[Pg 404]</a></span><i>Composition.</i></p> + +<p>It consists mainly of phosphate of lime, silicate of lime, free lime, +free magnesia, and oxides of iron and manganese. Its composition, of +course, naturally varies; but the following may be taken as an average +analysis:<a name="FNanchor_233_233" id="FNanchor_233_233"></a><a href="#Footnote_233_233" class="fnanchor">[233]</a>—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Precipitated"> + <tr> + <td class="tdc" width="2%"> </td> + <td class="tdl" width="86%"> </td> + <td class="tdc" width="12%">Per cent.</td> + </tr> + <tr> + <td class="tdc">*</td> + <td class="tdl">Phosphoric acid</td> + <td class="tdc">17</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Lime in combination with phosphoric, silicic, sulphuric, and carbonic acids</td> + <td class="tdc" style="vertical-align: bottom;">40</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Free lime</td> + <td class="tdc">15</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdl">Oxides of iron</td> + <td class="tdc">12</td> + </tr> + <tr> + <td class="tdc">*</td> + <td class="tdl">Equal to tricalcic phosphate</td> + <td class="tdc">37</td> + </tr> +</table> +</div> + +<p>As a rule, the phosphoric acid varies considerably, ranging from 10 to +20 per cent—that is, from 22 to 44 per cent tricalcic phosphate. This +is owing to the difference in the percentage of phosphorus in the raw +material and the quantity of lime added. Attempts have been made in +Germany during the last two or three years to obtain a slag richer in +phosphoric acid than that obtained heretofore, and a process for this +purpose has been patented by Professor Scheibler. This consists of a +slight modification in the ordinary process. Instead of treating the +pig-iron with an excessive quantity of lime, the amount added is not +sufficient to effect the complete dephosphorisation of the iron. The +resulting slag is very rich in phosphoric acid, and is correspondingly +poor in iron. The <span class='pagenum'><a name="Page_405" id="Page_405">[Pg 405]</a></span>iron is then again treated with fresh lime, and the +phosphorus completely removed, while the same lime may be used over +again. Such slag forms a very much more concentrated phosphatic manure +than the ordinary slag, and is known as <i>patent phosphate meal</i>.</p> + +<p>A point which not only renders the slag a product of peculiar interest +from a chemical point of view, but has a most important bearing on its +value as a manure, is the nature of the compound formed by the union of +the lime with the phosphoric acid.</p> + +<p>In the ordinary so-called raw phosphates, such as bone-meal, bone-ash, +coprolites, &c., the lime and phosphoric acid are combined in the form +of what is known, in chemical phraseology, as <i>tribasic phosphate of +lime</i>. That is to say, that for every equivalent of phosphoric acid +there are three equivalents of lime. Now it was naturally concluded at +first that the tribasic phosphate was the form in which these two +substances existed in the slag. This, however, was found out not to be +the case, in the following way. On allowing the slag to cool, it was +found that small but perfectly defined crystals were formed. These +crystals, by careful analysis, were shown, first by Hilgenstock, to +consist of a form of phosphate of lime hitherto unknown, in which four +equivalents of lime were combined with one equivalent of phosphoric +acid, and which was therefore called "tetrabasic phosphate."</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_406" id="Page_406">[Pg 406]</a></span><i>Processes for preparing Slag.</i></p> + +<p>As soon as the idea of utilising the slag as a manure was suggested, +various plans for extracting its phosphoric acid, and rendering it +available as plant-food, were devised. These were deemed necessary, it +was thought, by the very insoluble nature of the phosphates in the slag, +as well as by the supposed injurious action which would be exerted on +plant-life by the protoxide of iron it contained. Accordingly, a large +number of patents were taken out, "covering almost every conceivable +method for treating the slag, whether practicable or not. They all in +the main are combinations or variations of the following processes:—</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Precipitated"> + <tr> + <td class="tdr">"1.</td> + <td class="tdl" colspan="2"><i>Preliminary preparation of the Slag.</i></td> + </tr> + <tr> + <td class="tdl" width="5%"> </td> + <td class="tdlz" width="5%">(<i>a</i>)</td> + <td class="tdl" width="90%"> By treating molten, or otherwise, with superheated steam, or + cooling when hot with water, to reduce it to small pieces or to a fragile state.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">(<i>b</i>)</td> + <td class="tdl">Grinding.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">(<i>c</i>)</td> + <td class="tdl">Treating with water to wash out free lime, or with sugar solution.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">(<i>d</i>)</td> + <td class="tdl">Roasting in the air, or with some oxidising agent.</td> + </tr> + <tr> + <td class="tdr">"2.</td> + <td class="tdl" colspan="2"><i>Solution of the Slag.</i></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">(<i>a</i>)</td> + <td class="tdl"><i>Completely</i> in weak or strong acids (hydrochloric, sulphuric, &c.)</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdlz">(<i>b</i>)</td> + <td class="tdl"><i>Partially</i>, so as to dissolve the phosphates <span class='pagenum'><a name="Page_407" id="Page_407">[Pg 407]</a></span>and silicates of + lime, and leave most of the iron and manganese oxides.</td> + </tr> + <tr> + <td class="tdr">"3.</td> + <td class="tdl" colspan="2"><i>Precipitation</i> of the phosphoric acid, with lime or iron + salts: or,</td> + </tr> +</table> +</div> + +<p>"Processes in which the slag is smelted with charcoal, +to reduce phosphates to phosphides, treated with +acid, and the phosphuretted hydrogen burnt to phosphoric +acid; and,</p> + +<p>"Processes in which the slag is fused with soda or +potash salts,—caustic, chlorides, sulphates, carbonates,—with +or without steam being forced through, to form soluble alkaline +phosphates."<a name="FNanchor_234_234" id="FNanchor_234_234"></a><a href="#Footnote_234_234" class="fnanchor">[234]</a> +</p> + +<p>Many of these processes were tried; but it was found by experiment that +the best and most economical way was by applying the slag direct to the +ground in a state of very fine powder. Experiments further showed that +it had <i>not</i> the injurious effect on vegetation which it was feared it +would have from the protoxide of iron it contained. The discovery that +its phosphoric acid existed, as has been already explained, as a +tetrabasic phosphate of lime, has strengthened the opinion that this is +the best method of application.</p> + +<p>A good deal has been found to depend upon the fineness of the ground +slag, with the result that it is now commonly sold on a mechanical as +well as a <span class='pagenum'><a name="Page_408" id="Page_408">[Pg 408]</a></span>chemical analysis—<i>i.e.</i>, the slag is guaranteed to pass +through a sieve of a certain fineness.</p> + +<br /> +<p class="cen"><i>Solubility of Slag.</i></p> + +<p>Professor Wagner of Darmstadt has carried out some extremely interesting +experiments on the solubility of slag. He found that very finely +powdered slag was dissolved in carbonic acid water to the extent of 36 +per cent, while, similarly treated, phosphorite only dissolved to the +extent of 8 per cent.<a name="FNanchor_235_235" id="FNanchor_235_235"></a><a href="#Footnote_235_235" class="fnanchor">[235]</a> Another very important solvent is <i>citrate of +ammonia</i>. Reverted (or precipitated) phosphate is entirely soluble in +it, and phosphate soluble in it ought to be valued as worth more than +that which is not. Now, the solubility of Thomas-slag in citrate of +ammonia was found by Professor Wagner to be no less than 74 per cent, +while that of phosphorite only amounted to 4 per cent. These results +were corroborated by Professor S. W. Johnson, who found that of the +19.87 per cent of phosphoric acid contained in a sample of basic slag, +no less than 19.57 per cent was soluble in ammonium citrate, while a +finely ground sample of phosphatic rock yielded, on analysis, only 1.81 +per cent soluble in citrate of ammonia, of a total of 29.49 per cent +phosphoric acid which it contained. Professor Fleischer has also tested +the comparative solubility of basic slag and phosphorite, by boiling +<span class='pagenum'><a name="Page_409" id="Page_409">[Pg 409]</a></span>them in a solution of acetic acid. The former was found to have been +dissolved to the extent of 19 per cent, while the latter to only 5 per +cent. A highly interesting and most important experiment was performed +by Mr Heinrich Albert, of Biebrich. One gramme of basic slag and 100 +grammes of peat were mixed together in a litre of water, and it was +found that, after standing for fourteen days, 79 per cent of the +phosphoric acid contained in the slag was rendered soluble.</p> + +<p>In the above experiments it was found that the <i>fineness of grinding</i> +had a marked effect on the solubility of the slag, and that the finer it +was ground the greater was its solubility. This has been further +demonstrated in Professor Wagner's practical experiments. From these it +was found that finely ground slag has an action <i>four times</i> as quick as +coarse slag; but that, as far as practical results were concerned, there +seemed to be a limit to the fineness to which it was advisable to grind +the slag, as slag above a certain fineness did not give better results +than a coarser slag. At any rate, he found that slag of a fineness so +great that it all passed through a gauze sieve, gave no better results +in his experiments than slag which left 17 per cent behind. We may say, +however, that the <i>finer the slag is ground, the greater will its +activity as a manure be</i>; and that a certain degree of fineness is +absolutely necessary to constitute it an active fertiliser. As +<span class='pagenum'><a name="Page_410" id="Page_410">[Pg 410]</a></span>Professor Wagner's experiments are among the most valuable and complete +carried out on basic slag, we shall give a somewhat detailed account of +them.</p> + +<br /> +<p class="cen"><i>Darmstadt Experiments.</i></p> + +<p>Professor Wagner's experiments were carried out on such different kinds +of crops as flax, rape, wheat, rye, barley, peas, and white mustard, and +the object of the experiments was to ascertain the comparative activity +as fertilisers of superphosphate, basic slag of different degrees of +fineness, Peruvian guano, damped bone-meal, and very finely ground +coprolites. In order to obtain a correct estimate of the relative value +of these different forms of phosphatic manures, it was necessary to +render the nitrogen in the bone-meal and the nitrogen and potash +contained by the Peruvian guano inactive—<i>i.e.</i>, to limit the test +strictly to phosphoric acid. This was done by adding to the super, basic +slag, and coprolites, quantities of nitrogen and potash equal to those +contained by the other manures. There was further added to all the +experiments (the unmanured ones, of course, as well) an excess of +nitrogen and potash. In this way the increase in returns could only be +due to the phosphoric acid.</p> + +<p>The general results obtained from these experiments may be summed up as +follows: Taking the activity of "super" to be represented by 100, then +the relative activity of—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Peruvian"> + <tr> + <td class="tdl" width="90%"><span class='pagenum'><a name="Page_411" id="Page_411">[Pg 411]</a></span>Basic slag of No. 1<a name="FNanchor_236_236" id="FNanchor_236_236"></a><a href="#Footnote_236_236" class="fnanchor">[236]</a> fineness is</td> + <td class="tdr" width="10%">61</td> + </tr> + <tr> + <td class="tdl">Basic slag, No. 2<a name="FNanchor_237_237" id="FNanchor_237_237"></a><a href="#Footnote_237_237" class="fnanchor">[237]</a></td> + <td class="tdr">58</td> + </tr> + <tr> + <td class="tdl">Peruvian guano</td> + <td class="tdr">30</td> + </tr> + <tr> + <td class="tdl">Basic slag, No. 3<a name="FNanchor_238_238" id="FNanchor_238_238"></a><a href="#Footnote_238_238" class="fnanchor">[238]</a></td> + <td class="tdr">13</td> + </tr> + <tr> + <td class="tdl">Bone-meal</td> + <td class="tdr">10</td> + </tr> + <tr> + <td class="tdl">Coprolites</td> + <td class="tdr">9</td> + </tr> +</table> +</div> + +<p>From these results the value of the commercial article has been +attempted to be ascertained. As it contains 80 per cent or thereby of +fine meal and 20 per cent of coarse, its activity may be stated to be +50, or half as active as super. Thus 2 cwt. of basic slag is equal to 1 +cwt. of super. This only refers to the first year's effect. Professor +Wagner has made further experiments as to the after-effects of the +different manures, with the result that he has found that the +after-effects of the basic slag are even <i>better</i> than those of the +"super." This stands to reason, for if twice as much phosphoric acid be +added in the form of basic slag as is added in the form of "super," and +the effect of the first year is similar—that is, the same quantity of +phosphoric acid is assimilated by the plant from the soil in both +cases—there is naturally more phosphoric acid left behind in the soil +manured with basic slag than in that manured with superphosphate of +lime. For example, if 100 lb. of super has the same effect in the first +year as 200 lb. <span class='pagenum'><a name="Page_412" id="Page_412">[Pg 412]</a></span>of basic slag, and it is found that only 60 lb. of the +super and the basic slag have been assimilated the first year by the +plant, it is only natural to conclude that the remaining 140 lb. of the +basic slag will have a better after-effect than the remaining 40 lb. of +super. This has been actually proved to have been the case in +Professor's Wagner's experiments. The following are the results of some +experiments which Professor Wagner has carried out on the after-effects +of different manures:—</p> + +<p>Out of 100 parts of phosphoric acid, there was removed by the first +year's crop—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Peruvian"> + <tr> + <td class="tdl" width="90%">Super</td> + <td class="tdr" width="10%">63</td> + </tr> + <tr> + <td class="tdl">Peruvian guano</td> + <td class="tdr">22</td> + </tr> + <tr> + <td class="tdl">Bone-meal</td> + <td class="tdr">7</td> + </tr> + <tr> + <td class="tdl">Coprolites</td> + <td class="tdr">6</td> + </tr> + <tr> + <td class="tdl">Thomas-meal—</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> No. 1 fineness</td> + <td class="tdr">39</td> + </tr> + <tr> + <td class="tdl"> No. 2 fineness</td> + <td class="tdr">43</td> + </tr> + <tr> + <td class="tdl"> No. 3. fineness</td> + <td class="tdr">15</td> + </tr> +</table> +</div> + +<p>Out of 100 parts of phosphoric acid left by the first crop, there was +removed by the three succeeding crops—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Peruvian"> + <tr> + <td class="tdl" width="90%">Super</td> + <td class="tdr" width="10%">30</td> + </tr> + <tr> + <td class="tdl">Peruvian guano</td> + <td class="tdr">9</td> + </tr> + <tr> + <td class="tdl">Bone-meal</td> + <td class="tdr">13</td> + </tr> + <tr> + <td class="tdl">Coprolites</td> + <td class="tdr">6</td> + </tr> + <tr> + <td class="tdl">Thomas-meal—</td> + <td class="tdr"> </td> + </tr> + <tr> + <td class="tdl"> No. 1 fineness</td> + <td class="tdr">14</td> + </tr> + <tr> + <td class="tdl"> No. 2 fineness</td> + <td class="tdr">29</td> + </tr> + <tr> + <td class="tdl"> No. 3 fineness</td> + <td class="tdr">24</td> + </tr> +</table> +</div> + +<p>Numerous other experiments have been carried out <span class='pagenum'><a name="Page_413" id="Page_413">[Pg 413]</a></span>by various +experimenters in different parts of Germany which it is unnecessary to +cite here. None, however, are so complete as those of Professor Wagner.</p> + +<br /> +<p class="cen"><i>Results of other Experiments.</i></p> + +<p>In this country experiments have been carried out at Rothamsted, +Cirencester, Downton, Bangor, and by Dr Aitken at the Highland and +Agricultural Society's stations, as well as elsewhere. The results of +these various experiments naturally differ considerably, this being +owing to the difference in the nature of the soils upon which the +experiments were carried out, as well as the different degrees of +fineness of the slag used. They all, however, serve to confirm Professor +Wagner's general results. The results obtained in Scotland by Dr Aitken +at the Highland Society's stations were especially favourable to basic +slag as a phosphatic manure. The experiments were carried out on +turnips, and it was found that the Thomas-slag was, weight for weight, +superior to superphosphate. It may be added that the slag used in these +experiments was rich in phosphoric acid, and was in an unusually fine +state of division. Experiments carried out by the author have proved +slag to be, on various Scottish soils, one of the most economical +phosphatic manures to apply to turnips.<a name="FNanchor_239_239" id="FNanchor_239_239"></a><a href="#Footnote_239_239" class="fnanchor">[239]</a></p> + +<p>We will sum up, in conclusion, the deductions <span class='pagenum'><a name="Page_414" id="Page_414">[Pg 414]</a></span>which may be fairly drawn +from the results of all the above-mentioned experiments as to the value +of basic cinder as a manure.</p> + +<br /> +<p class="cen"><i>Soils most suited for Slag.</i></p> + +<p>Although its action is undoubtedly more favourable on some soils than +others, it may be broadly stated that generally its phosphoric acid is +<i>half as valuable</i> as that in soluble phosphate. The soils on which it +will have the most marked effect will be those of a <i>peaty</i> nature, +<i>poor</i> in lime, but <i>rich</i> in <i>organic matter</i>. The beneficial results +obtained by an application of lime to peaty soils are well known. As the +slag contains a large percentage of free lime, it thus performs on such +soils a double function. On meadow-lands, all kinds of pasture-lands (if +not of too dry a character), and clay soils poor in lime, its action has +been shown to be especially favourable. Of different kinds of crops, +those best suited to benefit from the slag as a phosphatic manure are +those of the leguminous kind. This arises from the fact that their +period of growth is longer than that of most other crops.</p> + +<br /> +<p class="cen"><i>Rate of Application.</i></p> + +<p>As to the rate per acre at which the slag ought to be applied, there +will naturally be a difference of opinion. Professor Wrightson, of +Downton Agricultural College, recommends that it should be applied at +the rate of from 6 to 10 cwt. per acre. This, of course, is very +<span class='pagenum'><a name="Page_415" id="Page_415">[Pg 415]</a></span>liberal manuring. We must remember, however, that phosphatic manures, +unlike nitrogenous manures, and to some extent potash manures, may be +applied in even excessive quantities without any risk of loss. It is +impossible to measure out our phosphate manures in the same accurate +manner as we measure out our nitrogen. It is safer, therefore, and on +that account more economical in the long-run, to apply our phosphate in +excessive quantity than the reverse. The reason of this may be shortly +explained. The phosphoric acid which is naturally present in most soils +is with difficulty soluble. Only a small quantity is yielded daily to +the plant. This quantity may, under favourable climatic conditions, be +sufficient; but these favourable influences never last very long at a +time.</p> + +<p>For three weeks, perhaps, the plant may experience drought, and during +this period it takes up no phosphoric acid, and its growth practically +comes to a standstill; but this period of drought is followed by rain +and warm weather, and the plant, if it is to be ripe by harvest-time, +must make up for lost time. It must grow as much the next few days under +these favourable climatic conditions as it would have grown under normal +conditions in double or treble the time. In order to do so, however, it +must be able to obtain plenty of phosphoric acid, and this is only +possible where there is a decided excess of phosphoric acid present in +the soil.</p> + +<p>The richness of a soil, therefore, in phosphoric acid, <span class='pagenum'><a name="Page_416" id="Page_416">[Pg 416]</a></span>must be such +that it is not only able to supply the ordinary wants of the plant, but +to provide an excess when such an excess will be needed; for one must +remember that the amount of plant-substance formed in the course of a +few days under favourable conditions is very great, and that the amount +consequently of phosphoric acid which plants assimilate during that +period must also be very considerable.</p> + +<br /> +<p class="cen"><i>Method of Application.</i></p> + +<p>In conclusion, as to the method of application of the slag, +agriculturists must be <i>warned against mixing it with sulphate of +ammonia</i>; for if this is done, a <i>considerable loss of ammonia</i> will +ensue, set free from the sulphate by the action of the free lime which +the Thomas-slag contains. With nitrate of soda and potash salts it may +be freely mixed. Such mixtures, however, are apt to form themselves into +little balls, which soon become very hard. They should therefore only be +mixed shortly before use. To overcome this difficulty, Professor Wagner +recommends the mixture of a little peat or sawdust with the slag.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_233_233" id="Footnote_233_233"></a><a href="#FNanchor_233_233"><span class="label">[233]</span></a> See Appendix, p. 417.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_234_234" id="Footnote_234_234"></a><a href="#FNanchor_234_234"><span class="label">[234]</span></a> <i>Vide</i> paper on "Basic Slag: Its Formation." By Stead and +Ribsdale. 'Journal of the Iron and Steel Institute,' 1887, p. 230.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_235_235" id="Footnote_235_235"></a><a href="#FNanchor_235_235"><span class="label">[235]</span></a> <i>Vide</i> Professor Wagner's pamphlet, 'Der Düngewerth und +die rationelle Verwendung der Thomas Schlacke,' Darmstadt, 1888.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_236_236" id="Footnote_236_236"></a><a href="#FNanchor_236_236"><span class="label">[236]</span></a> No. 1 fineness was such as passed entirely through a fine +gauze sieve of 250 wires to the linear inch.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_237_237" id="Footnote_237_237"></a><a href="#FNanchor_237_237"><span class="label">[237]</span></a> No. 2 fineness was such as passed entirely through the +regular standard sieve—<i>i.e.</i>, containing 120 wires to the linear +inch.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_238_238" id="Footnote_238_238"></a><a href="#FNanchor_238_238"><span class="label">[238]</span></a> No. 3 was what would not pass through the standard +sieve.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_239_239" id="Footnote_239_239"></a><a href="#FNanchor_239_239"><span class="label">[239]</span></a> 'Transactions of the Highland and Agricultural Society,' +1891; 'Chemical News,' 1893.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_417" id="Page_417">[Pg 417]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER XIV.</h2> +<br /> + +<p class="cen">NOTE (p. 404).</p> + +<p>For those more particularly interested, we append a full analysis of the +slag, taken from Messrs Stead and Ribsdale's paper in the 'Journal of +the Iron and Steel Institute,' 1887, vol. i. p. 222:—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="iron"> + <tr> + <td class="tdl" width="90%">Lime</td> + <td class="tdr" width="10%">41.58</td> + </tr> + <tr> + <td class="tdl">Magnesia</td> + <td class="tdr">6.14</td> + </tr> + <tr> + <td class="tdl">Alumina</td> + <td class="tdr">2.57</td> + </tr> + <tr> + <td class="tdl">Peroxide of iron</td> + <td class="tdr">8.54</td> + </tr> + <tr> + <td class="tdl">Protoxide of iron</td> + <td class="tdr">13.62</td> + </tr> + <tr> + <td class="tdl">Protoxide of manganese</td> + <td class="tdr">3.79</td> + </tr> + <tr> + <td class="tdl">Protoxide of vanadium</td> + <td class="tdr">1.29</td> + </tr> + <tr> + <td class="tdl">Silica</td> + <td class="tdr">7.38</td> + </tr> + <tr> + <td class="tdl">Sulphur }</td> + <td class="tdr">.23</td> + </tr> + <tr> + <td class="tdl">Calcium }</td> + <td class="tdr">.31</td> + </tr> + <tr> + <td class="tdl">Sulphuric anhydride</td> + <td class="tdr">.12</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdr"><span style="text-decoration: underline;">14.36</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdr">99.93</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_418" id="Page_418">[Pg 418]</a></span> +<br /> +<h2>CHAPTER XV.</h2> + +<h2>POTASSIC MANURES.</h2> + +<br /> +<p class="cen"><i>Relative Importance.</i></p> + +<p>In Chapter VI. we pointed out that of the three manurial ingredients +potash was the one most abundantly occurring, and that, consequently, +the necessity of adding it in the form of an artificial manure existed +less frequently than in the case of nitrogen or phosphoric acid. It was +further pointed out that, under the ordinary conditions of agriculture, +a greater restoration to the soil of the potash removed in the crops was +made in the straw used in farmyard manure than was the case with regard +to the other two ingredients. Despite these facts, there are many cases +where the addition of potassic manures is of the highest importance in +increasing plant-growth. It will be well, therefore, to devote a little +space to considering our different potassic manures and their respective +action.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_419" id="Page_419">[Pg 419]</a></span><i>Scottish Soils supplied with Potash.</i></p> + +<p>Potassic manures are not so valuable in this country since experience +has shown that most Scottish soils are abundantly supplied with this +manurial ingredient. Moreover, under the conditions of most European +farming, there seems to be a steady gain to the soil of potash. In +America, however, the action of potash as a manure seems to be more +strikingly illustrated. Indeed, wherever forage crops or straw are sold +off the farm in large quantities, or where beets, cabbages, carrots, +potatoes, onions, &c., are also grown in large quantities, the necessity +for potash manuring generally arises.</p> + +<br /> +<p class="cen"><i>Sources of Potassic Manures.</i></p> + +<p>The value of potash as a manure first came to be recognised from the +favourable action of wood-ashes. Of course their favourable action is +not due solely to potash, as they contain, in addition to the other ash +ingredients of the plant, phosphates; and their value as a manure may +also be said to depend not a little on their indirect action. They +contain a certain percentage of caustic alkali, which promotes the +decomposition of the nitrogenous matter of the soil. But making due +allowance for these other valuable properties, the chief value of +wood-ashes is undoubtedly due to the potash they contain. Hence the use +of the commercial article called <i>potash</i>, which is a <span class='pagenum'><a name="Page_420" id="Page_420">[Pg 420]</a></span>mixture of +potassium carbonate and hydrate, and which is obtained from wood-ashes, +was formerly common to a considerable extent as a manure, especially for +clover. <i>Barilla</i>, a rich potassic manure prepared by burning certain +strand plants, especially the saltwort, was also in the past largely +exported from Sicily and Spain. <i>Kelp</i>, a product got by burning +sea-weed in Scotland, is also a rich potassic manure. Since, however, +the discovery of the Stassfurt mines, all potassic manures have come +from these.</p> + +<br /> +<p class="cen"><i>Stassfurt Potash Salts.</i></p> + +<p>Huge salt deposits exist at Stassfurt in Germany. They have been formed +by the evaporation of an inland sea. Salt was first discovered in these +deposits in 1839, but for long the presence of potash salts was little +suspected, and it was not until 1862 that the potash salts were worked. +We have already, in the Appendix to Chapter VI., given a list of the +chief potash minerals occurring in the Stassfurt deposits. These +minerals are found in layers, the lowest layer consisting of almost pure +salt; while immediately above this we have a layer of salt mixed with +the mineral polyhallite (containing potassium sulphate) of about 100 +feet thick. Above this last layer there is a layer of about 90 feet, +containing kieserite (magnesium sulphate) mixed with potassium and +magnesium chlorides; and above this again is a layer (90 feet) of +carnallite, which furnishes the <span class='pagenum'><a name="Page_421" id="Page_421">[Pg 421]</a></span>chief source of the potash salts used +for manurial purposes.</p> + +<p>At first the crude salts, as obtained direct from the deposits, were +sold as manures under the name of <i>Abraum</i> salts. Now, however, they are +purified. Of potash salts in 1888 some 25,000 tons were exported from +Stassfurt for manurial purposes. Of these salts there may be mentioned, +viz., kainit, an impure form of the sulphate, containing on an average +about 12 per cent of potash, and the muriate and the sulphate—both +salts, in a more or less pure form, being used. A word or two may be +added on the effect of the two forms of potash—viz., as the sulphate +and as the muriate.</p> + +<br /> +<p class="cen"><i>Relative Merits of Sulphate and Muriate of Potash.</i></p> + +<p>It is a well-known fact that muriate of potash, far from having a +beneficial effect on certain crops, is actually harmful. Of these, +sugar-beets, potatoes, and tobacco may be mentioned. In the case of +beets it seems to have an effect in lessening the percentage of +crystallisable sugar, while potatoes are rendered waxy. With regard to +the tobacco-plant, it seems to impair the value of the leaf from the +smoker's point of view. That this deleterious action is due to the form +in which the potash is present, and not to the potash itself, seems to +be pretty clear, since potash in the form of sulphate has not this +deleterious effect on these plants. Another objection which has been +urged against muriate of potash is that, when applied as a <span class='pagenum'><a name="Page_422" id="Page_422">[Pg 422]</a></span>manure, it +is apt to give rise to the formation of calcium chloride,—a compound +which is distinctly hurtful to many plants. A similar charge cannot be +brought against sulphate of potash, since gypsum, which is the chief +compound it is likely to give rise to, is of much value, as we have +already pointed out, as an indirect manure. On the whole, therefore, +sulphate of potash seems to be the safest form in which to add potash. +Unfortunately, however, most of the commercial sulphates are very +impure, and contain generally considerable quantities of muriate. In +favour of the muriate, it may be said that it is the more concentrated +manure, and that it diffuses better in the soil than the sulphate—a +point of great importance. It has, moreover, been used without any bad +effect for clover, corn, grass, and some root crops.</p> + +<br /> +<p class="cen"><i>Application of Potash Manures.</i></p> + +<p>The extreme tenacity with which the soil-particles fix potash salts, +when applied as manures, is a point which ought to be borne in mind in +their application. This, as we have just noticed, is greater in the case +of the sulphate than in the case of muriate, and it has been observed +that certain other fertilisers seem to exercise a considerable influence +in hindering their fixation. Among these may be mentioned bone-meal and +farmyard manure. Nitrate of soda also seems to increase the +diffusibility of potash salts. Conversely, potash salts seem to help to +fix ammonia.</p> + +<p><span class='pagenum'><a name="Page_423" id="Page_423">[Pg 423]</a></span>For the above reasons potash manures ought to be applied to the soil a +considerable period before they are likely to be used by the crop. There +is little risk of any serious loss taking place owing to rain. Autumn +application is generally recommended. Even in very light soils it has +been proved in the Norfolk experiments that autumn application has an +immense advantage over spring application. It has been found that where +potash is applied as sulphate, little sulphuric acid is absorbed by the +plant.</p> + +<br /> +<p class="cen"><i>Soils and Crops suited for Potash Manures.</i></p> + +<p>Of soils best suited for potash manures, it has been found that light +soils, and those largely charged with peaty organic matter (such as the +moorland soils of Germany), are most benefited; while on heavy clayey +soils the percentage of potash which these latter contain is already +sufficiently abundant for the needs of plants. At Flitcham the value of +potash on chalk soils has been strikingly demonstrated. Of crops, it is +now pretty generally acknowledged that those of the leguminous order are +most benefited by potash. Especially in the case of clover has potash +always proved itself a manure worth applying.</p> + +<br /> +<p class="cen"><i>Rate of Application.</i></p> + +<p>Potash is best applied in small quantities. From 1 to 2 cwt. of the +muriate or sulphate is a common amount, and from 6 to 8 cwt. of kainit.</p> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_424" id="Page_424">[Pg 424]</a></span> +<br /> +<h2>CHAPTER XVI.</h2> + +<h2>MINOR ARTIFICIAL MANURES.</h2> +<br/> + +<p>In addition to the manures which have been discussed in previous +chapters, there are a number of minor manures which are used to a very +much smaller extent—dried blood, hoofs, horns, &c.</p> + +<p>Among these one of the most valuable is dried blood. Fresh blood, +containing 80 per cent of water, has from 2.5 to 3 per cent of nitrogen, +about .25 per cent of phosphoric acid, and about .5 per cent of +alkalies. When dried it forms a very concentrated and valuable +nitrogenous manure, which has long been used in France. The commercial +article contains, on an average, about 12 per cent of nitrogen, and +slightly over 1 per cent of phosphoric acid. When mixed with the soil it +ferments, and the nitrogen it contains is converted into ammonia. +Although not so quick-acting a manure as nitrate of soda or sulphate of +ammonia, it can by no means be described, as is done in ordinary +agricultural text-books, as a slow-acting <span class='pagenum'><a name="Page_425" id="Page_425">[Pg 425]</a></span>manure. Its nitrogen may be +regarded as of equal value to that in Peruvian guano. It is peculiarly +suited for horticulture, and is chiefly used in this country as a manure +for hops. It has also been used with beneficial results for wheat, +grass, and turnips. As a manure it is best suited for sandy or loamy +soils. Considerable quantities are exported to the sugar-growing +colonies as a manure for sugar-cane. Manures are made from other animal +refuse. It may be mentioned that lean flesh (containing 75 per cent of +water) has about 3 to 4 per cent of nitrogen,.5 per cent of alkalies, +and .5 per cent of phosphoric acid; that is to say, a ton of lean flesh +would contain about 70 lb. of nitrogen and 10 lb. of phosphoric acid. In +air-dried flesh, according to Payen and Boussingault (containing 8-1/2 +per cent of moisture), there is 13 per cent of nitrogen. Flesh, +therefore, is, when properly composted, a valuable nitrogenous manure. +Dried flesh is generally made into a manure called meat-meal guano, the +composition of which we have already referred to in the chapter on +Guano.<a name="FNanchor_240_240" id="FNanchor_240_240"></a><a href="#Footnote_240_240" class="fnanchor">[240]</a></p> + +<p>Hoofs, horns, hair, bristles, and wool, wool-waste and the intestines of +animals, have been used as manures. Hoofs and horns form a regular +source of artificial nitrogenous manure; the latter being obtained as a +bye-product in the manufacture of combs and other articles. They are in +the form of a fine powder; and in order to increase their rate of +action, which is very <span class='pagenum'><a name="Page_426" id="Page_426">[Pg 426]</a></span>slow, they are often composted in America with +horse-manure before use. They have also been composted with slaked lime. +There can be no doubt that such treatment increases very considerably +their value. Their percentage of nitrogen seems to vary very much +according to the kind of animal from which they are derived. In nine +samples of horn the nitrogen was found to vary from 7-1/2 to 14-1/4 per +cent; giving an average of 11-1/3 per cent. The nitrogen seems rarely to +exceed 15 per cent. The amount of phosphoric acid they contain has been +found by various investigators to range from 6 to 10 per cent. S. W. +Johnson found only from .08 to .15 per cent in buffalo-horn shavings. In +France what is known as "torrefied" horn has been used. This is horn +which has been subjected to the action of steam. The nitrogen in this +material is considered to be more active than in ordinary horn. +According to Way, horns have been used for the hop crop with good +results. Ground hoof is very similar in composition to horn, and +contains about 14 to 15 per cent of nitrogen. Considerable quantities +are now used. It must be remembered, however, that horns, hoofs, hair, +bristles, &c., although rich in nitrogen, possess a comparatively low +manurial value. The home production of these articles may be estimated +at 6000 to 7000 tons.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_427" id="Page_427">[Pg 427]</a></span><i>Scutch.</i></p> + +<p>Scutch is the name given to a manure made from the waste products +incidental to the manufacture of glue and the dressing of skins. It +contains about 7 per cent of nitrogen, and is manufactured in London to +the extent of several thousand tons annually.</p> + +<br /> +<p class="cen"><i>Shoddy and Wool-waste.</i></p> + +<p>Shoddy, which is a manure made from waste-wool products, is a material +largely manufactured in this country, and which was formerly (it is now +used to a considerably less extent) used to a large extent as a manure. +Its annual production amounts to about 12,000 tons. There are three +qualities,—the first containing 8 to 12 per cent of nitrogen; the +second, 6 to 8 per cent; and the third, 5 to 8 per cent. Shoddy is by no +means a very valuable manure. Woollen-waste products were formerly much +richer in nitrogen than is now the case. This is due to the fact of the +adulteration with cotton, now so prevalent in the manufacture of woollen +goods. Pure woollen rags should contain 17 to 18 per cent of nitrogen. +It has been strongly recommended to treat woollen waste with caustic +alkali before being used as a manure, in order to render their nitrogen +more quickly available; and there is a good deal to recommend this +treatment. When wool-waste is applied as a manure, it should in <span class='pagenum'><a name="Page_428" id="Page_428">[Pg 428]</a></span>every +case be in autumn, so as to allow as long a period as possible to elapse +before it is required for the plant's growth.</p> + +<p>Leather has also been used as a manure. Its nitrogen may be stated at +from 4 to 6 per cent; and it may safely be described as of all materials +used as nitrogenous manures the least valuable. Leather is, from its +very nature, admirably adapted to resist decomposition when applied to +the soil, and unless it is reduced to a very fine condition, might be +trusted to remain undecomposed for a long period. Torrefied leather, +however, is probably of greater value. It is obtained in the same way as +torrefied horn, already referred to—namely, by treatment with steam. +The grease and fatty matters which so largely aid it in resisting +decomposition being extracted, it is much better suited for manurial +purposes than ordinary leather. Torrefied leather contains from 5 to 8 +per cent of nitrogen.</p> + +<br /> +<p class="cen"><i>Soot.</i></p> + +<p>A manure which has long been used and highly esteemed is soot. Obtained +in the usual way, it generally contains some 3 per cent of nitrogen, +chiefly in the form of sulphate of ammonia, and small quantities of +potash and phosphates. A varying proportion of the nitrogen is present +in the form of ammonia salts; and this undoubtedly confers upon soot its +manurial value. It has long been used as a <span class='pagenum'><a name="Page_429" id="Page_429">[Pg 429]</a></span>top-dressing for young grain +and grass, and has been applied at the rate of from 40 to 60 bushels per +acre. It has an indirect value as a slug-destroyer.</p> + +<p>Many of the above-mentioned manures, of comparatively low value, will +probably be less used in the future than they have been in the past, +owing to the more abundant supplies of nitrate of soda and ammonia salts +which are now available. Many of these substances have probably been +used in mixed manures.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_240_240" id="Footnote_240_240"></a><a href="#FNanchor_240_240"><span class="label">[240]</span></a> See p. 324.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_430" id="Page_430">[Pg 430]</a></span> +<br /> +<h2>CHAPTER XVII.</h2> + +<h2>SEWAGE AS A MANURE.</h2> +<br /> + +<p>The value of sewage as a manure has been in the past enormously +overrated, and much misunderstanding has existed on the part of the +public on the question of the profitableness of the disposal of town +sewage as an agricultural manure. Not a few of the erroneous opinions +prevalent in the past regarding sewage have been due to statements made +by scientific and other writers as to the enormous wealth lost to the +world by many of the present methods of sewage disposal. Fortunately, +however, the sewage question is now increasingly regarded as a question, +in the first instance, of sanitary interest. As much has been written on +the subject, and many schemes have been devised, at the expense of much +ingenuity, for utilising its manurial properties, it may be desirable +here to say a few words on the purely agricultural side of the question.</p> + +<p>The two most important points about sewage are its enormous abundance +and its extremely poor quality. <span class='pagenum'><a name="Page_431" id="Page_431">[Pg 431]</a></span>If the most important consideration +were not the sanitary one, but its manurial value, then indeed our water +system, so universally used in towns, must be regarded as a most +wasteful one; for by its means the value of the excrementitious matter +from which it derives its manurial ingredients is tremendously lessened. +When we reflect that a ton of sewage, such as is produced in many +European cities, contains only 2 or 3 lb. of dry matter, and that the +total amount of nitrogen in this is only an ounce or two, while the +phosphoric acid is considerably less, and that it is on those two +ingredients that its value as a manure entirely depends, we see very +strikingly how poor a manurial substance sewage is. Various methods have +been devised and experimented with for extracting these manurial +ingredients, and many methods are in operation in different parts of the +world. The methods of utilising sewage for agricultural purposes may be +broadly divided into two classes.</p> + +<br /> +<p class="cen"><i>Irrigation.</i></p> + +<p>One of these, which may be classed under the heading of irrigation, +consists in pouring the sewage on to certain kinds of coarse green +crops. Sometimes the land is made to filter large quantities of sewage +by special arrangements of drains and ditches. The land is first +carefully and evenly graded down a gentle incline. At the top of the +field the sewage is conducted along an open ditch from which it is +permitted to escape, by the <span class='pagenum'><a name="Page_432" id="Page_432">[Pg 432]</a></span>force of gravity, by several smaller +ditches running at right angles from the main ditch. By means of stops +which may be shifted at will, the sewage can be directed to flow over +different parts of the field. Modifications in this plan may be made so +as to suit the nature of the ground. In the case, for example, of a +steep incline, the field may be sewaged by means of what are known as +"catch-work" trenches running horizontally along the hill. In this way +the sewage is allowed to pass over the whole of the field, and is caught +at the bottom in a deep ditch, whence it is allowed to flow into the +nearest river or stream. This is the system which has been employed at +the famous Beddington Meadows, near Croydon.</p> + +<p>Another method of distributing the sewage is by means of underground +pipes, which are laid in a sort of network over the ground to be +manured. At certain intervals pipes with couplings for hose are fitted +on, and by keeping a certain amount of pressure on the main pipes the +sewage may be distributed over the different parts of the field as it is +required.</p> + +<p>A third modification is subsoil irrigation. This resembles the +last-named system, with this difference, that the pipes used are either +porous or perforated with small holes.</p> + +<p>Total submersion can only be applied in the case of absolutely level +lands, and is practised to an enormous extent in Piedmont and Lombardy.</p> + +<p>There has been little dispute as to the thorough <span class='pagenum'><a name="Page_433" id="Page_433">[Pg 433]</a></span>efficiency of +irrigation—when conducted under favourable conditions—as a method of +purifying sewage and utilising to the full its constituents of manurial +value. It is the only method which has been conclusively shown to +extract from sewage that to which it owes most largely its value as a +manure—viz., ammonia; and from this fact it deserves a first place in +the consideration of agriculturists. For however admirable other methods +may be from a sanitary point of view, it is obvious that a method which +would allow the ammonia in sewage wholly, or at least to over 90 per +cent, to be lost, cannot claim the same place in the judgment of +agriculturists as a method which can extract for the soil not only the +whole of this valuable constituent, but all else in the sewage which in +any way is of value to plant-life.</p> + +<br /> +<p class="cen"><i>Effects of continued Application of Sewage.</i></p> + +<p>When sewage is continuously applied to the same land, what generally +takes place is this: At first the sewage is purified, and the soil +derives corresponding benefit from the valuable fertilising ingredients +it thus extracts. After a time, however, the land becomes what has been +termed "sewage-sick." The pores in the soil become choked up by the +slimy matter the sewage contains in suspension; the aeration of the +soil, which, as we have already mentioned, is so necessary, is +consequently to a large extent stopped; and the result is, that the land +rapidly deteriorates, and the sewage is no longer purified.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_434" id="Page_434">[Pg 434]</a></span><i>Intermittent Irrigation.</i></p> + +<p>This is obviated to some extent by intermittent irrigation. The land, +instead of receiving sewage continuously, only receives it at intervals, +and is allowed some time to recover between each dose. It is, however, +the opinion of those who have given the subject much attention, that +land, even although intermittently sewaged, never recovers its original +efficacy.</p> + +<p>Irrigation, therefore, under favourable conditions, is a most successful +method of utilising the manurial value of sewage; but the great +difficulty in practice is to obtain those favourable conditions. It has +long been known that if soil is properly to discharge its function as a +purifier of sewage water, it must be properly aerated; and we now know +that in every fertile soil the process of nitrification must be +permitted free development. Now the application of large quantities of +sewage to a soil is apt to prevent this free development. As we have +already seen, absence of air and the lowering of the temperature of the +soil distinctly tend to retard nitrification; and these two conditions +accompany the application of large quantities of sewage.</p> + +<br /> +<p class="cen"><i>Crops suited for Sewage.</i></p> + +<p>Another objection to irrigation has been found in the alleged limited +number of crops sewaged land is suited to yield. It has been repeatedly +stated that rye-grass is about the only crop it is profitable to grow +<span class='pagenum'><a name="Page_435" id="Page_435">[Pg 435]</a></span>on it. In opposition to this statement, however, is the opinion +expressed in the conclusions arrived at by the committee appointed by +the British Association for the consideration of the sewage question. A +vast number of experiments were carried out by them between the years +1868-72, and the result they arrived at was as follows: "It is certain +that all kinds of crops may be grown with sewage, so that the farmer can +grow such as he can best sell; nevertheless, the staple crops must be +cattle food, such as grass, roots, &c., with occasional crops of kitchen +vegetables and of corn." While, therefore, it is probably a mistake to +say that rye-grass is the only crop sewaged land is capable of growing +profitably, the bulk of experience goes to show that such a crop is best +suited for such land. This being so, the question naturally arises, What +is the farmer who uses sewage as a manure to do with the large green +crops he obtains from his land? He is, in most cases, unable to use them +himself or dispose of them at the time. And while this has hitherto +proved to be a most important drawback, now that we have in ensilage a +means of preserving our green crops in a condition suitable as fodder +for as long a time as is necessary, the grounds on which this objection +rests are almost entirely removed.</p> + +<p>It will be obvious, of course, that some soils are naturally much better +fitted to perform purification of sewage than others; but it must be +frankly admitted that even the best of soils can only deal with a +certain <span class='pagenum'><a name="Page_436" id="Page_436">[Pg 436]</a></span>quantity of sewage. Various calculations have been indulged in +as to the amount of sewage an acre of land can successfully deal with. +According to one of these, an acre can purify some 2000 gallons per day, +or that produced by 100 persons; while other calculations estimate it at +60 persons; and others, again, at 150. The capacity of a sandy soil in +this respect will be much greater than that of a heavier soil; and at +Dantzic an acre of the sand-dunes is regarded as being capable of +purifying the sewage of 600 persons. The late Dr Wallace has calculated +that, in order to treat the sewage of Glasgow, over twelve square miles +of land would be required. Of course, if the sewage is subjected to +previous treatment, which is often the case, by the method immediately +about to be described—namely, precipitation—the amount of sewage the +soil is capable of purifying will be correspondingly increased. A +difficulty which may also be pointed out in connection with irrigation +as a means of disposing of sewage, is the impossibility of carrying it +on during frosty weather, when the land is frost-bound. In warm climates +irrigation has much to recommend it as a means of sewage disposal. In +damp and cold climates, on the other hand, there are many objections.</p> + +<br /> +<p class="cen"><i>Treatment of Sewage by Precipitation, &c.</i></p> + +<p>We now come to consider the methods grouped under this second heading. +Mechanical filtration, of course, only aims at purifying sewage to the +extent of <span class='pagenum'><a name="Page_437" id="Page_437">[Pg 437]</a></span>removing all insoluble suspended matter which it contains. +Different substances have been used as filters, the most generally used +being charcoal. Charcoal mixed with burnt clay, gravel, sand, &c., has +also been used.</p> + +<p>In chemical precipitation, however, we have a method which claims to do +more. Beyond the extracting of all solid matters in suspension, it +removes (at any rate most chemical precipitants do) nearly all the +phosphoric acid, which, next to the ammonia, is the most valuable +constituent the sewage contains. Of all precipitants, lime has been the +most universally used; and on the whole, it is perhaps the best, for it +is both cheap and obtainable almost anywhere. According to an analysis +by the late Professor Way, the difference in the percentages of +phosphoric acid, potash, and ammonia, before and after treatment with +lime, in a sample of sewage, was as follows:—</p> + +<div class="centered"> +<table border="0" width="50%" cellpadding="2" cellspacing="0" summary="Grains"> + <tr> + <td class="tdc" colspan="3"><i>Grains per Gallon.</i></td> + </tr> + <tr> + <td class="tdl" width="60%"> </td> + <td class="tdc" width="20%">Before.</td> + <td class="tdc" width="20%">After.</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid</td> + <td class="tdc">2.63</td> + <td class="tdc"> .45</td> + </tr> + <tr> + <td class="tdl">Potash</td> + <td class="tdc">3.66</td> + <td class="tdc">3.80</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdc">7.48</td> + <td class="tdc">7.50</td> + </tr> +</table> +</div> + +<p>From the above we see that while sludge caused by lime as a precipitant +contains nearly all the phosphoric acid, there is not a trace of the +potash or ammonia removed. Sulphate of alumina has also been used, both +alone and in conjunction with lime. The advantage claimed by it over +lime is, that the resulting <span class='pagenum'><a name="Page_438" id="Page_438">[Pg 438]</a></span>precipitate is much less bulky. In other +respects, however, it does not seem to be any more efficient as a +precipitant. In the well-known A, B, C process, a mixture of alum, clay, +lime, charcoal, blood, and alkaline salts, in different proportions, has +been used. This mixture is said to extract, in addition to the +phosphoric acid, a certain proportion of the ammonia; but the amount is +so small as scarcely to be worth considering.</p> + +<p>Numerous other chemical substances have been used, alone and also in +conjunction with one another, such as perchloride of iron, copperas, +manganese, &c. All alike, however, have failed to do more than effect +partial purification,—the best results, it may be added, being obtained +when the sewage thus treated was fresh. With regard to the manurial +value of the resulting sludges, much difference of opinion has existed. +The small percentage of phosphoric acid and nitrogen they contain has +prevented them from being used to any extent as a manure, as their value +did not admit of carriage beyond the distance of a few miles. By the +introduction a few years ago of the filter-press, their value has been +considerably enhanced. The old method of dealing with the sludge at +precipitation-works was to allow it to dry gradually by exposure to the +atmosphere. The result, however, of leaving sewage-sludge with over 90 +per cent of water in it to dry in the air, was to encourage the rapid +decomposition and putrefaction of its organic <span class='pagenum'><a name="Page_439" id="Page_439">[Pg 439]</a></span>matter, so that in many +cases the decomposing sludge proved to be as great a nuisance as the +unpurified sewage itself would have been. By the use of Johnson's +filter-press, however, a sludge containing 90 per cent of water was at +once reduced to 50 per cent or even less. By this means the percentage +of its valuable constituents was very much increased, and the +sludge-cake, besides being much more portable, was neither so +objectionable nor so liable to decomposition as before.</p> + +<br /> +<p class="cen"><i>Value of Sewage-sludge.</i></p> + +<p>As to the value of this sludge-cake as a manure, we are happily in +possession of some very interesting and valuable experiments by +Professor Munro of Downton Agricultural College. The sludge experimented +upon was that produced by sulphate of alumina, lime, and sulphate of +iron, and contained, after being subjected to Johnson's filter-press, +from .6 to .9 per cent of nitrogen, and over 1 per cent of phosphoric +acid. It was found that the benefit resulting from the application of +the sludge was far from what in theory might have been expected. The +experiments were made with turnips; and the results obtained with +superphosphate and farmyard manure respectively, in the same field and +under exactly the same conditions, were contrasted with those obtained +with sludge. Thus it was found that 53 lb. of phosphoric acid as +superphosphate, or 60 lb. as farmyard <span class='pagenum'><a name="Page_440" id="Page_440">[Pg 440]</a></span>manure, produced a considerably +larger crop than 240 lb. of phosphoric acid in the sludge. That is to +say, that the phosphoric acid in the sludge did not exert more than +one-fifth of its theoretical effect. The explanation of this somewhat +strange result Dr Munro finds in the unsuitable physical character of +the sludge-cakes. In farmyard manure we have a loose texture and a large +amount of soluble constituents when well rotted. It thus quickly +distributes its fertilising elements throughout the soil. In the case of +the sludge, on the other hand, its composing particles are closely +compacted together, and thus offer the greatest resistance to mechanical +and chemical disintegration. "As a matter of fact," says Dr Munro, "the +sludge-plots in my experimental series were all readily identified, when +the roots were pulled, by the presence of unbroken and undecomposed +clods of cake, which had evidently given up, at most, a small portion of +their valuable ingredients to the soil."</p> + +<p>Briefly stated, therefore, the objections to chemical precipitation as a +means of dealing with sewage are these—viz., that while it relieves +sewage of all its organic matter, and to a large extent of its +phosphoric acid, it fails to extract any ammonia, which is thus lost; +that the resulting sludge is consequently so poor in fertilising matters +as scarcely to make it worth while to remove it any distance for +manuring purposes; and that, further, owing to its unfavourable +<span class='pagenum'><a name="Page_441" id="Page_441">[Pg 441]</a></span>physical character, as at present made, even the small percentage of +plant-food it contains is not realisable, within, at any rate, anything +like a reasonable time, to its full theoretical extent.</p> + +<p>The most profitable method of treating sewage must be determined by +various local conditions; and it must be clearly understood that the +question of sewage disposal is primarily a sanitary one, and that it +must be dealt with from the sanitary aspect. The most profitable way of +applying sewage as a manure, however, will doubtless be found by +combining chemical precipitation and land irrigation.</p> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_442" id="Page_442">[Pg 442]</a></span> +<br /> +<h2>CHAPTER XVIII.</h2> + +<h2>LIQUID MANURE.</h2> +<br /> + +<p>The adoption of irrigation as a means of utilising sewage, suggests a +short consideration of the value of liquid manures. It has been a custom +on many farms to apply the liquid manure got from the oozings of +manure-heaps, the drainings of the farmyard, byres, stables, piggeries, +&c., directly to the soil. Indeed, so strongly has the belief in the +superiority of liquid manure over other manure been held by certain +farmers, that they have washed the solid animal excreta with water, in +order to extract from it its soluble fertilising constituents. The late +Mr Mechi was one of the foremost exponents of the value of liquid +manure. His farm of Tiptree Hall was fitted up with iron pipes for the +distribution of the manure over the different fields. Superphosphate, it +may also be added, as first made from bones by Baron Liebig, was applied +in a liquid form. As to the general merits <span class='pagenum'><a name="Page_443" id="Page_443">[Pg 443]</a></span>of liquid manure, there can +be no doubt that it is the most valuable form in which to apply manure. +It secures for the manurial ingredients it contains a speedy and uniform +diffusion in the soil; but, on the other hand, the expense of +distributing it makes its application far from economical. The chief +ingredient in liquid manure is urine. Now the removal of urine from the +farmyard manure-heap entails a severe loss of the ingredient which is +most potent in promoting fermentation. Separation of the urine from the +solid excreta is on this very account not to be recommended. Urine, when +applied alone, is lacking in phosphoric acid, of which it contains mere +traces. It is not, therefore, suitable as a general manure. It has to be +pointed out, however, that the drainings from a manure-heap in this +respect are superior to pure urine, since they contain the soluble +phosphates washed out of the solid excreta. The objections against using +liquid manure may be summed up as follows:—</p> + +<p>First, it is too bulky a form in which to apply the manure, and hence +too expensive; secondly, it is not advisable to deprive the solid +excreta of the liquid excreta, as the one supplements the other; +thirdly, fermentation is largely fostered in the solid excreta by the +presence of the liquid excreta—hence fermentation will not take place +properly in the solid excreta when deprived of the liquid excreta.</p> + +<p>If, however, the production of liquid manure on the <span class='pagenum'><a name="Page_444" id="Page_444">[Pg 444]</a></span>farm is in excess +of what can be used for the proper fermentation of farmyard manure, it +will be best to utilise it for composts. No better addition to a compost +can be made than liquid manure, as it induces speedy fermentation in +nearly all kinds of organic matter.</p> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_445" id="Page_445">[Pg 445]</a></span> +<br /> +<h2>CHAPTER XIX.</h2> + +<h2>COMPOSTS.</h2> +<br /> + +<p>The use of composts is an old one. Before artificial manures were so +plentiful as they are at present, much attention was paid by farmers to +their preparation. A compost is generally made by mixing some substance +of animal origin which is rich in manurial ingredients with peat or +loam, and often along with lime, alkali salts, common salt, and indeed +any sort of refuse which may be regarded as possessing a manurial value. +Composting, in short, may be looked upon as a useful method of turning +to profitable use refuse of various kinds which accumulate on the farm. +The object of composting is to promote fermentation of the materials +forming the compost, and to convert the manurial ingredients they +contain into an available condition for plant needs. Composts often +serve a useful purpose in retaining valuable volatile manurial +ingredients, such as ammonia, formed in easily fermentable substances +like urine. In fact, <span class='pagenum'><a name="Page_446" id="Page_446">[Pg 446]</a></span>we may say that farmyard manure is the typical +compost, and its manufacture serves to illustrate the principles of +composting.</p> + +<br /> +<p class="cen"><i>Farmyard Manure a typical Compost.</i></p> + +<p>Farmyard manure as ordinarily made is not generally regarded as a +compost, but in the past it has been widely used for the purpose of +making composts. Thus the practice of mixing farmyard manure with large +quantities of peat has been in some parts of the world a common one. +Peat, as has already been pointed out in a previous chapter, is +comparatively rich in nitrogen. When it is mixed with urine or some +other putrescible substance, the peat undergoes fermentation, with the +result that its nitrogen is to a greater or less extent converted into +ammonia. The effect, therefore, of mixing peat with farmyard manure is +beneficial to both substances mixed: the escape of ammonia is rendered +impossible by the fixing properties of the peat, while the inert +nitrogen of the peat is largely converted by fermentation into an +available form. The proportion of peat which it is advisable to add in +composting farmyard manure will depend on the richness of the quality of +the manure: the richer the quality of the manure, the greater the amount +of peat it will be able to ferment. Composts of this kind are generally +made by piling up the manure in heaps, consisting of alternate layers of +peat and farmyard manure. From one to five parts of peat to every <span class='pagenum'><a name="Page_447" id="Page_447">[Pg 447]</a></span>one +part of farmyard manure is a common proportion. The use of such a +manure, containing so much organic matter, will exercise its best effect +on light sandy soils.</p> + +<br /> +<p class="cen"><i>Other Composts.</i></p> + +<p>But instead of farmyard manure, or in addition to farmyard manure, +various other substances may be added, as bones, flesh, fish-scrap, and +the offal of slaughter-houses. Sometimes leaves and the dried +bracken-fern are used for the manufacture of composts. Some of these +substances contain much nitrogen or phosphoric acid, but in their +natural condition ferment when applied to the soil at a slow rate. If +mixed together before application in pits with peat, leaves, +bracken-fern, or some other absorbent material, fermentation proceeds +evenly and rapidly. The addition of lime, potash, and soda salts has +been found to have a most beneficial effect in promoting fermentation. +These substances, as is well known, hasten putrefaction of organic +matter. Lime seems especially to be valuable in composting. This is no +doubt due to the fact that lime plays a valuable part in promoting the +action of various ferments, as has already been illustrated in the case +of nitrification. The effect of large quantities of sour organic acids +(humic and ulmic), which are the invariable products of the +decomposition of organic matter like peat, leaves, &c., is inimical to +micro-organic life. The action of lime is <span class='pagenum'><a name="Page_448" id="Page_448">[Pg 448]</a></span>to neutralise these acids. +There can be no doubt that composting is a useful process for increasing +the fertilising properties of different more or less inert manurial +substances. But in view of the abundant supply of concentrated +fertilisers, the use of composts may considerably decrease in future.</p> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_449" id="Page_449">[Pg 449]</a></span> +<br /> +<h2>CHAPTER XX.</h2> + +<h2>INDIRECT MANURES.</h2> + +<h2><span class="smcap">Lime.</span></h2> +<br /> + +<p>We now come to discuss those manures which we may class under the term +<i>Indirect</i>, because their value is due, not to their direct action as +suppliers of plant-food—like those manures we have hitherto been +engaged in discussing—but to their indirect action. Of these by far the +most important is lime.</p> + +<br /> +<p class="cen"><i>Antiquity of Lime as a Manure.</i></p> + +<p>Lime is one of the oldest and one of the most popular of all manures. It +is mentioned, and its wonderful action commented on, in the works of +several ancient writers, more especially Pliny. Of late years, perhaps, +its use has become restricted; and, as we shall point out by-and-by, it +is well that it is so.</p> + +<br /> +<p class="cen"><i>Action of Lime not thoroughly understood.</i></p> + +<p>Despite the fact of the long-established and almost <span class='pagenum'><a name="Page_450" id="Page_450">[Pg 450]</a></span>universal use of +lime, it can scarcely be said that we as yet clearly understand the +exact nature of its action. Much light, however, has been thrown of late +years on the subject by the great advance which has been made in our +knowledge of agricultural chemistry. Nevertheless, there are many points +connected with the action of lime on the soil which are still obscure. +Perhaps one reason for the conflicting ideas prevalent with regard to +the value of this substance in agriculture is to be found in the fact +that it acts in such a number of different ways, and that the nature of +the changes it gives rise to in the soil is most complicated. The +experience of agriculturists with lime in one part of the country often +seems contradictory to the experience of those in other parts of the +country. Its action on different soils is very dissimilar. For these +reasons, therefore, the discussion of the value of lime as a manure is +by no means an easy one.</p> + +<br /> +<p class="cen"><i>Lime a necessary Plant-food.</i></p> + +<p>Lime, as we have already pointed out in a former chapter, is a necessary +plant-food, and were it present in the soil to a less extent than is +actually the case, would be just as valuable a manure as the different +nitrogenous and phosphatic manures; and in certain circumstances this is +the case. There are soils, though they are by no means of common +occurrence, which actually lack sufficient lime for supporting +<span class='pagenum'><a name="Page_451" id="Page_451">[Pg 451]</a></span>plant-growth, and to which its addition directly promotes the growth of +the crop. Poor sandy soils are often of this nature. Another class of +soils are also apt to be lacking in lime—at any rate their surface-soil +is. These are permanent pasture-soils. Originally there may have been an +abundance of lime in the surface portion of the soil; but, as is well +known to every practical farmer, lime has a tendency to sink down in the +soil. This tendency in ordinary arable soils is largely counteracted by +ordinary tillage operations, such as ploughing, &c., by means of which +the lime is again brought to the surface. In permanent pasture-soils, +however, no such counteracting action takes place, hence impoverishment +of the surface-soil in lime eventually results. It is for this +reason—partly at any rate—that permanent pasture benefits in an +especial degree by the application of lime. We say <i>partly</i>, for there +are other important reasons. One is, that lime seems to have a striking +effect in improving the quality of pastures by inducing the finer +grasses to predominate. It has also a very favourable action in +promoting the growth of white clover. Another reason for the favourable +effect of lime on pasture-soils is doubtless on account of the action it +has in setting potash free from its compounds. Soils, however, which +directly benefit from the application of lime in the same way as they +benefit from the application of nitrogenous manures, may be safely said +to be rare. In the great majority of soils lime <span class='pagenum'><a name="Page_452" id="Page_452">[Pg 452]</a></span>exists, so far as the +demands of plant-life are concerned, in superabundance.</p> + +<br /> +<p class="cen"><i>Lime of abundant Occurrence.</i></p> + +<p>Indeed limestone is one of the most abundant of all rock substances, and +it has been calculated that it forms not less than one-sixth of the +rock-mass of the earth's crust. Nearly all the commonly occurring +minerals contain it, and in the course of their disintegration furnish +it to the soil. Vast tracts of country are composed of nothing but +limestone; and we have examples, even in this country, of so-called +chalk-soils, where it is the most abundant constituent. Nor can it be +classed amongst the insoluble mineral constituents of the soil; for +although insoluble in pure water, it is soluble in water—such as the +soil-water—which contains carbonic acid. This is proved by the fact +that it is the chief dissolved mineral ingredient in all natural waters.</p> + +<br /> +<p class="cen"><i>Lime returned to the Soil in ordinary Agricultural Practice.</i></p> + +<p>It may be further pointed out, as bearing upon the true function of lime +when applied as a manure, that in ordinary agricultural practice nearly +all the lime removed from the soil in crops finds its way back again to +the farm in the straw of the farmyard manure. For these reasons, then, +it is clear that the true function of lime is as an indirect manure.</p> + +<p><span class='pagenum'><a name="Page_453" id="Page_453">[Pg 453]</a></span>Let us now proceed to discuss its action. Before doing so, however, it +is important that we should clearly understand the different chemical +forms in which it occurs.</p> + +<br /> +<p class="cen"><i>Different Forms of Lime.</i></p> + +<p>Lime occurs chiefly as carbonate of lime in the forms of limestone, +marble, or chalk, which are all chemically the same. It occurs also as +sulphate of lime or gypsum, as well as in the forms of phosphate and +fluoride. In agriculture it is only used—if we except the phosphate, +which is applied not on account of its lime, but its phosphoric acid—in +the form of the carbonate or <i>mild</i> lime as it is commonly called, +burnt, caustic, or quick lime, and as gypsum. As the value of gypsum as +a manure is of such importance, and depends not entirely on its being a +compound of lime, we shall consider it by itself. Hence we have only to +consider here the action of mild and caustic lime.</p> + +<br /> +<p class="cen"><i>Caustic Lime.</i></p> + +<p>When limestone or mild lime is submitted to a great heat, such as is +practically done on a large scale in lime-kilns, it is converted into +caustic lime or lime proper. Limestone is made up, as we have just +mentioned, of lime and carbonic acid. The latter ingredient is expelled +in the form of a gas, and the lime is left behind. Lime never occurs +naturally as caustic lime, for the simple reason that it is impossible +for <span class='pagenum'><a name="Page_454" id="Page_454">[Pg 454]</a></span>it to remain in this state, owing to the great affinity it has both +for water and carbonic acid.</p> + +<p>When lime is burnt, and before it is applied to the field, some time is +allowed to elapse in order to permit of its absorbing moisture—or +becoming slaked, as it is technically called. This it does more or less +slowly by absorbing moisture from the air. As, however, the process +would take too long, and as, moreover, the absorption of carbonic acid +gas would also take place at the same time, lime is generally slaked in +another way. This can be done by simply adding water. An objection to +this method is, that the lime is not so uniformly slaked as is +desirable. It becomes gritty. The usual method is to cover it up with +damp earth in heaps, and allow the moisture of the earth to effect the +slaking. When lime absorbs water a new chemical compound is formed, +known as lime hydrate; and so rapidly does the lime unite with water, +that a great deal of heat is evolved in the operation, the temperature +produced being considerably above that of boiling-water. The conversion +of slaked lime into carbonate of lime or mild lime is a slower process. +Sooner or later, however, it takes place, whether the lime is left on +the surface of the soil or buried in it.</p> + +<p>A knowledge of these elementary chemical facts is necessary in order +clearly to understand the nature of the action of lime in agriculture.</p> + +<p>The respective action of quicklime and mild lime is, on the whole, +similar, although the former is in every <span class='pagenum'><a name="Page_455" id="Page_455">[Pg 455]</a></span>case very much more powerful +in its effects than the latter.</p> + +<br /> +<p class="cen"><i>Lime acts both mechanically and chemically.</i></p> + +<p>Lime may be said to act on the soil both mechanically and chemically. It +alters the texture of the soil, and affects its mechanical properties, +such as its absorptive, retentive, and capillary powers with regard to +water. It acts upon its dormant fertility, and decomposes its mineral +substances as well as its organic matter. Lastly, its influence on the +micro-organic life of the soil, which plays such an important part in +the preparation and elaboration of plant-food, is of the highest +importance. We cannot do better, therefore, than discuss its properties +under the headings <i>mechanical</i>, <i>chemical</i>, and <i>biological</i>.</p> + +<br /> +<p class="cen">I. <span class="smcap">Mechanical Functions of Lime.</span></p> + +<p class="cen"><i>Action on Soil's Texture.</i></p> + +<p>The effect of lime upon the texture of a soil is among its most striking +properties. Every farmer knows well what a transformation is effected in +the texture of a stiff clay soil by the application of a dressing of +lime. The adhesive property of the soil—its objectionable tendency to +puddle when mixed with water—is greatly lessened, and the soil is +rendered very much more friable when it becomes dry. Several reasons +exist for this change. In the <span class='pagenum'><a name="Page_456" id="Page_456">[Pg 456]</a></span>first place, the tendency to puddle in a +clayey soil is due to the fine state of division of the soil-particles. +The way in which lime counteracts this adhesive property is by causing a +coagulation of the fine soil-particles. This flocculation or aggregation +of the fine clay-particles, when mixed with water by lime, is strikingly +demonstrated by adding to some muddy water a little lime-water. The +result will be that the water will speedily be rendered clear, the fine +clay-particles coming together and sinking to the bottom of the vessel. +Even a very small quantity of lime will effect this change. This +property possessed by lime, we may mention, is utilised in the treatment +of sewage. As it is the fine clay-particles that are the chief cause of +the puddling of clay soils, their flocculation does much to destroy this +objectionable property. Another reason why lime renders a clay soil more +friable when dry is, that lime does not undergo any shrinkage in dry +weather. As clay soils shrink very much in drying, the mixture with such +a substance as lime tends to minimise this tendency to cake in hard +lumps. The effect of even a very small addition of lime to a clay soil, +in the way of increasing its friable nature, is very striking, and can +be easily illustrated by taking two portions of clay, into one of which +a small percentage of lime is introduced, and working both into a +plastic mass with water, and then allowing them to dry. It will be found +that while the one is hard and resists <span class='pagenum'><a name="Page_457" id="Page_457">[Pg 457]</a></span>disintegration, that portion to +which the lime has been added crumbles away easily to a powder. This +effect which lime has in "lightening" heavy soils has been known to last +for years. The disintegrating effect of quicklime when applied to heavy +soils is also due, it may be added, to the change undergone by the lime +itself from the caustic state to the mild state.</p> + +<br /> +<p class="cen"><i>Lime renders light Soils more cohesive.</i></p> + +<p>Although it may seem somewhat paradoxical, lime, it would appear, in +some cases exercises an effect upon the soil exactly the reverse of what +has just been stated. That lime should act as a binding agent is only +natural when we reflect on the way in which it acts when used as mortar. +It is quite to be understood, therefore, that its action on light +friable soils should be to increase their cohesive powers, and at the +same time to increase the capillary power of the soil to absorb water +from the lower layers. The extent of this action, of course, would +depend on the form in which the lime is applied, and the amount. A +striking example of the binding power of lime is to be found in certain +soils extremely rich in lime, in which what is known as a lime-pan has +been formed at some distance from the surface.</p> + +<br /> +<p class="cen">II. <span class="smcap">Chemical Action of Lime.</span></p> + +<p>But more important probably than even its mechanical action is the +chemical action of lime. It is a most <span class='pagenum'><a name="Page_458" id="Page_458">[Pg 458]</a></span>important agent in unlocking the +inert fertility of the soil. This it does by decomposing different +minerals and setting free the potash they contain. The disintegrating +power of lime in this respect depends, of course, on its chemical +condition, the caustic form being much more potent than the other forms. +Its action in decomposing vegetable matter and rendering the inert +nitrogen it contains available for the plant's use, is also one of its +most important properties, and accounts for its beneficial action when +applied to soils, such as peaty soils, rich in organic matter. Again, +its use as a corrective for sour lands has long been practically +recognised. The presence of acidity in a soil is hurtful to vegetable +life. Lime, by neutralising this acidity, removes the sourness of the +land, and does much to restore it to a condition suitable for the growth +of cultivated crops. The generation of sourness in a soil is almost sure +to give rise to certain poisonous compounds. Lime, therefore, in +sweetening a soil, prevents the formation of these poisonous compounds. +Badly drained and sour meadow-lands, as every farmer knows, are +immensely benefited by the application of this useful manure; for not +merely is their sourness removed and their general condition +ameliorated, but many of the coarser and lower forms of plant-life, +which alone flourish on such soils, are killed out, and the more +nutritive grasses are allowed to flourish instead. The action of lime in +promoting the formation of a class of compounds of great <span class='pagenum'><a name="Page_459" id="Page_459">[Pg 459]</a></span>importance in +the soil—viz., hydrated silicates—is worthy of notice. According to +the commonly accepted theory, much of the available mineral fertilising +matter of the soil is retained in the form of these hydrated silicates. +Hence lime, by increasing these compounds, not merely adds to the amount +of the available fertility in the soil, but also increases its +absorptive power for food-constituents.</p> + +<br /> +<p class="cen">III. <span class="smcap">Biological Action of Lime.</span></p> + +<p>The last way in which lime acts is what we have termed biological. By +this we mean the important <i>rôle</i> lime plays in promoting or retarding, +as the case may be, the various kinds of fermentative action which go on +so abundantly in all soils. The presence of carbonate of lime in the +soil is a necessary condition for the process of nitrification. Lime is +the base with which the nitric acid, when it is formed, combines; and as +we have seen, when discussing nitrification, soils of a chalky nature +are among those best suited to promote the natural formation of +nitrates. This is one of the reasons for the beneficial effects produced +by lime when applied to peaty soils. Not merely does it help to +decompose the organic matter so abundant in such soils, but it also +furnishes the base with which the nitric acid may combine when it is +formed. But while the action of lime is to promote fermentation, it must +not be forgotten that there may be cases <span class='pagenum'><a name="Page_460" id="Page_460">[Pg 460]</a></span>in which its action is rather +the reverse of this. Fermentation of organic matter goes on when there +is a certain amount of alkalinity present; while, on the other hand, the +presence of acidity seems to retard and check it. Too great an amount of +alkalinity, however, would, in the first instance, retard fermentation +as much as too great acidity. It has been claimed that the addition of +caustic lime to fresh urine may act in this way; and if this were so, +the addition of lime to farmyard manure might, to a certain extent, be +defended. The experiment, however, would be a hazardous one and not to +be recommended, as loss of ammonia would most likely ensue.</p> + +<br /> +<p class="cen"><i>Action of Lime on Nitrogenous Organic Matter.</i></p> + +<p>The action of lime on nitrogenous organic matter is of a very striking +kind, and is by no means very clearly understood. As we have pointed +out, it sometimes acts as an antiseptic or preservative; and this +antiseptic or preservative action has been explained on the assumption +that insoluble albuminates of lime are formed. Its action in such +industries as calico-printing, where it has been used along with casein +for fixing colouring matter; or in sugar-refining, where it is used for +clarifying the sugar by precipitating the albuminous matter in solution +in the saccharine liquor; or lastly, in purifying sewage,—has been +cited in support of this theory. While, however, there may be +circumstances in which lime, especially in its caustic form, acts as <span class='pagenum'><a name="Page_461" id="Page_461">[Pg 461]</a></span>an +antiseptic, its general tendency is to promote these fermentative +changes, such as nitrification, so important to plant-life.</p> + +<p>An important use of lime in agriculture is in preventing the action of +certain fungoid diseases, such as "rust," "smut," "finger-and-toe," &c., +as well as in killing, as every horticulturist and farmer knows, slugs, +&c.</p> + +<br /> +<p class="cen"><i>Recapitulation.</i></p> + +<p>We may, in conclusion, sum up in a single paragraph the different ways +in which lime acts. Its action is mechanical, chemical, and biological. +It acts on the texture of the soil, rendering clay soils more friable, +and exerting a certain binding effect on loose soils. It decomposes the +minerals containing potash and other food-constituents, and renders them +available for the plant's needs. It further decomposes organic matter, +and promotes the important process of nitrification. It increases the +power of a soil to fix such valuable food-constituents as ammonia and +potash. It neutralises sourness, and prevents the formation of poisonous +compounds in the soil. It increases the capillary condition of the soil, +prevents fungoid diseases, and promotes the growth of the more nutritive +herbage in pasture-land.</p> + +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_462" id="Page_462">[Pg 462]</a></span> +<br /> +<h2>CHAPTER XXI.</h2> + +<h2>INDIRECT MANURES—GYPSUM, SALT, ETC.</h2> +<br /> + +<p class="cen"><span class="smcap">Gypsum.</span></p> + +<p>In the previous chapter mention was made of gypsum as a compound of +lime, but no reference to its action as a manure was made. In the past, +gypsum was used extensively and highly valued. It was found to be of +especial value for clover; and there is a story told of Benjamin +Franklin which illustrates the very striking nature of its action on +this crop. It is related that he once printed with gypsum the words +"This has been plastered" on a field of clover, and that for a long time +afterwards the legend was plainly discernible on account of the +luxuriance of the clover on the parts of the field which had been thus +treated.</p> + +<br /> +<p class="cen"><i>Mode in which gypsum acts.</i></p> + +<p>Despite the fact that gypsum is a most ancient manure, it is only of +late years that we have come to understand the true nature of its +action. For long it <span class='pagenum'><a name="Page_463" id="Page_463">[Pg 463]</a></span>was believed that the reason of its striking effect +in promoting clover was due to the fact that, as clover was a +lime-loving plant, the action of gypsum was owing to the lime it +contained. That, however, the action of gypsum is not due to the fact +that it supplies lime to the plant, seems evident when it is stated that +were this so, any other form of lime would have the same beneficial +effect. It is well known, however, that this is not so. Besides, as we +have already pointed out, lime is not a constituent which most soils +lack, so far as the needs of the crop are concerned. There is a certain +amount of truth in the old belief that gypsum enriches the soil in +ammonia by fixing it from the air. The power that gypsum has as a fixer +of ammonia has already been referred to in the chapter on Farmyard +Manure; but in this case the gypsum is brought in contact with the +ammonia. The origin of this old belief was due to a misconception as to +the amount of ammonia in the atmosphere. No doubt gypsum greatly +increases the power of a soil to absorb ammonia from the air; but the +quantity of ammonia in the air is so very trifling, that its action in +this respect is hardly worth considering. The true explanation of the +action of gypsum is to be found in its effect on the double silicates, +which it decomposes, the potash being set free. Its action is similar to +that of other lime compounds, only more characteristic. As a manure, +therefore, its action is indirect, and its true function <span class='pagenum'><a name="Page_464" id="Page_464">[Pg 464]</a></span>is to oust the +potash from its compounds. Its peculiarly favourable action on clover is +due to the fact that clover specially benefits by potash, and that +adding gypsum practically amounts to adding potash. Of course it should +be borne in mind that the soil must contain potash compounds if gypsum +is to have its full effect. Now, however, that potash salts suitable for +manuring purposes are abundant, it may well be doubted whether it is not +better to apply potash directly. Further, it must be borne in mind that +gypsum is applied to the soil whenever it receives a dressing of +superphosphate of lime, as gypsum is one of the products formed by +treating insoluble phosphate of lime with sulphuric acid.</p> + +<p>It is possible that gypsum may act as an oxidising agent in the soil, +just as iron in the ferric condition does. It has a large quantity of +oxygen in its composition, and under certain conditions may act as a +carrier of oxygen to the lower layers of the soil. When it is used, it +should be applied some months before the crop is sown.</p> + +<p>Gypsum, therefore, although it contains two necessary +plant-constituents, lime and sulphuric acid, cannot be regarded as a +direct manure; and as its action comes to be more fully understood, its +use, which was never very abundant in this country, will probably +decrease. We have already, in the chapter on Nitrification, referred to +the action of gypsum in promoting nitrification.</p> + +<br /> +<p class="cen"><span class="smcap">Salt.</span><span class='pagenum'><a name="Page_465" id="Page_465">[Pg 465]</a></span></p> + +<p>The action of salt as a manure presents a problem which is at once of +the highest interest and surrounded with the greatest difficulties. In +view of the large quantities now used for agricultural purposes, a +somewhat detailed examination of the nature of its action is not out of +place in a work such as the present.</p> + +<br /> +<p class="cen"><i>Antiquity of the Use of Salt.</i></p> + +<p>The recognition of the manurial functions of salt dates back to the very +earliest times. Its use among the ancients is testified by numerous +allusions in the Old Testament; while, according to Pliny, it was a +well-known manure in Italy. The Persians and the Chinese seem also to +have used it from time immemorial, the former more especially for +date-trees.</p> + +<br /> +<p class="cen"><i>Nature of its Action.</i></p> + +<p>Despite, however, the great antiquity of its use, much difference of +opinion seems always to have existed as to the exact method of its +action, and as to its merits as a manure in promoting vegetable growth. +It furnishes, in fact, a good example of the difficulty which exists in +the case of many manures, whose action is chiefly indirect, of fully +understanding their influence on the soil and on the crop. In fact, the +action of salt is probably more complicated than that of any other +manurial substance.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_466" id="Page_466">[Pg 466]</a></span><i>Salt not a necessary Plant-food.</i></p> + +<p>We have already seen that neither sodium nor chlorine—the two +constituent elements of salt—are in all probability absolutely +necessary plant-foods. If they are necessary, the plant only requires +them in minute quantities. Despite this fact, soda is an ash-constituent +of nearly every plant, and in many cases one of the most abundant. In +amount it is one of the most variable of all the ash-constituents, being +present in some plants only in minute quantities, while in others it +occurs in large quantities. Mangel and plants of the cabbage tribe may +be cited as examples of plants containing large amounts of soda in their +composition. But the plants which contain it in largest quantity are +those which thrive on the sea-coast, and it has been thought that for +them at least salt is a necessary manure. This, however, does not seem +to be the case. In fact, the amount of soda in a plant seems to be +largely a matter of accident. It may be added that the succulent +portions of a plant are generally richest in soda.</p> + +<br /> +<p class="cen"><i>Can Soda replace Potash?</i></p> + +<p>Again, it has been believed that soda is capable of replacing potash in +the plant; but this does not seem to be the case to any extent. The view +that soda is able to replace potash, it has been thought, is supported +by the variation which exists in the proportion of soda <span class='pagenum'><a name="Page_467" id="Page_467">[Pg 467]</a></span>and potash in +different plants. It must be remembered, however, that it is highly +probable that most plants contain a larger quantity of ash-constituents +than is absolutely necessary for their healthy growth. Especially is +this the case with such a necessary plant-food as potash, of which there +is generally present, in all likelihood, an excess. The variation in the +quantity of potash and soda present in many plants under different +circumstances can scarcely, therefore, be regarded as furnishing a proof +of the replacement of potash by soda. Incidentally we may mention, as a +fact worthy of notice, that cultivated plants have more potash and less +soda in their composition than wild plants. What has been said of soda +may be held to apply equally to chlorine, as it seems to be chiefly in +the form of common salt that soda enters the plant. The amount of salt, +therefore, present in plants must be regarded as largely accidental and +dependent on external circumstances, such as the nature of the soil, &c.</p> + +<br /> +<p class="cen"><i>Salt of universal Occurrence.</i></p> + +<p>But even were salt a necessary plant-food, its occurrence in the soil is +already of sufficient abundance to obviate any necessity for its +application. It may be said to be of almost universal occurrence. Even +the air contains it in traces. That this is the case in the +neighbourhood of the sea-coast is well known; but even in air far +inland, accurate analysis of the air would probably demonstrate its +presence in greater <span class='pagenum'><a name="Page_468" id="Page_468">[Pg 468]</a></span>quantity than is commonly believed. It is a wise +provision that plants absorb salt, for it increases their efficiency as +food,—the function of salt as a constituent of animal food being of the +very highest importance. It is an indispensable food-ingredient for +animal life. With regard to ordinary farm-stock, the amount of salt +which naturally occurs in their food is quite sufficient. In the case, +however, of pastures in countries far removed from the sea, the custom +of specially supplying stock with salt is common. This is done by +placing a piece of rock-salt in the fields.</p> + +<br /> +<p class="cen"><i>Special Sources of Salt.</i></p> + +<p>The salt of commerce is obtained from various sources. Besides the sea, +we have ample sources of salt in the large saline deposits found in many +parts of Europe, especially in Austria, and in England in Cheshire.</p> + +<br /> +<p class="cen"><i>The Action of Salt indirect.</i></p> + +<p>From what has been said above, it is clear that the action of salt as a +manure is indirect and not direct. What the nature of that indirect +action is we shall now proceed to discuss.</p> + +<p>In considering the evidence of the manurial value of salt, we are at +once brought face to face with the fact that the experience of its +action in the past has as often been unfavourable as favourable. Salt, +it is well known, is both an antiseptic and a germicide. It is, indeed, +one of the most commonly used of <span class='pagenum'><a name="Page_469" id="Page_469">[Pg 469]</a></span>preservatives. When applied in large +quantities to the soil, it has a most deleterious action on vegetation. +This hurtful action of salt has long been known; and it is as often +mentioned in the writings of antiquity on account of its unfavourable as +on account of its favourable action. Thus, for example, among the +ancient Jews it was customary, after the conquest of a hostile town, to +strew salt on the enemy's fields, for the purpose of rendering them +barren and unfertile. And again, among the Romans, for the same purpose, +salt was often spread on a spot where some great crime had been +committed.</p> + +<p>While, therefore, its unfavourable action has long been known, the fact +that there are circumstances under which its action is, on the contrary, +favourable for promoting vegetable growth has also been long recognised. +The difficulty for the agricultural student is to reconcile these two +seemingly contradictory experiences. For the English agriculturist the +subject possesses especial interest, since in England it has been in the +past most generally used and its action most discussed since the time of +Lord Bacon, who discusses in his writings the action of solutions of it +on different plants.</p> + +<p>The true explanation of salt being so different in its action is to be +found in the quantity applied, the nature of the soil, the crop to which +it is applied, and the conditions under which it is applied—<i>i.e.</i>, +whether it is applied alone or along with other manures.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_470" id="Page_470">[Pg 470]</a></span><i>Mechanical Action on Soils.</i></p> + +<p>In the first place, it must be noted that salt exerts a mechanical +action on the soil of a very similar kind to that exercised by lime. +When applied to clay soils it causes a flocculation or coagulation of +the fine clay-particles, and thus prevents the soil from puddling to the +same extent as would otherwise be the case. In fact, an example of this +action of salt when in solution causing the precipitation of fine +suspended clayey matter, is afforded by the formation of deltas at the +mouths of rivers. The power of clarifying muddy water is common indeed +to saline solutions. Schloesing attributes the clarifying power of a +soil to the presence of the saline matters it contains; and from this +point of view it would appear that manures containing any saline +substance may exert an important mechanical influence on the soil.</p> + +<br /> +<p class="cen"><i>Solvent Action.</i></p> + +<p>But a much more important property of salt is its solvent action on the +plant-food present in the soil. Its action in decomposing the minerals +containing lime, magnesia, potash, &c., is similar to the action of +gypsum. By acting upon the double silicates it liberates these necessary +plant-foods. It is not only on the basic substances upon which it acts, +but also on the phosphoric and silicic acids, which it sets free. Its +power of dissolving ammonia from the soil is <span class='pagenum'><a name="Page_471" id="Page_471">[Pg 471]</a></span>considerable. Experiments +with a weak solution of salt on a soil by Peters and Eichhorn to test +its solvent power, showed that the salt solution dissolved more than +twice as much potash and nearly thirty times as much ammonia as an equal +quantity of pure water did. When applied to the soil, it seems chiefly +to liberate lime and magnesia. The exact nature of the chemical action +taking place is a point of some dubiety. According to some, it is +changed into nitrate of soda; according to others, into carbonate of +soda. The latter theory seems to be the more probable one. Its action on +the lime and magnesia compounds is to convert them into chlorides; and +this chemical reaction explains the action that salt has in increasing +the water-retaining and water-absorbing power of the soil; for the +chlorides of magnesia and lime are salts which have a great power of +attracting water from the air.</p> + +<p>Again, the very fact that salt acts as an antiseptic may serve to +explain its beneficial action in certain cases where it prevents +rankness of growth. No doubt this was its function when applied along +with Peruvian guano. This it might do by preventing too rapid +fermentation (nitrification) of the manure, or by actually weakening the +plant. Its action when applied with farmyard manure may also be similar. +But while its effect in many cases may be towards retarding +fermentation, on the other hand its action, when applied along with lime +to compost-heaps, is <span class='pagenum'><a name="Page_472" id="Page_472">[Pg 472]</a></span>towards promoting more rapid decomposition. +Probably a reaction takes place between the lime and the salt, the +result of which is the formation of caustic soda.</p> + +<p>Such are some of the ways in which salt may act. It must at once be seen +how its action in one case will be favourable and in another case +unfavourable. There must be fertilising matter present in the soil if it +is to act favourably. Again, it will only be under such circumstances, +where rankness of growth is likely to ensue, that its antiseptic +properties will act favourably and not unfavourably.</p> + +<br /> +<p class="cen"><i>Best used in small Quantities along with Manures.</i></p> + +<p>Probably it is for these reasons that its action has been found to be +most favourable when applied along with other manures and not alone. +Applied along with nitrate of soda, as is commonly done, it doubtless +increases the efficiency of the nitrate. Some plants seem to be +undoubtedly benefited by salt: of these flax may be mentioned. The +application of salt to plants of the cabbage tribe seems also to be +highly beneficial. On mangels, along with other manures, it has also +been found to have a very favourable effect. But with many crops its +action has been proved to be less favourable.</p> + +<br /> +<p class="cen"><i>Affects Quality of Crop.</i></p> + +<p>Although salt has often been found to increase the quantity of a crop, +the quality of the crop has been <span class='pagenum'><a name="Page_473" id="Page_473">[Pg 473]</a></span>made to suffer. Its action on beetroot +has been more especially studied. The effect of its application is to +lessen the total quantity of dry matter and sugar in the plant. This has +been found to be the case both when the salt was applied alone and along +with nitrate of soda and other manures. On potatoes, again, its action +has been found to be deleterious, lessening their percentage of starch. +The deleterious action of chlorides on the quality of potatoes is also +seen when potassium chloride is applied. It is for this reason that +potash should never be applied to the potato crop in the form of +chloride.</p> + +<p>In the late Dr Voelcker's opinion, the conditions under which salt had +the most favourable action on the mangel crop was in the case of a light +sandy soil, and applied at the rate of 4 to 5 cwt. per acre. Its action +when applied to clay soils was not so favourable.</p> + +<br /> +<p class="cen"><i>Rate of Application.</i></p> + +<p>Lastly, the rate at which it may be applied will naturally vary. From 1 +cwt. and even less, up to 6 cwt. or even more, has been the rate at +which it has been commonly applied in the past. From what has been said, +it will be seen that it is more likely to exert a favourable influence +when applied only in small quantities.</p> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_474" id="Page_474">[Pg 474]</a></span> +<br /> +<h2>CHAPTER XXII.</h2> + +<h2>THE APPLICATION OF MANURES.</h2> +<br /> + +<p>The conditions which regulate the application of manures are many and +varied, and the subject, it must be admitted, despite the large amount +of investigation already carried out, is most imperfectly understood. +For these reasons it is impossible to do little more than lay down +certain general principles which may be of service to the agriculturist +in guiding him in carrying out the manuring of his crops.</p> + +<br /> +<p class="cen"><i>Influence of Manures in increasing Soil-fertility.</i></p> + +<p>In the first place it may be asked, How far can what we may call the +permanent fertility of a field be influenced by the application of +manures? And to this question the answer must be made, that the +influence of manuring in increasing soil-fertility is very slight and +only very gradually felt. This is illustrated by the difficulty +experienced in attempting to restore to a fertile condition a soil which +has long been treated by <span class='pagenum'><a name="Page_475" id="Page_475">[Pg 475]</a></span>an exhaustive system of cultivation. In such a +case it will be found impossible to restore the fertility of the soil, +except very gradually. Farmers who farm in new countries, and in rich +virgin soils, little realise sometimes how quickly they may impoverish +the fertility of their soils by exhaustive treatment, and how slow the +process of restoration is. Nor is this strange when we reflect on the +relatively small quantities of fertilising ingredients we are in the +habit of adding to the soil by the application of manures, and the +nature of their action. The small rate at which they are applied, and +the impossibility of distributing them equally in the soil, explain how +comparatively limited their action must necessarily be. Some manures, it +is true—viz., those which are soluble—are more equally distributed; +but then such manures, from their very nature, are little likely to +affect the permanent fertility of the soil.</p> + +<br /> +<p class="cen"><i>Influence of Farmyard Manure on the Soil.</i></p> + +<p>Of manures which have the best effect in improving a soil's permanent +fertility, farmyard manure is undoubtedly the most important. This is +owing partly to the fact that it is applied in such large quantities, +and partly on account of its composition. Liberal manuring with farmyard +manure, systematically carried out, will in time do much to build up a +soil's fertility. But liberal manuring with artificial manures will also +effect the same end. This it does in an indirect manner <span class='pagenum'><a name="Page_476" id="Page_476">[Pg 476]</a></span>by means of the +increased crop residues obtained under such treatment. Indeed one of the +speediest methods of bringing a soil into good condition is by heavily +manuring certain green crops, and then ploughing them in.</p> + +<br /> +<p class="cen"><i>Farmyard Manure v. Artificials.</i></p> + +<p>The question how far farmyard manure may be supplanted by artificials is +one often discussed. We have already referred to this question in the +chapter on Farmyard Manure. It is possible that, with our increasing +knowledge of agricultural science, we may in the future be able to +dispense with farmyard manure, and make shift to do with artificials +alone. At present, however, all our experience points to the fact that +the most satisfactory results are obtained from manures by using +artificials in conjunction with farmyard manure. It is better both for +farmyard manure and artificial manures to be applied together,<a name="FNanchor_241_241" id="FNanchor_241_241"></a><a href="#Footnote_241_241" class="fnanchor">[241]</a> so +that they may mutually act as supplementary the one to the other. While +this is so, there may be circumstances in which it will be best to use +artificials alone. Where, for example, fields, owing to their situation, +are inaccessible, and where the expense of conveying the bulky farmyard +manure would be very considerable, it may be found more economical to +apply the more concentrated artificial manures. With <span class='pagenum'><a name="Page_477" id="Page_477">[Pg 477]</a></span>few exceptions, +however, it will be found most desirable to use artificial manures as +supplementary to farmyard manure, and not as substitutes for it.</p> + +<br /> +<p class="cen"><i>Farmyard Manure not favourable to certain Crops.</i></p> + +<p>While the above is true, it may be well to point out one or two facts +regarding the nature of the influence of farmyard manure on certain +crops. For instance, it has long been recognised as inadvisable in +strong rich soils to apply it directly to certain grain crops, such as +barley and wheat, since such a practice is apt to encourage rankness of +growth—an undue development of straw at the expense of the grain. It is +consequently customary to apply farmyard manure to the preceding crop. +The direct application of farmyard manure to wheat, however, according +to Sir J. B. Lawes, is not fraught with unfavourable results where the +soil is a light one; it is only when the soil is of a heavy nature that +it is best to apply it to the preceding crop. Potatoes are another crop +to which it is best not to apply it directly. On the other hand, many +are of the opinion that mangels seem to be able to benefit from large +applications of farmyard manure.</p> + +<br /> +<p class="cen"><i>Conditions determining the Application of Artificial Manures.</i></p> + +<p>In the application of artificial manures a large number of +considerations have to be taken into account. <span class='pagenum'><a name="Page_478" id="Page_478">[Pg 478]</a></span>Among these may be +mentioned the nature of the manure itself, and its mechanical and +chemical condition; the nature of the soil and its previous treatment +with manures, as well as the nature of the climate, the nature of the +crop, and the previous cropping. It may be well, therefore, to examine +somewhat in detail some of these considerations.</p> + +<br /> +<p class="cen"><i>Nature of the Manure.</i></p> + +<p>Nitrogen, phosphoric acid, and potash exist in the common manures, as +has already been pointed out, in different states of availability. +Nitrogen, for example, may exist in a soluble or insoluble condition, as +nitrates, as ammonia, or in various organic forms. Phosphoric acid, +similarly, may exist in a soluble form, as it does in superphosphate of +lime, or in an insoluble form, as it does in bones or basic slag. +Potash, on the other hand, exists—or should exist—in artificial +manures only in a soluble form. Now a correct knowledge of the behaviour +of these different forms of the common manurial ingredients when applied +to the soil is, in the first place, necessary for their successful and +economical use.</p> + +<br /> +<p class="cen"><i>Nitrogenous Manures.</i></p> + +<p>Thus our knowledge of the inability of the soil-particles to retain +nitrogen in the form of nitric acid, as well as our knowledge of the +fact that nitrogen is in this form immediately available for <span class='pagenum'><a name="Page_479" id="Page_479">[Pg 479]</a></span>the +plant's needs, teaches us that nitrate of soda should never be applied +before the plant is ready to utilise it—in short, that it should only +be applied as a top-dressing; and further, that the use of such a +fertiliser in a damp season is less likely to be economical than in a +dry one. Again, with regard to nitrogen in the form of ammonia salts, +our knowledge of the fact that ammonia is retained by the +soil-particles, and that before it becomes available for the plant's +needs it has to undergo the process of nitrification, teaches us the +desirability of applying it a short time before it is likely to be used. +While, lastly, with regard to the nitrogen in the various organic forms +in which it occurs, our knowledge of the rate at which these are +converted into an available form in the soil will determine when they +are best applied. Some forms of organic nitrogen are in a soluble +condition, and are quite as speedy in their action as sulphate of +ammonia. This is the case with a considerable proportion of the +different organic forms of nitrogen present in guano. Other forms of +organic nitrogen are only slightly less so—as, for example, dried +blood, which ferments very speedily. With regard, therefore, to nitrates +and ammonia salts, as well as the more quickly available organic forms +of nitrogen, they should either be applied as a top-dressing after the +plant has started growth, or only shortly before seed-time. Bones, +shoddy, and the various so-called native guanos, should <span class='pagenum'><a name="Page_480" id="Page_480">[Pg 480]</a></span>be applied a +considerable period before they are likely to be required—not later +than the previous autumn.</p> + +<br /> +<p class="cen"><i>Phosphatic Manures.</i></p> + +<p>With regard to phosphatic manures the same considerations hold good. +Inasmuch as phosphoric acid, whether applied in the soluble condition, +as in superphosphate, or the insoluble form, as in bones, basic slag, +&c., is not liable to be washed out of the soil, the risk of loss is +very slight, and need not be taken into account. As we have pointed out +in considering the action of superphosphate, phosphoric acid in this +latter form is more speedily available to the crop, and the necessity of +applying it much before it is likely to be used does not exist. Hence +superphosphate and manures which contain any appreciable amount of +soluble phosphoric acid, such as guano, should only be applied shortly +before seed-time. Bones, basic slag, or mineral phosphate ought to be +applied, on the other hand, a long time before they are likely to be +used. Hence an autumn application is to be recommended in the case of +such manures.</p> + +<br /> +<p class="cen"><i>Potash Manures.</i></p> + +<p>Lastly, with regard to potash manures, as these are soluble, there is no +necessity for applying them much before they are likely to be absorbed +by the plant. Some are of the opinion that potash is, except in the case +of sandy soils, best applied some <span class='pagenum'><a name="Page_481" id="Page_481">[Pg 481]</a></span>little time before it is likely to be +used, so as to permit of its being washed down into the soil—a process +which takes place only comparatively slowly. As potash manures have +often been found to give a better result on pastures during the second +year than during the first, they are best applied in the autumn.</p> + +<p>The above statement as to the behaviour of the different fertilisers +when applied to the soil, has a not unimportant bearing on the +quantities in which they may safely be respectively applied. The rate at +which manures may be applied depends, as we shall immediately see, on +other conditions; but what it is here desirable to point out is, that it +is not safe to apply such manures as nitrate of soda, or, for that +matter, sulphate of ammonia, in large quantities at a time. In fact +these manures, especially the former, will best be applied in very small +quantities, and rather in several doses. With regard to other manures, +more especially phosphatic manures, the same reasons for small +application do not exist.</p> + +<p>The truth of the above statements is so obvious that it may be regarded +as superfluous to make them. As, however, their clear apprehension is +essential to understanding the conditions of successful manuring, no +apology need be made for making them.</p> + +<br /> +<p class="cen"><i>Nature of Soil.</i></p> + +<p>Another condition which has to be taken into account in considering the +application of manures is <span class='pagenum'><a name="Page_482" id="Page_482">[Pg 482]</a></span>the nature of the soil, as well as its +previous treatment. Soils poor in organic matter are those which are +most likely to be benefited by the application of nitrogenous manures. +Soils of a dry light character require less phosphoric acid than they do +of nitrogen and potash; while on a damp and heavy soil phosphatic +manures are more likely to be beneficial than nitrogenous or potassic +manures. Lastly, a soil rich in organic matter generally requires +phosphates, and possibly potash. A point of considerable importance to +notice is, that a soil rich in lime can stand a larger application of +phosphoric acid than one poor in lime. As a rule, it will be found that +the best results with potash will be obtained when applied to a sandy +soil. The nature of the soil is an important consideration in +determining how far it is advisable to apply readily soluble manures. To +a very light and non-retentive soil the risk of loss in applying an +easily soluble manure is considerably increased. The nature of the +climate is also of importance. Thus, in a dry climate, manures of a +soluble nature will have a better effect than in a wet climate, while +the opposite will be the case with the more slowly acting manures.</p> + +<br /> +<p class="cen"><i>Nature of previous Manuring.</i></p> + +<p>A consideration of equal importance is the previous treatment of the +soil with manure. For example, where a soil has been liberally treated +with farmyard manure, it has been found that mineral manures have <span class='pagenum'><a name="Page_483" id="Page_483">[Pg 483]</a></span>a +very inferior effect to that obtained by nitrogenous manure. Lawes and +Gilbert have found this to be strikingly the case in their experiments +on the growth of wheat. In these experiments it was found that the +application of mineral manures was accompanied with little or no benefit +to the crop, whereas very striking results followed the application of +nitrogen. This they attributed to the fact that the supply of mineral +fertilisers in the straw of the farmyard manure is largely in excess of +the supply of nitrogen. The nature of the action of the manure +previously applied is also to be taken into account in determining how +long its influence may probably last. Where, for example, the manure has +been nitrate of soda or sulphate of ammonia, it may be safely concluded +that its direct influence is no longer felt a year after application. +The influence of superphosphate of lime, while scarcely so temporary, +may be said to last only for a comparatively short time.<a name="FNanchor_242_242" id="FNanchor_242_242"></a><a href="#Footnote_242_242" class="fnanchor">[242]</a> On the +other hand, when the manure applied is of a slow-acting nature, such as +bones or basic slag, its influence will probably be felt for a number of +years.</p> + +<br /> +<p class="cen"><i>Nature of the Crop.</i></p> + +<p>But more important than any of the above-mentioned conditions is the +nature of the crop itself. <span class='pagenum'><a name="Page_484" id="Page_484">[Pg 484]</a></span>Our knowledge of the requirements of the +different farm crops is still very imperfect. A very wide experience, +however, of the effect of different manures on different crops, has +conclusively proved that their manurial requirements differ very +considerably. The subject is complicated by other considerations, such +as the nature of the soil, &c.; but notwithstanding this fact, certain +points seem to be pretty well established.</p> + +<p>In seeking to understand the respective requirements of the different +crops for different fertilisers, two important considerations must be +borne in mind. These are—(1) <i>the quantities of the three fertilising +ingredients—nitrogen, phosphoric acid, and potash—which different +crops remove from the soil;</i> and (2) <i>the different power crops possess +of assimilating these ingredients.</i></p> + +<br /> +<p class="cen"><i>Amounts of Fertilising Ingredients removed from the Soil by different +Crops.</i></p> + +<p>The most convenient way of instituting a comparison between the +requirements of the different crops in this respect is by calculating +the amount, in pounds, of nitrogen, phosphoric acid, and potash, which +average amounts of the different crops remove per acre. The following +table shows this for the common crops:—</p> + +<span class='pagenum'><a name="Page_485" id="Page_485">[Pg 485]</a></span> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Mangels"> + <tr> + <td class="tdltb" colspan="2"> </td> + <td class="tdctlb">Nitrogen.</td> + <td class="tdctlb">Phosphoric Acid.</td> + <td class="tdctlb">Potash.</td> + </tr> + <tr> + <td class="tdl" width="20%">Mangels</td> + <td class="tdl" width="35%">Root, 22 tons</td> + <td class="tdcl" width="15%"> 87</td> + <td class="tdcl" width="15%">36.4</td> + <td class="tdcl" width="15%">222.8</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Leaf</td> + <td class="tdclb"> 51</td> + <td class="tdclb">16.5</td> + <td class="tdclb"> 77.9</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb">138</td> + <td class="tdclb">52.9</td> + <td class="tdclb">300.7</td> + </tr> + <tr> + <td class="tdl">Turnips</td> + <td class="tdl">Root, 17 tons</td> + <td class="tdcl"> 63</td> + <td class="tdcl">22.4</td> + <td class="tdcl">108.6</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Leaf</td> + <td class="tdclb"> 49</td> + <td class="tdclb">10.7</td> + <td class="tdclb">108.6</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb">112</td> + <td class="tdclb">33.1</td> + <td class="tdclb">148.8</td> + </tr> + <tr> + <td class="tdl">Beans</td> + <td class="tdl">Grain, 30 bushels</td> + <td class="tdcl"> 77</td> + <td class="tdcl">22.8</td> + <td class="tdcl"> 24.3</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Straw</td> + <td class="tdclb"> 29</td> + <td class="tdclb"> 6.3</td> + <td class="tdclb"> 42.8</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb">106</td> + <td class="tdclb">29.1</td> + <td class="tdclb"> 67.1</td> + </tr> + <tr> + <td class="tdl" colspan="2">Red clover hay, 2 tons</td> + <td class="tdclb">102</td> + <td class="tdclb">24.9</td> + <td class="tdclb"> 83.4</td> + </tr> + <tr> + <td class="tdl">Swedes</td> + <td class="tdl">Root, 14 tons</td> + <td class="tdcl"> 70</td> + <td class="tdcl">16.9</td> + <td class="tdcl"> 63.3</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Leaf</td> + <td class="tdclb"> 28</td> + <td class="tdclb"> 4.8</td> + <td class="tdclb"> 16.4</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb"> 98</td> + <td class="tdclb">21.7</td> + <td class="tdclb"> 79.7</td> + </tr> + <tr> + <td class="tdl">Oats</td> + <td class="tdl">Grain, 45 bushels</td> + <td class="tdcl"> 38</td> + <td class="tdcl">13.0</td> + <td class="tdcl"> 9.1</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Straw</td> + <td class="tdclb"> 17</td> + <td class="tdclb"> 6.4</td> + <td class="tdclb"> 37.0</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb"> 55</td> + <td class="tdclb">19.4</td> + <td class="tdclb"> 46.1</td> + </tr> + <tr> + <td class="tdl" colspan="2">Meadow hay, 1-1/2 ton</td> + <td class="tdclb"> 49</td> + <td class="tdclb">12.3</td> + <td class="tdclb"> 50.9</td> + </tr> + <tr> + <td class="tdl">Wheat</td> + <td class="tdl">Grain, 30 bushels</td> + <td class="tdcl"> 33</td> + <td class="tdcl">16.0</td> + <td class="tdcl"> 9.8</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Straw</td> + <td class="tdclb"> 15</td> + <td class="tdclb"> 4.7</td> + <td class="tdclb"> 25.9</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb"> 48</td> + <td class="tdclb">20.7</td> + <td class="tdclb"> 35.7</td> + </tr> + <tr> + <td class="tdl">Barley</td> + <td class="tdl">Grain, 30 bushels</td> + <td class="tdcl"> 35</td> + <td class="tdcl">16.0</td> + <td class="tdcl"> 9.8</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Straw</td> + <td class="tdclb"> 13</td> + <td class="tdclb"> 4.7</td> + <td class="tdclb"> 25.9</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl"> Total crop</td> + <td class="tdclb"> 48</td> + <td class="tdclb">20.7</td> + <td class="tdclb"> 35.7</td> + </tr> + <tr> + <td class="tdl" colspan="2">Potatoes, 6 tons</td> + <td class="tdclb"> 47</td> + <td class="tdclb">21.5</td> + <td class="tdclb"> 76.5</td> + </tr> + <tr> + <td class="tdl">Maize</td> + <td class="tdl">Grain, 30 bushels</td> + <td class="tdcl"> 28</td> + <td class="tdcl">10.0</td> + <td class="tdcl"> 6.5</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdl">Stalks, &c.</td> + <td class="tdclb"> 15</td> + <td class="tdclb"> 8.0</td> + <td class="tdclb"> 29.8</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdlb"> Total crop</td> + <td class="tdclb"> 43</td> + <td class="tdclb">18.0</td> + <td class="tdclb"> 363</td> + </tr> +</table> +</div> +<br /> + +<p><span class='pagenum'><a name="Page_486" id="Page_486">[Pg 486]</a></span>From the table it will be seen that the crops which remove the largest +quantities of all three fertilising ingredients are the root +crops—mangels and turnips; that beans remove twice as much nitrogen as +the cereals—oats, barley, and wheat—which, in this respect, +practically differ very little from one another; while potatoes remove +about the same quantity of nitrogen as the cereals. It will further be +noticed that the amounts of phosphoric acid removed by the different +crops differ very much less than those of nitrogen and potash. Mangels +remove slightly more, and turnips slightly less, than double the amount +removed by cereals. Meadow-hay, it will be seen, of all crops removes +the least phosphoric acid.</p> + +<p>In looking at the amounts of potash, we are at once struck by their +great discrepancy. Such a crop as mangels removes more than six times as +much potash from the soil as the cereals. Turnips also make large +demands on this ingredient, removing over four times as much as the +cereals. Leguminous crops, such as red clover and beans, remove about +twice as much.</p> + +<br /> +<p class="cen"><i>Capacity of Crops for assimilating Manures.</i></p> + +<p>Instructive though these figures undoubtedly are, <i>they must not be +regarded, as often erroneously they are, as furnishing by themselves +sufficient data upon which to base the practice of manuring</i>. A +consideration which is of much greater importance is the capacity that +different crops possess for assimilating the <span class='pagenum'><a name="Page_487" id="Page_487">[Pg 487]</a></span>various manurial +ingredients from the soil. Considered from the point of view of absolute +amount, there is in most soils an abundant supply of plant-food; but of +this amount only a small proportion is available. Further, the amount of +this available plant-food will vary with different crops—one crop being +able to grow where another crop would starve. As illustrative of this, +in the Norfolk experiments it was found that the turnip was able to +assimilate potash from a soil on which the swede was practically +starved. It is on this fact more than any other that the principles of +manuring are based. Several explanations of the different capacities +crops possess of assimilating their food may be put forward. And we may +here point out that crops belonging to the same class exhibit, on the +whole, a certain amount of similarity in their manurial requirements. +Thus, for example, we may say that <i>gramineous crops</i> so far resemble +one another in possessing <i>small capacity for assimilating nitrogen</i>, +<i>root crops for assimilating phosphoric acid</i>, and <i>leguminous crops for +assimilating potash</i>, and that, consequently, these crops are generally +most benefited by the application, respectively, of nitrogen, phosphoric +acid, and potash. But while a certain general resemblance exists, crops +belonging to the same class differ in many cases very considerably, as +we shall immediately see.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_488" id="Page_488">[Pg 488]</a></span><i>Difference in Root Systems of different Crops.</i></p> + +<p>One explanation of the different capacity possessed by different crops +for absorbing plant-food from the soil is to be found in the difference +of their root systems. Every agriculturist knows that crops in this +respect differ very widely. Crops having deep roots will naturally have +a larger surface of soil from which to draw their food-supplies than +crops having shallower roots. Such crops as red clover, wheat, and +mangels are able to draw their food-supplies from the subsoil to an +extent not possessed by shallower-rooted crops, such as barley, turnips, +and grass. Crops having surface-roots, on the other hand, have often +greater capacity for assimilating nitrogen,—this ingredient, as has +already been pointed out, being chiefly located in the surface-soil. The +tendency of growing shallow-rooted crops will therefore be towards +impoverishing the surface-soil; whereas the occasional growth of a +deep-rooted crop brings the plant-food in the subsoil into requisition. +In this connection it may be well to draw attention to the singular +capacity possessed by certain crops for absorbing nitrogen. Of these the +case of clover is the most striking, and has long puzzled +agriculturists. The discovery, which has been repeatedly referred to in +these pages, that the leguminous order of crops, to which clover +belongs, have the power of absorbing the free nitrogen of the air +through the agency of micro-organic life in the plant and in <span class='pagenum'><a name="Page_489" id="Page_489">[Pg 489]</a></span>the soil, +has furnished an explanation of this long-debated problem.</p> + +<br /> +<p class="cen"><i>Period of Growth.</i></p> + +<p>A further reason is the difference in the period of a crop's growth. A +crop which grows quickly, and consequently occupies the ground during a +comparatively short period, will naturally require a richer soil, and +therefore a more liberal treatment with manure, than one whose growth is +more gradual.</p> + +<p>Another consideration is the season of the year during which active +growth of the crops takes place. For example, in the case of the wheat +crop, active growth takes place in spring and ceases early in the +summer. Since, however, nitrification goes on right through the summer, +and nitrates are most abundant in the soil in late summer and autumn, +such a crop as wheat is ill suited to obtain any benefit from this +bountiful provision of nature, and is consequently particularly +benefited by the application of nitrogenous manures. Root crops, on the +other hand, sown in summer, continue their active growth into autumn, +and are thus enabled to utilise the nitrates formed in the process of +nitrification. The custom of sowing a quickly growing green crop, such +as rye, mustard, rape, &c., after a wheat crop, is a practice which aims +at conserving the nitrates and preventing their loss by autumn and +winter rains. The name "catch crop" has been applied to such a crop. By +<span class='pagenum'><a name="Page_490" id="Page_490">[Pg 490]</a></span>ploughing under the green crop, the nitrogen removed from the soil in +the form of easily soluble nitrates is restored in an insoluble organic +form, and the soil is at the same time enriched by the addition of much +valuable organic matter.<a name="FNanchor_243_243" id="FNanchor_243_243"></a><a href="#Footnote_243_243" class="fnanchor">[243]</a></p> + +<p>It is chiefly the above facts that form the scientific basis of the +long-pursued practice of the rotation of crops.</p> + +<br /> +<p class="cen"><i>Variation in Composition of Crops.</i></p> + +<p>A point of considerable interest is the influence exerted by manures on +the composition of crops. It has been assumed in the preceding pages +that the composition of crops of the same plant is uniform; but this is +not strictly the case, as it has been proved that not merely the manure +and soil have an appreciable influence on the crop's composition, but so +also has the climate.</p> + +<br /> +<p class="cen"><i>Absorption of Plant-food.</i></p> + +<p>The laws regulating the absorption of plant-food are most interesting, +although, unfortunately, very imperfectly understood as yet. The +fertilising ingredients are capable of considerable movement in the +plant, and are only absorbed up to a certain period of growth. This in +many plants is reached when they flower. After this period they are no +<span class='pagenum'><a name="Page_491" id="Page_491">[Pg 491]</a></span>longer capable of absorbing any more food. The popular belief that +plants in ripening exhaust the soil of its fertilising matters is +consequently a fallacy.</p> + +<br /> +<p class="cen"><i>Fertilising Ingredients lodge in the Seed.</i></p> + +<p>The tendency of fertilising matters is to move upward in the plant as it +matures, and finally to become lodged in the seed. It is for this reason +that the cereals prove such an exhaustive crop. That nature, however, +can in certain cases be very economical of her food-supplies, is +strikingly illustrated by the fact that much of the fertilising matter +contained in the mature leaves in autumn passes back into the tree +before the leaves fall from it.</p> + +<br /> +<p class="cen"><i>Forms in which Nitrogen exists in Plants.</i></p> + +<p>The form in which nitrogen is present in the plant is chiefly as +albuminoids. As, however, albuminoids belong to that class of bodies +known as colloids, which cannot easily pass through porous membranes +like those forming the walls of plant-cells, they are changed during +certain periods of the plant's growth into amides, which are +crystalloids, and consequently able to move freely about in the plant. +Amides are most abundant in young plants during the period of their most +active growth, and as the plant ripens the amides seem to be largely +converted into albuminoids.</p> + +<p>While the subject is not very clearly understood, it would seem to be +pretty conclusively proved that <span class='pagenum'><a name="Page_492" id="Page_492">[Pg 492]</a></span>there is a direct relation between the +amount of the phosphoric acid and of the nitrogen absorbed.</p> + +<br /> +<p class="cen"><i>Bearing of above Facts on Agricultural Practice.</i></p> + +<p>The bearing of these facts upon practice is obvious. In the first place, +they show how important it is that plants should be well fed when they +are young, and that in the practice of green manuring it is best to +plough in the crop when it is in flower, as no additional benefit is +gained by allowing it to ripen, seeing that no further absorption of +fertilising ingredients takes place after the period of flowering.</p> + +<br /> +<p class="cen"><i>Influence of excessive Manuring of Crops.</i></p> + +<p>The influence of large quantities of manures is seen in the case of +certain root crops. It is found, in such a case, that while the roots +are larger, they are more watery in composition and of less nutritive +value. Again, it seems to be a fact pretty generally known to practical +men, that nitrate of soda seems to have a bad effect on the quality of +hay. It would seem, further, that the influence of nitrogenous +fertilisers on cereals is to increase the percentage of nitrogen in the +grain, but that they have no such influence in the case of leguminous +crops. Phosphatic manures, on the other hand, in the case of leguminous +crops, seem to have the effect of diminishing the amount of nitrogen in +the seed.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_241_241" id="Footnote_241_241"></a><a href="#FNanchor_241_241"><span class="label">[241]</span></a> Though not necessarily at the same time or to each +succeeding crop. There may be comparatively long intervals between the +applications of farmyard manure in many cases.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_242_242" id="Footnote_242_242"></a><a href="#FNanchor_242_242"><span class="label">[242]</span></a> Of course what is meant here is the direct influence of +such manures. Their indirect value may be shown in the soil by the +increased crop residues they give rise to.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_243_243" id="Footnote_243_243"></a><a href="#FNanchor_243_243"><span class="label">[243]</span></a> This is very concisely and clearly put in Mr Warington's +admirable 'Chemistry of the Farm.'</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_493" id="Page_493">[Pg 493]</a></span> +<br /> +<h2>CHAPTER XXIII.</h2> + +<h2>MANURING OF THE COMMON FARM CROPS.</h2> +<br /> + +<p>In this chapter we shall attempt to summarise briefly the results of +experiments on the manuring of some of the commoner crops, and we shall +start with the manuring of cereals.</p> + +<br /> +<p class="cen">CEREALS.</p> + +<p>As we have already pointed out, a certain similarity in the manurial +requirements of the different members of this class exists. They are +characterised, for one thing, by the comparatively small quantity of +nitrogen they remove from the soil—less than either leguminous or root +crops. Of this nitrogen the larger proportion—amounting to +two-thirds—is contained in the grain, the straw only containing about a +quarter of the total amount of nitrogen in the plant. The amount of +phosphoric acid they remove from the soil is not much <span class='pagenum'><a name="Page_494" id="Page_494">[Pg 494]</a></span>less than that +removed by the other two classes of crops; but this, again, is also +chiefly in the grain. It is on this account that the cereals may be +regarded, in a sense, as exhaustive crops, seeing that the grain is +almost invariably sold off the farm. But, on the other hand, owing to +the comparatively small demands they make on fertilising ingredients, +cereals will continue to grow on poor land for a longer period than most +crops,—a fact of very great importance for mankind.</p> + +<br /> +<p class="cen"><i>Especially benefited by Nitrogenous Manures.</i></p> + +<p>Despite the fact that cereals remove comparatively little nitrogen from +the soil, it is somewhat striking to find that they are chiefly +benefited by the application of nitrogenous manures. This fact may be +explained by the shortness of the period of their growth, and the fact +that they assimilate their nitrogen in spring and early summer, and are +thus unable to utilise to the full the nitrates which accumulate in the +soil during later summer and autumn. As they seem to absorb their +nitrogen almost exclusively in the form of nitrates, they are especially +benefited by the application of nitrate of soda.</p> + +<br /> +<p class="cen"><i>Power of absorbing Silicates.</i></p> + +<p>A characteristic feature in the composition of cereals is the large +amount of silica they contain. In common with the grasses, they seem to +possess a <span class='pagenum'><a name="Page_495" id="Page_495">[Pg 495]</a></span>power, not possessed by other crops, of feeding upon +silicates.</p> + +<p>The special manure, therefore, required for cereals is a nitrogenous +manure, and that, as a rule, of a speedily available character, such as +nitrate of soda or sulphate of ammonia. Furthermore, certain members of +the group are also specially benefited by phosphatic manures.</p> + +<p>We shall now consider individually a few of the more important cereal +crops.</p> + +<br /> +<p class="cen"><span class="smcap">Barley.</span></p> + +<p>Of cereal crops barley deserves to be considered first, owing to the +fact that it is, of all grain crops, the most widely distributed. In +England, in amount, it comes next to wheat among cereals. Its habits +have also been studied in a very elaborate and careful manner, and have +been made the subject of many experiments, both in this country and +abroad.</p> + +<br /> +<p class="cen"><i>Period of Growth.</i></p> + +<p>The first point to notice about barley is the fact that its period of +growth is a short one. This has a most important bearing on its +treatment with manure. It may be said to ripen, on an average, in +thirteen or fourteen weeks in this country; although in Norway and +Sweden its period of growth is much less—viz., from six to seven weeks. +Indeed no fewer than three <span class='pagenum'><a name="Page_496" id="Page_496">[Pg 496]</a></span>crops have been obtained in one year in +certain districts in these countries, and two crops are common. With +regard to the period of its growth, it differs from wheat, which in its +general manurial requirements it resembles. Wheat, which is largely sown +in autumn, has four or five months' start of barley. From the fact that +it is a short-lived crop, and that its roots are shallower than wheat, +and draw their nourishment chiefly from the surface-soil, it benefits to +a greater extent from liberal manuring than wheat, which is more +independent of artificial supplies of fertilisers.</p> + +<br /> +<p class="cen"><i>Most suitable Soil.</i></p> + +<p>Again, while wheat does well on a heavy soil, and does not require a +fine surface-tilth, barley does best on a light, rich, friable soil. It +has, however, been very successfully grown on a heavy soil after wheat. +Barley benefits more than wheat does from the application of +superphosphate of lime, or some other readily available phosphatic +manure. This may be accounted for by its shorter period of growth and +shallower root system, which thus prevent it drawing much mineral +sustenance from the subsoil. In fact, spring-sown crops, as a rule, +benefit more from superphosphate than autumn-sown crops. The exhaustion +of a soil under barley is essentially, as in the case of wheat, one of +nitrogen, as Sir J. Henry Gilbert has pointed out.<a name="FNanchor_244_244" id="FNanchor_244_244"></a><a href="#Footnote_244_244" class="fnanchor">[244]</a></p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_497" id="Page_497">[Pg 497]</a></span><i>Farmyard Manure not suitable.</i></p> + +<p>It has been urged, with some show of reason, that farmyard manure is not +suitable for barley, as its action is too slow to have much influence on +so short-lived a plant, and that only quick-acting manures should be +used. Where farmyard manure is applied, it should be to the preceding +crop; and this is advisable for more reasons than one.</p> + +<br /> +<p class="cen"><i>Importance of uniform Manuring of Barley.</i></p> + +<p>The use to which barley is put—viz., for malting purposes—renders the +uniformity of its composition a point of great importance. Since its +quality is very largely influenced by its treatment with manures, +special care has to be exercised in their application. Grown as it +generally is after roots, fed off with sheep, its quality, it is +alleged, is apt to suffer from the unequal distribution of the manure +applied in this way. It has consequently been recommended, in order to +avoid this inequality, rather to grow a wheat crop immediately preceding +the barley.</p> + +<br /> +<p class="cen"><i>Norfolk Experiments on Barley.</i></p> + +<p>Mr Cooke, in summing up the results of the interesting Norfolk +experiments on barley, points out that in these experiments barley +always was benefited by nitrogenous manures, sometimes by superphosphate +<span class='pagenum'><a name="Page_498" id="Page_498">[Pg 498]</a></span>of lime, and more rarely by potash; that of nitrogenous manures those +of quickest action exerted the best influence. On an average it was +found that 1 cwt. nitrate of soda per acre gave an increase of 8 bushels +of barley, and 2 cwt. gave 14 bushels; while 3/4 cwt. sulphate of +ammonia (<i>i.e.</i>, the amount containing the same quantity of nitrogen as +1 cwt. nitrate of soda) gave only 5-1/2 bushels of an increase, and +1-1/2 cwt. (= 2 cwt. nitrate of soda) gave 10 bushels.</p> + +<p>Mr Cooke recommends the following manures for the barley crop. From 1/4 +to 1 cwt. of nitrate of soda, according to previous treatment of soil; +from 1 to 2 cwt. super; and where it is required, from 1/2 to 1 cwt. +muriate of potash.</p> + +<br /> +<p class="cen"><i>Proportion of Grain to Straw.</i></p> + +<p>Professor Hellriegel, the distinguished German investigator, has carried +out most elaborate experiments on a small scale, with a view to +investigating the habits of the barley plant. In the most perfectly +developed of these plants, grown under the most favourable conditions, +he found that the grain and straw were about equal in weight. Such a +proportion of grain is, however, never realised in practice, the +proportion of 2 of grain to 3 of straw being probably the common one.</p> + +<br /> +<p class="cen"><span class="smcap">Wheat.</span><span class='pagenum'><a name="Page_499" id="Page_499">[Pg 499]</a></span></p> + +<p>Wheat occupies the first position amongst cereals, in respect of extent +of cultivation, in England. As a rule it is sown in autumn, although it +is also sown in spring. It is generally taken after rotation grasses or +a leguminous crop, such as peas or beans, or after potatoes or roots.</p> + +<p>Unlike barley, it does best on a clay soil, or at any rate on a firm +soil, and requires a moist seed-bed. From the fact that wheat is often +sown after such a crop as potatoes or a root crop to which a liberal +application of manure has been given, it is not so necessary to manure +it except with a top-dressing of nitrate of soda. In short, it is +usually considered highly desirable to get land into "good heart" before +wheat, so that the wheat may obtain its nourishment from the residue of +the previous crop and the farmyard manure previously applied.</p> + +<p>Although, therefore, as a rule, the only manure it will be found +necessary to add to wheat is a nitrogenous manure, such as nitrate of +soda or sulphate of ammonia, still there are circumstances in which it +will be well to supplement these by phosphatic or even potassic manures. +On a light soil it may be advisable to add superphosphate of lime, +guano, or bone-meal, in quantities of 2 to 3 cwt. per acre, in addition +to a nitrogenous manure.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_500" id="Page_500">[Pg 500]</a></span><i>Rothamsted Experiments on Wheat.</i></p> + +<p>Of experiments carried out on the growth of wheat, those which have now +been in progress for over half a century at Rothamsted are the most +valuable and famous. In these experiments the comparative value of +nitrogen and mineral manures on this crop was strikingly exemplified. +The former gave a most marked increase in the crop, while with the +latter little or no increase was obtained. A combination of nitrogenous +and mineral manures, on the other hand, gave the most striking results. +An explanation of these results may be afforded by the fact that in +ordinary farming an excess of mineral matter, as compared with nitrates, +is returned to the soil in the crop residues and in the straw of the +farmyard manure.</p> + +<p>Of nitrogenous manures, nitrate of soda, on the whole, showed better +results than sulphate of ammonia.</p> + +<br /> +<p class="cen"><i>Continuous Growth of Wheat.</i></p> + +<p>The possibility of growing fair crops of wheat year after year for fifty +years on the same land, and that without any manure whatever, is among +the most striking of the results of these famous Rothamsted wheat +experiments.</p> + +<br /> +<p class="cen"><i>Flitcham Experiments.</i></p> + +<p>In conclusion, we may refer to Mr Cooke's Flitcham experiments. These +were carried out for the purpose <span class='pagenum'><a name="Page_501" id="Page_501">[Pg 501]</a></span>of ascertaining the most suitable +manure for the wheat crop under different conditions.</p> + +<p>It will be sufficient here to give the recommendations made by Mr Cooke +as the practical outcome of these experiments.</p> + +<p>He recommends the application of 10 tons of farmyard manure on light or +mixed soils, after rotation seeds, ploughed in in the autumn, with from +1/4 to 1 cwt. of nitrate of soda, sown in the spring. In certain cases +farmyard manure will be sufficient without the nitrate of soda. When +farmyard manure is not available, the most effective and economical +substitute is 4 cwt. per acre of rape-cake, ploughed in in the autumn, +or 1 cwt. of sulphate of ammonia, sown in the spring, with, in either +case, 1 cwt. of nitrate of soda as a spring top-dressing. In addition to +the above, on land in doubtful agricultural condition, or exceptionally +deficient in one or other of these ingredients, Mr Cooke recommends the +addition of 2 cwt. superphosphate, or 1 cwt. muriate of potash, or both +of these manures, ploughed or harrowed in in autumn.</p> + +<br /> +<p class="cen"><span class="smcap">Oats.</span></p> + +<p>Like barley, oats are generally sown in spring, and, like barley, may be +described as a shallow-rooted crop. They require, therefore, manures +which are readily available, and their demands on the different +fertilising ingredients are very similar to <span class='pagenum'><a name="Page_502" id="Page_502">[Pg 502]</a></span>barley. The manures which +will pay best, consequently, for oats, are nitrate of soda, used as a +top-dressing, and superphosphate of lime, applied along with the seed. +Probably upon no other crop is nitrate of soda so safe and so effective +as upon oats. In some respects, however, oats differ strikingly from +barley.</p> + +<br /> +<p class="cen"><i>A very hardy Crop.</i></p> + +<p>In the first place, oats are a much hardier crop than barley or wheat. +They can grow on a wonderfully wide range of soil, and under +comparatively adverse circumstances, both of climate and situation. They +are better suited for a damp climate such as our own than a warm +climate. They may be described as of all crops the least fastidious, and +will flourish on sandy, peaty, or clayey soils. While this is so, they +show a preference for soils rich in decayed vegetable matter. It is for +this reason that they flourish so well on soils freshly broken up from +pasture, and are often the first crop to be grown on such soils.</p> + +<br /> +<p class="cen"><i>Require mixed Nitrogenous Manuring.</i></p> + +<p>Stoeckhardt has found, in experiments on the manuring of the oat crop, +that they greedily absorb nitrogen during nearly the whole period of +their growth, and that, consequently, it is desirable to manure them +with a mixed nitrogenous manure which shall contain nitrogen, both in a +readily available form to supply the plant during the early stages of +its growth, and in a <span class='pagenum'><a name="Page_503" id="Page_503">[Pg 503]</a></span>less available form for the later stages of +growth. He was of the opinion that in this way a continuous and +satisfactory growth of the crop would be promoted.</p> + +<br /> +<p class="cen"><i>Arendt's Experiments.</i></p> + +<p>The oat-plant has been made the subject of many elaborate +investigations. Of these, those carried out by Arendt are the most +elaborate and best known. In these experiments the composition of the +oat-plant at different stages of growth was investigated. It was found +that the oat-plant increased during the whole period of its life, and +that two-thirds of the nitrogen absorbed was absorbed during the later +period of growth. It has since been shown, however, that the absorption +of nitrogen is very much influenced by circumstances. Indeed its +composition is peculiarly susceptible to the influence of manures, and +especially the influence of weather. Thus Arendt found that the +assimilation of nitrogen is checked by cold wet weather; while, on the +other hand, it is promoted by warm dry weather. The grain of oats grown +in warm seasons is better developed, and in composition more nutritious +(<i>i.e.</i>, contains more nitrogen), than that of oats grown in wet +seasons, while the reverse is the case with the straw.</p> + +<br /> +<p class="cen">"<i>Avenine.</i>"</p> + +<p>A point of considerable interest in connection with the composition of +oats is the fact that it contains a <span class='pagenum'><a name="Page_504" id="Page_504">[Pg 504]</a></span>body which exerts a strikingly +stimulating effect on the nervous system of the animal, and to which the +name "avenine" has been given.</p> + +<br /> +<p class="cen"><i>Quantities of Manures.</i></p> + +<p>The quantities of manures which may be applied to the oat crop are +similar in amount to those which ought to be applied to barley—from 1/2 +to 1 cwt. of nitrate of soda, and from 2 to 3 cwt. superphosphate of +lime. Very often, however, the oat crop receives directly little or no +manure. In the Highland and Agricultural Society of Scotland's +experiments, sulphate of ammonia was found to be of very much less value +than nitrate of soda as a manure for oats. Potash manures, especially +muriate of potash, had a very beneficial effect. The general conclusions +drawn from these experiments were, that the treatment of the land should +be such as to accumulate organic matter in it, to prevent too great a +loss of moisture, and to provide the young plant with manures that come +speedily into operation.</p> + +<br /> +<p class="cen">GRASS.</p> + +<p>The manuring of grass is a question of very great interest and +importance, but is, at the same time, beset with peculiar difficulties. +Grass is grown under two conditions—first, that grown on soils +exclusively <span class='pagenum'><a name="Page_505" id="Page_505">[Pg 505]</a></span>set apart for its continuous growth (permanent pasture); +and secondly, that grown for the purpose of being converted into hay and +of providing pasture in the ordinary rotation of crops (rotation seeds). +The manuring of the former is somewhat different from the manuring of +the latter.</p> + +<br /> +<p class="cen"><i>Effect of Manure on Herbage of Pastures.</i></p> + +<p>The nature of the herbage growing on pasture is very much influenced by +the manure applied. This, indeed, is one of the most noteworthy features +connected with the manuring of grass, and has been especially observed +in the Rothamsted experiments, where the influence of the different +manures on the various kinds of herbage has been investigated with great +care. The herbage constituting pasture is, as every farmer knows, of a +varied description. We have in pastures a mixture of plants belonging +both to the gramineous and leguminous classes, as well as a variety of +weeds. Now the result of the application of different manures tends +respectively to foster the different kinds of grasses. Thus when one +kind of manure is applied, grasses of one kind tend to predominate and +crowd out grasses of another. It has been found that <i>the more highly +pasture-land is manured the simpler is the nature of its herbage</i> (that +is, the fewer are the different kinds of herbage growing on it). +<i>Unmanured pasture, on the other hand, is more complex in its herbage.</i> +The result is, that the <span class='pagenum'><a name="Page_506" id="Page_506">[Pg 506]</a></span>application of manure to pasture-land is +attended with certain dangers. To maintain good pasture it is desirable +to effect a proper balance between the different kinds of grasses. For +this reason permanent pasture may be said to be, of all crops, the least +commonly manured. As a rule it is only manured by the droppings of the +cattle and sheep feeding upon it.</p> + +<br /> +<p class="cen"><i>Influence of Farmyard Manure.</i></p> + +<p>It is found that the influence of farmyard manure upon the composition +of the pasture does not tend, to the same extent, to the undue +development of one type of herbage over another; and in this respect it +is probably to be preferred to artificial manures.</p> + +<p>The same reasons, however, do not hold with regard to rotation seeds, +where an abundant growth is desired, and complexity of herbage is not so +important. A further reason which exists for the manuring of meadow-land +is the greater impoverishment of the soil taking place under such +conditions. As illustrating the influence of different manures on +different kinds of herbage, it may be mentioned that in New England +wood-ashes, a manure commonly used there, have been observed, when +applied to pasture, to bring in white clover, and that the application +of gypsum had the same effect. An explanation of this fact may be found +in the influence of potash on leguminous crops. The chief value of +wood-ashes as a manure is due to the large percentage of potash they +<span class='pagenum'><a name="Page_507" id="Page_507">[Pg 507]</a></span>contain, while the value of gypsum is probably to be accounted for by +the fact that it has an indirect action, and sets free potash from its +inert compounds in the soil. In the Rothamsted experiments this point +has been verified, and potash has been shown to increase the proportion +of leguminous plants on a grass-field. Nitrogenous manures, on the other +hand, more especially sulphate of ammonia, have been found to increase +the proportion of grasses proper, and to diminish the proportion of +leguminous plants. The effect of farmyard manure, while less marked in +inducing simplicity of herbage, has a similar effect to sulphate of +ammonia; while phosphates and other mineral manures exercise an +influence similar to that of potash. Mixtures of mineral and nitrogenous +manures gave the largest returns obtained, but their influence was to +increase the proportion of grasses proper. Sewage irrigation also tends +chiefly to develop grasses.</p> + +<br /> +<p class="cen"><i>Influence of Soil and Season on Pastures.</i></p> + +<p>Manures are not the only factors influencing the quality of pastures. +The nature of the soil, as well as the age of the pasture and the +character of the season, exert a very considerable influence. Grass +growing on damp or badly drained soil is invariably of poor quality, the +coarser grasses predominating. Old pastures, again, are generally of +better quality than new ones.</p> + +<br /> +<p class="cen"><span class="smcap">Manuring of Meadow-Land.</span><span class='pagenum'><a name="Page_508" id="Page_508">[Pg 508]</a></span></p> + +<p>Nitrate of soda is a common manure for grass grown for hay. It is often +applied at the rate of 2 or 3 cwt. per acre. It is best, however, to +apply it in smaller doses. On soils where lime is abundant, +superphosphate may be applied, if necessary, at the rate of 2 or 3 cwt. +per acre, or bones at a similar rate. Basic slag has been found to meet +with good results as a manure for grass-land, especially where the soil +is rich in organic matter.</p> + +<br /> +<p class="cen"><i>Bangor Experiments.</i></p> + +<p>Mr Gilchrist of University College, Bangor, as a result of numerous +experiments carried out in different parts of Wales, recommends for +rye-grass and clover hay on land in good condition 1 cwt. of nitrate of +soda or sulphate of ammonia per acre, the former being applied about the +middle of April, the latter during March. For land in poor condition, +the addition of 2 cwt. of superphosphate is recommended—this to be +applied some time between December and March. Farmyard manure may be +usefully applied to young grass and clover seeds in the autumn, more +especially on light soils. For meadow-land which is growing hay every +year, Mr Gilchrist further recommends the following 4-course rotation of +manuring:—</p> + +<p>First year, 15 tons farmyard manure, applied in the autumn.</p> + +<p><span class='pagenum'><a name="Page_509" id="Page_509">[Pg 509]</a></span>Second year, 1 cwt. nitrate of soda.</p> + +<p>Third year, 4 cwt. basic slag or 3 cwt. superphosphate and 1 cwt. +nitrate of soda.</p> + +<p>Fourth year, 1 cwt. nitrate of soda.</p> + +<br /> +<p class="cen"><i>Norfolk Experiments.</i></p> + +<p>Mr Cooke, from his Norfolk experiments, recommends the following manures +for rotation seeds:—</p> + +<p>One to 1-1/2 cwt. nitrate of soda as a top-dressing in early spring. +Where the clover plant is a good one, and it is particularly desired to +cultivate it, he recommends as a dressing 1 cwt. of muriate of potash +per acre, to be applied immediately after the clover is sown. The +practice of dressing growing seeds in their first winter has, so far as +the experiments in Norfolk go, less to recommend it than the earlier +dressing.</p> + +<br /> +<p class="cen"><span class="smcap">Manuring of Permanent Pastures.</span></p> + +<p>In this case the manure should be applied so as not to impair the +quality of the herbage. Slow-acting manures are consequently best, such +as basic slag or bones, which have been found to be of special value. On +wet or marshy land after draining, lime is perhaps one of the best +manures to apply in the first instance. As we have already said, +farmyard manure will do more to maintain the quality of pasture than any +kind of artificial manure. Mr Cooke is of opinion that no system of +manuring yet discovered will both <span class='pagenum'><a name="Page_510" id="Page_510">[Pg 510]</a></span>thicken and improve the herbage at +all equally in success to the careful and regular feeding upon the grass +of cattle or sheep, the animals having a good allowance of decorticated +cotton-cake, or even of linseed-cake.</p> + +<br /> +<p class="cen">ROOTS.</p> + +<p>Of all crops roots may be said to require the most liberal application +of manure, and to respond most freely to it. They contain large +quantities of the fertilising ingredients—nitrogen, phosphates, and +potash—and may be regarded as exceedingly exhaustive crops. This is +especially the case with regard to mangels, which make particularly +large demands on a soil's fertilising ingredients.</p> + +<p>Turnips are characterised by the large amount of sulphur they contain; +and, according to some, this explains the beneficial effect which gypsum +has when applied to them as a manure. This, however, is more probably to +be explained by the indirect action of gypsum in setting free the potash +of the soil. The fact that the successful cultivation of root crops +depends on the application of large quantities of manure, is recognised +in practice, as they receive the most manure of any crop of the +rotation. Roots flourish best on a light soil which is neither too wet +nor too dry; but with liberal manuring and careful tillage, they may be +said to do well on any soil. Mangels <span class='pagenum'><a name="Page_511" id="Page_511">[Pg 511]</a></span>are generally more benefited by +the application of nitrogenous manures than are turnips or swedes, +which, it would seem, have a greater power of absorbing nitrogen from +the soil than the first-named crop; but it is a mistake to suppose that +any of the root crops are not dependent on a ready supply of nitrogen; +and the fact that large crops of turnips can often be grown by the +application of superphosphate alone, may be taken as a proof that the +soil contains plenty of nitrogen. Mangels are, from their deeper roots, +more capable of drawing their supply of phosphoric acid from the soil +than turnips. They respond, therefore, as a rule, less freely than +turnips or swedes to an application of superphosphate. Generally +speaking, we may say that the characteristic manure for turnips is +superphosphate, and that for mangels is a nitrogenous manure such as +nitrate of soda or sulphate of ammonia.</p> + +<p>A special reason for manuring root crops is the fact that they are more +liable to disease than other crops; and this is especially the case in +the early stages of their growth. One of the great benefits conferred on +the turnip crop by an application of superphosphate, is the help it +gives the crop to pass safely the critical period of its growth. The +superphosphate is best drilled in with the seed, in quantities varying +from 3 to 5 cwt. In Scotland, it may be well to point out, the manure +applied to this crop is very much in excess of the amount customarily +applied in England; for in the former country larger applications of +manure <span class='pagenum'><a name="Page_512" id="Page_512">[Pg 512]</a></span>may be profitably employed. Roots generally receive a large +dressing of farmyard manure. Salt has been found in some districts to +have a very good effect on the mangel crop, and potash is often found to +amply repay application.</p> + +<br /> +<p class="cen"><i>Influence of Manure on Composition.</i></p> + +<p>A most interesting point in connection with the manuring of roots is the +effect of manure on their composition. This has been most elaborately +investigated at Rothamsted and elsewhere. Thus it has been found that +the effect of the application of excessive quantities of nitrogenous +manures is to produce too great a development of leaves at the expense +of the roots.</p> + +<br /> +<p class="cen"><i>Nitrogenous Manures increase Sugar in Roots.</i></p> + +<p>Nitrogenous manures also tend to increase the proportion of sugar and +diminish the proportion of nitrogenous matter in roots. This has an +important bearing on the treatment of roots which are cultivated for +their sugar, such as beets, in the growth of which nitrate of soda is +the chief artificial manure applied.<a name="FNanchor_245_245" id="FNanchor_245_245"></a><a href="#Footnote_245_245" class="fnanchor">[245]</a></p> + +<p>The leaf, it may be pointed out, contains a larger percentage of dry +matter, both in swedes and in turnips, than the root.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_513" id="Page_513">[Pg 513]</a></span><i>Amount of Nitrogen recovered in Increase of Crop.</i></p> + +<p>With regard to the amount of nitrogen recovered in the increased crop of +mangel and roots when manured with different nitrogenous manures, it was +found at Rothamsted, as an average of six years, that the following +percentages of nitrogen were recovered: When nitrate of soda was +applied, 60 per cent of the nitrogen it contained was recovered in the +increased crop; when ammonia salts were applied, 52 per cent; when +rape-cake was used, 50 per cent; and when a mixture of rape-cake and +ammonia salts was used, 46 per cent.</p> + +<p>It may be pointed out that the influence of season and climate on the +composition of root crops is very great—greater, indeed, than on any +other crop. Like oats, turnips grow better in Scotland than in England, +the moister climate of the former country being more suitable for their +maximum development, and hence the economy of maximum dressings in +Scotland.</p> + +<br /> +<p class="cen"><i>Norfolk Experiments.</i></p> + +<p>In conclusion, a few words may be said on the Norfolk experiments, +carried out under the direction of Mr Cooke for the purpose of +ascertaining the best and most economical manure for mangels and swedes +on different Norfolk soils. In most of these experiments it was found +that superphosphate had not much effect in producing increase of crop in +the case <span class='pagenum'><a name="Page_514" id="Page_514">[Pg 514]</a></span>of mangels; that the best nitrogenous manure was nitrate of +soda; and that on the whole it was not economical to apply farmyard +manure at the rate of more than 10 tons per acre. It was further found +that, although either potash or common salt gave a decided increase in +weight of roots, it was not necessary to give both these manures at +once, either of them being about as effective as the other.</p> + +<p>Mr Cooke recommends the following manures as best suited for +mangels—viz., 2 cwt. nitrate, 3 cwt. common salt, and 2 cwt. +superphosphate. Upon certain soils peculiarly adapted to mangels, and in +warm localities where larger crops than 25 to 30 tons per acre are +habitually grown, it would probably pay to increase or to double the +above quantity of nitrate of soda. Ten tons of farmyard manure may, if +preferred, be substituted for all or a part of the nitrate of soda, or +may even be used in addition to it, according to the resources of the +farmer in respect of it, and the return he desires to get from the dung +in the first year of application or in future ones. It is best to apply +the nitrate of soda in two instalments—half at the time of seeding, and +half as a top-dressing immediately after the first hand-hoeing of the +roots. A third dressing may often be given with advantage a month later.</p> + +<br /> +<p class="cen"><i>Manure for Swedes.</i></p> + +<p>As a complete and economical dressing for swedes in Norfolk, Mr Cooke +recommends 3 to 4 cwt. <span class='pagenum'><a name="Page_515" id="Page_515">[Pg 515]</a></span>superphosphate, 1 cwt. sulphate of ammonia, and +1/2 cwt. of muriate of potash. Occasionally it may be found advisable to +reduce the quantity of sulphate of ammonia, or to leave it out +altogether; and in other cases the potash may be judiciously omitted. +The entire mixture should be sown at the time of drilling the turnips. +If farmyard manure is used—and if used it should be applied in a +well-decomposed state—no other manure than 3 cwt. of superphosphate +will be required.</p> + +<br /> +<p class="cen"><i>Highland Society's Experiments.</i></p> + +<p>Valuable experiments have been carried out on the subject of manuring of +turnips by Dr A. P. Aitken, for the Highland and Agricultural Society of +Scotland. The following are some of the results to be gathered from +these experiments. The effect of a dissolved phosphate as compared with +a ground phosphate is to produce a turnip of less feeding value. +Superphosphate had a better effect when applied in April than when +applied with the seed in June. It was further found that when the +nitrogenous manure was given entirely in the form of nitrate of soda or +sulphate of ammonia, the latter produced a denser and sounder turnip. +Lastly, with regard to the application of potash, it was found that the +best way was to apply it several months before sowing. The effect of +potash manures is to increase the amount of turnips, but to retard the +ripening of the bulbs. The effect of excessive potash manuring is to +greatly injure the crop.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_516" id="Page_516">[Pg 516]</a></span><i>Manuring for rich Crops of Turnips.</i></p> + +<p>In Dr Aitken's own words: "In order to grow a large and at the same time +a healthy and nutritious crop of turnips, such a system of manuring or +treatment of the soil, by feeding or otherwise, should be practised as +will result in the general enriching and raising of the condition of the +land, so that the crop may grow naturally and gradually to maturity. For +that purpose a larger application of slowly acting manures, of which +bone-meal may be taken as the type, is much better suited than smaller +applications of the more quickly acting kind. A certain amount of +quickly acting manure is very beneficial to the crop, especially in its +youth; but the great bulk of the nourishment which the crop requires +should be of the slowly rotting or dissolving kind, as uniformly +distributed through the soil as possible."</p> + +<br /> +<p class="cen"><i>Experiments by the Author.</i></p> + +<p>Experiments by the author on turnip-manuring, carried out in different +parts of the South and West of Scotland, showed that while farmyard +manure is valuable in giving the crop a good start and bringing it well +forward during the period of germination and early growth, by supplying +a certain amount of easily assimilable plant-food, and in the case of +dry weather attracting a quantity of moisture, its application in +quantities of 20 or even 10 tons per <span class='pagenum'><a name="Page_517" id="Page_517">[Pg 517]</a></span>acre can scarcely be regarded as +profitable, giving to farmyard manure a nominal value of a few shillings +a ton. In these experiments slag proved itself a most valuable manure, +indeed one of the most economical of all the manures experimented with. +They further showed that heavy dressings with superphosphate, amounting +to as much as 8 cwt. per acre, are, from an economical point of view, as +a rule justifiable in Scotland; and that nitrate of soda and sulphate of +ammonia possess practically equal value as a manure for turnips. In +almost every one of the experiments the benefit of supplementing +superphosphate with nitrogenous manure was shown. Potash was also found +in many cases to be a thoroughly paying manure for the turnip crop, when +it was applied along with nitrogen and phosphates; but when applied +alone, far from exercising any appreciable benefit, it seemed to exert +an injurious action.</p> + +<br /> +<p class="cen"><span class="smcap">Potatoes.</span></p> + +<p>Potatoes are often classed along with the root crops, and in their +manurial requirements they offer many points of similarity. Next to root +crops, they may be said to make the most exhaustive demands on the soil, +and therefore require a liberal general manuring. A point of importance +in the manuring of potatoes is a good tilth in the soil, so as to enable +a free expansion of the tubers to take place. They may be said to <span class='pagenum'><a name="Page_518" id="Page_518">[Pg 518]</a></span>grow +best on deep warm soils; but, like roots, if liberally manured, they may +be successfully grown on any kind of soil. Farmyard manure has long been +regarded as specially valuable for the potato crop. In many parts of +Scotland it is applied in enormous quantities, ranging from 20 to even +40 tons per acre. There can be little doubt that the value of farmyard +manure, as well as other bulky manures, for the potato crop, is partly +due to their mechanical influence on the soil. Potatoes are +surface-feeders, and require their food in a readily available +condition. It is found desirable, therefore, to supplement farmyard +manure by readily available artificial manures. Potatoes repay the +application of a mixed manure containing all the fertilising +ingredients—nitrogen, phosphoric acid, and potash—better than most +crops.</p> + +<br /> +<p class="cen"><i>Highland Society's Experiments on Potatoes.</i></p> + +<p>The nitrogen is, according to the Highland Society's experiments, best +applied in the form of nitrate of soda. Sulphate of ammonia does not +seem, when farmyard manure is also applied, to have an equally valuable +effect, as it influences the size of the tuber, producing an undue +proportion of small potatoes. When no farmyard manure is applied, +however, sulphate of ammonia seems to have a good effect, especially in +wet seasons.</p> + +<p>With regard to the nature of the phosphatic manure to be applied, +superphosphate is to be preferred. <span class='pagenum'><a name="Page_519" id="Page_519">[Pg 519]</a></span>Potatoes make large demands on +potash, and consequently require potassic manures. In consequence of the +fact that they receive large applications of farmyard manure, the +necessity for adding potash in the form of artificial manures does not +generally exist. Potash, if applied in too large quantities, has been +found to exert a deleterious effect. We have already pointed out that +muriate of potash tends to produce a waxy potato.</p> + +<br /> +<p class="cen"><i>The Rothamsted Experiments with Potatoes.</i></p> + +<p>The Rothamsted experimenters have very fully investigated the conditions +of the manurial requirements of potatoes. In these experiments potatoes +were grown year after year in the same field. It was found that the +effect of mineral manures alone was greater than the effect of +nitrogenous manures alone, and that of mineral manures phosphates, as a +rule, had a better effect than potash; that under the action of the +growth of potatoes a greater exhaustion of phosphates than of potash +takes place in the soil; and lastly, that it is essential to have an +abundant supply of the different fertilising ingredients in order to +grow successful crops. In the Rothamsted experiments, the slow action of +farmyard manure in supplying fertilising ingredients to the potatoes is +strikingly demonstrated. Thus, although farmyard manure was applied at +such a rate that more than 200 lb. of nitrogen were added to the soil, +the result was inferior to that obtained <span class='pagenum'><a name="Page_520" id="Page_520">[Pg 520]</a></span>from the application of 86 lb. +of nitrogen applied in the form of readily available artificial manure.</p> + +<br /> +<p class="cen"><i>Effect of Farmyard Manure on Potatoes.</i></p> + +<p>It may be said, in this respect, that the potato is less able to utilise +the fertilising ingredients of farmyard manure than any other of the +farm crops. Yet, despite this fact, farmyard manure has been found to be +one of the best manures to apply. The reconciliation of these seemingly +contradictory statements depends on the influence exerted by the +farmyard manure on the mechanical condition of the soil, rendering it +more porous and easily permeable to the surface-roots, upon the +development of which the success of the crop so much depends. The +beneficial effect of farmyard manure is also doubtless due to the +increased temperature which large applications of it produce in a soil.</p> + +<p>Sir J. Henry Gilbert, in his well-known Cirencester Lecture on the +Growth of Potatoes, cites several examples of the manurial treatment of +potatoes in different parts of the country. In Forfarshire, farmyard +manure or stable manure is largely employed (at the rate of 12 to 14 +tons, and in some cases even 20 tons per acre), and it is also largely +supplemented by artificial manures. These latter are applied to the +extent of about 10 cwt., and consist of superphosphate, dissolved bones, +and potash salts. Six tons of potatoes are considered a fair crop. In +<span class='pagenum'><a name="Page_521" id="Page_521">[Pg 521]</a></span>East Lothian the manuring is similar, with the exception that farmyard +manure is applied in even larger quantities—30 to 40 tons being often +used. Sometimes potatoes are grown with artificial manures alone. It +would seem that the usual crop of potatoes ranges from 4 to 8 tons per +acre.</p> + +<br /> +<p class="cen"><i>Manuring of Potatoes in Jersey.</i></p> + +<p>The manuring of the potato crop, so largely grown in Jersey in the +Channel Islands, is of interest. Potatoes are there grown two or three +years, then corn, then grass for a few years, then potatoes again, no +special rotation of crops being followed. Either farmyard manure or +sea-weed is applied at the rate of 25 to 30 tons per acre, supplemented +by 8 to 12 cwt. of artificial manures.</p> + +<p>These statements show how prevalent the practice of heavily manuring the +potato crop is.</p> + +<br /> +<p class="cen"><i>The Influence of Manure on the Composition of the Potato.</i></p> + +<p>The influence of manure on the composition of the potato crop is of much +interest. Potatoes grown without manure, just as in the case of roots, +are found to have a larger percentage of nitrogen than potatoes grown +with manure. The effect of manuring, therefore, is to increase the +proportion of starch, which is the most important constituent of the +potato. Mineral manures have a greater effect in increasing <span class='pagenum'><a name="Page_522" id="Page_522">[Pg 522]</a></span>the +percentage of starch than purely nitrogenous manures; but when used +together, a still greater increase is obtained than when used singly. +The effect of nitrogenous manures on the composition of roots and +potatoes is thus seen to be similar. In the case of both crops the +effect is to increase the proportion of the characteristic carbohydrate +constituent, which in roots is sugar, and in potatoes starch. Potatoes, +like roots, are also much influenced by the season. The effect of season +and manuring on the potato disease is worthy of notice. Wet seasons are +favourable to the development of the disease. It has been found that in +a highly nitrogenous manured crop the proportion of diseased tubers is +greater than in a non-manured crop.</p> + +<br /> +<p class="cen">LEGUMINOUS CROPS.</p> + +<p>We have already referred to the manuring of crops of the leguminous +class in discussing the manuring of meadows and permanent pasture. It +was there pointed out that the tendency of certain manures was to +encourage the growth of the leguminous plants of the herbage, while +other manures had the effect of encouraging those of the gramineous +class. It was pointed out that a manure which had this effect was +potash, or any manure which owed its characteristic action to the fact +that it supplied potash to the soil or set it free in the soil.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_523" id="Page_523">[Pg 523]</a></span><i>Leguminous Plants benefit by Potash.</i></p> + +<p>This is one of the most important points to notice in manuring +leguminous plants. Just as we can say that nitrogenous manures are +specially beneficial to cereals, and phosphatic manures to roots, so +potash is the special manure for leguminous crops.</p> + +<br /> +<p class="cen"><i>Nitrogenous Manures may actually be hurtful.</i></p> + +<p>But we have, further, an even more striking characteristic of leguminous +crops to notice. We have seen that, with regard to the crops already +discussed, while there are cases in which a fertilising ingredient may +be of no value, or may positively exert a hurtful action on the crops, +such cases are only exceptional. With regard to leguminous crops, +however, we find that almost invariably they derive little or no benefit +from the use of artificial nitrogenous manures. And this is all the more +striking since they contain large quantities of nitrogen in their +composition—twice as much as the cereals. The fact, which has long been +noticed with regard to certain members of this class of plants, such as +clover, that not only do they contain a large amount of nitrogen, but +that by growing them on a soil the soil is largely enriched in this +valuable fertilising constituent, has long waited for a satisfactory +explanation, which at last has been forthcoming. The discovery that +leguminous crops can <span class='pagenum'><a name="Page_524" id="Page_524">[Pg 524]</a></span>draw on the boundless store of nitrogen present in +the air has done much to clear up the mystery. There are, however, other +problems with regard to the growth of leguminous plants which still +await solution.</p> + +<br /> +<p class="cen"><i>Clover-sickness.</i></p> + +<p>One of these is the fact that land on which a leguminous crop like +clover has been growing for a number of years becomes unfit to support +its growth any longer. Such a soil is termed "clover-sick"; and many +have been the theories put forward to explain the phenomenon, but none +of them can be regarded as satisfactory.</p> + +<p>The knowledge that leguminous plants have the power of deriving their +nitrogen from the air, furnishes us with an economical means of +enriching our soils in nitrogen. By growing leguminous crops alternately +with cereals, for example, the air should be made to furnish the +necessary nitrogenous manure. As a matter of fact, modified forms of +such a practice have long been in use—indeed the ordinary rotations of +crops are, to a certain extent, adaptations of this practice.</p> + +<br /> +<p class="cen"><i>Alternate Wheat and Beans Rotation.</i></p> + +<p>An interesting experiment carried out at Rothamsted may be here cited +which illustrates in a striking manner the truth of the above statement. +Wheat and the leguminous crop beans were grown <span class='pagenum'><a name="Page_525" id="Page_525">[Pg 525]</a></span>alternately. It was +found that almost as much wheat (containing nearly as much nitrogen) was +yielded in eight crops of wheat so grown as was yielded by sixteen crops +of wheat grown consecutively in an adjoining field.</p> + +<p>The most commonly cultivated leguminous crops are clover, beans, and +peas. Clover having been already discussed, we need only say a word or +two on the manuring of beans and peas.</p> + +<br /> +<p class="cen"><span class="smcap">Beans.</span></p> + +<p>Beans do best on strong land, and, unlike some of the crops considered, +do not require a particularly fine tilth. They are generally grown after +cereals, and as a rule are sown in spring. More rarely, however, they +are sown in autumn. Spring-sown beans take about seven months to come to +maturity. They are much affected, like other crops, but to a greater +extent, by the nature of the season—a wet season inducing an undue +development of straw.</p> + +<br /> +<p class="cen"><i>Manure for Beans.</i></p> + +<p>In common practice the manure used for the bean crop is farmyard manure, +applied to the soil in autumn after the harvest of the wheat, barley, or +other cereal crop grown. So common is this practice, that the belief +commonly exists that farmyard manure is necessary for a successful bean +crop. But <span class='pagenum'><a name="Page_526" id="Page_526">[Pg 526]</a></span>experiments conducted at the Highland Society's Experiment +Station at Pumpherston show that full crops of beans may be grown with +the aid of artificial manures on soils which have received no +application of farmyard manure for ten years.</p> + +<br /> +<p class="cen"><i>Relative Value of Manurial Ingredients.</i></p> + +<p>In the Appendix<a name="FNanchor_246_246" id="FNanchor_246_246"></a><a href="#Footnote_246_246" class="fnanchor">[246]</a> will be found a table giving the results of +manurial experiments with the nitrogenous, phosphatic, and potash +manures on beans, carried out by Dr A. P. Aitken at the Highland +Society's Experiment Station. From these experiments it will be seen +that the application of phosphates and nitrogenous manures, either alone +or together, exerted a comparatively small effect in increasing the +yield of beans compared with that obtained with potash, either alone or +combined with phosphates. As Dr Aitken says, "Without potash in the +manure, the other two ingredients are of very little use, unless, +indeed, the land be very rich in potash."</p> + +<br /> +<p class="cen"><i>Gypsum.</i></p> + +<p>Gypsum has a good effect on the bean crop, both on account of the lime +it contains, and of its indirect action in setting free potash.</p> + +<p>Superphosphate is a much better manure than insoluble phosphates, and +similarly, in the few cases where nitrogenous manures are beneficial, +the speediest acting are best. Hence nitrate of soda is to be <span class='pagenum'><a name="Page_527" id="Page_527">[Pg 527]</a></span>preferred +to other nitrogenous manures. When it is applied, it should be applied +in small quantities. A slow-acting nitrogenous manure is positively +injurious; so also, according to Dr Aitken, is nitrate of soda, applied +as a top-dressing to the crop.</p> + +<p>Of potash manures, the muriate seems to be more effective than the +sulphate.</p> + +<br /> +<p class="cen"><i>Effect of Manure on Composition of Crop.</i></p> + +<p>Lastly, we may refer to the effect of manures on the composition of the +crop. This is, on the whole, very slight, especially when compared with +the effect manures exert on the composition of such crops as turnips or +potatoes. It is the quantity and not the quality of the crop which the +manure affects in the case of beans.</p> + +<br /> +<p class="cen"><span class="smcap">Peas.</span></p> + +<p>Peas are not grown to anything like the same extent as beans. As a rule, +when they are cultivated it is along with beans, when they are +necessarily manured in a similar manner. If grown alone, however, it may +be well to point out that peas do best, unlike beans, on light, friable, +chalky loam. When grown in clay they tend to develop an undue amount of +straw. The effect of season on the crop is similar to that exerted on +the bean crop. In conclusion, it may be pointed out that it is alleged +that the effect of farmyard manure on peas is to force the straw.</p> + +<p><span class='pagenum'><a name="Page_528" id="Page_528">[Pg 528]</a></span>In concluding this chapter a word or two may be said on the manuring of +two other crops which are cultivated to a considerable extent in this +country—viz., hops and cabbages.</p> + +<br /> +<p class="cen"><span class="smcap">Hops.</span></p> + +<p>The requirements of the hop crop in the matter of manures are rather +singular. It has been pointed out that in the case of most crops +quick-acting manures are to be preferred to slow-acting manures. With +hops, however, the case is very different; for they require, and cannot +be successfully cultivated without, slow-acting manures. Hops are +especially benefited by bulky nitrogenous manures—such as shoddy, +horn-meal, hide-scraps, hoofs, rape-dust, &c.; and it is only when +quick-acting manures are applied along with such slow-acting manures +that they will exercise their full influence. It is best to manure hops +twice a-year,—in spring with farmyard manure, supplemented by a +slow-acting nitrogenous manure, such as shoddy; and again in summer with +a more quickly acting manure. The dressings applied to hops are enormous +relatively to those used on other farm crops.</p> + +<br /> +<p class="cen"><span class="smcap">Cabbages.</span></p> + +<p>Cabbages belong to that class of crops known as gross feeders, to which +any sort of manure, applied in almost any quantities, does not come +amiss. <span class='pagenum'><a name="Page_529" id="Page_529">[Pg 529]</a></span>Cabbages grow best on good loams with a well-drained porous +subsoil, although they also do well on clay soils. The quantity of +fertilising ingredients, especially potash, which a large crop of +cabbage removes from the soil is very great. They consequently require +large quantities of manure, and are especially benefited by saline +manures—such as kainit and common salt—and liberal doses of nitrate of +soda, which may be regarded as the most effective of manures for all the +cabbage tribe. Farmyard manure may be applied with benefit in larger +quantities than it would be applied to any other crop.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_244_244" id="Footnote_244_244"></a><a href="#FNanchor_244_244"><span class="label">[244]</span></a> See his Lecture on the Growth of Barley.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_245_245" id="Footnote_245_245"></a><a href="#FNanchor_245_245"><span class="label">[245]</span></a> Small roots are found to contain a larger proportion of +sugar than large roots.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_246_246" id="Footnote_246_246"></a><a href="#FNanchor_246_246"><span class="label">[246]</span></a> See Note I., p. 530.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_530" id="Page_530">[Pg 530]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER XXIII.</h2> +<br /> + +<p class="cen">NOTE I. (p. 526).</p> + +<p class="cen"><span class="smcap">Experiments on the Manuring of Beans.</span></p> + +<p>Experiments with beans carried out at the Highland and Agricultural +Society's Experiment Station at Pumpherston, showing the effect of +potash:—</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Kind"> + <tr> + <td class="tdl">No. of</td> + <td class="tdc"> </td> + <td class="tdc">Bushels dressed</td> + </tr> + <tr> + <td class="tdl" width="20%">plots.</td> + <td class="tdc" width="60%">Kind of manure.</td> + <td class="tdl" width="20%">grain, per acre.</td> + </tr> + <tr> + <td class="tdl"> 27.</td> + <td class="tdl">No manure</td> + <td class="tdc"> 2-1/2</td> + </tr> + <tr> + <td class="tdl"> 12.</td> + <td class="tdl">Phosphate (bone-ash)</td> + <td class="tdc"> 5-1/6</td> + </tr> + <tr> + <td class="tdl"> 18.</td> + <td class="tdl">Nitrate</td> + <td class="tdc"> 6-1/4</td> + </tr> + <tr> + <td class="tdl"> 21.</td> + <td class="tdl">Phosphate and nitrate</td> + <td class="tdc"> 5-1/3</td> + </tr> + <tr> + <td class="tdl"> 22.</td> + <td class="tdl"><i>Potash</i></td> + <td class="tdc">26-1/2</td> + </tr> + <tr> + <td class="tdl"> 17.</td> + <td class="tdl"><i>Potash</i> and phosphate</td> + <td class="tdc">42-1/3</td> + </tr> + <tr> + <td class="tdl"> 10.</td> + <td class="tdl"><i>Potash</i>, phosphate, and nitrate</td> + <td class="tdc">45-1/2</td> + </tr> + <tr> + <td class="tdl"> 38.</td> + <td class="tdl"><i>Potash</i>, phosphate, nitrate, and gypsum</td> + <td class="tdc">51 </td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_531" id="Page_531">[Pg 531]</a></span> +<br /> +<h2>CHAPTER XXIV.</h2> + +<h2>ON THE METHOD OF APPLICATION AND<br /> ON THE MIXING OF MANURES.</h2> +<br /> + +<p>Having considered the manuring of the different crops, we may now pass +on to the consideration of some points in the method of application and +on the mixing of manures.</p> + +<br /> +<p class="cen"><i>Equal Distribution of Manures.</i></p> + +<p>A most important object in applying manures is to effect equal +distribution of the manure in the soil. This is often, however, +unusually difficult to do, especially in the case of artificial manures, +where the quantity to be spread over a large area of the soil is +extremely small. The difficulty in the case of farmyard or other very +bulky manure is not so great. In order to overcome this difficulty in +the case of artificial manures, it is often advisable to mix them with +some such substance as sand, ashes, loam, peat, or salt. The manure is +thus diluted in strength, and a very much larger bulk of substance is +obtained <span class='pagenum'><a name="Page_532" id="Page_532">[Pg 532]</a></span>to work with. Circumstances must decide which of these +substances to use. If the soil be a heavy clay, the addition of sand or +ashes may have an important mechanical effect in improving its texture; +while, on the other hand, if it be a light soil, the addition of peat +may improve its mechanical condition. It must also be remembered that +peat itself contains a large amount of nitrogen, and thus forms a manure +of some value. In using loam or peat to mix with artificial manures, +they should be first dried and then riddled; while if ashes be used, +they should be previously reduced to a fine state. Wood-ashes, however, +must be used with caution, and ought not to be mixed with ammoniacal +manures, as they are apt to contain caustic alkali, which would tend to +drive off the ammonia in a volatile state.</p> + +<p>It has been recommended, in order to save trouble and effect equal +distribution, that the manure to be applied should always be made up to +the same amount, so that the farmer by experience may ascertain the rate +at which to apply it. And here it may be well to say a word or two on +the subject of mixing manures—a subject with which the farmer is not +always so conversant as it is desirable in the interests of his own +pocket he should be.</p> + +<br /> +<p class="cen"><i>Mixing Manures.</i></p> + +<p>It is to be feared that not unfrequently indiscriminate mixing may cause +very serious loss in the most <span class='pagenum'><a name="Page_533" id="Page_533">[Pg 533]</a></span>valuable constituent of a manure. It may +be well, therefore, to point out one or two of the causes of the loss +that is apt to ensue on the mixing of different kinds of manures +together.</p> + +<p>As the subject depends for its clear comprehension on certain chemical +elementary principles, it may be well for the benefit of non-chemical +readers to state these pretty fully.</p> + +<br /> +<p class="cen"><i>Risks of Loss in Mixtures.</i></p> + +<p>The risks of loss which may occur from the mixing of artificial manures +together may be of different kinds. One is the risk of actual loss of a +valuable ingredient through volatilisation; another is the risk of the +deterioration of the value of a mixture through change of the chemical +state of a valuable ingredient. Undoubtedly the most common and most +serious source of loss is the former. Of the three valuable manurial +ingredients—nitrogen, phosphoric acid, and potash—only the first is +liable to loss by volatilisation, and this generally only when the +nitrogen is either in the form of ammonia or nitric acid.</p> + +<br /> +<p class="cen"><i>Loss of Ammonia.</i></p> + +<p>Ammonia, when uncombined, is a very volatile gas with a pungent smell, a +property which enables its escape from a manure mixture to be very +easily detected. It belongs to a class of substances which are known +chemically as bases, and which have the power <span class='pagenum'><a name="Page_534" id="Page_534">[Pg 534]</a></span>of combining with acids +and forming salts. Sulphate of ammonia is a salt formed—as its name +indicates—by the union of the base, ammonia, with the acid, sulphuric +acid. Now when ammonia unites with sulphuric acid and forms sulphate of +ammonia, it is no longer volatile and liable to escape as a gas, but +becomes "fixed," as it is called.</p> + +<p>Although most salts are more or less stable bodies—not liable to +change—if left alone, and not submitted to a high temperature or +chemical action, they can be easily decomposed if they are heated or +brought into contact with some other substance which will give rise to +chemical action. Sulphate of ammonia is a salt that is very easily +decomposed. This is due to the fact that its base, ammonia, is very +volatile, and not capable of being held very firmly by an acid, even by +sulphuric, which is among the least volatile of all the common acids. +If, therefore, sulphate of ammonia be heated above the boiling-point of +water, or brought in contact with any other substance which will give +rise to chemical action, it is easily decomposed. Now a salt may be +acted upon by a base or an acid or another salt. When it is brought in +contact with a base, if the base with which it is brought in contact be +a stronger base than the base of the salt, the salt is decomposed, and a +new salt is formed. The acid, in short, exchanges its old base for the +new one.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_535" id="Page_535">[Pg 535]</a></span><i>Effect of Lime on Ammonia Salt.</i></p> + +<p>This is exactly what takes place when the base lime comes in contact +with an ammonium salt, such as sulphate of ammonia. The sulphuric acid +exchanges its old base, ammonia, for the stronger base, lime, and +sulphate of lime is formed, and ammonia is set free as a gas, and +escapes and is lost. Sulphate of ammonia, or any substance in which +there is an ammonia salt, must never be brought in contact with free +lime, otherwise the ammonia will be lost, and should be harrowed in on +chalky soils for this reason.</p> + +<p>It is different entirely with gypsum—which is sulphate of lime—or +phosphate of lime, both of which may be safely mixed with sulphate of +ammonia without any danger of escape of ammonia. It follows from the +above that a mixture which must on no account be tried is slag phosphate +and sulphate of ammonia. This is because the slag phosphate contains a +large percentage of free lime, which would at once, on being brought in +contact with the sulphate of ammonia, decompose it, and cause the +ammonia to be lost. For this same reason guano must not be mixed with +slag. It is perhaps unnecessary, however, to warn one against so doing, +as it is not likely such a mixture would be made, as the ratio of +phosphoric acid to nitrogen in guanos is generally greater than is +required. If it be desired to mix the slag with a quickly available form +of nitrogen, nitrate of soda <span class='pagenum'><a name="Page_536" id="Page_536">[Pg 536]</a></span>is not liable to loss; although for other +reasons it is not desirable to apply nitrate of soda along with the +slag, as the former manure should be applied almost always as a +top-dressing.</p> + +<br /> +<p class="cen"><i>Loss of Nitric Acid.</i></p> + +<p>The risks of the loss of nitrogen in the form of nitric acid, although +not so great as they are in the case of ammonia, are still considerable. +As nitric acid is not a base but an acid, what is to be avoided in +mixing nitrates is bringing them in contact with any other manure which +contains another free and stronger acid—as, for example, +superphosphate. The free acid present in superphosphate has the tendency +to drive out the nitric acid from the nitrate and usurp its place. The +risk of loss of expulsion in the above cases is always augmented by the +rise of temperature which invariably accompanies chemical action of any +kind; and although the loss of nitrogen, in the form of nitric acid, +caused by mixing superphosphate and nitrate of soda, might, under +ordinary circumstances, amount to very little, yet, if the mixture were +to be allowed to stand any time, and the temperature of the mass to be +heightened, the loss which would undoubtedly then ensue would be +considerable.</p> + +<p>The nitrogen salt which it is safe to mix with superphosphate is +sulphate of ammonia.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_537" id="Page_537">[Pg 537]</a></span><i>Reversion of Phosphates.</i></p> + +<p>But, as has already been mentioned, there is another loss which may +result from the mixing of manures. This is the deterioration of the +value of an ingredient by reason of change of chemical condition. This +is a source of loss that was little suspected a number of years ago, but +it is now well known that superphosphate of lime, under certain +conditions, is changed from its soluble to an insoluble form. We have +already referred to the reversion of phosphate in the chapter on the +Manufacture of Superphosphates.<a name="FNanchor_247_247" id="FNanchor_247_247"></a><a href="#Footnote_247_247" class="fnanchor">[247]</a> It was there pointed out that +reversion is often caused by the presence of iron and alumina or +undissolved phosphate, and that the risk of reversion is therefore very +much less in a well-made article, made from pure raw material, than in +one made from a raw phosphate containing much iron and alumina. +Superphosphates containing a large percentage of insoluble phosphates +ought not to be kept too long before being used as a manure, otherwise +much of the labour and expense involved in their manufacture will be +lost by the reversion of their soluble phosphate. Further, it is highly +inadvisable to mix superphosphates with basic slag, which contains a +large percentage of both iron and free lime. Lastly, if it is desired to +mix superphosphate with insoluble phosphate, the mixture ought to be +made just previous to application.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_538" id="Page_538">[Pg 538]</a></span><i>Manurial Ingredients should be applied separately.</i></p> + +<p>The question of applying manure in mixtures is one on which considerable +difference of opinion may exist. For many reasons manures are often +better applied in the unmixed condition. For example, a mixture of a +quickly acting nitrogenous manure with a slowly acting phosphatic manure +is not suitable. In such a case either the nitrogenous manure will be +applied too long before it is required by the plant, and thus suffer +from risk of loss, or the phosphatic manure will not be applied long +enough before it is likely to be used. By applying manures in an unmixed +condition the chances are that a more economical use of them is made +than would otherwise be the case. On the other hand, while the +application of the separate constituents may be desirable from the +scientific point of view, it involves a considerable amount of extra +trouble. Of course a further consideration is the desirability in many +cases of having a complete manure. The above hints, therefore, on the +risks of loss which exist in mixing manures, may be of service to the +agricultural student.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_247_247" id="Footnote_247_247"></a><a href="#FNanchor_247_247"><span class="label">[247]</span></a> See p. 389.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_539" id="Page_539">[Pg 539]</a></span> +<br /> +<h2>CHAPTER XXV.</h2> + +<h2>ON THE VALUATION AND ANALYSIS OF MANURES.</h2> +<br /> + +<p class="cen"><i>Value of Chemical Analysis.</i></p> + +<p>The value of a manure to the farmer depends on the proportion of +<i>nitrogen</i>, <i>phosphoric acid</i>, and <i>potash</i> it contains, as well as—and +this is hardly less important—the condition in which the ingredients +are present. Since these facts can alone be determined by a chemical +analysis, it is obvious that manures should always be purchased with a +chemical analysis. It is unfortunate, however, that very often a +chemical analysis, even when procured, is unintelligible. It may be of +advantage, therefore, to say a word or two on the correct interpretation +of the significance of the data furnished in the ordinary chemical +analysis of manures.</p> + +<br /> +<p class="cen"><i>Interpretation of Chemical Analysis.</i></p> + +<p>The first thing that the farmer ought to look for in the analysis of a +manure is the amount of <span class='pagenum'><a name="Page_540" id="Page_540">[Pg 540]</a></span>nitrogen, phosphoric acid, and potash which the +manure contains.</p> + +<br /> +<p class="cen"><i>Nitrogen.</i></p> + +<p>The percentage of nitrogen in a manure is generally stated as equal to +its equivalent percentage of ammonia. Very often, indeed, in the older +analyses, its equivalent of ammonia was alone stated. Now this statement +does not necessarily imply that the nitrogen in a manure is actually +present in the form of ammonia. Thus, for example, when it is stated in +an analysis of bone-meal that it contains 3.5 per cent of nitrogen, +equal to 4.20 per cent of ammonia, it is not to be inferred that +bone-meal actually contains nitrogen in the form of ammonia. In point of +fact the nitrogen is present in an insoluble, slowly available, organic +form, which possesses a manurial value very inferior to that possessed +by ammonia. This custom is a most unfortunate one, and is much to be +regretted, as it is often liable to give rise to serious +misunderstanding. It must be remembered, therefore, that an ordinary +chemical analysis does not always specify the exact form in which +nitrogen is actually present. It is nevertheless of importance for the +farmer to know this, of which the nature of the manure analysed is +generally a good indication. Unfortunately this is not shown in the case +of <i>mixed</i> manures; and this constitutes one of the reasons why mixed +manures are sometimes to be regarded with suspicion.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_541" id="Page_541">[Pg 541]</a></span><i>Phosphoric Acid.</i></p> + +<p>The amount of phosphates present in a manure is usually stated in its +analysis as so much phosphoric acid, while in a footnote the quantity of +tricalcic (or ordinary bone) phosphate this amount is equivalent to is +also given, this being the unit of valuation. When the phosphates are in +a soluble condition they are stated as such, and at the same time a +statement is made as to the quantity of tricalcic phosphate which would +be required to furnish this amount by treatment with sulphuric acid. +Thus, for example, in an analysis of a superphosphate of lime, the +statement, <i>monocalcic phosphate, 17.3 per cent, equal to tricalcic +phosphate rendered "soluble," 27.2 per cent</i>, means that it would +require 27.2 per cent of tricalcic phosphate to furnish 17.3 per cent of +soluble phosphate. Paradoxically enough, the former amount is called +<i>"soluble" phosphate</i>, and such a superphosphate as the above would be +described as containing 27.2 per cent of "soluble" phosphate.</p> + +<p>Again, there are different forms of the so-called "insoluble" +phosphates,<a name="FNanchor_248_248" id="FNanchor_248_248"></a><a href="#Footnote_248_248" class="fnanchor">[248]</a> although they are often not distinguished in a chemical +analysis. As we have already pointed out in the chapter on Basic Slag, +phosphoric acid occurs in the slag in the form of tetrabasic phosphate +of lime, although it is invariably stated in <span class='pagenum'><a name="Page_542" id="Page_542">[Pg 542]</a></span>analysis as so much +tricalcic phosphate. Then we have the so-called dibasic phosphate of +lime, the form into which soluble phosphate in superphosphate is +converted when "reversion" takes place. Hitherto it has not been +customary in this country—although the custom is prevalent both on the +Continent and in America—to distinguish in the analysis of a +superphosphate the "reverted" phosphate from the undissolved phosphate; +since the superior value of the former as a manure is not recognised in +the manure-trade.<a name="FNanchor_249_249" id="FNanchor_249_249"></a><a href="#Footnote_249_249" class="fnanchor">[249]</a></p> + +<br /> +<p class="cen"><i>Importance of Mechanical Condition of Phosphate.</i></p> + +<p>A further point to which it is desirable to draw attention is the +<i>mechanical</i> condition of the different insoluble phosphates, which has +an important influence on their value. A very wide difference, for +example, exists between the value of phosphate of lime in such a manure +as Malden guano and in the crystalline mineral apatite; although, +chemically considered, the form in which the phosphoric acid is present +is the same in both substances.</p> + +<br /> +<p class="cen"><i>Potash.</i></p> + +<p>Potash ought only to occur in a soluble form in manures. It is generally +stated as so much potash, and in a footnote the equivalent amount of +muriate <span class='pagenum'><a name="Page_543" id="Page_543">[Pg 543]</a></span>or sulphate of potash is given, the former being the more +concentrated form of potash.</p> + +<p>For purposes of reference a table will be found in the Appendix<a name="FNanchor_250_250" id="FNanchor_250_250"></a><a href="#Footnote_250_250" class="fnanchor">[250]</a> +giving some useful factors for converting different forms of nitrogen, +phosphoric acid, and potash into one another.</p> + +<br /> +<p class="cen"><i>Other Items in the Chemical Analysis of Manures.</i></p> + +<p>The other items in the analysis of a manure are of comparatively +secondary importance compared with those already named. Among them may +be mentioned the <i>moisture</i>, the <i>insoluble matter</i>, and the <i>organic +matter</i>. The amount of moisture and the amount of sand are two items of +importance, since, if these are excessive, they afford presumption that +the manure has been adulterated.</p> + +<br /> +<p class="cen"><i>Fertilisers and Feeding Stuffs Act.</i></p> + +<p>An Act was passed, and came into operation in January 1894, for the +purpose of compelling every vendor of manure manufactured in this +country or imported from abroad to give to the purchaser "an invoice +stating the name of the article, and whether it is an artificially +compounded article or not, and what is at least the percentage of the +nitrogen, soluble and insoluble phosphates, and potash, if any, +contained in the article, and this invoice shall have the <span class='pagenum'><a name="Page_544" id="Page_544">[Pg 544]</a></span>same effect +as a warranty by the seller of the statements contained therein."</p> + +<br /> +<p class="cen"><i>Different Methods of Valuing Manures.</i></p> + +<p>The monetary value of a manure depends upon a number of more or less +complicated commercial considerations, such as the questions of supply +and demand, &c., which need not here be discussed, and which similarly +regulate the monetary value of any other article of commerce.</p> + +<br /> +<p class="cen"><i>"Unit" Value of Manurial Ingredients.</i></p> + +<p>For the purpose of affording data for ascertaining the approximate value +of a manure, tables have been drawn up giving what is called the "unit" +value of the different manurial ingredients in various manures. This is +obtained by dividing the market value of a manure per ton by the +percentage of nitrogen, phosphoric acid, and potash it contains. Thus, +for example, sulphate of ammonia of 97 per cent purity contains 25 per +cent of ammonia, and at present (Dec. 1893) is valued at £13, 15s. per +ton. In order to obtain the unit value of ammonia in sulphate of +ammonia, we have only to divide £13, 15s. by 25, which gives us 11s. The +value of such tables depends on the competence of those drawing them up, +and they require to be subjected to constant revision. In the Appendix +will be found two of these tables, taken from the <span class='pagenum'><a name="Page_545" id="Page_545">[Pg 545]</a></span>'Transactions of the +Highland and Agricultural Society of Scotland.'<a name="FNanchor_251_251" id="FNanchor_251_251"></a><a href="#Footnote_251_251" class="fnanchor">[251]</a></p> + +<br /> +<p class="cen"><i>Intrinsic Value of Manures.</i></p> + +<p>But there is another way of valuing manures, and that is by attempting +to ascertain what their intrinsic worth is in producing an increase in +the returns of the crops. Of course it may be said that the intrinsic +worth of manure affects directly its market value. This is doubtless +true, but it is not the only factor in determining the market value of a +manure.</p> + +<p>Again, the intrinsic worth of a manure may be said to vary according to +the soil to which it is applied and the climatic conditions. This being +so, it is important for every farmer to try and ascertain for himself +what the intrinsic value of different manures is on the soil of his +farm; and this can only be done by carrying out manuring experiments for +himself. This leads us to say a word or two on the important subject of</p> + +<br /> +<p class="cen"><i>Field Experiments.</i></p> + +<p>It is impossible that every farm should be able to support an experiment +station for the purpose of carrying out elaborate experiments on the +effect of different manures on different crops. Nevertheless it is +possible and highly desirable for <i>every</i> farmer who is engaged in +arable farming on any scale to carry out simple experiments for the +purpose of <span class='pagenum'><a name="Page_546" id="Page_546">[Pg 546]</a></span>ascertaining the characteristic manurial requirements of his +soil. This can be done at the expenditure of a little time and trouble, +and should be carried out in the following way. The field on which it is +desired to carry out the experiments should be divided into the +requisite number of experiment plots. These, which may be the tenth, +twentieth, or fortieth of an acre in extent, should be, if possible, on +a level piece of ground—all of them equally free from the shelter of +hedge or tree, and otherwise subjected to the same conditions. The +nature of the soil of the different plots, as well as its past +treatment, should be similar. It is desirable, in order to minimise +experimental error as much as possible, to carry out the experiments in +duplicate, or even triplicate. In the first place, there should be what +is called a <i>nothing</i> plot—<i>i.e.</i>, a plot receiving no manure. The +produce obtained from this plot, compared with the produce obtained from +the other manured plots, will thus furnish data for estimating the +respective amounts of increase obtained by different manures. One very +simple kind of experiment is what is called the "seven-plot" test. It +consists in testing the results obtained by using nitrogenous, +phosphatic, and potash manures alone and in different combinations. Thus +the plots would be manured respectively as follows:—</p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="Nothing"> + <tr> + <td class="tdl" width="100%">No.</td> + </tr> + <tr> + <td class="tdl"> 1. Nothing plot.</td> + </tr> + <tr> + <td class="tdl"> 2. Nitrogen.</td> + </tr> + <tr> + <td class="tdl"> 3. Phosphates.</td> + </tr> + <tr> + <td class="tdl"> 4. Potash.</td> + </tr> + <tr> + <td class="tdl"> 5. Nitrogen and phosphates.</td> + </tr> + <tr> + <td class="tdl"> 6. Nitrogen and potash.</td> + </tr> + <tr> + <td class="tdl"> 7. Phosphates and potash.</td> + </tr> +</table> +</div> + +<p><span class='pagenum'><a name="Page_547" id="Page_547">[Pg 547]</a></span>The subjects of other experiments might be such as the respective values +of nitrogen in the different forms of sulphate of ammonia and nitrate of +soda; phosphoric acid as superphosphate, and in an undissolved form as +Thomas-slag; the relative importance of artificial and farmyard manure; +the effect of manures applied at different times, as well as the effect +of different quantities of the same manure; the most economical manures +for different kinds of crops; and numerous other interesting problems +connected with the practical application of manures.</p> + +<p>In carrying out these experiments, care should be taken not to have the +experimental plots <i>immediately</i> adjoining one another, as the manure +applied to the one plot may, by soaking through the soil, affect the +result on the adjoining plot. Especial note ought to be taken of the +weather during the progress of the experiment. In order to make such +experiments as valuable as possible, they ought to be continued year +after year. At the conclusion of the experiment the produce obtained +from each plot should be carefully weighed.</p> + +<br /> +<p class="cen"><i>Educational Value of Field Experiments.</i></p> + +<p>The educative value of such experiments is very great, and in this +connection the remarks made by Mr F. J. Cooke, in a recent lecture +delivered to the London Farmers' Club, are worthy of most careful +consideration.</p> + +<p>"Local experiments," he says, "teach the simple <span class='pagenum'><a name="Page_548" id="Page_548">[Pg 548]</a></span>principles which should +determine the selection of manures, as well as scientific accuracy and +method in their use. The value of experiments is thus brought home to +men who would not go far to discover it; and the practice of a few +simple trials upon a correct system, each on his own farm, is +encouraged. That such trials may be conducted with very little expense +to the farmer, or other difficult qualifications, and yet to his great +practical advantage, I will venture to assert on the ground of my own +personal experience. For some twenty years I have annually conducted +private experiments on a very humble scale, and am not aware of any +other separate practice which has been so useful to me. It has been +pursued upon two light-land farms in different parts of the same county. +Yet, in respect of manurial requirements, the proper treatment for one +of them has differed so essentially from the other that a common +practice upon both would have been simply ruinous."</p> + +<br /> +<p class="cen"><i>Value of Manures deduced from Experiments.</i></p> + +<p>Tables have been constructed for the purpose of showing the comparative +value of different kinds of manures as deduced from such experiments, +and may be fittingly compared with the tables giving the trade prices. +We have already quoted some of these tables in the Appendix to the +chapter on Mineral Phosphates. These tables show the relative intrinsic +value of different forms of phosphatic manures. In <span class='pagenum'><a name="Page_549" id="Page_549">[Pg 549]</a></span>the Appendix<a name="FNanchor_252_252" id="FNanchor_252_252"></a><a href="#Footnote_252_252" class="fnanchor">[252]</a> to +this chapter tables showing the relative value of different kinds of +nitrogenous and potash manures will be found.</p> + +<br /> +<p class="cen"><i>Value of Unexhausted Manures.</i></p> + +<p>A subject which has had much attention devoted to it of late years is +the question of the value of unexhausted manures in the soil. In the +Agricultural Holdings Act special provision is made for giving +compensation to the out-going tenant of a farm for unexhausted manures +in the soil. The Act has given rise to endless disputes between landlord +and tenant, owing to the extreme difficulty of arriving at a +satisfactory estimate of what the value of the unexhausted manures in +reality is. The difficulty arises from the fact that we have not +sufficient data available for guiding us in estimating this value, which +further varies under different conditions. The fertilising ingredients +of a soil are present in the soil for the most part in an inert +condition, from which they are only slowly converted into an available +form.</p> + +<br /> +<p class="cen"><i>Potential Fertility of a Soil.</i></p> + +<p>As indicating the total amount of the more important mineral ingredients +present in a soil, it may be mentioned that it has been calculated, in +the case of a poor sandy soil, <i>that the amount of potash it contains</i> +(<i>provided it were in an available condition</i>) would <span class='pagenum'><a name="Page_550" id="Page_550">[Pg 550]</a></span>be sufficient to +yield three or four average crops of potatoes; of phosphates, nineteen +average crops; and of lime, seventy-three. But then only a very small +amount of this fertilising matter is in a readily available form.</p> + +<p>It is for this reason that artificial manures, although added in such +small amounts, exercise so striking an influence in increasing plants' +growth. Their effect, however, is to a large extent only of a temporary +nature; and in attempting to assess the unexhausted value of a manure a +year or two after its application, we must remember this fact.</p> + +<p>Some manures are very speedily taken up by plants, and some are very +easily washed out of the soil. Others, again, it would seem highly +probable, have a tendency to become converted into a more or less inert +condition after a while. This remark may be especially applied to the +fertilising constituents (chiefly nitrogen) in farmyard manure.<a name="FNanchor_253_253" id="FNanchor_253_253"></a><a href="#Footnote_253_253" class="fnanchor">[253]</a> The +whole question, however, is little understood. One or two points may be +drawn attention to. In the first place, it may be safely affirmed that +little direct effect can be expected from such quickly available and +easily soluble forms of nitrogenous manures as nitrate of soda and +sulphate of ammonia a year after application. Potash and phosphates, on +the other hand, may exercise an effect for a considerably longer period; +and what the length of this period may be will <span class='pagenum'><a name="Page_551" id="Page_551">[Pg 551]</a></span>depend on their amount +and condition. Thus it is not likely that superphosphate will have much +effect more than two years after application. On the other hand, such +manures as bones, basic slag, and farmyard manure may exert an +appreciable influence for a number of years. How long exactly, it is +wellnigh impossible to say, the rate at which they are applied and the +nature of the soil having an important influence.</p> + +<br /> +<p class="cen"><i>Tables of Value of Unexhausted Manures.</i></p> + +<p>Numerous tables have been drawn up for the purpose of guiding farmers in +estimating this unexhausted value at different periods after +application, and in the case of different manures. Such tables, as a +rule, furnish only very rough approximations, and are little better than +mere guess-work. Still more complicated is the attempt to assess the +manurial value of foods consumed by the stock of the farm. Lawes and +Gilbert have devoted much attention to the elucidation of this difficult +question, and have drawn up most elaborate and valuable tables, +furnishing data for calculating unexhausted manure value in the case of +commonly used foods. These tables are given in the Appendix.<a name="FNanchor_254_254" id="FNanchor_254_254"></a><a href="#Footnote_254_254" class="fnanchor">[254]</a> In +them will be found the manurial value of different cattle-foods, +calculated on the basis of numerous experiments carried out at +Rothamsted.</p> + +<p><span class='pagenum'><a name="Page_552" id="Page_552">[Pg 552]</a></span>Thus these experiments have demonstrated that, on an average, probably +not more than <i>one-tenth</i> of the nitrogen, phosphoric acid, and potash a +food contains is removed from the food in its passage through the animal +system. The exact amount will obviously depend on a variety of +conditions, referred to already in a previous chapter.<a name="FNanchor_255_255" id="FNanchor_255_255"></a><a href="#Footnote_255_255" class="fnanchor">[255]</a></p> + +<p>In explanation of these tables, it may be pointed out that Table I. +gives the total quantities of the three fertilising ingredients in +various foods; while Table II. shows the proportion retained in the +animal body and the proportion voided in the manure, as well as the +manurial value of the food, assuming that it exercises its full +theoretical effect. As this, however, is never fully realised, it is +necessary to make some deduction. The deduction suggested by the +Rothamsted experimenters, on the basis of their wide experience, is 50 +per cent for food consumed within the last year. That is to say, the +manurial value of food consumed during the last year is <i>only one-half +its theoretical value</i>. For food consumed within the last year but one, +they suggest a deduction of one-third of the allowance for last year; +while for food consumed three years back, a deduction of one-third from +this latter sum should be made; and so on for whatever number of years, +down to eight, may be taken.</p> + +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_248_248" id="Footnote_248_248"></a><a href="#FNanchor_248_248"><span class="label">[248]</span></a> The term <i>insoluble phosphates</i> is an unfortunate one, as +the word insoluble is purely relative in its significance. <i>Undissolved</i> +phosphates would be a better term.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_249_249" id="Footnote_249_249"></a><a href="#FNanchor_249_249"><span class="label">[249]</span></a> The amount of "reverted" phosphate is estimated by <i>the +ammonium citrate process</i>.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_250_250" id="Footnote_250_250"></a><a href="#FNanchor_250_250"><span class="label">[250]</span></a> See Note I., p. 553.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_251_251" id="Footnote_251_251"></a><a href="#FNanchor_251_251"><span class="label">[251]</span></a> See Note II., p. 554.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_252_252" id="Footnote_252_252"></a><a href="#FNanchor_252_252"><span class="label">[252]</span></a> See Note III., p. 556.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_253_253" id="Footnote_253_253"></a><a href="#FNanchor_253_253"><span class="label">[253]</span></a> See Chapter on Farmyard Manure, p. 271.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_254_254" id="Footnote_254_254"></a><a href="#FNanchor_254_254"><span class="label">[254]</span></a> See Note IV., p. 557.</p></div> + +<div class="footnote"><p class="noin"><a name="Footnote_255_255" id="Footnote_255_255"></a><a href="#FNanchor_255_255"><span class="label">[255]</span></a> See Chapter on Farmyard Manure, pp. 224-236.</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_553" id="Page_553">[Pg 553]</a></span> +<br /> +<h2>APPENDIX TO CHAPTER XXV.</h2> +<br /> + +<p class="cen">NOTE I. (p. 543).</p> + +<p class="cen"><span class="smcap">Useful Factors for calculating the Percentage of important Manurial +Ingredients<br /> in a Manure into their different Compounds.</span><br /> (From the +'Transactions of the Highland and Agricultural Society.')</p> + +<div class="centered"> +<table border="0" width="90%" cellpadding="2" cellspacing="0" summary="Phosphate"> + <tr> + <td class="tdc" style="border-top: .5pt black solid; border-bottom: .5pt black solid;" width="40%">Amount of</td> + <td class="tdctlb" width="20%">Multiplied by</td> + <td class="tdctlb" width="40%">Gives corresponding amount of</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdcl">1.214</td> + <td class="tdllp">Ammonia.</td> + </tr> + <tr> + <td class="tdl">Nitrogen</td> + <td class="tdcl">6.3 </td> + <td class="tdllp">Albuminoid matter.</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl"> .824</td> + <td class="tdllp">Nitrogen.</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl">3.882</td> + <td class="tdllp">Sulphate of ammonia.</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl">3.147</td> + <td class="tdllp">Muriate of ammonia.</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl">3.706</td> + <td class="tdllp">Nitric acid.</td> + </tr> + <tr> + <td class="tdl">Ammonia</td> + <td class="tdcl">5.0 </td> + <td class="tdllp">Nitrate of soda.</td> + </tr> + <tr> + <td class="tdl">Potash (anhydrous)</td> + <td class="tdcl">1.85 </td> + <td class="tdllp">Sulphate of potash.</td> + </tr> + <tr> + <td class="tdl">Potash (anhydrous)</td> + <td class="tdcl">1.585</td> + <td class="tdllp">Muriate of potash.</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid (anhydrous)</td> + <td class="tdcl">2.183</td> + <td class="tdllp">Phosphate of lime.</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid (anhydrous)</td> + <td class="tdcl">1.4 </td> + <td class="tdllp">Biphosphate.</td> + </tr> + <tr> + <td class="tdl">Phosphoric acid (anhydrous)</td> + <td class="tdcl">1.648</td> + <td class="tdllp">Soluble phosphate.</td> + </tr> + <tr> + <td class="tdl">Soluble phosphate</td> + <td class="tdcl">1.325</td> + <td class="tdllp">Phosphate of lime.</td> + </tr> + <tr> + <td class="tdl">Biphosphate</td> + <td class="tdcl">1.566</td> + <td class="tdllp">Phosphate of lime.</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdcl">1.845</td> + <td class="tdllp">Phosphate of lime.</td> + </tr> + <tr> + <td class="tdl">Lime</td> + <td class="tdcl">1.786</td> + <td class="tdllp">Carbonate of lime.</td> + </tr> + <tr> + <td class="tdlb">Chlorine</td> + <td class="tdclb">1.648</td> + <td class="tdllp" style="border-bottom: .5pt black solid;">Chloride of sodium.</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_554" id="Page_554">[Pg 554]</a></span>NOTES II. (p. 545).</p> + +<p class="cen"><span class="smcap">Units to be used in determining the Commercial Value of +Manures.</span></p> + +<p class="cen"><i>For Season 1893.</i></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Ichaboe"> + <tr> + <td class="tdct"> </td> + <td class="tdctl"> </td> + <td class="tdctl" colspan="2"> </td> + <td class="tdctl"> </td> + <td class="tdctl"> </td> + <td class="tdctl" colspan="2">Prices per ton,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdclb" colspan="2">Phosphates</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdclb" colspan="2">March 1893</td> + </tr> + <tr> + <td class="tdc" style="border-bottom: .5pt black solid;" width="23%">Items to be valued.</td> + <td class="tdclb" width="11%">Classes</td> + <td class="tdclb" width="11%">Dissolved</td> + <td class="tdclb" width="11%">Undissolved</td> + <td class="tdclb" width="11%">Ammonia</td> + <td class="tdclb" width="11%">Potash</td> + <td class="tdclb" width="11%">From</td> + <td class="tdclb" width="11%">To</td> + </tr> + <tr> + <td class="tdl">Guanos.</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> Ichaboe.</td> + <td class="tdcl">Genuine.</td> + <td class="tdcl">—</td> + <td class="tdcl">2/-</td> + <td class="tdcl">16/-</td> + <td class="tdcl">—</td> + <td class="tdcl">250/-</td> + <td class="tdcl">270/-</td> + </tr> + <tr> + <td class="tdlb"> Peruvian (riddled)</td> + <td class="tdclb">Genuine.</td> + <td class="tdclb">—</td> + <td class="tdclb">2/-</td> + <td class="tdclb">17/6</td> + <td class="tdclb">3/6</td> + <td class="tdclb">230/-</td> + <td class="tdclb">290/-</td> + </tr> + <tr> + <td class="tdl">Scrap manures.</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> Fish guano.</td> + <td class="tdcl"> </td> + <td class="tdcl">—</td> + <td class="tdcl">1/5</td> + <td class="tdcl">10/-</td> + <td class="tdcl">—</td> + <td class="tdcl">130/-</td> + <td class="tdcl">150/-</td> + </tr> + <tr> + <td class="tdlb"> Frey Bentos guano.</td> + <td class="tdclb"><i>a.</i></td> + <td class="tdclb">—</td> + <td class="tdclb">1/6</td> + <td class="tdclb">11/6</td> + <td class="tdclb">—</td> + <td class="tdclb">150/-</td> + <td class="tdclb">180/-</td> + </tr> + <tr> + <td class="tdl">Bone-meal</td> + <td class="tdcl"><i>a.</i></td> + <td class="tdcl">—</td> + <td class="tdcl">1/4</td> + <td class="tdcl">10/-</td> + <td class="tdcl">—</td> + <td class="tdcl">105/-</td> + <td class="tdcl">115/-</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb"><i>b.</i></td> + <td class="tdclb">—</td> + <td class="tdclb">1/3</td> + <td class="tdclb"> 9/6</td> + <td class="tdclb">—</td> + <td class="tdclb">100/-</td> + <td class="tdclb">110/-</td> + </tr> + <tr> + <td class="tdlb">Steamed bone-flour.</td> + <td class="tdclb"><i>a.</i></td> + <td class="tdclb">—</td> + <td class="tdclb">1/5</td> + <td class="tdclb">10/-</td> + <td class="tdclb">—</td> + <td class="tdclb"> 95/-</td> + <td class="tdclb">110/-</td> + </tr> + <tr> + <td class="tdl">Dissolved or</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdlb">vitriolated bones.</td> + <td class="tdclb"> </td> + <td class="tdclb">2/6</td> + <td class="tdclb">1/6</td> + <td class="tdclb">11/6</td> + <td class="tdclb">—</td> + <td class="tdclb"> 95/-</td> + <td class="tdclb">110/-</td> + </tr> + <tr> + <td class="tdlb">Superphosphates.</td> + <td class="tdclb"> </td> + <td class="tdclb">—</td> + <td class="tdclb"> 1/11</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb"> 45/-</td> + <td class="tdclb"> 60/-</td> + </tr> + <tr> + <td class="tdl">Dissolved compounds.</td> + <td class="tdcl">From</td> + <td class="tdcl">2/-</td> + <td class="tdcl">1/3</td> + <td class="tdcl">10/-</td> + <td class="tdcl">3/4</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">To</td> + <td class="tdcl">2/6</td> + <td class="tdcl">1/9</td> + <td class="tdcl">12/-</td> + <td class="tdcl">3/8</td> + <td class="tdcl">—</td> + <td class="tdcl">—</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">Average.</td> + <td class="tdclb">2/3</td> + <td class="tdclb">1/6</td> + <td class="tdclb">11/-</td> + <td class="tdclb">3/6</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class="smcap">Cash Prices of different Manures, March 1893</span>.<span class='pagenum'><a name="Page_555" id="Page_555">[Pg 555]</a></span></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Guarantee"> + <tr> + <td class="tdct" width="48%"> </td> + <td class="tdctl" width="18%"> </td> + <td class="tdctl" width="16%">Price per</td> + <td class="tdctl" width="18%"> </td> + </tr> + <tr> + <td class="tdc" style="border-bottom: .5pt black solid;"><span class="smcap">Manures</span></td> + <td class="tdclb">Guarantee.</td> + <td class="tdclb">ton.</td> + <td class="tdclb">Unit.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Per cent.</td> + <td class="tdcl"> <i>£ s. d.</i></td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl">Sulphate of ammonia, 97 per cent</td> + <td class="tdcl">24 Am.</td> + <td class="tdcl">11 10 0</td> + <td class="tdcl">Am. = 9/7</td> + </tr> + <tr> + <td class="tdl">Nitrate of soda, 95 per cent</td> + <td class="tdcl">19 Am.</td> + <td class="tdcl">10 5 0</td> + <td class="tdcl">Am. = 10/9</td> + </tr> + <tr> + <td class="tdl">Castor-cake dust</td> + <td class="tdcl"> 5.5 Am.</td> + <td class="tdcl"> 3 10 0</td> + <td class="tdcl">Am. = 12/9</td> + </tr> + <tr> + <td class="tdl">Horn-dust</td> + <td class="tdcl">15 Am.</td> + <td class="tdcl"> 8 10 0</td> + <td class="tdcl">Am. = 11/4</td> + </tr> + <tr> + <td class="tdl">Dried blood</td> + <td class="tdcl">15 Am.</td> + <td class="tdcl"> 8 0 0</td> + <td class="tdcl">Am. = 10/7</td> + </tr> + <tr> + <td class="tdl">Muriate of potash, 80 per cent</td> + <td class="tdcl">50 Pot.</td> + <td class="tdcl"> 8 15 0</td> + <td class="tdcl">Pot. = 3/6 </td> + </tr> + <tr> + <td class="tdl">Sulphate of potash, 50 per cent</td> + <td class="tdcl">27 Pot.</td> + <td class="tdcl"> 5 5 0</td> + <td class="tdcl">Pot. = 3/10</td> + </tr> + <tr> + <td class="tdl">Kainit, 23 per cent</td> + <td class="tdcl">12 Pot.</td> + <td class="tdcl"> 2 0 0</td> + <td class="tdcl">Pot. = 3/4 </td> + </tr> + <tr> + <td class="tdl">Nitrate of potash, 73 per cent</td> + <td class="tdcl">{14 Am.<br />{40 Pot.</td> + <td class="tdcl">14 10 0</td> + <td class="tdcl">{Am. = 10/<br/>{Pot. = 3/9</td> + </tr> + <tr> + <td class="tdl">Ground Charleston phosphate</td> + <td class="tdcl">57 Phos.</td> + <td class="tdcl"> 3 0 0</td> + <td class="tdcl">Phos. = 1/ </td> + </tr> + <tr> + <td class="tdl">Belgian phosphate</td> + <td class="tdcl">50 Phos.</td> + <td class="tdcl"> 2 5 0</td> + <td class="tdcl"> Phos. = 0/11</td> + </tr> + <tr> + <td class="tdl">Thomas-slag (fine) Scotch</td> + <td class="tdcl">30 Phos.</td> + <td class="tdcl"> 1 16 0</td> + <td class="tdcl">Phos. = 1/2</td> + </tr> + <tr> + <td class="tdl">Thomas-slaag (fine) English</td> + <td class="tdcl">37 Phos.</td> + <td class="tdcl"> 2 3 0</td> + <td class="tdcl">Phos. = 1/2</td> + </tr> + <tr> + <td class="tdlb">Phosphatic guano</td> + <td class="tdclb">{67 Phos.<br />{ 1 Am.</td> + <td class="tdclb"> 5 0 0</td> + <td class="tdclb">{Phos. = 1/4<br />{ Am. = 10/</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_556" id="Page_556">[Pg 556]</a></span>NOTE III. (p. 549).</p> + +<p class="cen"><span class="smcap">Tables showing relative Manurial Value of Nitrogen and Potash in +different Substances.</span></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Wolff"> + <tr> + <td class="tdc" colspan="2"><i>Wolff, 1893.</i></td> + </tr> + <tr> + <td class="tdl" width="90%">Nitrogen in form of ammonia and nitrates, and easily decomposable + organic compounds, as dried blood, flesh-meal, meat-meal, Peruvian guano, and as urate</td> + <td class="tdrb" width="10%">100</td> + </tr> + <tr> + <td class="tdl">Nitrogen in fine steamed bone-meal, fish-guano, oilcakes, and better kinds of + artificial guano</td> + <td class="tdrb">85</td> + </tr> + <tr> + <td class="tdl">Nitrogen in fine bone-meal and horn-meal</td> + <td class="tdr">77</td> + </tr> + <tr> + <td class="tdl">Nitrogen in coarse bones and horn-shavings, woollen refuse, farmyard manure, + and poudrette</td> + <td class="tdrb">61</td> + </tr> + <tr> + <td class="tdc" colspan="2"><i>American, 1892.</i></td> + </tr> + <tr> + <td class="tdl">Nitrogen in ammonia salts</td> + <td class="tdr">100</td> + </tr> + <tr> + <td class="tdl">Nitrogen as nitrates</td> + <td class="tdr">86</td> + </tr> + <tr> + <td class="tdl">Nitrogen in dry and fine-ground fish, meat, and blood</td> + <td class="tdr">91</td> + </tr> + <tr> + <td class="tdl">Nitrogen in cotton-seed meal, and castor pomace</td> + <td class="tdr">86</td> + </tr> + <tr> + <td class="tdl">Nitrogen in fine bone and tankage</td> + <td class="tdr">86</td> + </tr> + <tr> + <td class="tdl">Nitrogen in medium bone and tankage</td> + <td class="tdr">68</td> + </tr> + <tr> + <td class="tdl">Nitrogen in coarser bone and tankage</td> + <td class="tdr">43</td> + </tr> + <tr> + <td class="tdl">Nitrogen in hair and horn-shavings, and coarse fish scrap</td> + <td class="tdr">40</td> + </tr> + <tr> + <td class="tdl">Potash as high-grade sulphate, and in forms free from muriates (or chlorides)</td> + <td class="tdrb">100</td> + </tr> + <tr> + <td class="tdl">Potash as muriate</td> + <td class="tdr">82</td> + </tr> +</table> +</div> + +<p>Professor Wagner has drawn up, from numerous experiments, the relative +manurial values of different nitrogenous manures, which he rates as +follows:—</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Nitrate"> + <tr> + <td class="tdl" width="90%">Nitrate of soda</td> + <td class="tdr" width="10%">100</td> + </tr> + <tr> + <td class="tdl">Sulphate of ammonia</td> + <td class="tdr">90</td> + </tr> + <tr> + <td class="tdl">Blood-meal, horn-meal, and green vegetable matter</td> + <td class="tdr">70</td> + </tr> + <tr> + <td class="tdl">Finely ground steamed bone-meal, fish-meal, and meat-meal guano</td> + <td class="tdrb">60</td> + </tr> + <tr> + <td class="tdl">Farmyard manure</td> + <td class="tdr">45</td> + </tr> + <tr> + <td class="tdl">Shoddy</td> + <td class="tdr">30</td> + </tr> + <tr> + <td class="tdl">Leather-meal</td> + <td class="tdr">20</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_557" id="Page_557">[Pg 557]</a></span>NOTE IV. (p. 551).</p> + +<p class="cen">TABLE I.—<span class="smcap">Average Composition, per cent and per ton, of +Cattle-Foods.</span></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="cattle-foods"> + <tr> + <td class="tdct"> </td> + <td class="tdcl" style="border-top: .5pt black solid;"> </td> + <td class="tdctlb" colspan="5"><span class="smcap">Per Cent.</span></td> + <td class="tdctlb" colspan="3"><span class="smcap">Per Ton.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Mineral</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Dry</td> + <td class="tdcl"> </td> + <td class="tdcl">Matter</td> + <td class="tdcl">Phosphoric</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Phosphoric</td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdlb" width="3%">No</td> + <td class="tdclb" width="25%"><span class="smcap">Foods.</span></td> + <td class="tdclb" width="9%">Matter.</td> + <td class="tdclb" width="9%">Nitrogen.</td> + <td class="tdclb" width="9%">(Ash).</td> + <td class="tdclb" width="9%">Acid.</td> + <td class="tdclb" width="9%">Potash.</td> + <td class="tdclb" width="9%">Nitrogen.</td> + <td class="tdclb" width="9%">Acid.</td> + <td class="tdclb" width="9%">Potash.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">per cent.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl"> 1</td> + <td class="tdll">Linseed</td> + <td class="tdcl">90.00</td> + <td class="tdcl">3.60</td> + <td class="tdcl">4.00</td> + <td class="tdcl">1.54</td> + <td class="tdcl">1.37</td> + <td class="tdcl"> 80.64</td> + <td class="tdcl">34.50</td> + <td class="tdcl">30.69</td> + </tr> + <tr> + <td class="tdl"> 2</td> + <td class="tdll">Linseed-cake</td> + <td class="tdcl">88.50</td> + <td class="tdcl">4.75</td> + <td class="tdcl">6.50</td> + <td class="tdcl">2.00</td> + <td class="tdcl">1.40</td> + <td class="tdcl">106.40</td> + <td class="tdcl">44.80</td> + <td class="tdcl">31.36</td> + </tr> + <tr> + <td class="tdlz"> 3</td> + <td class="tdll">Decorticated cotton-cake</td> + <td class="tdcly">90.00</td> + <td class="tdcly">6.60</td> + <td class="tdcly">7.00</td> + <td class="tdcly">3.10</td> + <td class="tdcly">2.00</td> + <td class="tdcly">147.84</td> + <td class="tdcly">69.44</td> + <td class="tdcly">44.80</td> + </tr> + <tr> + <td class="tdl"> 4</td> + <td class="tdll">Palm-nut cake</td> + <td class="tdcl">91.00</td> + <td class="tdcl">2.50</td> + <td class="tdcl">3.60</td> + <td class="tdcl">1.20</td> + <td class="tdcl">0.50</td> + <td class="tdcl"> 56.00</td> + <td class="tdcl">26.88</td> + <td class="tdcl">11.20</td> + </tr> + <tr> + <td class="tdlz"> 5</td> + <td class="tdll">Undecorticated cotton-cake</td> + <td class="tdcly">87.00</td> + <td class="tdcly">3.75</td> + <td class="tdcly">6.00</td> + <td class="tdcly">2.00</td> + <td class="tdcly">2.00</td> + <td class="tdcly"> 84.00</td> + <td class="tdcly">44.80</td> + <td class="tdcly">44.80</td> + </tr> + <tr> + <td class="tdl"> 6</td> + <td class="tdll">Cocoa-nut-cake</td> + <td class="tdcl">90.00</td> + <td class="tdcl">3.40</td> + <td class="tdcl">6.00</td> + <td class="tdcl">1.40</td> + <td class="tdcl">2.00</td> + <td class="tdcl"> 76.16</td> + <td class="tdcl">31.36</td> + <td class="tdcl">44.80</td> + </tr> + <tr> + <td class="tdl"> 7</td> + <td class="tdll">Rape-cake</td> + <td class="tdclb">89.00</td> + <td class="tdclb">4.90</td> + <td class="tdclb">7.50</td> + <td class="tdclb">2.50</td> + <td class="tdclb">1.50</td> + <td class="tdclb">109.76</td> + <td class="tdclb">56.00</td> + <td class="tdclb">33.60</td> + </tr> + <tr> + <td class="tdl"> 8</td> + <td class="tdll">Peas</td> + <td class="tdcl">85.00</td> + <td class="tdcl">3.60</td> + <td class="tdcl">2.50</td> + <td class="tdcl">0.85</td> + <td class="tdcl">0.96</td> + <td class="tdcl"> 80.64</td> + <td class="tdcl">19.04</td> + <td class="tdcl">21.50</td> + </tr> + <tr> + <td class="tdl"> 9</td> + <td class="tdll">Beans</td> + <td class="tdcl">85.00</td> + <td class="tdcl">4.00</td> + <td class="tdcl">3.00</td> + <td class="tdcl">1.10</td> + <td class="tdcl">1.30</td> + <td class="tdcl"> 89.60</td> + <td class="tdcl">24.64</td> + <td class="tdcl">29.12</td> + </tr> + <tr> + <td class="tdl">10</td> + <td class="tdll">Lentils</td> + <td class="tdcl">88.00</td> + <td class="tdcl">4.20</td> + <td class="tdcl">4.00</td> + <td class="tdcl">0.75</td> + <td class="tdcl">0.70</td> + <td class="tdcl"> 94.08</td> + <td class="tdcl">16.80</td> + <td class="tdcl">15.68</td> + </tr> + <tr> + <td class="tdl">11</td> + <td class="tdll">Tares (seed)</td> + <td class="tdclb">84.00</td> + <td class="tdclb">4.20</td> + <td class="tdclb">2.50</td> + <td class="tdclb">0.80</td> + <td class="tdclb">0.80</td> + <td class="tdclb"> 94.08</td> + <td class="tdclb">17.92</td> + <td class="tdclb">17.92</td> + </tr> + <tr> + <td class="tdl">12</td> + <td class="tdll">Indian corn</td> + <td class="tdcl">88.00</td> + <td class="tdcl">1.70</td> + <td class="tdcl">1.40</td> + <td class="tdcl">0.60</td> + <td class="tdcl">0.37</td> + <td class="tdcl"> 38.08</td> + <td class="tdcl">13.44</td> + <td class="tdcl"> 8.29</td> + </tr> + <tr> + <td class="tdl">13</td> + <td class="tdll">Wheat</td> + <td class="tdcl">85.00</td> + <td class="tdcl">1.80</td> + <td class="tdcl">1.70</td> + <td class="tdcl">0.85</td> + <td class="tdcl">0.53</td> + <td class="tdcl"> 40.32</td> + <td class="tdcl">19.04</td> + <td class="tdcl">11.87</td> + </tr> + <tr> + <td class="tdl">14</td> + <td class="tdll">Malt</td> + <td class="tdcl">94.00</td> + <td class="tdcl">1.70</td> + <td class="tdcl">2.50</td> + <td class="tdcl">0.80</td> + <td class="tdcl">0.50</td> + <td class="tdcl"> 38.08</td> + <td class="tdcl">17.92</td> + <td class="tdcl">11.20</td> + </tr> + <tr> + <td class="tdl">15</td> + <td class="tdll">Barley</td> + <td class="tdcl">84.00</td> + <td class="tdcl">1.65</td> + <td class="tdcl">2.20</td> + <td class="tdcl">0.75</td> + <td class="tdcl">0.55</td> + <td class="tdcl"> 36.96</td> + <td class="tdcl">16.80</td> + <td class="tdcl">12.32</td> + </tr> + <tr> + <td class="tdl">16</td> + <td class="tdll">Oats</td> + <td class="tdcl">86.00</td> + <td class="tdcl">2.00</td> + <td class="tdcl">2.80</td> + <td class="tdcl">0.60</td> + <td class="tdcl">0.50</td> + <td class="tdcl"> 44.80</td> + <td class="tdcl">13.44</td> + <td class="tdcl">11.20</td> + </tr> + <tr> + <td class="tdl">17</td> + <td class="tdll">Rice-meal*</td> + <td class="tdcl">90.00</td> + <td class="tdcl">1.90</td> + <td class="tdcl">7.50</td> + <td class="tdcl">(0.60)</td> + <td class="tdcl">(0.37)</td> + <td class="tdcl"> 42.56</td> + <td class="tdcl">(13.44)</td> + <td class="tdcl"> (8.29)</td> + </tr> + <tr> + <td class="tdl">18</td> + <td class="tdll">Locust-beans*</td> + <td class="tdclb">85.00</td> + <td class="tdclb">1.20</td> + <td class="tdclb">2.50</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb"> 26.88</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> + <tr> + <td class="tdl">19</td> + <td class="tdll">Malt-combs</td> + <td class="tdcl">90.00</td> + <td class="tdcl">3.90</td> + <td class="tdcl">8.00</td> + <td class="tdcl">2.00</td> + <td class="tdcl">2.00</td> + <td class="tdcl"> 87.36</td> + <td class="tdcl">44.80</td> + <td class="tdcl">44.80</td> + </tr> + <tr> + <td class="tdl">20</td> + <td class="tdll">Fine pollard</td> + <td class="tdcl">86.00</td> + <td class="tdcl">2.45</td> + <td class="tdcl">5.50</td> + <td class="tdcl">2.90</td> + <td class="tdcl">1.46</td> + <td class="tdcl"> 54.88</td> + <td class="tdcl">64.96</td> + <td class="tdcl">32.70</td> + </tr> + <tr> + <td class="tdl">21</td> + <td class="tdll">Coarse pollard</td> + <td class="tdcl">86.00</td> + <td class="tdcl">2.50</td> + <td class="tdcl">6.40</td> + <td class="tdcl">3.50</td> + <td class="tdcl">1.50</td> + <td class="tdcl"> 56.00</td> + <td class="tdcl">78.40</td> + <td class="tdcl">33.60</td> + </tr> + <tr> + <td class="tdl">22</td> + <td class="tdll">Bran</td> + <td class="tdclb">86.00</td> + <td class="tdclb">2.50</td> + <td class="tdclb">6.50</td> + <td class="tdclb">3.60</td> + <td class="tdclb">1.45</td> + <td class="tdclb"> 56.00</td> + <td class="tdclb">80.64</td> + <td class="tdclb">32.48</td> + </tr> + <tr> + <td class="tdl">23</td> + <td class="tdll">Clover-hay</td> + <td class="tdcl">83.00</td> + <td class="tdcl">2.40</td> + <td class="tdcl">7.00</td> + <td class="tdcl">0.57</td> + <td class="tdcl">1.50</td> + <td class="tdcl"> 53.76</td> + <td class="tdcl">12.77</td> + <td class="tdcl">33.60</td> + </tr> + <tr> + <td class="tdl">24</td> + <td class="tdll">Meadow-hay</td> + <td class="tdclb">84.00</td> + <td class="tdclb">1.50</td> + <td class="tdclb">6.50</td> + <td class="tdclb">0.40</td> + <td class="tdclb">1.60</td> + <td class="tdclb"> 33.60</td> + <td class="tdclb"> 8.96</td> + <td class="tdclb">35.84</td> + </tr> + <tr> + <td class="tdl">25</td> + <td class="tdll">Pea-straw</td> + <td class="tdcl">82.50</td> + <td class="tdcl">1.00</td> + <td class="tdcl">5.50</td> + <td class="tdcl">0.35</td> + <td class="tdcl">1.00</td> + <td class="tdcl"> 22.40</td> + <td class="tdcl"> 7.84</td> + <td class="tdcl">22.40</td> + </tr> + <tr> + <td class="tdl">26</td> + <td class="tdll">Oat-straw</td> + <td class="tdcl">83.00</td> + <td class="tdcl">0.50</td> + <td class="tdcl">5.50</td> + <td class="tdcl">0.24</td> + <td class="tdcl">1.00</td> + <td class="tdcl"> 11.20</td> + <td class="tdcl"> 5.38</td> + <td class="tdcl">22.40</td> + </tr> + <tr> + <td class="tdl">27</td> + <td class="tdll">Wheat-straw</td> + <td class="tdcl">84.00</td> + <td class="tdcl">0.45</td> + <td class="tdcl">5.00</td> + <td class="tdcl">0.24</td> + <td class="tdcl">0.80</td> + <td class="tdcl"> 10.08</td> + <td class="tdcl"> 5.38</td> + <td class="tdcl">17.92</td> + </tr> + <tr> + <td class="tdl">28</td> + <td class="tdll">Barley-straw</td> + <td class="tdcl">85.00</td> + <td class="tdcl">0.40</td> + <td class="tdcl">4.50</td> + <td class="tdcl">0.18</td> + <td class="tdcl">1.00</td> + <td class="tdcl"> 8.96</td> + <td class="tdcl"> 4.03</td> + <td class="tdcl">22.40</td> + </tr> + <tr> + <td class="tdl">29</td> + <td class="tdll">Bean-straw</td> + <td class="tdclb">82.50</td> + <td class="tdclb">0.90</td> + <td class="tdclb">5.00</td> + <td class="tdclb">0.30</td> + <td class="tdclb">1.00</td> + <td class="tdclb"> 20.16</td> + <td class="tdclb"> 6.72</td> + <td class="tdclb">22.40</td> + </tr> + <tr> + <td class="tdl">30</td> + <td class="tdll">Potatoes</td> + <td class="tdcl">25.00</td> + <td class="tdcl">0.25</td> + <td class="tdcl">1.00</td> + <td class="tdcl">0.15</td> + <td class="tdcl">0.55</td> + <td class="tdcl"> 5.60</td> + <td class="tdcl"> 3.36</td> + <td class="tdcl">12.32</td> + </tr> + <tr> + <td class="tdl">31</td> + <td class="tdll">Carrots</td> + <td class="tdcl">14.00</td> + <td class="tdcl">0.20</td> + <td class="tdcl">0.90</td> + <td class="tdcl">0.09</td> + <td class="tdcl">0.28</td> + <td class="tdcl"> 4.48</td> + <td class="tdcl"> 2.02</td> + <td class="tdcl"> 6.27</td> + </tr> + <tr> + <td class="tdl">32</td> + <td class="tdll">Parsnips</td> + <td class="tdcl">16.00</td> + <td class="tdcl">0.22</td> + <td class="tdcl">1.00</td> + <td class="tdcl">0.19</td> + <td class="tdcl">0.36</td> + <td class="tdcl"> 4.93</td> + <td class="tdcl"> 4.26</td> + <td class="tdcl"> 8.06</td> + </tr> + <tr> + <td class="tdl">33</td> + <td class="tdll">Swedish turnips</td> + <td class="tdcl">11.00</td> + <td class="tdcl">0.25</td> + <td class="tdcl">0.60</td> + <td class="tdcl">0.06</td> + <td class="tdcl">0.22</td> + <td class="tdcl"> 5.60</td> + <td class="tdcl"> 1.34</td> + <td class="tdcl"> 4.93</td> + </tr> + <tr> + <td class="tdl">34</td> + <td class="tdll">Mangel-wurzels</td> + <td class="tdcl">12.50</td> + <td class="tdcl">0.22</td> + <td class="tdcl">1.00</td> + <td class="tdcl">0.07</td> + <td class="tdcl">0.40</td> + <td class="tdcl"> 4.93</td> + <td class="tdcl"> 1.57</td> + <td class="tdcl"> 8.96</td> + </tr> + <tr> + <td class="tdl">35</td> + <td class="tdll">Yellow turnips*</td> + <td class="tdcl"> 9.00</td> + <td class="tdcl">0.20</td> + <td class="tdcl">0.65</td> + <td class="tdcl">(0.06)</td> + <td class="tdcl">(0.22)</td> + <td class="tdcl"> 4.48</td> + <td class="tdcl"> (1.34)</td> + <td class="tdcl"> (4.93)</td> + </tr> + <tr> + <td class="tdlb">36</td> + <td class="tdllb">White turnips</td> + <td class="tdclb"> 8.00</td> + <td class="tdclb">0.18</td> + <td class="tdclb">0.68</td> + <td class="tdclb">0.05</td> + <td class="tdclb">0.30</td> + <td class="tdclb"> 4.03</td> + <td class="tdclb"> 1.12</td> + <td class="tdclb"> 6.72</td> + </tr> + <tr> + <td class="tdl" colspan="10">* In the case of neither rice-meal, locust-beans, nor yellow + turnips have records of ash analyses been found. For rice-meal the same percentages of + phosphoric acid and potash as in Indian corn, and for yellow turnips the same as in swedes, + are provisionally adopted; but in all the Tables the assumed results are given in + parentheses. For locust-beans no figure has been assumed, and the columns are left blank.</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_558" id="Page_558">[Pg 558]</a></span>NOTE IV.—<i>continued</i></p> + +<p class="cen">TABLE II.—<span class="smcap">Lawes' & Gilbert's Tables for Calculating Unexhausted +Value of Manures.</span></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Fattening"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="2">Fattening</td> + <td class="tdctlb" colspan="7"><span class="smcap">Nitrogen.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="2">Increase in</td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl" colspan="2">In Fattening</td> + <td class="tdcl" colspan="3"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="2">Live Weight</td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl" colspan="2">Increase (at</td> + <td class="tdcl" colspan="3"> </td> + </tr> + <tr> + <td class="tdl">No.</td> + <td class="tdcl"><span class="smcap">Description</span></td> + <td class="tdclb" colspan="2">(Oxen or Sheep).</td> + <td class="tdclb" colspan="2">In Food.</td> + <td class="tdclb" colspan="2">1.27 per cent).</td> + <td class="tdclb" colspan="3">In Manure.</td> + </tr> + <tr> + <td class="tdl" width="3%"> </td> + <td class="tdcl" width="23%"><span class="smcap">of Food.</span></td> + <td class="tdcl" width="9%"> </td> + <td class="tdcl" width="9%"> </td> + <td class="tdcl" width="5%"> </td> + <td class="tdcl" width="7%"> </td> + <td class="tdcl" width="5%"> </td> + <td class="tdcl" width="10%"> </td> + <td class="tdcl" width="10%"> </td> + <td class="tdcl" width="10%"> </td> + <td class="tdcl" width="9%">Value </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Increase</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">From</td> + <td class="tdcl">Per cent</td> + <td class="tdcl">Total</td> + <td class="tdcl"> </td> + <td class="tdcl">of</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Food</td> + <td class="tdcl">per ton</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">1 ton</td> + <td class="tdcl">of</td> + <td class="tdcl">remaining</td> + <td class="tdcl">Nitrogen</td> + <td class="tdcl">Ammonia</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">to 1</td> + <td class="tdcl">of</td> + <td class="tdcl">Per</td> + <td class="tdcl">Per</td> + <td class="tdcl">of</td> + <td class="tdcl">total</td> + <td class="tdcl">for</td> + <td class="tdcl">equal</td> + <td class="tdcl">at 6d.</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb"> </td> + <td class="tdclb">Increase</td> + <td class="tdclb">Food.</td> + <td class="tdclb">cent.</td> + <td class="tdclb">ton.</td> + <td class="tdclb">Food.</td> + <td class="tdclb">consumed.</td> + <td class="tdclb">Manure.</td> + <td class="tdclb">Ammonia.</td> + <td class="tdclb">per lb.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">%</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">%</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl"><i>£ s. d.</i></td> + </tr> + <tr> + <td class="tdl"> 1</td> + <td class="tdll">Linseed</td> + <td class="tdcl"> 5.0</td> + <td class="tdcl">448.0</td> + <td class="tdcl">3.60</td> + <td class="tdcl"> 80.64</td> + <td class="tdcl">5.69</td> + <td class="tdcl"> 7.06</td> + <td class="tdcl"> 74.95</td> + <td class="tdcl"> 91.0</td> + <td class="tdcl">2 5 6</td> + </tr> + <tr> + <td class="tdl"> 2</td> + <td class="tdll">Linseed-cake</td> + <td class="tdcl"> 6.0</td> + <td class="tdcl">373.3</td> + <td class="tdcl">4.75</td> + <td class="tdcl">106.40</td> + <td class="tdcl">4.74</td> + <td class="tdcl"> 4.45</td> + <td class="tdcl">101.66</td> + <td class="tdcl">123.4</td> + <td class="tdcl">3 1 8</td> + </tr> + <tr> + <td class="tdlz"> 3</td> + <td class="tdll">Decorticated cotton-cake</td> + <td class="tdcly"> 6.5</td> + <td class="tdcly">344.6</td> + <td class="tdcly">6.60</td> + <td class="tdcly">147.84</td> + <td class="tdcly">4.38</td> + <td class="tdcly"> 2.96</td> + <td class="tdcly">143.46</td> + <td class="tdcly">174.2</td> + <td class="tdcly">4 7 1</td> + </tr> + <tr> + <td class="tdl"> 4</td> + <td class="tdll">Palm-nut-cake</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl">320.0</td> + <td class="tdcl">2.50</td> + <td class="tdcl"> 56.00</td> + <td class="tdcl">4.06</td> + <td class="tdcl"> 7.25</td> + <td class="tdcl"> 51.94</td> + <td class="tdcl"> 63.1</td> + <td class="tdcl">1 11 7</td> + </tr> + <tr> + <td class="tdlz"> 5</td> + <td class="tdll">Undecorticated cotton-cake</td> + <td class="tdcly"> 8.0</td> + <td class="tdcly">280.0</td> + <td class="tdcly">3.75</td> + <td class="tdcly"> 84.00</td> + <td class="tdcly">3.56</td> + <td class="tdcly"> 4.24</td> + <td class="tdcly"> 80.44</td> + <td class="tdcly"> 97.7</td> + <td class="tdcly">2 8 10</td> + </tr> + <tr> + <td class="tdlz"> 6</td> + <td class="tdll">Cocoa-nut-cake</td> + <td class="tdcly"> 8.0</td> + <td class="tdcly">280.0</td> + <td class="tdcly">3.40</td> + <td class="tdcly"> 76.16</td> + <td class="tdcly">3.56</td> + <td class="tdcly"> 4.67</td> + <td class="tdcly"> 72.60</td> + <td class="tdcly"> 88.2</td> + <td class="tdcly">2 4 1</td> + </tr> + <tr> + <td class="tdl"> 7</td> + <td class="tdll">Rape-cake</td> + <td class="tdclb">(10)</td> + <td class="tdclb">(224)</td> + <td class="tdclb">4.90</td> + <td class="tdclb">109.76</td> + <td class="tdclb">2.84</td> + <td class="tdclb"> 2.59</td> + <td class="tdclb">106.92</td> + <td class="tdclb">129.8</td> + <td class="tdclb">3 4 11</td> + </tr> + <tr> + <td class="tdl"> 8</td> + <td class="tdll">Peas</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl">320.0</td> + <td class="tdcl">3.60</td> + <td class="tdcl"> 80.64</td> + <td class="tdcl">4.06</td> + <td class="tdcl"> 5.03</td> + <td class="tdcl"> 76.58</td> + <td class="tdcl"> 93.0</td> + <td class="tdcl">2 6 6</td> + </tr> + <tr> + <td class="tdl"> 9</td> + <td class="tdll">Beans</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl">320.0</td> + <td class="tdcl">4.00</td> + <td class="tdcl"> 89.60</td> + <td class="tdcl">4.06</td> + <td class="tdcl"> 4.53</td> + <td class="tdcl"> 85.54</td> + <td class="tdcl">103.9</td> + <td class="tdcl">2 11 11</td> + </tr> + <tr> + <td class="tdl">10</td> + <td class="tdll">Lentils</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl">320.0</td> + <td class="tdcl">4.20</td> + <td class="tdcl"> 94.08</td> + <td class="tdcl">4.06</td> + <td class="tdcl"> 4.32</td> + <td class="tdcl"> 90.02</td> + <td class="tdcl">109.3</td> + <td class="tdcl">2 14 8</td> + </tr> + <tr> + <td class="tdl">11</td> + <td class="tdll">Tares (seed)</td> + <td class="tdclb"> 7.0</td> + <td class="tdclb">320.0</td> + <td class="tdclb">4.20</td> + <td class="tdclb"> 94.08</td> + <td class="tdclb">4.06</td> + <td class="tdclb"> 4.32</td> + <td class="tdclb"> 90.02</td> + <td class="tdclb">109.3</td> + <td class="tdclb">2 14 8</td> + </tr> + <tr> + <td class="tdl">12</td> + <td class="tdll">Indian corn</td> + <td class="tdcl"> 7.2</td> + <td class="tdcl">311.1</td> + <td class="tdcl">1.70</td> + <td class="tdcl"> 38.08</td> + <td class="tdcl">3.95</td> + <td class="tdcl">10.37</td> + <td class="tdcl"> 34.13</td> + <td class="tdcl"> 41.4</td> + <td class="tdcl">1 0 9</td> + </tr> + <tr> + <td class="tdl">13</td> + <td class="tdll">Wheat</td> + <td class="tdcl"> 7.2</td> + <td class="tdcl">311.1</td> + <td class="tdcl">1.80</td> + <td class="tdcl"> 40.32</td> + <td class="tdcl">3.95</td> + <td class="tdcl"> 9.80</td> + <td class="tdcl"> 36.37</td> + <td class="tdcl"> 44.2</td> + <td class="tdcl">1 2 1</td> + </tr> + <tr> + <td class="tdl">14</td> + <td class="tdll">Malt</td> + <td class="tdcl"> 7.0</td> + <td class="tdcl">320.0</td> + <td class="tdcl">1.70</td> + <td class="tdcl"> 38.08</td> + <td class="tdcl">4.06</td> + <td class="tdcl">10.66</td> + <td class="tdcl"> 34.02</td> + <td class="tdcl"> 41.3</td> + <td class="tdcl">1 0 8</td> + </tr> + <tr> + <td class="tdl">15</td> + <td class="tdll">Barley</td> + <td class="tdcl"> 7.2</td> + <td class="tdcl">311.1</td> + <td class="tdcl">1.65</td> + <td class="tdcl"> 36.96</td> + <td class="tdcl">3.95</td> + <td class="tdcl">10.69</td> + <td class="tdcl"> 33.01</td> + <td class="tdcl"> 40.1</td> + <td class="tdcl">1 0 1</td> + </tr> + <tr> + <td class="tdl">16</td> + <td class="tdll">Oats</td> + <td class="tdcl"> 7.5</td> + <td class="tdcl">298.7</td> + <td class="tdcl">2.00</td> + <td class="tdcl"> 44.80</td> + <td class="tdcl">3.79</td> + <td class="tdcl"> 8.46</td> + <td class="tdcl"> 41.01</td> + <td class="tdcl"> 49.8</td> + <td class="tdcl">1 4 11</td> + </tr> + <tr> + <td class="tdl">17</td> + <td class="tdll">Rice-meal</td> + <td class="tdcl"> 7.5</td> + <td class="tdcl">298.7</td> + <td class="tdcl">1.90</td> + <td class="tdcl"> 42.56</td> + <td class="tdcl">3.79</td> + <td class="tdcl"> 8.91</td> + <td class="tdcl"> 38.77</td> + <td class="tdcl"> 47.1</td> + <td class="tdcl">1 3 6</td> + </tr> + <tr> + <td class="tdl">18</td> + <td class="tdll">Locust-beans</td> + <td class="tdclb"> 9.0</td> + <td class="tdclb">248.9</td> + <td class="tdclb">1.20</td> + <td class="tdclb"> 26.88</td> + <td class="tdclb">3.16</td> + <td class="tdclb">11.76</td> + <td class="tdclb"> 23.72</td> + <td class="tdclb"> 28.8</td> + <td class="tdclb">0 14 5</td> + </tr> + <tr> + <td class="tdl">19</td> + <td class="tdll">Malt-combs</td> + <td class="tdcl"> 8.0</td> + <td class="tdcl">248.9</td> + <td class="tdcl">3,90</td> + <td class="tdcl"> 87.36</td> + <td class="tdcl">3.56</td> + <td class="tdcl"> 4.08</td> + <td class="tdcl"> 83.80</td> + <td class="tdcl">101.8</td> + <td class="tdcl">2 10 11</td> + </tr> + <tr> + <td class="tdl">20</td> + <td class="tdll">Fine pollard</td> + <td class="tdcl"> 7.5</td> + <td class="tdcl">298.7</td> + <td class="tdcl">2.45</td> + <td class="tdcl"> 54.88</td> + <td class="tdcl">3.79</td> + <td class="tdcl"> 6.91</td> + <td class="tdcl"> 51.09</td> + <td class="tdcl"> 62.0</td> + <td class="tdcl">1 11 0</td> + </tr> + <tr> + <td class="tdl">21</td> + <td class="tdll">Coarse pollard</td> + <td class="tdcl"> 8.0</td> + <td class="tdcl">280.0</td> + <td class="tdcl">2.50</td> + <td class="tdcl"> 56.00</td> + <td class="tdcl">3.50</td> + <td class="tdcl"> 6.35</td> + <td class="tdcl"> 52.44</td> + <td class="tdcl"> 63.7</td> + <td class="tdcl">1 11 10</td> + </tr> + <tr> + <td class="tdl">22</td> + <td class="tdll">Bran</td> + <td class="tdclb"> 9.0</td> + <td class="tdclb">248.9</td> + <td class="tdclb">2.50</td> + <td class="tdclb"> 56.00</td> + <td class="tdclb">3.16</td> + <td class="tdclb"> 5.64</td> + <td class="tdclb"> 52.84</td> + <td class="tdclb"> 64.2</td> + <td class="tdclb">1 12 1</td> + </tr> + <tr> + <td class="tdl">23</td> + <td class="tdll">Clover-hay</td> + <td class="tdcl"> 14.0</td> + <td class="tdcl">160.0</td> + <td class="tdcl">2.40</td> + <td class="tdcl"> 53.76</td> + <td class="tdcl">2.03</td> + <td class="tdcl"> 3.78</td> + <td class="tdcl"> 51.73</td> + <td class="tdcl"> 62.8</td> + <td class="tdcl">1 11 5</td> + </tr> + <tr> + <td class="tdl">24</td> + <td class="tdll">Meadow-hay</td> + <td class="tdclb"> 15.0</td> + <td class="tdclb">149.3</td> + <td class="tdclb">1.50</td> + <td class="tdclb"> 33.60</td> + <td class="tdclb">1.90</td> + <td class="tdclb"> 5.65</td> + <td class="tdclb"> 31.70</td> + <td class="tdclb"> 38.5</td> + <td class="tdclb">0 19 3</td> + </tr> + <tr> + <td class="tdl">25</td> + <td class="tdll">Pea-straw</td> + <td class="tdcl"> 16.0</td> + <td class="tdcl">140.0</td> + <td class="tdcl">1.00</td> + <td class="tdcl"> 22.40</td> + <td class="tdcl">1.78</td> + <td class="tdcl"> 7.95</td> + <td class="tdcl"> 20.62</td> + <td class="tdcl"> 25.0</td> + <td class="tdcl">0 12 6</td> + </tr> + <tr> + <td class="tdl">26</td> + <td class="tdll">Oat-straw</td> + <td class="tdcl"> 18.0</td> + <td class="tdcl">124.4</td> + <td class="tdcl">0.50</td> + <td class="tdcl"> 11.20</td> + <td class="tdcl">1.58</td> + <td class="tdcl">14.11</td> + <td class="tdcl"> 9.62</td> + <td class="tdcl"> 11.7</td> + <td class="tdcl">0 5 10</td> + </tr> + <tr> + <td class="tdl">27</td> + <td class="tdll">Wheat-straw</td> + <td class="tdcl"> 21.0</td> + <td class="tdcl">106.7</td> + <td class="tdcl">0.45</td> + <td class="tdcl"> 10.08</td> + <td class="tdcl">1.36</td> + <td class="tdcl">13.49</td> + <td class="tdcl"> 8.72</td> + <td class="tdcl"> 10.6</td> + <td class="tdcl">0 5 4</td> + </tr> + <tr> + <td class="tdl">28</td> + <td class="tdll">Barley-straw</td> + <td class="tdcl"> 23.0</td> + <td class="tdcl"> 97.4</td> + <td class="tdcl">0.40</td> + <td class="tdcl"> 8.96</td> + <td class="tdcl">1.24</td> + <td class="tdcl">13.84</td> + <td class="tdcl"> 7.72</td> + <td class="tdcl"> 9.4</td> + <td class="tdcl">0 4 8</td> + </tr> + <tr> + <td class="tdl">29</td> + <td class="tdll">Bean-straw</td> + <td class="tdclb"> 22.0</td> + <td class="tdclb">101.8</td> + <td class="tdclb">0.90</td> + <td class="tdclb">20.16</td> + <td class="tdclb">1.29</td> + <td class="tdclb"> 6.39</td> + <td class="tdclb"> 18.87</td> + <td class="tdclb"> 22.9</td> + <td class="tdclb">0 11 6</td> + </tr> + <tr> + <td class="tdl">30</td> + <td class="tdll">Potatoes</td> + <td class="tdcl"> 60.0</td> + <td class="tdcl"> 37.3</td> + <td class="tdcl">0.25</td> + <td class="tdcl"> 5.60</td> + <td class="tdcl">0.47</td> + <td class="tdcl"> 8.39</td> + <td class="tdcl"> 5.13</td> + <td class="tdcl"> 6.2</td> + <td class="tdcl">0 3 1</td> + </tr> + <tr> + <td class="tdl">31</td> + <td class="tdll">Carrots</td> + <td class="tdcl"> 85.7</td> + <td class="tdcl"> 26.1</td> + <td class="tdcl">0.20</td> + <td class="tdcl"> 4.48</td> + <td class="tdcl">0.33</td> + <td class="tdcl"> 7.37</td> + <td class="tdcl"> 4.15</td> + <td class="tdcl"> 5.0</td> + <td class="tdcl">0 2 6</td> + </tr> + <tr> + <td class="tdl">32</td> + <td class="tdll">Parsnips</td> + <td class="tdcl"> 75.0</td> + <td class="tdcl"> 29.9</td> + <td class="tdcl">0.22</td> + <td class="tdcl"> 4.93</td> + <td class="tdcl">0.38</td> + <td class="tdcl"> 7.71</td> + <td class="tdcl"> 4.55</td> + <td class="tdcl"> 5.5</td> + <td class="tdcl">0 2 9</td> + </tr> + <tr> + <td class="tdl">33</td> + <td class="tdll">Swedish turnips</td> + <td class="tdcl">109.1</td> + <td class="tdcl"> 20.5</td> + <td class="tdcl">0.25</td> + <td class="tdcl"> 5.60</td> + <td class="tdcl">0.26</td> + <td class="tdcl"> 4.64</td> + <td class="tdcl"> 5.34</td> + <td class="tdcl"> 6.5</td> + <td class="tdcl">0 3 3</td> + </tr> + <tr> + <td class="tdl">34</td> + <td class="tdll">Mangel-wurzels</td> + <td class="tdcl"> 96.0</td> + <td class="tdcl"> 23.3</td> + <td class="tdcl">0.22</td> + <td class="tdcl"> 4.93</td> + <td class="tdcl">0.30</td> + <td class="tdcl"> 6.09</td> + <td class="tdcl"> 4.63</td> + <td class="tdcl"> 5.6</td> + <td class="tdcl">0 2 10</td> + </tr> + <tr> + <td class="tdl">35</td> + <td class="tdll">Yellow turnips</td> + <td class="tdcl">133.3</td> + <td class="tdcl"> 16.8</td> + <td class="tdcl">0.20</td> + <td class="tdcl"> 4.48</td> + <td class="tdcl">0.21</td> + <td class="tdcl"> 4.69</td> + <td class="tdcl"> 4.27</td> + <td class="tdcl"> 5.2</td> + <td class="tdcl">0 2 7</td> + </tr> + <tr> + <td class="tdlb">36</td> + <td class="tdllb">White turnips</td> + <td class="tdclb">150.0</td> + <td class="tdclb"> 14.9</td> + <td class="tdclb">0.18</td> + <td class="tdclb"> 4.03</td> + <td class="tdclb">0.19</td> + <td class="tdclb"> 4.71</td> + <td class="tdclb"> 3.84</td> + <td class="tdclb"> 4.7</td> + <td class="tdclb">0 2 4</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">NOTE IV.—continued<span class='pagenum'><a name="Page_559" id="Page_559">[Pg 559]</a></span></p> + +<p class="cen">TABLE II.—continued</p> + +<div class="centered"> +<table border="0" width="90%" cellpadding="2" cellspacing="0" summary="Fattening cont."> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdctlb" colspan="6"><span class="smcap">Phosphoric Acid.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl" colspan="2">In Fattening</td> + <td class="tdcl" colspan="2"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl" colspan="2">Increase at</td> + <td class="tdcl" colspan="2"> </td> + </tr> + <tr> + <td class="tdl">No.</td> + <td class="tdcl"><span class="smcap">Description</span></td> + <td class="tdclb" colspan="2">In Food.</td> + <td class="tdclb" colspan="2">(0.86 per cent).</td> + <td class="tdclb" colspan="3">In Manure.</td> + </tr> + <tr> + <td class="tdl" width="3%"> </td> + <td class="tdcl" width="25%"><span class="smcap">of Food.</span></td> + <td class="tdcl" width="12%"> </td> + <td class="tdcl" width="12%"> </td> + <td class="tdcl" width="12%"> </td> + <td class="tdcl" width="12%"> </td> + <td class="tdcl" width="12%"> </td> + <td class="tdcl" width="12%"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">From</td> + <td class="tdcl">Per cent</td> + <td class="tdcl">Total</td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">1 ton</td> + <td class="tdcl">of</td> + <td class="tdcl">remaining</td> + <td class="tdcl">Value</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Per</td> + <td class="tdcl">Per</td> + <td class="tdcl">of</td> + <td class="tdcl">total</td> + <td class="tdcl">for</td> + <td class="tdcl">at 3d.</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb"> </td> + <td class="tdclb">cent.</td> + <td class="tdclb">ton.</td> + <td class="tdclb">Food.</td> + <td class="tdclb">consumed.</td> + <td class="tdclb">Manure.</td> + <td class="tdclb">per lb.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl">%</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">%</td> + <td class="tdcl">lb.</td> + <td class="tdcl"><i>s. d.</i></td> + </tr> + <tr> + <td class="tdl"> 1</td> + <td class="tdll">Linseed</td> + <td class="tdcl">1.54</td> + <td class="tdcl">34.50</td> + <td class="tdcl">3.85</td> + <td class="tdcl">11.16</td> + <td class="tdcl">30.65</td> + <td class="tdcl"> 7 8</td> + </tr> + <tr> + <td class="tdl"> 2</td> + <td class="tdll">Linseed-cake</td> + <td class="tdcl">2.00</td> + <td class="tdcl">44.80</td> + <td class="tdcl">3.21</td> + <td class="tdcl"> 7.17</td> + <td class="tdcl">41.59</td> + <td class="tdcl">10 5</td> + </tr> + <tr> + <td class="tdlz"> 3</td> + <td class="tdll">Decorticated cotton-cake</td> + <td class="tdcly">3.10</td> + <td class="tdcly">69.44</td> + <td class="tdcly">2.96</td> + <td class="tdcly"> 4.26</td> + <td class="tdcly">66.48</td> + <td class="tdcly">16 8</td> + </tr> + <tr> + <td class="tdl"> 4</td> + <td class="tdll">Palm-nut-cake</td> + <td class="tdcl">1.20</td> + <td class="tdcl">26.88</td> + <td class="tdcl">2.75</td> + <td class="tdcl">10.23</td> + <td class="tdcl">24.13</td> + <td class="tdcl"> 6 0</td> + </tr> + <tr> + <td class="tdlz"> 5</td> + <td class="tdll">Undecorticated cotton-cake</td> + <td class="tdcly">2.00</td> + <td class="tdcly">44.80</td> + <td class="tdcly">2.41</td> + <td class="tdcly"> 5.38</td> + <td class="tdcly">42.39</td> + <td class="tdcly">10 7</td> + </tr> + <tr> + <td class="tdlz"> 6</td> + <td class="tdll">Cocoa-<br /> nut-cake</td> + <td class="tdcly">1.40</td> + <td class="tdcly">31.36</td> + <td class="tdcly">2.41</td> + <td class="tdcly"> 7.69</td> + <td class="tdcly">28.95</td> + <td class="tdcly"> 7 3</td> + </tr> + <tr> + <td class="tdl"> 7</td> + <td class="tdll">Rape-cake</td> + <td class="tdclb">2.50</td> + <td class="tdclb">56.00</td> + <td class="tdclb">1.93</td> + <td class="tdclb"> 3.45</td> + <td class="tdclb">54.07</td> + <td class="tdclb">13 6</td> + </tr> + <tr> + <td class="tdl"> 8</td> + <td class="tdll">Peas</td> + <td class="tdcl">0.85</td> + <td class="tdcl">19.04</td> + <td class="tdcl">2.75</td> + <td class="tdcl">14.44</td> + <td class="tdcl">16.29</td> + <td class="tdcl"> 4 1</td> + </tr> + <tr> + <td class="tdl"> 9</td> + <td class="tdll">Beans</td> + <td class="tdcl">1.10</td> + <td class="tdcl">24.64</td> + <td class="tdcl">2.75</td> + <td class="tdcl">11.10</td> + <td class="tdcl">21.89</td> + <td class="tdcl"> 5 6</td> + </tr> + <tr> + <td class="tdl">10</td> + <td class="tdll">Lentils</td> + <td class="tdcl">0.75</td> + <td class="tdcl">16.80</td> + <td class="tdcl">2.75</td> + <td class="tdcl">16.37</td> + <td class="tdcl">14.05</td> + <td class="tdcl"> 3 6</td> + </tr> + <tr> + <td class="tdl">11</td> + <td class="tdll">Tares (seed)</td> + <td class="tdclb">0.80</td> + <td class="tdclb">17.92</td> + <td class="tdclb">2.75</td> + <td class="tdclb">15.36</td> + <td class="tdclb">15.17</td> + <td class="tdclb"> 3 9</td> + </tr> + <tr> + <td class="tdl">12</td> + <td class="tdll">Indian corn</td> + <td class="tdcl">0.60</td> + <td class="tdcl">13.44</td> + <td class="tdcl">2.68</td> + <td class="tdcl">19.94</td> + <td class="tdcl">10.76</td> + <td class="tdcl"> 2 8</td> + </tr> + <tr> + <td class="tdl">13</td> + <td class="tdll">Wheat</td> + <td class="tdcl">9.85</td> + <td class="tdcl">19.04</td> + <td class="tdcl">2.68</td> + <td class="tdcl">14.08</td> + <td class="tdcl">16.36</td> + <td class="tdcl"> 4 1</td> + </tr> + <tr> + <td class="tdl">14</td> + <td class="tdll">Malt</td> + <td class="tdcl">0.80</td> + <td class="tdcl">17.92</td> + <td class="tdcl">2.75</td> + <td class="tdcl">15.35</td> + <td class="tdcl">15.17</td> + <td class="tdcl"> 3 9</td> + </tr> + <tr> + <td class="tdl">15</td> + <td class="tdll">Barley</td> + <td class="tdcl">0.75</td> + <td class="tdcl">16.80</td> + <td class="tdcl">2.68</td> + <td class="tdcl">15.95</td> + <td class="tdcl">14.12</td> + <td class="tdcl"> 3 6</td> + </tr> + <tr> + <td class="tdl">16</td> + <td class="tdll">Oats</td> + <td class="tdcl">0.60</td> + <td class="tdcl">13.44</td> + <td class="tdcl">2.57</td> + <td class="tdcl">(19.12)</td> + <td class="tdcl">10.87</td> + <td class="tdcl"> 2 8</td> + </tr> + <tr> + <td class="tdl">17</td> + <td class="tdll">Rice-meal</td> + <td class="tdcl">(0.60)</td> + <td class="tdcl">(13.44)</td> + <td class="tdcl">2.57</td> + <td class="tdcl">(19.12)</td> + <td class="tdcl">(10.87)</td> + <td class="tdcl"> 2 8</td> + </tr> + <tr> + <td class="tdl">18</td> + <td class="tdll">Locust-beans</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">2.14</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> + <tr> + <td class="tdl">19</td> + <td class="tdll">Malt-combs</td> + <td class="tdcl">2.00</td> + <td class="tdcl">44.80</td> + <td class="tdcl">2.41</td> + <td class="tdcl"> 5.38</td> + <td class="tdcl">42.39</td> + <td class="tdcl">10 7</td> + </tr> + <tr> + <td class="tdl">20</td> + <td class="tdll">Fine pollard</td> + <td class="tdcl">2.90</td> + <td class="tdcl">64.96</td> + <td class="tdcl">2.57</td> + <td class="tdcl"> 3.96</td> + <td class="tdcl">62.39</td> + <td class="tdcl">15 7</td> + </tr> + <tr> + <td class="tdl">21</td> + <td class="tdll">Coarse pollard</td> + <td class="tdcl">3.50</td> + <td class="tdcl">78.40</td> + <td class="tdcl">2.41</td> + <td class="tdcl"> 3.07</td> + <td class="tdcl">75.99</td> + <td class="tdcl">19 0</td> + </tr> + <tr> + <td class="tdl">22</td> + <td class="tdll">Bran</td> + <td class="tdclb">3.60</td> + <td class="tdclb">80.64</td> + <td class="tdclb">2.14</td> + <td class="tdclb"> 2.65</td> + <td class="tdclb">78.50</td> + <td class="tdclb">19 8</td> + </tr> + <tr> + <td class="tdl">23</td> + <td class="tdll">Clover-hay</td> + <td class="tdcl">0.57</td> + <td class="tdcl">12.77</td> + <td class="tdcl">1.38</td> + <td class="tdcl">10.81</td> + <td class="tdcl">11.39</td> + <td class="tdcl"> 2 10</td> + </tr> + <tr> + <td class="tdl">24</td> + <td class="tdll">Meadow-hay</td> + <td class="tdclb">0.40</td> + <td class="tdclb"> 8.96</td> + <td class="tdclb">1.28</td> + <td class="tdclb">14.28</td> + <td class="tdclb"> 7.68</td> + <td class="tdclb"> 1 11</td> + </tr> + <tr> + <td class="tdl">25</td> + <td class="tdll">Pea-straw</td> + <td class="tdcl">0.35</td> + <td class="tdcl"> 7.84</td> + <td class="tdcl">1.20</td> + <td class="tdcl">15.31</td> + <td class="tdcl"> 6.64</td> + <td class="tdcl"> 1 8</td> + </tr> + <tr> + <td class="tdl">26</td> + <td class="tdll">Oat-straw</td> + <td class="tdcl">0.24</td> + <td class="tdcl"> 5.38</td> + <td class="tdcl">1.07</td> + <td class="tdcl">19.89</td> + <td class="tdcl"> 4.31</td> + <td class="tdcl"> 1 1</td> + </tr> + <tr> + <td class="tdl">27</td> + <td class="tdll">Wheat-straw</td> + <td class="tdcl">0.24</td> + <td class="tdcl"> 5.38</td> + <td class="tdcl">0.92</td> + <td class="tdcl">17.10</td> + <td class="tdcl"> 4.46</td> + <td class="tdcl"> 1 1</td> + </tr> + <tr> + <td class="tdl">28</td> + <td class="tdll">Barley-straw</td> + <td class="tdcl">0.18</td> + <td class="tdcl"> 4.03</td> + <td class="tdcl">0.84</td> + <td class="tdcl">20.84</td> + <td class="tdcl"> 3.19</td> + <td class="tdcl"> 0 9</td> + </tr> + <tr> + <td class="tdl">29</td> + <td class="tdll">Bean-straw</td> + <td class="tdclb">0.30</td> + <td class="tdclb"> 6.72</td> + <td class="tdclb">0.88</td> + <td class="tdclb">13.10</td> + <td class="tdclb"> 5.84</td> + <td class="tdclb"> 1 5</td> + </tr> + <tr> + <td class="tdl">30</td> + <td class="tdll">Potatoes</td> + <td class="tdcl">0.15</td> + <td class="tdcl"> 3.36</td> + <td class="tdcl">0.32</td> + <td class="tdcl"> 9.52</td> + <td class="tdcl"> 3.04</td> + <td class="tdcl"> 0 9</td> + </tr> + <tr> + <td class="tdl">31</td> + <td class="tdll">Carrots</td> + <td class="tdcl">0.09</td> + <td class="tdcl"> 2.02</td> + <td class="tdcl">0.22</td> + <td class="tdcl">10.89</td> + <td class="tdcl"> 1.80</td> + <td class="tdcl"> 0 5</td> + </tr> + <tr> + <td class="tdl">32</td> + <td class="tdll">Parsnips</td> + <td class="tdcl">0.19</td> + <td class="tdcl"> 4.29</td> + <td class="tdcl">0.26</td> + <td class="tdcl"> 6.10</td> + <td class="tdcl"> 4.00</td> + <td class="tdcl"> 1 0</td> + </tr> + <tr> + <td class="tdl">33</td> + <td class="tdll">Swedish turnips</td> + <td class="tdcl">0.06</td> + <td class="tdcl"> 1.34</td> + <td class="tdcl">0.18</td> + <td class="tdcl">13.43</td> + <td class="tdcl"> 1.16</td> + <td class="tdcl"> 0 4</td> + </tr> + <tr> + <td class="tdl">34</td> + <td class="tdll">Mangel-wurzels</td> + <td class="tdcl">0.07</td> + <td class="tdcl"> 1.57</td> + <td class="tdcl">0.20</td> + <td class="tdcl">12.74</td> + <td class="tdcl"> 1.37</td> + <td class="tdcl"> 0 4</td> + </tr> + <tr> + <td class="tdl">35</td> + <td class="tdll">Yellow turnips</td> + <td class="tdcl">(0.06)</td> + <td class="tdcl"> (1.34)</td> + <td class="tdcl">0.14</td> + <td class="tdcl">(10.78)</td> + <td class="tdcl"> (1.20)</td> + <td class="tdcl"> (0 4)</td> + </tr> + <tr> + <td class="tdlb">36</td> + <td class="tdllb">White turnips</td> + <td class="tdclb">0.05</td> + <td class="tdclb"> 1.12</td> + <td class="tdclb">0.13</td> + <td class="tdclb">11.61</td> + <td class="tdclb"> 0.99</td> + <td class="tdclb"> 0 3</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">NOTE IV.—continued</p> + +<p class="cen">TABLE II.—continued</p> + +<div class="centered"> +<table border="0" width="90%" cellpadding="2" cellspacing="0" summary="Fattening cont."> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdctlb" colspan="6"><span class="smcap">Potash.</span></td> + <td class="tdctl"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl" colspan="2">In Fattening</td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl" colspan="2">Increase at</td> + <td class="tdcl" colspan="2"> </td> + <td class="tdcl">Total</td> + </tr> + <tr> + <td class="tdl">No.</td> + <td class="tdcl"><span class="smcap">Description</span></td> + <td class="tdclb" colspan="2">In Food.</td> + <td class="tdclb" colspan="2">(0.11 per cent).</td> + <td class="tdclb" colspan="2">In Manure.</td> + <td class="tdcl">original</td> + </tr> + <tr> + <td class="tdl" width="3%"> </td> + <td class="tdcl" width="23%"><span class="smcap">of Food.</span></td> + <td class="tdcl" width="9%"> </td> + <td class="tdcl" width="11%"> </td> + <td class="tdcl" width="11%"> </td> + <td class="tdcl" width="11%"> </td> + <td class="tdcl" width="11%"> </td> + <td class="tdcl" width="11%"> </td> + <td class="tdcl" width="10%">Manure</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">From</td> + <td class="tdcl">Per cent</td> + <td class="tdcl">Total</td> + <td class="tdcl">Value</td> + <td class="tdcl">value</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">1 ton</td> + <td class="tdcl">of</td> + <td class="tdcl">remaining</td> + <td class="tdcl">at</td> + <td class="tdcl">per ton</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl">Per</td> + <td class="tdcl">Per</td> + <td class="tdcl">of</td> + <td class="tdcl">total</td> + <td class="tdcl">for</td> + <td class="tdcl">2-1/2d.</td> + <td class="tdcl">of Food</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb"> </td> + <td class="tdclb">cent.</td> + <td class="tdclb">ton.</td> + <td class="tdclb">Food.</td> + <td class="tdclb">consumed.</td> + <td class="tdclb">Manure.</td> + <td class="tdclb">per lb.</td> + <td class="tdclb">consumed.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl">%</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">%</td> + <td class="tdcl">lb.</td> + <td class="tdcl"><i>s. d.</i></td> + <td class="tdcl"><i>£ s. d.</i></td> + </tr> + <tr> + <td class="tdl"> 1</td> + <td class="tdll">Linseed</td> + <td class="tdcl">1.37</td> + <td class="tdcl">30.69</td> + <td class="tdcl">0.49</td> + <td class="tdcl">1.60</td> + <td class="tdcl">30.20</td> + <td class="tdcl">6 3</td> + <td class="tdcl">2 19 5</td> + </tr> + <tr> + <td class="tdl"> 2</td> + <td class="tdll">Linseed-cake</td> + <td class="tdcl">1.40</td> + <td class="tdcl">31.36</td> + <td class="tdcl">0.41</td> + <td class="tdcl">1.31</td> + <td class="tdcl">30.95</td> + <td class="tdcl">6 5</td> + <td class="tdcl">3 18 6</td> + </tr> + <tr> + <td class="tdlz"> 3</td> + <td class="tdll">Decorticated cotton-cake</td> + <td class="tdcly">2.00</td> + <td class="tdcly">44.80</td> + <td class="tdcly">0.38</td> + <td class="tdcly">0.85</td> + <td class="tdcly">44.42</td> + <td class="tdcly">9 3</td> + <td class="tdcly">5 13 0</td> + </tr> + <tr> + <td class="tdl"> 4</td> + <td class="tdll">Palm-nut-cake</td> + <td class="tdcl">0.50</td> + <td class="tdcl">11.20</td> + <td class="tdcl">0.35</td> + <td class="tdcl">3.13</td> + <td class="tdcl">10.85</td> + <td class="tdcl">2 3</td> + <td class="tdcl">1 19 10</td> + </tr> + <tr> + <td class="tdlz"> 5</td> + <td class="tdll">Undecorticated cotton-cake</td> + <td class="tdcly">2.00</td> + <td class="tdcly">44.80</td> + <td class="tdcly">0.31</td> + <td class="tdcly">0.69</td> + <td class="tdcly">44.49</td> + <td class="tdcly">5 11</td> + <td class="tdcly">3 5 4</td> + </tr> + <tr> + <td class="tdl"> 6</td> + <td class="tdll">Cocoa-<br /> nut-cake</td> + <td class="tdcl">2.00</td> + <td class="tdcl">44.80</td> + <td class="tdcl">0.31</td> + <td class="tdcl">0.69</td> + <td class="tdcl">44.49</td> + <td class="tdcl">9 3</td> + <td class="tdcl">3 0 7</td> + </tr> + <tr> + <td class="tdl"> 7</td> + <td class="tdll">Rape-cake</td> + <td class="tdclb">1.50</td> + <td class="tdclb">33.60</td> + <td class="tdclb">0.25</td> + <td class="tdclb">0.74</td> + <td class="tdclb">33.35</td> + <td class="tdclb">6 11</td> + <td class="tdclb">4 5 4</td> + </tr> + <tr> + <td class="tdl"> 8</td> + <td class="tdll">Peas</td> + <td class="tdcl">0.96</td> + <td class="tdcl">21.50</td> + <td class="tdcl">0.35</td> + <td class="tdcl">1.63</td> + <td class="tdcl">21.15</td> + <td class="tdcl">4 5</td> + <td class="tdcl">2 15 0</td> + </tr> + <tr> + <td class="tdl"> 9</td> + <td class="tdll">Beans</td> + <td class="tdcl">1.30</td> + <td class="tdcl">29.12</td> + <td class="tdcl">0.35</td> + <td class="tdcl">1.20</td> + <td class="tdcl">28.77</td> + <td class="tdcl">6 0</td> + <td class="tdcl">3 3 5</td> + </tr> + <tr> + <td class="tdl">10</td> + <td class="tdll">Lentils</td> + <td class="tdcl">0.70</td> + <td class="tdcl">15.68</td> + <td class="tdcl">0.35</td> + <td class="tdcl">2.23</td> + <td class="tdcl">15.33</td> + <td class="tdcl">3 2</td> + <td class="tdcl">3 1 4</td> + </tr> + <tr> + <td class="tdl">11</td> + <td class="tdll">Tares (seed)</td> + <td class="tdclb">0.80</td> + <td class="tdclb">17.92</td> + <td class="tdclb">0.35</td> + <td class="tdclb">1.95</td> + <td class="tdclb">17.57</td> + <td class="tdclb">3 8</td> + <td class="tdclb">3 2 1</td> + </tr> + <tr> + <td class="tdl">12</td> + <td class="tdll">Indian corn</td> + <td class="tdcl">0.37</td> + <td class="tdcl"> 8.29</td> + <td class="tdcl">0.34</td> + <td class="tdcl">4.10</td> + <td class="tdcl"> 7.95</td> + <td class="tdcl">1 8</td> + <td class="tdcl">1 5 1</td> + </tr> + <tr> + <td class="tdl">13</td> + <td class="tdll">Wheat</td> + <td class="tdcl">0.53</td> + <td class="tdcl">11.87</td> + <td class="tdcl">0.34</td> + <td class="tdcl">2.86</td> + <td class="tdcl">11.53</td> + <td class="tdcl">2 5</td> + <td class="tdcl">1 8 7</td> + </tr> + <tr> + <td class="tdl">14</td> + <td class="tdll">Malt</td> + <td class="tdcl">0.50</td> + <td class="tdcl">11.20</td> + <td class="tdcl">0.35</td> + <td class="tdcl">3.13</td> + <td class="tdcl">10.85</td> + <td class="tdcl">2 3</td> + <td class="tdcl">1 6 8</td> + </tr> + <tr> + <td class="tdl">15</td> + <td class="tdll">Barley</td> + <td class="tdcl">0.55</td> + <td class="tdcl">12.32</td> + <td class="tdcl">0.34</td> + <td class="tdcl">2.76</td> + <td class="tdcl">11.98</td> + <td class="tdcl">2 6</td> + <td class="tdcl">1 6 1</td> + </tr> + <tr> + <td class="tdl">16</td> + <td class="tdll">Oats</td> + <td class="tdcl">0.50</td> + <td class="tdcl">11.20</td> + <td class="tdcl">0.33</td> + <td class="tdcl">2.94</td> + <td class="tdcl">10.87</td> + <td class="tdcl">2 3</td> + <td class="tdcl">1 9 10</td> + </tr> + <tr> + <td class="tdl">17</td> + <td class="tdll">Rice-meal</td> + <td class="tdcl">(0.37)</td> + <td class="tdcl"> (8.29)</td> + <td class="tdcl">0.33</td> + <td class="tdcl">(4.00)</td> + <td class="tdcl"> (7.96)</td> + <td class="tdcl">(1 8)</td> + <td class="tdcl">(1 7 10)</td> + </tr> + <tr> + <td class="tdl">18</td> + <td class="tdll">Locust-beans</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">0.27</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + <td class="tdclb">—</td> + </tr> + <tr> + <td class="tdl">19</td> + <td class="tdll">Malt-combs</td> + <td class="tdcl">2.00</td> + <td class="tdcl">44.80</td> + <td class="tdcl">0.31</td> + <td class="tdcl">0.69</td> + <td class="tdcl">44.49</td> + <td class="tdcl">9 3</td> + <td class="tdcl">3 10 9</td> + </tr> + <tr> + <td class="tdl">20</td> + <td class="tdll">Fine pollard</td> + <td class="tdcl">1.46</td> + <td class="tdcl">32.70</td> + <td class="tdcl">0.33</td> + <td class="tdcl">1.01</td> + <td class="tdcl">32.37</td> + <td class="tdcl">6 9</td> + <td class="tdcl">2 13 4</td> + </tr> + <tr> + <td class="tdl">21</td> + <td class="tdll">Coarse pollard</td> + <td class="tdcl">1.50</td> + <td class="tdcl">33.60</td> + <td class="tdcl">0.31</td> + <td class="tdcl">0.92</td> + <td class="tdcl">33.29</td> + <td class="tdcl">6 11</td> + <td class="tdcl">2 17 9</td> + </tr> + <tr> + <td class="tdl">22</td> + <td class="tdll">Bran</td> + <td class="tdclb">1.45</td> + <td class="tdclb">32.48</td> + <td class="tdclb">0.27</td> + <td class="tdclb">0.83</td> + <td class="tdclb">32.21</td> + <td class="tdclb">6 8</td> + <td class="tdclb">2 18 5</td> + </tr> + <tr> + <td class="tdl">23</td> + <td class="tdll">Clover-hay</td> + <td class="tdcl">1.50</td> + <td class="tdcl">33.60</td> + <td class="tdcl">0.18</td> + <td class="tdcl">0.54</td> + <td class="tdcl">33.42</td> + <td class="tdcl">7 0</td> + <td class="tdcl">2 1 3</td> + </tr> + <tr> + <td class="tdl">24</td> + <td class="tdll">Meadow-hay</td> + <td class="tdclb">1.60</td> + <td class="tdclb">35.84</td> + <td class="tdclb">0.16</td> + <td class="tdclb">0.45</td> + <td class="tdclb">35.68</td> + <td class="tdclb">7 5</td> + <td class="tdclb">1 8 7</td> + </tr> + <tr> + <td class="tdl">25</td> + <td class="tdll">Pea-straw</td> + <td class="tdcl">1.00</td> + <td class="tdcl">22.40</td> + <td class="tdcl">0.15</td> + <td class="tdcl">0.67</td> + <td class="tdcl">22.25</td> + <td class="tdcl">4 8</td> + <td class="tdcl">0 18 10</td> + </tr> + <tr> + <td class="tdl">26</td> + <td class="tdll">Oat-straw</td> + <td class="tdcl">1.00</td> + <td class="tdcl">22.40</td> + <td class="tdcl">0.14</td> + <td class="tdcl">0.63</td> + <td class="tdcl">22.26</td> + <td class="tdcl">4 8</td> + <td class="tdcl">1 11 7</td> + </tr> + <tr> + <td class="tdl">27</td> + <td class="tdll">Wheat-straw</td> + <td class="tdcl">0.80</td> + <td class="tdcl">17.92</td> + <td class="tdcl">0.12</td> + <td class="tdcl">0.67</td> + <td class="tdcl">17.80</td> + <td class="tdcl">3 8</td> + <td class="tdcl">0 10 1</td> + </tr> + <tr> + <td class="tdl">28</td> + <td class="tdll">Barley-straw</td> + <td class="tdcl">1.00</td> + <td class="tdcl">22.40</td> + <td class="tdcl">0.11</td> + <td class="tdcl">0.49</td> + <td class="tdcl">22.29</td> + <td class="tdcl">4 8</td> + <td class="tdcl">0 10 1</td> + </tr> + <tr> + <td class="tdl">29</td> + <td class="tdll">Bean-straw</td> + <td class="tdclb">1.00</td> + <td class="tdclb">22.40</td> + <td class="tdclb">0.11</td> + <td class="tdclb">0.49</td> + <td class="tdclb">22.29</td> + <td class="tdclb">4 8</td> + <td class="tdclb">0 17 7</td> + </tr> + <tr> + <td class="tdl">30</td> + <td class="tdll">Potatoes</td> + <td class="tdcl">0.55</td> + <td class="tdcl">12.32</td> + <td class="tdcl">0.04</td> + <td class="tdcl">0.32</td> + <td class="tdcl">12.28</td> + <td class="tdcl">2 7</td> + <td class="tdcl">0 6 5</td> + </tr> + <tr> + <td class="tdl">31</td> + <td class="tdll">Carrots</td> + <td class="tdcl">0.28</td> + <td class="tdcl"> 6.27</td> + <td class="tdcl">0.03</td> + <td class="tdcl">0.48</td> + <td class="tdcl"> 6.24</td> + <td class="tdcl">1 4</td> + <td class="tdcl">0 4 3</td> + </tr> + <tr> + <td class="tdl">32</td> + <td class="tdll">Parsnips</td> + <td class="tdcl">0.36</td> + <td class="tdcl"> 8.06</td> + <td class="tdcl">0.03</td> + <td class="tdcl">0.37</td> + <td class="tdcl"> 8.03</td> + <td class="tdcl">1 8</td> + <td class="tdcl">0 5 5</td> + </tr> + <tr> + <td class="tdl">33</td> + <td class="tdll">Swedish turnips</td> + <td class="tdcl">0.22</td> + <td class="tdcl"> 4.93</td> + <td class="tdcl">0.02</td> + <td class="tdcl">0.41</td> + <td class="tdcl"> 4.91</td> + <td class="tdcl">1 0</td> + <td class="tdcl">0 4 7</td> + </tr> + <tr> + <td class="tdl">34</td> + <td class="tdll">Mangel-wurzels</td> + <td class="tdcl">0.40</td> + <td class="tdcl"> 8.90</td> + <td class="tdcl">0.03</td> + <td class="tdcl">0.34</td> + <td class="tdcl"> 8.93</td> + <td class="tdcl">1 10</td> + <td class="tdcl">0 5 0</td> + </tr> + <tr> + <td class="tdl">35</td> + <td class="tdll">Yellow turnips</td> + <td class="tdcl">(0.22)</td> + <td class="tdcl"> (4.93)</td> + <td class="tdcl">0.02</td> + <td class="tdcl">(0.34)</td> + <td class="tdcl"> (4.91)</td> + <td class="tdcl">(1 0)</td> + <td class="tdcl">(0 3 11)</td> + </tr> + <tr> + <td class="tdlb">36</td> + <td class="tdllb">White turnips</td> + <td class="tdclb">0.30</td> + <td class="tdclb"> 6.72</td> + <td class="tdclb">0.02</td> + <td class="tdclb">0.30</td> + <td class="tdclb"> 6.70</td> + <td class="tdclb">1 5</td> + <td class="tdclb">0 4 0</td> + </tr> +</table> +</div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_560" id="Page_560">[Pg 560]</a></span> +<br /> +<h2>CHAPTER XXVI</h2> + +<h2>THE ROTHAMSTED EXPERIMENTS.</h2> +<br /> + +<p>Reference has been so repeatedly made in the preceding pages to the +Rothamsted experiments on manures, that it may form a fitting conclusion +to the present treatise to give a short account of these famous +experiments.</p> + +<p>In describing these experiments, the author has remarked elsewhere<a name="FNanchor_256_256" id="FNanchor_256_256"></a><a href="#Footnote_256_256" class="fnanchor">[256]</a> +"that, in respect of their wide scope, dealing as they have done with +almost every department of farming, the elaborate care and accuracy with +which they have been carried out, the length of time they have been in +progress, and, lastly, in respect of the important bearing their results +have had on agricultural practice, these famous experiments may be +justly described as unrivalled by any other similar ones."</p> + +<p>Started on a small scale in 1837 by Sir John (then Mr) Lawes, they were +placed on a systematic basis in 1843, in which year Sir John Lawes +associated with <span class='pagenum'><a name="Page_561" id="Page_561">[Pg 561]</a></span>himself Sir (then Dr) J. Henry Gilbert. They have thus +been in progress for a period of fifty years—a fact which was +celebrated a few months ago by the presentation of numerous +congratulatory addresses from various learned and agricultural societies +to the distinguished investigators, and the erection of a memorial +granite slab at Rothamsted. What increases the feeling of gratitude due +to Sir John Lawes by the agricultural community, is the fact that the +entire expense of conducting these experiments has been borne by +himself, and he has further most generously handed over to the nation a +large sum of money and a certain area of land for carrying them on in +perpetuity.</p> + +<br /> +<p class="cen"><i>Nature of Experiments on Crops and Manures.</i></p> + +<p>The earliest systematic experiments were on turnips, and since then +almost every common crop has been experimented on. Table I. (p. 562) is +a list of the different experiments, with their duration, area, and +number of plots.</p> + +<br /> +<p class="cen"><i>Soil of Rothamsted.</i></p> + +<p>Before describing the more striking results of these experiments, it may +be advisable to say that the elevation of the land at Rothamsted is +about 400 feet above sea-level; that the average rainfall is about 28 +inches per annum; and that the surface-soil is a heavy loam, and the +subsoil a stiff clay, resting on chalk.</p> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_562" id="Page_562">[Pg 562]</a></span>TABLE I.—<span class="smcap">List of Rothamsted Field Experiments.</span></p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="Crops"> + <tr> + <td class="tdct" style="border-bottom: .5pt black solid" width="50%">Crops.</td> + <td class="tdctlb" width="15%">Duration.</td> + <td class="tdctlb" width="15%">Area.</td> + <td class="tdctlb" width="20%">Plots.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Years.</td> + <td class="tdcl">Acres.</td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl">Wheat (various manures)</td> + <td class="tdcl">50</td> + <td class="tdcl">11</td> + <td class="tdcl">34 (or 37)</td> + </tr> + <tr> + <td class="tdl">Wheat alternated with fallow</td> + <td class="tdcl">42</td> + <td class="tdcl"> 1</td> + <td class="tdcl"> 2</td> + </tr> + <tr> + <td class="tdl">Wheat (varieties)</td> + <td class="tdcl">15</td> + <td class="tdcl">4-8 </td> + <td class="tdcl">about 20</td> + </tr> + <tr> + <td class="tdl">Barley (various manures)</td> + <td class="tdcl">42</td> + <td class="tdcl">4-1/4</td> + <td class="tdcl">29</td> + </tr> + <tr> + <td class="tdl">Oats (various manures)</td> + <td class="tdcl"> 10<sup>1</sup></td> + <td class="tdcl">0-3/4</td> + <td class="tdcl"> 6</td> + </tr> + <tr> + <td class="tdl">Beans (various manures)</td> + <td class="tdcl"> 32<sup>2</sup></td> + <td class="tdcl">1-1/4</td> + <td class="tdcl">10</td> + </tr> + <tr> + <td class="tdl">Beans (various manures)</td> + <td class="tdcl"> 27<sup>3</sup></td> + <td class="tdcl"> 1</td> + <td class="tdcl"> 5</td> + </tr> + <tr> + <td class="tdl">Beans, alternated with wheat</td> + <td class="tdcl"> 28<sup>4</sup></td> + <td class="tdcl"> 1</td> + <td class="tdcl">10</td> + </tr> + <tr> + <td class="tdl">Clover (various manures)</td> + <td class="tdcl"> 29<sup>5</sup></td> + <td class="tdcl"> 3</td> + <td class="tdcl">18</td> + </tr> + <tr> + <td class="tdl">Various leguminous plants</td> + <td class="tdcl">15</td> + <td class="tdcl"> 3</td> + <td class="tdcl">18</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl">Turnips (various manures)</td> + <td class="tdcl"> 28<sup>6</sup></td> + <td class="tdcl"> 8</td> + <td class="tdcl">40</td> + </tr> + <tr> + <td class="tdl">Sugar-beet (various manures)</td> + <td class="tdcl"> 5</td> + <td class="tdcl"> 8</td> + <td class="tdcl">41</td> + </tr> + <tr> + <td class="tdl">Mangel-wurzel (various manures)</td> + <td class="tdclb">18</td> + <td class="tdcl"> 8</td> + <td class="tdcl">41</td> + </tr> + <tr> + <td class="tdl"> Total root crops</td> + <td class="tdclb">51</td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdl">Potatoes (various manures)</td> + <td class="tdcl">18</td> + <td class="tdcl"> 2</td> + <td class="tdcl">10</td> + </tr> + <tr> + <td class="tdl">Rotation (various manures)</td> + <td class="tdcl">46</td> + <td class="tdcl"> 3</td> + <td class="tdcl">12</td> + </tr> + <tr> + <td class="tdlb">Permanent grass (various manures)</td> + <td class="tdclb">38</td> + <td class="tdclb"> 7</td> + <td class="tdclb">22</td> + </tr> + <tr> + <td class="tdl"></td> + <td class="tdcl"></td> + <td class="tdcl"></td> + <td class="tdcl"></td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>1</sup>Including one year fallow.</td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>2</sup>Including one year wheat and five years fallow.</td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>3</sup>Including four years fallow.</td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>4</sup>Including two years fallow.</td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>5</sup>Clover, twelve times sown (first in 1848), eight yielding + crops, but four of these very small, one year wheat, five years barley, twelve years fallow.</td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>6</sup>Including barley without manure three years (eleventh, twelfth, + and thirteenth seasons).</td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class="smcap">Wheat Experiments.</span></p> + +<p>The first experiments we shall refer to are those on <i>wheat</i>, since they +are among the oldest, and their results the most striking of any.</p> + +<br /> +<p class="cen"><i>Unmanured Plots.</i></p> + +<p>Wheat has been continuously grown year after year on three plots for +fifty years, without the application of any manure whatever.</p> + +<p><span class='pagenum'><a name="Page_563" id="Page_563">[Pg 563]</a></span>We shall first give the results of the first eight years as illustrating +the effect of season, which accounts for the irregular results obtained. +But for the difference in seasons, we should expect to find a steady +decrease in the amount of produce; and this is shown in taking the +average of groups of years, as we shall do in the next table.</p> + +<br /> +<p class="cen"><span class="smcap">Wheat grown continuously on same Land</span> (unmanured).</p> + +<p class="cen"><span class="smcap">Table II.</span>—(a.) <i>Remits of first Eight Years (1844 to 1851).</i></p> + +<div class="centered"> +<table border="0" width="40%" cellpadding="2" cellspacing="0" summary="Year."> + <tr> + <td class="tdl" width="50%">Year.</td> + <td class="tdr" width="50%">Bushels.</td> + </tr> + <tr> + <td class="tdl">1844</td> + <td class="tdr">15 </td> + </tr> + <tr> + <td class="tdl">1845</td> + <td class="tdr">23-1/4</td> + </tr> + <tr> + <td class="tdl">1846</td> + <td class="tdr">18 </td> + </tr> + <tr> + <td class="tdl">1847</td> + <td class="tdr">16-7/8</td> + </tr> + <tr> + <td class="tdl">1848</td> + <td class="tdr">14-3/4</td> + </tr> + <tr> + <td class="tdl">1849</td> + <td class="tdr">19-1/4</td> + </tr> + <tr> + <td class="tdl">1850</td> + <td class="tdr">15-7/8</td> + </tr> + <tr> + <td class="tdl">1851</td> + <td class="tdr"><span style="text-decoration: underline;">15-7/8</span></td> + </tr> + <tr> + <td class="tdl">Average of 8 years</td> + <td class="tdr"><span style="text-decoration: underline;">17-3/8</span></td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class="smcap">Table III.</span>—(b.) <i>Results of subsequent Forty Years (1852 to +1891).</i></p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Grain"> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdc" width="20%">Grain</td> + <td class="tdc" width="20%">Weight per</td> + <td class="tdc" width="20%">Straw</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">(bushels).</td> + <td class="tdc">bushel.</td> + <td class="tdc">(cwts.)</td> + </tr> + <tr> + <td class="tdl">20 years (1852-1871)</td> + <td class="tdc">14-1/2</td> + <td class="tdc">57-5/8</td> + <td class="tdc">13 </td> + </tr> + <tr> + <td class="tdl">20 years (1872-1891)</td> + <td class="tdc">11-1/2</td> + <td class="tdc">58-3/4</td> + <td class="tdc"> 8-5/8</td> + </tr> + <tr> + <td class="tdl">40 years (1852-1891)</td> + <td class="tdc">13 </td> + <td class="tdc">58-1/4</td> + <td class="tdc">10-5/8</td> + </tr> + <tr> + <td class="tdl">49th season (1891)</td> + <td class="tdc"> 9-3/8</td> + <td class="tdc">59-1/2</td> + <td class="tdc"> 7-1/2</td> + </tr> +</table> +</div> + +<p>It is interesting to notice the comparatively slight decrease which has +taken place in the yield of wheat during these fifty years. With such +wide variations, due to season, it is extremely difficult, as Sir J. +Henry Gilbert has pointed out, to estimate rate of decline due to +exhaustion. Excluding the very bad seasons, this may be reckoned at from +one-fourth to one-third of a bushel per acre per annum. <i>The return of +the first year is 15 bushels, while the yield of the forty-ninth season +is 9-3/8 bushels.</i> The average of the returns <span class='pagenum'><a name="Page_564" id="Page_564">[Pg 564]</a></span>obtained during these +fifty years is really in <i>excess of the average yield of the principal +wheat-producing countries in the world</i>. This is truly a most astounding +result.</p> + +<p>The next experiments we shall describe are those on the influence of +farmyard manure on the wheat crop when grown continuously.</p> + +<br /> +<p class="cen">TABLE IV.—<span class="smcap">Wheat grown continuously with Farmyard Manure</span> (14 +tons per annum).</p> + +<div class="centered"> +<table border="0" width="70%" cellpadding="2" cellspacing="0" summary="Weight"> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdc" width="20%"> </td> + <td class="tdc" width="20%">Weight per</td> + <td class="tdc" width="20%">Straw</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdc">Bushels.</td> + <td class="tdc">bushel (lb.)</td> + <td class="tdc">(cwts.)</td> + </tr> + <tr> + <td class="tdl"> 8 years (1844-1852)</td> + <td class="tdc">28 </td> + <td class="tdc">—</td> + <td class="tdc">—</td> + </tr> + <tr> + <td class="tdl">20 years (1852-1871)</td> + <td class="tdc">35-7/8</td> + <td class="tdc">60 </td> + <td class="tdc">33-7/8</td> + </tr> + <tr> + <td class="tdl">20 years (1872-1891)</td> + <td class="tdc">33-1/2</td> + <td class="tdc">60-3/8</td> + <td class="tdc">31-3/8</td> + </tr> + <tr> + <td class="tdl">40 years (1852-1891)</td> + <td class="tdc">34-7/8</td> + <td class="tdc">60-1/4</td> + <td class="tdc">32-5/8</td> + </tr> +</table> +</div> + +<p>It will be seen from the above results, which contain merely a selection +from a very much greater number of experiments, that farmyard manure +gives as good an average over the forty years as most of the artificial +mixtures do. That this is due to the nitrogen it contains, is strikingly +illustrated by the fact that mixed mineral manures alone give less than +half the return, and also by the fact that ammonia salts alone give a +return twice as great as mineral mixtures; while, lastly, the mixture of +mineral manures and ammonia salts gives but a slight increase over that +obtained with ammonia salts alone.</p> + +<p>The remaining results, selected from a much larger number, need no +comment, and we shall give them in tabular form.</p> + +<p class="cen"><span class='pagenum'><a name="Page_565" id="Page_565">[Pg 565]</a></span>Table V.—<span class="smcap">Wheat grown continuously with Artificial Manures, Farmyard +Manure, and Unmanured.</span></p> + +<p class="cen"><i>Average of Forty Years (1852-91).</i></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="annum"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Produce per Acre—Average per Annum.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="3">Dressed grain.</td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdclb" colspan="3">Quantity.</td> + </tr> + <tr> + <td class="tdl" width="55%"> </td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">40 years,</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1852-71.</td> + <td class="tdclb">1872-91.</td> + <td class="tdclb">1852-91.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">bush.</td> + <td class="tdcl">bush.</td> + <td class="tdcl">bush.</td> + </tr> + <tr> + <td class="tdl">Farmyard manure, 14 tons per annum since 1843</td> + <td class="tdcl">35-7/8</td> + <td class="tdcl">33-1/2</td> + <td class="tdcl">34-7/8</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">14-1/2</td> + <td class="tdcl">11-1/2</td> + <td class="tdcl">13 </td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures<sup>1</sup> and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">17 </td> + <td class="tdcly">12-7/8</td> + <td class="tdcly">15 </td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate, 200 lb. ammonium salts</td> + <td class="tdcly">26-1/2</td> + <td class="tdcly">21-3/4</td> + <td class="tdcly">24-1/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures and 3-1/2 cwt. superphosphate, 600 lb. ammonium salts</td> + <td class="tdcly">38-1/4</td> + <td class="tdcly">34-3/4</td> + <td class="tdcly">36-1/2</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate, 275 lb. nitrate of soda</td> + <td class="tdcly">36-7/8</td> + <td class="tdcly">34 </td> + <td class="tdcly">35-3/8</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">26 </td> + <td class="tdcl">19-3/8</td> + <td class="tdcl">22-3/4</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts every year since 1845</td> + <td class="tdcl">22-1/2</td> + <td class="tdcl">19 </td> + <td class="tdcl">22-1/2</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">28 </td> + <td class="tdcl">22-1/4</td> + <td class="tdcl">25-1/8</td> + </tr> + <tr> + <td class="tdlb">Mineral manure, 3-1/2 cwt. superphosphate, 400 lb. ammonium salts in autumn.</td> + <td class="tdclb" style="vertical-align: bottom;">31-5/8</td> + <td class="tdclb" style="vertical-align: bottom;">29-1/2</td> + <td class="tdclb" style="vertical-align: bottom;">30-1/2</td> + </tr> + <tr> + <td class="tdl" colspan="4"><sup>1</sup>By the term mixed mineral manures is meant a mixture of mineral + fertilisers, not including phosphates.</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE V.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="annum"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Produce per Acre—Average per Annum.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="3">Dressed grain.</td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdclb" colspan="3">Weight per bushel.</td> + </tr> + <tr> + <td class="tdl" width="55%"> </td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">40 years,</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1852-71.</td> + <td class="tdclb">1872-91.</td> + <td class="tdclb">1852-91.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl">Farmyard manure, 14 tons per annum since 1843</td> + <td class="tdcl">60 </td> + <td class="tdcl">60-3/8</td> + <td class="tdcl">60-1/4</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">57-5/8</td> + <td class="tdcl">58-3/4</td> + <td class="tdcl">58-1/4</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures and 3-1/2 cwt. superphosphate</td> + <td class="tdcl">58-7/8</td> + <td class="tdcl">59 </td> + <td class="tdcl">58-7/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate, 200 lb. ammonium salts</td> + <td class="tdcly">59-3/8</td> + <td class="tdcly">60 </td> + <td class="tdcly">59-5/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures and 3-1/2 cwt. superphosphate, 600 lb. ammonium salts</td> + <td class="tdcly">59 </td> + <td class="tdcly">60 </td> + <td class="tdcly">59-1/2</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate, 275 lb. nitrate of soda</td> + <td class="tdcly">58-3/8</td> + <td class="tdcly">59-5/8</td> + <td class="tdcly">59 </td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">56-5/8</td> + <td class="tdcl">56-5/8</td> + <td class="tdcl">56-5/8</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts every year since 1845</td> + <td class="tdcl">58 </td> + <td class="tdcl">57-3/8</td> + <td class="tdcl">57-5/8</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">57-3/8</td> + <td class="tdcl">58 </td> + <td class="tdcl">57-5/8</td> + </tr> + <tr> + <td class="tdlb">Mineral manure, 3-1/2 cwt. superphosphate, 400 lb. ammonium salts in autumn</td> + <td class="tdclb" style="vertical-align: bottom;">59-1/2</td> + <td class="tdclb" style="vertical-align: bottom;">60 </td> + <td class="tdclb" style="vertical-align: bottom;">59-3/4</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE V.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="annum"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Produce per Acre—Average per Annum.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl" colspan="3"> </td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdclb" colspan="3">Total straw.</td> + </tr> + <tr> + <td class="tdl" width="55%"> </td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">40 years,</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1852-71.</td> + <td class="tdclb">1872-91.</td> + <td class="tdclb">1852-91.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + </tr> + <tr> + <td class="tdl">Farmyard manure, 14 tons per annum since 1843</td> + <td class="tdcl">33-7/8</td> + <td class="tdcl">31-3/8</td> + <td class="tdcl">32-5/8</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">13 </td> + <td class="tdcl">8-5/8</td> + <td class="tdcl">10-5/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">15 </td> + <td class="tdcly">9-3/4</td> + <td class="tdcly">12-3/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate, 200 lb. ammonium salts</td> + <td class="tdcly">24-1/2</td> + <td class="tdcly">19-1/8</td> + <td class="tdcly">21-7/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures and 3-1/2 cwt. superphosphate, 600 lb. ammonium salts</td> + <td class="tdcly">41-3/8</td> + <td class="tdcly">39-5/8</td> + <td class="tdcly">40-1/2</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate, 275 lb. nitrate of soda</td> + <td class="tdcly">41-1/2</td> + <td class="tdcly">37-3/4</td> + <td class="tdcly">39-5/8</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">28-1/4</td> + <td class="tdcl">18-1/2</td> + <td class="tdcl">23-3/8</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts every year since 1845</td> + <td class="tdcl">24-3/4</td> + <td class="tdcl">16-1/4</td> + <td class="tdcl">20-1/2</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">26-3/8</td> + <td class="tdcl">21 </td> + <td class="tdcl">23-3/4</td> + </tr> + <tr> + <td class="tdlb">Mineral manure, 3-1/2 cwt. superphosphate, 400 lb. ammonium salts in autumn</td> + <td class="tdclb" style="vertical-align: bottom;">31-1/4</td> + <td class="tdclb" style="vertical-align: bottom;">28-3/8</td> + <td class="tdclb" style="vertical-align: bottom;">29-3/4</td> + </tr> +</table> +</div> + +<br /> +<br /> +<p class="cen"><span class='pagenum'><a name="Page_566" id="Page_566">[Pg 566]</a></span>TABLE VI.—<span class="smcap">Experiments on the Growth of Barley for Forty Years, 1852-91.</span></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Dressed"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Produce per Acre—Average per Annum.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="3">Dressed grain.</td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdclb" colspan="3">Quantity.</td> + </tr> + <tr> + <td class="tdl" width="55%"> </td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">40 years,</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1852-71.</td> + <td class="tdclb">1872-91.</td> + <td class="tdclb">1852-91.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">bush.</td> + <td class="tdcl">bush.</td> + <td class="tdcl">bush.</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">20 </td> + <td class="tdcl">25-1/2</td> + <td class="tdcl">16-1/2</td> + </tr> + <tr> + <td class="tdl">3-1/2 cwt. superphosphate of lime</td> + <td class="tdcl">25-1/2</td> + <td class="tdcl">17-3/4</td> + <td class="tdcl">21-3/4</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures</td> + <td class="tdcl">22-1/2</td> + <td class="tdcl">13-1/2</td> + <td class="tdcl">18 </td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">27-1/2</td> + <td class="tdcl">17-1/4</td> + <td class="tdcl">22-3/8</td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts</td> + <td class="tdcl">32-1/2</td> + <td class="tdcl">25-5/8</td> + <td class="tdcl">29 </td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">47 </td> + <td class="tdcl">38-1/2</td> + <td class="tdcl">42-3/4</td> + </tr> + <tr> + <td class="tdl">200lb. ammonium salts, mixed mineral manures</td> + <td class="tdcl">35 </td> + <td class="tdcl">27-3/4</td> + <td class="tdcl">31-3/8</td> + </tr> + <tr> + <td class="tdl">Manures, 3-1/2 cwt. superphosphate of lime</td> + <td class="tdcl">46-1/4</td> + <td class="tdcl">40-3/4</td> + <td class="tdcl">43-1/2</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">37 </td> + <td class="tdcl">28-3/8</td> + <td class="tdcl">32-3/4</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">49-1/4</td> + <td class="tdcl">42-1/4</td> + <td class="tdcl">45-3/4</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, mixed mineral manures</td> + <td class="tdcl">37-3/8</td> + <td class="tdcl">29-1/2</td> + <td class="tdcl">33-1/2</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, mixed mineral manures, 3-1/2 cwt. superphosphate</td> + <td class="tdcly">49-3/4</td> + <td class="tdcly">41-1/4</td> + <td class="tdcly">45-1/2</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake</td> + <td class="tdcl">45-1/4</td> + <td class="tdcl">37-1/8</td> + <td class="tdcl">41-1/4</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">46-3/4</td> + <td class="tdcl">40 </td> + <td class="tdcl">43-3/8</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, mixed mineral manures</td> + <td class="tdcl">43-5/8</td> + <td class="tdcl">35-5/8</td> + <td class="tdcl">39-1/2</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, mixed mineral manures, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">47-3/8</td> + <td class="tdcly">39 </td> + <td class="tdcly">43-1/4</td> + </tr> + <tr> + <td class="tdlb">Farmyard manure, 14 tons every year</td> + <td class="tdclb">48-1/4</td> + <td class="tdclb">49 </td> + <td class="tdclb">48-5/8</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE VI.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Dressed"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Produce per Acre—Average per Annum.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="3">Dressed grain.</td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdclb" colspan="3">Weight per bushel.</td> + </tr> + <tr> + <td class="tdl" width="55%"> </td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">40 years,</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1852-71.</td> + <td class="tdclb">1872-91.</td> + <td class="tdclb">1852-91.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">lb.</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">52-3/8</td> + <td class="tdcl">51-3/4</td> + <td class="tdcl">52 </td> + </tr> + <tr> + <td class="tdl">3-1/2 cwt. superphosphate of lime</td> + <td class="tdcl">53-1/4</td> + <td class="tdcl">53 </td> + <td class="tdcl">53-1/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures</td> + <td class="tdcl">53 </td> + <td class="tdcl">51-7/8</td> + <td class="tdcl">52-1/2</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/ cwt. superphosphate</td> + <td class="tdcl">53-3/8</td> + <td class="tdcl">52-3/8</td> + <td class="tdcl">53 </td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts</td> + <td class="tdcl">52-1/8</td> + <td class="tdcl">52 </td> + <td class="tdcl">52 </td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">53-3/8</td> + <td class="tdcl">52-1/4</td> + <td class="tdcl">52-7/8</td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts, mixed mineral manures</td> + <td class="tdcl">52-3/4</td> + <td class="tdcl">52-1/2</td> + <td class="tdcl">52-5/8</td> + </tr> + <tr> + <td class="tdl">Manures, 3-1/2 cwt. superphosphate of lime</td> + <td class="tdcl">54 </td> + <td class="tdcl">54-1/8</td> + <td class="tdcl">54 </td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">52 </td> + <td class="tdcl">52-1/8</td> + <td class="tdcl">52 </td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">53-3/8</td> + <td class="tdcl">53-1/4</td> + <td class="tdcl">53-1/4</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, mixed mineral manures</td> + <td class="tdcl">52-1/4</td> + <td class="tdcl">52-3/4</td> + <td class="tdcl">52-1/2</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, mixed mineral manures, 3-1/2 cwt. superphosphate</td> + <td class="tdcly">53-3/8</td> + <td class="tdcly">54 </td> + <td class="tdcly">53-5/8</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake</td> + <td class="tdcl">53-3/4</td> + <td class="tdcl">53-7/8</td> + <td class="tdcl">53-7/8</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">53-7/8</td> + <td class="tdcl">54-3/8</td> + <td class="tdcl">54-1/8</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, mixed mineral manures</td> + <td class="tdcl">53-3/4</td> + <td class="tdcl">54-1/8</td> + <td class="tdcl">54 </td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, mixed mineral manures, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">53-5/8</td> + <td class="tdcly">54-1/4</td> + <td class="tdcly">53-7/8</td> + </tr> + <tr> + <td class="tdlb">Farmyard manure, 14 tons every year</td> + <td class="tdclb">54-3/8</td> + <td class="tdclb">54-1/4</td> + <td class="tdclb">54-1/4</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE VI.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="Dressed"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Produce per Acre—Average per Annum.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl" colspan="3"> </td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdclb" colspan="3">Total straw.</td> + </tr> + <tr> + <td class="tdl" width="55%"> </td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">20 years,</td> + <td class="tdcl" width="15%">40 years,</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1852-71.</td> + <td class="tdclb">1872-91.</td> + <td class="tdclb">1852-91.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">11-3/4</td> + <td class="tdcl"> 6-7/8</td> + <td class="tdcl"> 9-3/8</td> + </tr> + <tr> + <td class="tdl">3-1/2 cwt. superphosphate of lime</td> + <td class="tdcl">13-3/8</td> + <td class="tdcl"> 8-1/4</td> + <td class="tdcl">10-3/4</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures</td> + <td class="tdcl">12-1/4</td> + <td class="tdcl">7 </td> + <td class="tdcl"> 9-5/8</td> + </tr> + <tr> + <td class="tdl">Mixed mineral manures, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">14-3/8</td> + <td class="tdcl"> 8-3/8</td> + <td class="tdcl">11-3/8</td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts</td> + <td class="tdcl">18-1/2</td> + <td class="tdcl">13-1/2</td> + <td class="tdcl">16 </td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">27-5/8</td> + <td class="tdcl">20-1/8</td> + <td class="tdcl">23-7/8</td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts, mixed mineral manures</td> + <td class="tdcl">20-1/4</td> + <td class="tdcl">15-1/8</td> + <td class="tdcl">18 </td> + </tr> + <tr> + <td class="tdl">Manures, 3-1/2 cwt. superphosphate of lime</td> + <td class="tdcl">28-1/2</td> + <td class="tdcl">23-3/8</td> + <td class="tdcl">25-7/8</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">22-1/8</td> + <td class="tdcl">15-7/8</td> + <td class="tdcl">19 </td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">30-1/2</td> + <td class="tdcl">23-3/8</td> + <td class="tdcl">27 </td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, mixed mineral manures</td> + <td class="tdcl">23-7/8</td> + <td class="tdcl">17-1/2</td> + <td class="tdcl">20-3/4</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, mixed mineral manures, 3-1/2 cwt. superphosphate</td> + <td class="tdcly">32-3/8</td> + <td class="tdcly">24-1/2</td> + <td class="tdcly">28-1/2</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake</td> + <td class="tdcl">26-7/8</td> + <td class="tdcl">20 </td> + <td class="tdcl">23-3/8</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, 3-1/2 cwt. superphosphate</td> + <td class="tdcl">28-3/8</td> + <td class="tdcl">21-1/2</td> + <td class="tdcl">24-7/8</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, mixed mineral manures</td> + <td class="tdcl">27-1/8</td> + <td class="tdcl">19-7/8</td> + <td class="tdcl">23-1/2</td> + </tr> + <tr> + <td class="tdl">1000 lb. rape-cake, mixed mineral manures, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">29-3/4</td> + <td class="tdcly">21-7/8</td> + <td class="tdcly">25-5/8</td> + </tr> + <tr> + <td class="tdlb">Farmyard manure, 14 tons every year</td> + <td class="tdclb">28-1/4</td> + <td class="tdclb">29-3/4</td> + <td class="tdclb">29 </td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_567" id="Page_567">[Pg 567]</a></span>TABLE VII.</p> + +<p class="cen"><span class="smcap">Experiments on the Growth of Oats</span>, 1869-78.</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="straw"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="3"><span class="smcap">Average per Annum.<br />5 years, 1869-73.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="2">Dressed grain.</td> + <td class="tdcl"> </td> + </tr> + <tr> + <td class="tdc" width="55%"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdcl" width="15%"> </td> + <td class="tdcl" width="15%">Weight</td> + <td class="tdcl" width="15%">Total</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">Quantity.</td> + <td class="tdclb">per bushel.</td> + <td class="tdclb">straw.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">bush.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">cwt.</td> + </tr> + <tr> + <td class="tdl">Unmanured</td> + <td class="tdcl">19-7/8</td> + <td class="tdcl">33-3/4</td> + <td class="tdcl">10-3/8</td> + </tr> + <tr> + <td class="tdl">200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and + 3-1/2 cwt. superphosphate of lime</td> + <td class="tdcly">24-1/2</td> + <td class="tdcly">35 </td> + <td class="tdcly">13-3/8</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts</td> + <td class="tdcl">47 </td> + <td class="tdcl">35-7/8</td> + <td class="tdcl">28-1/2</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. + sulphate magnesia, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">59 </td> + <td class="tdcly">37 </td> + <td class="tdcly">41-1/8</td> + </tr> + <tr> + <td class="tdl">550 lb. nitrate of soda</td> + <td class="tdcl">47-1/8</td> + <td class="tdcl">35-1/2</td> + <td class="tdcl">27-1/2</td> + </tr> + <tr> + <td class="tdlb">550 lb. nitrate of soda, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. + sulphate magnesia, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly" style="border-bottom: .5pt black solid">57-1/2</td> + <td class="tdcly" style="border-bottom: .5pt black solid">35-3/4</td> + <td class="tdcly" style="border-bottom: .5pt black solid">35 </td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb" colspan="3"><span class="smcap">Average per Annum.<br />4 years, 1874-78.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">Bushels.</td> + <td class="tdcl">lb.</td> + <td class="tdcl">cwt.</td> + </tr> + <tr> + <td class="tdl">Unmanured</td> + <td class="tdcl">13-3/4</td> + <td class="tdcl">31-1/4</td> + <td class="tdcl">6 </td> + </tr> + <tr> + <td class="tdl">200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. sulphate magnesia, and + 3-1/2 cwt. superphosphate of lime</td> + <td class="tdcly">13-1/8</td> + <td class="tdcly">31-5/8</td> + <td class="tdcly"> 6-1/8</td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts</td> + <td class="tdcl">28-7/8</td> + <td class="tdcl">33-1/4</td> + <td class="tdcl">14-1/8</td> + </tr> + <tr> + <td class="tdl">200 lb. ammonium salts, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 lb. + sulphate magnesia, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">38 </td> + <td class="tdcly">35-1/2</td> + <td class="tdcly">20 </td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda</td> + <td class="tdcl">26-3/8</td> + <td class="tdcl">31-5/8</td> + <td class="tdcl">11-1/8</td> + </tr> + <tr> + <td class="tdlb">275 lb. nitrate of soda, 200 lb. sulphate potash, 100 lb. sulphate soda, 100 + lb. sulphate magnesia, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly" style="border-bottom: .5pt black solid">28-1/2</td> + <td class="tdcly" style="border-bottom: .5pt black solid">34-1/8</td> + <td class="tdcly" style="border-bottom: .5pt black solid">14 </td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_568" id="Page_568">[Pg 568]</a></span>TABLE VIII.—<span class="smcap">Experiments on Root Crops: Swedish Turnips.</span></p> + +<p class="cen"><i>Fifteen Seasons</i>, 1856-70.<sup>1</sup> Roots and Leaves carted off the Land.</p> + +<div class="centered"> +<table border="0" width="80%" cellpadding="2" cellspacing="0" summary="standard"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 1.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">Standard manures</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">only.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">STANDARD MANURES.</td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdlb">Plots.</td> + <td class="tdclb"> </td> + <td class="tdclb" colspan="4"> </td> + </tr> + <tr> + <td class="tdc" width="5%"></td> + <td class="tdcl" width="45%"> </td> + <td class="tdclb" colspan="2">Roots.</td> + <td class="tdclb" colspan="2">Leaves.</td> + </tr> + <tr> + <td class="tdc" width="5%"> </td> + <td class="tdll" width="63%"> </td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdc" width="8%">cwt.</td> + <td class="tdcl" width="8%">Tons.</td> + <td class="tdc" width="8%">cwt.</td> + </tr> + <tr> + <td class="tdc"> 1</td> + <td class="tdll">Farmyard manure, 14 tons</td> + <td class="tdcl"> 6</td> + <td class="tdc"> 4</td> + <td class="tdcl"> 0</td> + <td class="tdc">17</td> + </tr> + <tr> + <td class="tdc"> 2</td> + <td class="tdll">Farmyard manure, 14 tons, and superphosphate</td> + <td class="tdcl"> 6</td> + <td class="tdc"> 7</td> + <td class="tdcl"> 0</td> + <td class="tdc">16</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdll"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdc"> 3</td> + <td class="tdll">Without manure, 1846, and since</td> + <td class="tdcl"> 0</td> + <td class="tdc">11</td> + <td class="tdcl"> 0</td> + <td class="tdc"> 3</td> + </tr> + <tr> + <td class="tdcz"> 4</td> + <td class="tdll">Superphosphate, each year; sulphate potash, soda, and magnesia, 1856-60</td> + <td class="tdcly"> 2</td> + <td class="tdcy">16</td> + <td class="tdcly"> 0</td> + <td class="tdcy"> 8</td> + </tr> + <tr> + <td class="tdc"> 5</td> + <td class="tdll">Superphosphate, each year</td> + <td class="tdcl"> 2</td> + <td class="tdc">12</td> + <td class="tdcl"> 0</td> + <td class="tdc"> 9</td> + </tr> + <tr> + <td class="tdcz"> 6</td> + <td class="tdll">Superphosphate, each year; sulphate potash, 1856-60</td> + <td class="tdcly"> 2</td> + <td class="tdcy"> 7</td> + <td class="tdcly"> 0</td> + <td class="tdcy"> 7</td> + </tr> + <tr> + <td class="tdcz"> 7</td> + <td class="tdll">Superphosphate, each year; sulphate, potash, and 36-1/2 lb. ammonium salts, 1856-60</td> + <td class="tdcly"> 2</td> + <td class="tdcy">12</td> + <td class="tdcly"> 0</td> + <td class="tdcy"> 7</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdll"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;"> 8</td> + <td class="tdllb">Unmanured 1853, and since; previously part unmanured; part superphosphate</td> + <td class="tdclby"> 1</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 3</td> + <td class="tdclby"> 0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 4</td> + </tr> + <tr> + <td class="tdl" colspan="6"><i>Note.</i>—Sulphate of ammonia is estimated to contain 23 + per cent ammonia, and muriate of ammonia 27 per cent. Ammonium salts, in each case, equal + parts sulphate and muriate of ammonia of commerce; and the mixture is estimated to contain + 25 per cent ammonia. The 328 lb. nitric acid (sp. gr. 1.35) mixed with sawdust, and used as + a cross-dressing on the plots of Series 2 from 1856-60, were estimated to contain nitrogen + = 50 lb. ammonia.</td> + </tr> + <tr> + <td class="tdl" colspan="6"> </td> + </tr> + <tr> + <td class="tdl" colspan="6"><sup>1</sup>The crops of 1859 and 1860 failed, and were ploughed + in; but as the manures were applied, and there would be accumulation with the soil for the + succeeding crops, the average produce is calculated as for fifteen years—that is, the + produce of the thirteen years is, in each case, divided by 15.</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE VIII.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="standard"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 2.</span></td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 3.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="4"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">Standard manures,</td> + <td class="tdcl" colspan="4">Standard manures,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">and cross-dressed with—</td> + <td class="tdcl" colspan="4">and cross-dressed with—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">5 years, 1856-60,</td> + <td class="tdcl" colspan="4">5 years, 1856-60,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">3000 lb. sawdust, and</td> + <td class="tdcl" colspan="4">200 lb. ammonium</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">328 lb. nitric acid.</td> + <td class="tdcl" colspan="4">salts.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"></td> + <td class="tdcl" colspan="4"></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">STANDARD MANURES.</td> + <td class="tdcl" colspan="4">10 years, 1861-70,</td> + <td class="tdcl" colspan="4">10 years, 1861-70,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">550 lb. nitrate soda.</td> + <td class="tdcl" colspan="4">400 lb. ammonium salts.</td> + </tr> + <tr> + <td class="tdlb">Plots.</td> + <td class="tdclb"> </td> + <td class="tdcl" colspan="4"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc"></td> + <td class="tdcl"> </td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + </tr> + <tr> + <td class="tdc" width="4%"> </td> + <td class="tdll" width="40%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + </tr> + <tr> + <td class="tdc">1</td> + <td class="tdll">Farmyard manure, 14 tons</td> + <td class="tdcl"> 7</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 2</td> + <td class="tdcl"> 8</td> + <td class="tdc"> 8</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 4</td> + </tr> + <tr> + <td class="tdcz">2</td> + <td class="tdll">Farmyard manure, 14 tons, and superphosphate</td> + <td class="tdcl"> 7</td> + <td class="tdc">13</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 3</td> + <td class="tdcl"> 8</td> + <td class="tdc"> 5</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 5</td> + </tr> + <tr> + <td class="tdc">3</td> + <td class="tdll">Without manure, 1846, and since</td> + <td class="tdcl"> 0</td> + <td class="tdc">19</td> + <td class="tdcl"> 0</td> + <td class="tdc"> 4</td> + <td class="tdcl"> 0</td> + <td class="tdc">13</td> + <td class="tdcl"> 0</td> + <td class="tdc">3</td> + </tr> + <tr> + <td class="tdcz">4</td> + <td class="tdll">Superphosphate, each year; sulphate potash, soda, and magnesia, 1856-60</td> + <td class="tdcl"> 5</td> + <td class="tdc">2</td> + <td class="tdcl"> 0</td> + <td class="tdc">16</td> + <td class="tdcl"> 4</td> + <td class="tdc">12</td> + <td class="tdcl"> 0</td> + <td class="tdc">14</td> + </tr> + <tr> + <td class="tdc">5</td> + <td class="tdll">Superphosphate, each year</td> + <td class="tdcl"> 4</td> + <td class="tdc">13</td> + <td class="tdcl"> 0</td> + <td class="tdc">18</td> + <td class="tdcl"> 3</td> + <td class="tdc">16</td> + <td class="tdcl"> 0</td> + <td class="tdc">15</td> + </tr> + <tr> + <td class="tdcz">6</td> + <td class="tdll">Superphosphate, each year; sulphate potash, 1856-60</td> + <td class="tdcl"> 4</td> + <td class="tdc">11</td> + <td class="tdcl"> 0</td> + <td class="tdc">14</td> + <td class="tdcl"> 4</td> + <td class="tdc"> 5</td> + <td class="tdcl"> 0</td> + <td class="tdc">13</td> + </tr> + <tr> + <td class="tdcz">7</td> + <td class="tdll">Superphosphate, each year; sulphate, potash, and 36-1/2 lb. ammonium salts, + 1856-60</td> + <td class="tdcl"> 4</td> + <td class="tdc">13</td> + <td class="tdcl"> 0</td> + <td class="tdc">14</td> + <td class="tdcl"> 4</td> + <td class="tdc">12</td> + <td class="tdcl"> 0</td> + <td class="tdc">14</td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;">8</td> + <td class="tdllb">Unmanured 1853, and since; previously part unmanured; part superphosphate</td> + <td class="tdclby"> 1</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">13</td> + <td class="tdclby"> 0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 5</td> + <td class="tdclby"> 1</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 2</td> + <td class="tdclby"> 0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 5</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE VIII.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="standard"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 4.</span></td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 5.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="4"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">Standard manures,</td> + <td class="tdcl" colspan="4">Standard manures,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">and cross-dressed with—</td> + <td class="tdcl" colspan="4">and cross-dressed with—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">5 years, 1856-60,</td> + <td class="tdcl" colspan="4">5 years, 1856-60,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">200 lb. ammonium salts,</td> + <td class="tdcl" colspan="4">3000 lb. sawdust.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">and 3000 lb. sawdust.</td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"></td> + <td class="tdcl" colspan="4"></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">STANDARD MANURES.</td> + <td class="tdcl" colspan="4">10 years, 1861-70,</td> + <td class="tdcl" colspan="4">10 years, 1861-70,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">400 lb. ammonium salts,</td> + <td class="tdcl" colspan="4">2000 lb. rape-cake.</td> + </tr> + <tr> + <td class="tdlb">Plots.</td> + <td class="tdclb"> </td> + <td class="tdcl" colspan="4">and 2000 .b. rape-cake.</td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc"></td> + <td class="tdcl"> </td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + </tr> + <tr> + <td class="tdc" width="4%"> </td> + <td class="tdll" width="40%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + </tr> + <tr> + <td class="tdc">1</td> + <td class="tdll">Farmyard manure, 14 tons</td> + <td class="tdcl"> 8</td> + <td class="tdc">16</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 8</td> + <td class="tdc"> 0</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 4</td> + </tr> + <tr> + <td class="tdcz">2</td> + <td class="tdll">Farmyard manure, 14 tons, and superphosphate</td> + <td class="tdcl"> 8</td> + <td class="tdc">14</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 7</td> + <td class="tdc">16</td> + <td class="tdcl"> 1</td> + <td class="tdc">2</td> + </tr> + <tr> + <td class="tdc">3</td> + <td class="tdll">Without manure, 1846, and since</td> + <td class="tdcl"> 3</td> + <td class="tdc"> 6</td> + <td class="tdcl"> 0</td> + <td class="tdc">14</td> + <td class="tdcl"> 3</td> + <td class="tdc"> 8</td> + <td class="tdcl"> 0</td> + <td class="tdc">13</td> + </tr> + <tr> + <td class="tdcz">4</td> + <td class="tdll">Superphosphate, each year; sulphate potash, soda, and magnesia, 1856-60</td> + <td class="tdcl"> 6</td> + <td class="tdc">12</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 5</td> + <td class="tdcl"> 5</td> + <td class="tdc"> 8</td> + <td class="tdcl"> 0</td> + <td class="tdc">17</td> + </tr> + <tr> + <td class="tdc">5</td> + <td class="tdll">Superphosphate, each year</td> + <td class="tdcl"> 5</td> + <td class="tdc">16</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 7</td> + <td class="tdcl"> 5</td> + <td class="tdc"> 0</td> + <td class="tdcl"> 0</td> + <td class="tdc">19</td> + </tr> + <tr> + <td class="tdcz">6</td> + <td class="tdll">Superphosphate, each year; sulphate potash, 1856-60</td> + <td class="tdcl"> 6</td> + <td class="tdc"> 6</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 2</td> + <td class="tdcl"> 5</td> + <td class="tdc"> 3</td> + <td class="tdcl"> 0</td> + <td class="tdc">16</td> + </tr> + <tr> + <td class="tdcz">7</td> + <td class="tdll">Superphosphate, each year; sulphate, potash, and 36-1/2 lb. ammonium salts, + 1856-60</td> + <td class="tdcl"> 6</td> + <td class="tdc">15</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 4</td> + <td class="tdcl"> 5</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 0</td> + <td class="tdc">17</td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;">8</td> + <td class="tdllb">Unmanured 1853, and since; previously part unmanured; part superphosphate</td> + <td class="tdclby"> 3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">19</td> + <td class="tdclby"> 0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">18</td> + <td class="tdclby"> 3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">14</td> + <td class="tdclby"> 0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">19</td> + </tr> +</table> +</div> + +<br /> +<p><span class='pagenum'><a name="Page_569" id="Page_569">[Pg 569]</a></span>TABLE IX.—<span class="smcap">Experiments on Mangel-Wurzel.</span></p> + +<p><i>Average of Sixteen Seasons</i>, 1876-92. Manures per Acre per Annum.</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="farmyard"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 1.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="2"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">STANDARD MANURES.</td> + <td class="tdcl" colspan="4">Standard manures</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">only.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdlb">Plots.</td> + <td class="tdllb"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc"></td> + <td class="tdcl"> </td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + </tr> + <tr> + <td class="tdc" width="4%"> </td> + <td class="tdll" width="68%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + </tr> + <tr> + <td class="tdc">1</td> + <td class="tdll">Farmyard manure, 14 tons</td> + <td class="tdcl">16</td> + <td class="tdc"> 6</td> + <td class="tdcl"> 2</td> + <td class="tdc">17</td> + </tr> + <tr> + <td class="tdc">2</td> + <td class="tdll">Farmyard manure, 14 tons, and 3-1/2 cwt. superphosphate</td> + <td class="tdcl"> 4</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 8</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdll"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdc">3</td> + <td class="tdll">Without manure, 1846, and since</td> + <td class="tdcl"> 4</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 8</td> + </tr> + <tr> + <td class="tdcz">4</td> + <td class="tdll">3-1/2 cwt. superphosphate, 500 lb. sulphate of potash and 400 lb. mixed + mineral manure</td> + <td class="tdcly"> 5</td> + <td class="tdcy"> 8</td> + <td class="tdcly"> 1</td> + <td class="tdcy"> 1</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdll"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdc">5</td> + <td class="tdll">3-1/2 cwt. superphosphate</td> + <td class="tdcl"> 5</td> + <td class="tdc"> 0</td> + <td class="tdcl"> 1</td> + <td class="tdc"> 1</td> + </tr> + <tr> + <td class="tdc">6</td> + <td class="tdll">3-1/2 cwt. superphosphate, and 500 lb. sulphate of potash</td> + <td class="tdcl"> 4</td> + <td class="tdc"> 9</td> + <td class="tdcl"> 0</td> + <td class="tdc">18</td> + </tr> + <tr> + <td class="tdc"> </td> + <td class="tdll"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + <td class="tdcl"> </td> + <td class="tdc"> </td> + </tr> + <tr> + <td class="tdcz">7</td> + <td class="tdll">3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 36-1/2 lb. ammonium + salts</td> + <td class="tdcly"> 5</td> + <td class="tdcy">17</td> + <td class="tdcly"> 1</td> + <td class="tdcy"> 8</td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdllb"> </td> + <td class="tdllb"> </td> + <td class="tdlb"> </td> + <td class="tdllb"> </td> + <td class="tdlb"> </td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE IX.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="farmyard"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 2.</span></td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 3.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="4"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">STANDARD MANURES</td> + <td class="tdcl" colspan="4">Standard manures,</td> + <td class="tdcl" colspan="4">Standard manures,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">and cross-dressed with—</td> + <td class="tdcl" colspan="4">and cross-dressed with—</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">550 lb. nitrate of soda.</td> + <td class="tdcl" colspan="4">400 lb. amonium salts.</td> + </tr> + <tr> + <td class="tdlb">Plots.</td> + <td class="tdllb"> </td> + <td class="tdcl" colspan="4"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc"></td> + <td class="tdcl"> </td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + </tr> + <tr> + <td class="tdc" width="4%"> </td> + <td class="tdll" width="40%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + </tr> + <tr> + <td class="tdc">1</td> + <td class="tdll">Farmyard manure, 14 tons</td> + <td class="tdcl">22</td> + <td class="tdc">11</td> + <td class="tdcl"> 4</td> + <td class="tdc"> 2</td> + <td class="tdcl">22</td> + <td class="tdc"> 3</td> + <td class="tdcl"> 5</td> + <td class="tdc"> 7</td> + </tr> + <tr> + <td class="tdcz">2</td> + <td class="tdll">Farmyard manure, 14 tons, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">23</td> + <td class="tdcy">12</td> + <td class="tdcly"> 4</td> + <td class="tdcy">14</td> + <td class="tdcly">21</td> + <td class="tdcy"> 8</td> + <td class="tdcly"> 5</td> + <td class="tdcy"> 6</td> + </tr> + <tr> + <td class="tdc">3</td> + <td class="tdll">Without manure, 1846, and since</td> + <td class="tdcl">13</td> + <td class="tdc"> 7</td> + <td class="tdcl"> 3</td> + <td class="tdc"> 4</td> + <td class="tdcl"> 6</td> + <td class="tdc">14</td> + <td class="tdcl"> 2</td> + <td class="tdc">18</td> + </tr> + <tr> + <td class="tdcz">4</td> + <td class="tdll">3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 400 lb. mixed + mineral manure</td> + <td class="tdcly">12</td> + <td class="tdcy">17</td> + <td class="tdcly"> 3</td> + <td class="tdcy">15</td> + <td class="tdcly">16</td> + <td class="tdcy"> 2</td> + <td class="tdcly"> 3</td> + <td class="tdcy"> 0</td> + </tr> + <tr> + <td class="tdc">5</td> + <td class="tdll">3-1/2 cwt. superphosphate</td> + <td class="tdcly">15</td> + <td class="tdcy">13</td> + <td class="tdcly"> 3</td> + <td class="tdcy"> 5</td> + <td class="tdcly"> 8</td> + <td class="tdcy">10</td> + <td class="tdcly"> 3</td> + <td class="tdcy"> 1</td> + </tr> + <tr> + <td class="tdcz">6</td> + <td class="tdll">3-1/2 cwt. superphosphate, and 500 lb. sulphate of potash</td> + <td class="tdcly">15</td> + <td class="tdcy">15</td> + <td class="tdcly"> 2</td> + <td class="tdcy">18</td> + <td class="tdcly">14</td> + <td class="tdcy"> 6</td> + <td class="tdcly"> 2</td> + <td class="tdcy">16</td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;">7</td> + <td class="tdllb">3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 36-1/2 lb. + ammonium salts</td> + <td class="tdclby">16</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 0</td> + <td class="tdclby"> 3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 1</td> + <td class="tdclby">16</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 3</td> + <td class="tdclby"> 3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 0</td> + </tr> +</table> +</div> + +<br /> +<p class="cen">TABLE IX.—continued</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="farmyard"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 4.</span></td> + <td class="tdct" style="border-left: .5pt black solid;" colspan="4"><span class="smcap">Series 5.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl"> </td> + <td class="tdcl" colspan="4"> </td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">STANDARD MANURES</td> + <td class="tdcl" colspan="4">Standard manures,</td> + <td class="tdcl" colspan="4">Standard manures,</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">and cross-dressed with</td> + <td class="tdcl" colspan="4">and cross-dressed with</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdll"> </td> + <td class="tdcl" colspan="4">2000 lb. rape-cake, and</td> + <td class="tdcl" colspan="4">2000 lb. rape-cake.</td> + </tr> + <tr> + <td class="tdlb">Plots.</td> + <td class="tdllb"> </td> + <td class="tdcl" colspan="4">400 lb. ammonium salts.</td> + <td class="tdcl" colspan="4"> </td> + </tr> + <tr> + <td class="tdc"></td> + <td class="tdcl"> </td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + <td class="tdctlb" colspan="2">Roots.</td> + <td class="tdctlb" colspan="2">Leaves.</td> + </tr> + <tr> + <td class="tdc" width="4%"> </td> + <td class="tdll" width="40%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="7%">cwt.</td> + </tr> + <tr> + <td class="tdc">1</td> + <td class="tdll">Farmyard manure, 14 tons</td> + <td class="tdcl">24</td> + <td class="tdc">11</td> + <td class="tdcl"> 6</td> + <td class="tdc"> 1</td> + <td class="tdcl">23</td> + <td class="tdc"> 7</td> + <td class="tdcl"> 4</td> + <td class="tdc"> 6</td> + </tr> + <tr> + <td class="tdcz">2</td> + <td class="tdll">Farmyard manure, 14 tons, and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">23</td> + <td class="tdcy">12</td> + <td class="tdcly"> 6</td> + <td class="tdcy"> 1</td> + <td class="tdcly">23</td> + <td class="tdcy"> 1</td> + <td class="tdcly"> 4</td> + <td class="tdcy"> 6</td> + </tr> + <tr> + <td class="tdc">3</td> + <td class="tdll">Without manure, 1846, and since</td> + <td class="tdcl">10</td> + <td class="tdc">11</td> + <td class="tdcl"> 3</td> + <td class="tdc">17</td> + <td class="tdcl">11</td> + <td class="tdc"> 2</td> + <td class="tdcl"> 3</td> + <td class="tdc"> 0</td> + </tr> + <tr> + <td class="tdcz">4</td> + <td class="tdll">3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 400 lb. mixed + mineral manure</td> + <td class="tdcly">24</td> + <td class="tdcy">18</td> + <td class="tdcly"> 5</td> + <td class="tdcy"> 7</td> + <td class="tdcly">20</td> + <td class="tdcy"> 4</td> + <td class="tdcly"> 3</td> + <td class="tdcy"> 9</td> + </tr> + <tr> + <td class="tdc">5</td> + <td class="tdll">3-1/2 cwt. superphosphate</td> + <td class="tdcly">11</td> + <td class="tdcy"> 7</td> + <td class="tdcly"> 4</td> + <td class="tdcy"> 2</td> + <td class="tdcly">12</td> + <td class="tdcy"> 3</td> + <td class="tdcly"> 3</td> + <td class="tdcy"> 2</td> + </tr> + <tr> + <td class="tdcz">6</td> + <td class="tdll">3-1/2 cwt. superphosphate, and 500 lb. sulphate of potash</td> + <td class="tdcly">21</td> + <td class="tdcy"> 6</td> + <td class="tdcly"> 5</td> + <td class="tdcy"> 7</td> + <td class="tdcly">16</td> + <td class="tdcy">14</td> + <td class="tdcly"> 2</td> + <td class="tdcy">15</td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;">7</td> + <td class="tdllb">3-1/2 cwt. superphosphate, 500 lb. sulphate of potash, and 36-1/2 lb. + ammonium salts</td> + <td class="tdclby">21</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 6</td> + <td class="tdclby"> 5</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 9</td> + <td class="tdclby">17</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">10</td> + <td class="tdclby"> 3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 3</td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_570" id="Page_570">[Pg 570]</a></span>TABLE X.—<span class="smcap">Experiments with different Manures on Permanent Meadow-land.</span></p> + +<p class="cen"><i>Thirty-six Years</i>, 1856-91.</p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="produce"> + <tr> + <td class="tdct"> </td> + <td class="tdctlb" colspan="6"><span class="smcap">Produce per Acre, weighed as Hay.</span></td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl" colspan="3">Average per annum,</td> + <td class="tdcl" colspan="3">Average per annum,</td> + </tr> + <tr> + <td class="tdc"><span class="smcap">Manures per Acre per Annum.</span></td> + <td class="tdcl" colspan="3">20 years, 1856-75</td> + <td class="tdcl" colspan="3">16 years, 1876-91</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdclb" colspan="3">(1st crops only).</td> + <td class="tdclb" colspan="3">(1st and 2d crops).</td> + </tr> + <tr> + <td class="tdl" width="40%"> </td> + <td class="tdcl" width="10%">10 years,</td> + <td class="tdcl" width="10%">10 years,</td> + <td class="tdcl" width="10%">20 years,</td> + <td class="tdcl" width="10%">1st</td> + <td class="tdcl" width="10%">2nd</td> + <td class="tdcl" width="10%"> </td> + </tr> + <tr> + <td class="tdlb"> </td> + <td class="tdclb">1856-65.</td> + <td class="tdclb">1866-75.</td> + <td class="tdclb">1856-75.</td> + <td class="tdclb">crops.</td> + <td class="tdclb">crops.</td> + <td class="tdclb">Total.</td> + </tr> + <tr> + <td class="tdl"> </td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + <td class="tdcl">cwt.</td> + </tr> + <tr> + <td class="tdl">Unmanured continuously</td> + <td class="tdcl">22-1/2</td> + <td class="tdcl">20 </td> + <td class="tdcl">21-1/4</td> + <td class="tdcl">18 </td> + <td class="tdcl"> 8-1/2</td> + <td class="tdcl">26-1/2</td> + </tr> + <tr> + <td class="tdl">3-12 cwt. superphosphate of lime</td> + <td class="tdcl">23-14</td> + <td class="tdcl">21-1/4</td> + <td class="tdcl">22-1/4</td> + <td class="tdcl">18 </td> + <td class="tdcl">9 </td> + <td class="tdcl">27-1/2</td> + </tr> + <tr> + <td class="tdl">3-1/2 cwt. superphosphate of lime, and 400 lb. ammonium salts</td> + <td class="tdcly">33-7/8</td> + <td class="tdcly">30-1/2</td> + <td class="tdcly">32-1/4</td> + <td class="tdcly">30-3/4</td> + <td class="tdcly">10-1/2</td> + <td class="tdcly">41-1/4</td> + </tr> + <tr> + <td class="tdl">400 lb. ammonium salts</td> + <td class="tdcl">30-1/2</td> + <td class="tdcl">22 </td> + <td class="tdcl">26-1/4</td> + <td class="tdcl">18-1/4</td> + <td class="tdcl">10-1/8</td> + <td class="tdcl">27-3/8</td> + </tr> + <tr> + <td class="tdl">275 lb. nitrate of soda, 3-1/2 cwt. superphosphate, and mixed mineral manure</td> + <td class="tdcly">45-1/4</td> + <td class="tdcly">47-5/8</td> + <td class="tdcly">46-1/2</td> + <td class="tdcly">41-1/8</td> + <td class="tdcly">12-1/8</td> + <td class="tdcly">53-1/4</td> + </tr> + <tr> + <td class="tdlb">275 lb. nitrate of soda</td> + <td class="tdclb">34-1/4</td> + <td class="tdclb">33-1/2</td> + <td class="tdclb">33-7/8</td> + <td class="tdclb">30-1/8</td> + <td class="tdclb">10 </td> + <td class="tdclb">40-1/8</td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_571" id="Page_571">[Pg 571]</a></span>TABLE XI.—<span class="smcap">Experiments on the Growth of Potatoes.</span></p> + +<p class="cen"><i>Average of Five Seasons, 1876-80.</i><sup>1</sup></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="unmanured"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdctlb" colspan="8"><span class="smcap">Produce per Acre—Tubers.</span></td> + </tr> + <tr> + <td class="tdlb">Plot.</td> + <td class="tdclb"><span class="smcap">Manures per Acre per Annum</span></td> + <td class="tdclb" colspan="2">Good.</td> + <td class="tdclb" colspan="2">Small.</td> + <td class="tdclb" colspan="2">Diseased.</td> + <td class="tdclb" colspan="2">Total.</td> + </tr> + <tr> + <td class="tdl" width="4%"> </td> + <td class="tdll" width="32%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + </tr> + <tr> + <td class="tdc"> 1</td> + <td class="tdll">Unmanured</td> + <td class="tdcl">1</td> + <td class="tdc">18 </td> + <td class="tdcl">0</td> + <td class="tdc"> 6-1/4</td> + <td class="tdcl">0</td> + <td class="tdc"> 2-1/4</td> + <td class="tdcl">2</td> + <td class="tdc"> 7-1/2</td> + </tr> + <tr> + <td class="tdc"> 2</td> + <td class="tdll">Farmyard manure (14 tons)</td> + <td class="tdcl">3</td> + <td class="tdc">19-3/8</td> + <td class="tdcl">0</td> + <td class="tdc"> 7-5/8</td> + <td class="tdcl">0</td> + <td class="tdc"> 6-5/8</td> + <td class="tdcl">4</td> + <td class="tdc">13-5/8</td> + </tr> + <tr> + <td class="tdcz"> 3</td> + <td class="tdll">Farmyard manure (14 tons), and 3-1/2 cwt. superphosphate</td> + <td class="tdcly">4</td> + <td class="tdcy"> 9-1/2</td> + <td class="tdcly">0</td> + <td class="tdcy">8 </td> + <td class="tdcly">0</td> + <td class="tdcy"> 8-3/4</td> + <td class="tdcly">5</td> + <td class="tdcy"> 6-1/4</td> + </tr> + <tr> + <td class="tdcz"> 4</td> + <td class="tdll">Farmyard manure (14 tons), 3-1/2 cwt. superphosphate, and 550 lb. nitrate of soda</td> + <td class="tdcly">5</td> + <td class="tdcy">8 </td> + <td class="tdcly">0</td> + <td class="tdcy">7 </td> + <td class="tdcly">0</td> + <td class="tdcy">19-1/2</td> + <td class="tdcly">6</td> + <td class="tdcy">14-1/2</td> + </tr> + <tr> + <td class="tdcz"> 5</td> + <td class="tdll">400 lb. ammonium salts</td> + <td class="tdcly">1</td> + <td class="tdcy">19-1/2</td> + <td class="tdcly">0</td> + <td class="tdcy"> 7-1/8</td> + <td class="tdcly">0</td> + <td class="tdcy"> 3-1/2</td> + <td class="tdcly">2</td> + <td class="tdcy">10-1/8</td> + </tr> + <tr> + <td class="tdc"> 6</td> + <td class="tdll">550 lb. nitrate of soda</td> + <td class="tdcl">2</td> + <td class="tdc">11-7/8</td> + <td class="tdcl">0</td> + <td class="tdc"> 6-7/8</td> + <td class="tdcl">0</td> + <td class="tdc"> 5-1/4</td> + <td class="tdcl">3</td> + <td class="tdc">4 </td> + </tr> + <tr> + <td class="tdcz"> 7</td> + <td class="tdll">400 lb. ammonium salts, 3-1/2 cwt. superphosphate, 300 lb. sulphate potash, + 100 lb. sulphate soda, 100 lb. sulphate magnesia</td> + <td class="tdcly">5</td> + <td class="tdcy">14-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 8-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy">14-3/4</td> + <td class="tdcly">6</td> + <td class="tdcy">17-1/4</td> + </tr> + <tr> + <td class="tdcz"> 8</td> + <td class="tdll">550 lb. nitrate of soda, 33-1/2 cwt. superphosphate, 300 lb. sulphate potash, + 100 lb. sulphate soda, 100 lb. sulphate magnesia </td> + <td class="tdcly">5</td> + <td class="tdcy">19-7/8</td> + <td class="tdcly">0</td> + <td class="tdcy"> 7-7/8</td> + <td class="tdcly">0</td> + <td class="tdcy">19-1/8</td> + <td class="tdcly">7</td> + <td class="tdcy"> 6-7/8</td> + </tr> + <tr> + <td class="tdc"> 9</td> + <td class="tdll">3-1/2 cwt. superphosphate</td> + <td class="tdcl">3</td> + <td class="tdc"> 0-3/4</td> + <td class="tdcl">0</td> + <td class="tdc">8 </td> + <td class="tdcl">0</td> + <td class="tdc"> 4-5/8</td> + <td class="tdcl">3</td> + <td class="tdc">13-3/8</td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;">10</td> + <td class="tdllb">3-1/2 cwt. superphosphate, 300 lb. sulphate potash, 100 lb. sulphate soda, + and 100 lb. sulphate magnesia</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 4-1/2</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 6-1/2</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 4-7/8</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;">15-7/8</td> + </tr> + <tr> + <td class="tdl" colspan="10">1. In each year the tops were spread on the respective plots.</td> + </tr> +</table> +</div> + +<br /> +<p class="cen"><span class='pagenum'><a name="Page_572" id="Page_572">[Pg 572]</a></span>TABLE XII.—<span class="smcap">Experiments on the Growth of Potatoes</span>—<i>Continued</i>.</p> + +<p class="cen"><i>Average of Twelve Seasons, 1881-92.</i></p> + +<div class="centered"> +<table border="0" width="100%" cellpadding="2" cellspacing="0" summary="tubers"> + <tr> + <td class="tdct"> </td> + <td class="tdct" style="border-left: .5pt black solid;"> </td> + <td class="tdctlb" colspan="8"><span class="smcap">Produce per Acre—Tubers.</span></td> + </tr> + <tr> + <td class="tdlb">Plot.</td> + <td class="tdclb"><span class="smcap">Manures per Acre per Annum</span></td> + <td class="tdclb" colspan="2">Good.</td> + <td class="tdclb" colspan="2">Small.</td> + <td class="tdclb" colspan="2">Diseased.</td> + <td class="tdclb" colspan="2">Total.</td> + </tr> + <tr> + <td class="tdl" width="4%"> </td> + <td class="tdll" width="32%"> </td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + <td class="tdcl" width="7%">Tons.</td> + <td class="tdc" width="9%">cwt.</td> + </tr> + <tr> + <td class="tdcz"> 1</td> + <td class="tdll">Unmanured in 1876, and each year since</td> + <td class="tdcly">1</td> + <td class="tdcy"> 3-3/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 3-3/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 0-1/4</td> + <td class="tdcly">1</td> + <td class="tdcy"> 7-3/4</td> + </tr> + <tr> + <td class="tdcz"> 2</td> + <td class="tdll">Unmanured in 1882, and since; previously farmyard manure (14 tons)</td> + <td class="tdcly">2</td> + <td class="tdcy">14-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-3/4</td> + <td class="tdcly">0</td> + <td class="tdcy">2 </td> + <td class="tdcly">3</td> + <td class="tdcy">1 </td> + </tr> + <tr> + <td class="tdcz"> 3</td> + <td class="tdll">Farmyard manure (14 tons) alone, 1883, and since; previously 3-1/2 cwt. + superphosphate also</td> + <td class="tdcly">4</td> + <td class="tdcy"> 3-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-1/2</td> + <td class="tdcly">4</td> + <td class="tdcy">12 </td> + </tr> + <tr> + <td class="tdcz"> 4</td> + <td class="tdll">Farmyard manure (14 tons) alone, 1883, and since. In 1882 and previously 3-1/2 + cwt. superphosphate, and in 1881 and previously 550 lb. nitrate of soda also</td> + <td class="tdcly">4</td> + <td class="tdcy"> 6-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-1/2</td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-3/4</td> + <td class="tdcly">4</td> + <td class="tdcy">15-1/2</td> + </tr> + <tr> + <td class="tdc"> 5</td> + <td class="tdll">400 lb. ammonium salts</td> + <td class="tdcl">1</td> + <td class="tdc"> 2-3/4</td> + <td class="tdcl">0</td> + <td class="tdc"> 4-3/4</td> + <td class="tdcl">0</td> + <td class="tdc"> 0-1/2</td> + <td class="tdcl">1</td> + <td class="tdc">8 </td> + </tr> + <tr> + <td class="tdc"> 6</td> + <td class="tdll">550 lb. nitrate of soda</td> + <td class="tdcl">1</td> + <td class="tdc">17-3/4</td> + <td class="tdcl">0</td> + <td class="tdc"> 3-3/4</td> + <td class="tdcl">0</td> + <td class="tdc"> 0-3/4</td> + <td class="tdcl">2</td> + <td class="tdc"> 2-1/4</td> + </tr> + <tr> + <td class="tdcz"> 7</td> + <td class="tdll">400 lb. ammonium salts, 3-1/2 cwt. superphosphate, 300 lb. sulphate of potash, + and 200 lb. mixed mineral manure</td> + <td class="tdcly">5</td> + <td class="tdcy"> 6-3/4</td> + <td class="tdcly">0</td> + <td class="tdcy">5 </td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-1/2</td> + <td class="tdcly">5</td> + <td class="tdcy">16-1/4</td> + </tr> + <tr> + <td class="tdcz"> 8</td> + <td class="tdll">550 lb. nitrate of soda, 3-1/2 cwt. superphosphate, 300 lb. sulphate of potash, + and 200 lb. mixed mineral manure</td> + <td class="tdcly">5</td> + <td class="tdcy"> 7-1/2</td> + <td class="tdcly">0</td> + <td class="tdcy"> 4-1/4</td> + <td class="tdcly">0</td> + <td class="tdcy"> 3-3/4</td> + <td class="tdcly">5</td> + <td class="tdcy">15-1/2</td> + </tr> + <tr> + <td class="tdc"> 9</td> + <td class="tdll">3-1/2 cwt. superphosphate</td> + <td class="tdcl">2</td> + <td class="tdc">17-3/4</td> + <td class="tdcl">0</td> + <td class="tdc"> 3-1/4</td> + <td class="tdcl">0</td> + <td class="tdc">1 </td> + <td class="tdcl">3</td> + <td class="tdc">2 </td> + </tr> + <tr> + <td class="tdcz" style="border-bottom: .5pt black solid;">10</td> + <td class="tdllb">3-1/2 cwt. superphosphate, 300 lb. sulphate of potash, and 200 lb. mixed + mineral manure</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 2-1/4</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 3-1/4</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">0</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 1-1/4</td> + <td class="tdcly" style="border-bottom: .5pt black solid;">3</td> + <td class="tdcy" style="border-bottom: .5pt black solid;"> 6-3/4</td> + </tr> +</table> +</div> + +<br /> +<br /> +<h4>FOOTNOTES:</h4> + +<div class="footnote"><p class="noin"><a name="Footnote_256_256" id="Footnote_256_256"></a><a href="#FNanchor_256_256"><span class="label">[256]</span></a> See Sir John Bennet Lawes, Bart., and the Rothamsted +Experiments. By C. M. Aikman. ('Scottish Farmer' Office, Glasgow.)</p></div> + +<br /> +<br /> +<br /> +<br /> +<hr /><span class='pagenum'><a name="Page_573" id="Page_573">[Pg 573]</a></span> +<h2><a name="INDEX" id="INDEX"></a>INDEX.</h2> + + +<ul><li> Abraum salts, <a href="#Page_421">421</a>.</li> + +<li> Absorptive power of soils for water, <a href="#Page_67">67</a>, <a href="#Page_98">98</a>; + <ul class="nest"> + <li> how to increase, <a href="#Page_74">74</a>.</li> + </ul> +</li> + +<li> Acidity in soils neutralised by lime, <a href="#Page_458">458</a>.</li> + +<li> Acids fixed by soil, <a href="#Page_58">58</a>.</li> + +<li> Adametz on organisms in soil, <a href="#Page_92">92</a>.</li> + +<li> Adulteration of guano, <a href="#Page_318">318</a>-320.</li> + +<li> Africa, guano from, <a href="#Page_298">298</a>, <a href="#Page_328">328</a>.</li> + +<li> Agricultural chemistry, historical introduction to, <a href="#Page_3">3</a>-61; + <ul class="nest"> + <li> Liebig's researches on, <a href="#Page_23">23</a>-32;</li> + <li> Liebig's services to, <a href="#Page_31">31</a>.</li> + </ul> +</li> + +<li> Agronomy, <a href="#Page_56">56</a>.</li> + +<li> Air, ammonia in, <a href="#Page_48">48</a>, <a href="#Page_118">118</a>; + <ul class="nest"> + <li> nitrates in, <a href="#Page_118">118</a>;</li> + <li> nitrogen in, <a href="#Page_116">116</a>;</li> + <li> organic nitrogen in, <a href="#Page_118">118</a>.</li> + </ul> +</li> + +<li> Aitken, Dr, experiments with basic slag, <a href="#Page_413">413</a> + <ul class="nest"> + <li> —with beans, <a href="#Page_526">526</a>, <a href="#Page_530">530</a>;</li> + <li> on germ-life in bones, <a href="#Page_368">368</a>;</li> + <li> on manuring of turnips, <a href="#Page_515">515</a>.</li> + </ul> +</li> + +<li> Albert, Heinrich, on solubility of basic slag, <a href="#Page_409">409</a>.</li> + +<li> Albite, composition of, <a href="#Page_103">103</a>.</li> + +<li> Albuminates, <a href="#Page_460">460</a>.</li> + +<li> Albuminoids, in plants, <a href="#Page_491">491</a>; + <ul class="nest"> + <li> of milk, nitrification in, <a href="#Page_182">182</a>;</li> + <li> phosphorus in, <a href="#Page_205">205</a>.</li> + </ul> +</li> + +<li> Algerian phosphate, <a href="#Page_379">379</a>.</li> + +<li> Algoa Bay, guano deposits at, <a href="#Page_328">328</a>.</li> + +<li> Alkalies, in cow-dung, <a href="#Page_226">226</a>, <a href="#Page_227">227</a> + <ul class="nest"> + <li> —cow-urine, <a href="#Page_230">230</a></li> + <li> —horse-dung, <a href="#Page_226">226</a>, <a href="#Page_227">227</a></li> + <li> —horse-urine, <a href="#Page_230">230</a></li> + <li> —pig-dung, <a href="#Page_226">226</a>, <a href="#Page_227">227</a></li> + <li> —pig-urine, <a href="#Page_230">230</a></li> + <li> —sheep-dung, <a href="#Page_226">226</a>, <a href="#Page_227">227</a></li> + <li> —sheep-urine, <a href="#Page_230">230</a>.</li> + </ul> +</li> + +<li> Alkalinity necessary for nitrification, <a href="#Page_172">172</a>.</li> + +<li> Alumina, in ash of plants, <a href="#Page_55">55</a>; + <ul class="nest"> + <li> compounds, reversion caused by, <a href="#Page_388">388</a>, <a href="#Page_400">400</a>;</li> + <li> salts, in <i>salinas</i>, <a href="#Page_335">335</a>.</li> + </ul> +</li> + +<li> America, virgin soils of, <a href="#Page_133">133</a>.</li> + +<li> American farming, <a href="#Page_86">86</a>.</li> + +<li> Amides, <a href="#Page_501">501</a>.</li> + +<li> Ammonia, absorbed by soil, <a href="#Page_81">81</a>; + <ul class="nest"> + <li> amount dissolved in rain, <a href="#Page_49">49</a>;</li> + <li> amount in air, <a href="#Page_48">48</a>;</li> + <li> amount in soil, <a href="#Page_127">127</a>;</li> + <li> amount supplied to soil by rain, <a href="#Page_155">155</a>;</li> + <li> converted into nitrates in soil, <a href="#Page_50">50</a>;</li> + <li> converted into nitrous acid, <a href="#Page_167">167</a>;</li> + <li> fixed by soil, <a href="#Page_58">58</a>;</li> + <li> from decomposition of farmyard manure, <a href="#Page_258">258</a>;</li> + <li> from gas-works, <a href="#Page_353">353</a>;</li> + <li> lost in mixing manures, <a href="#Page_533">533</a>;</li> + <li> relation of, to plants, <a href="#Page_48">48</a>-50;</li> + <li> salts, most easily nitrifiable, <a href="#Page_191">191</a>;</li> + <li> salts of, in farmyard manure, <a href="#Page_257">257</a>;</li> + <li> sulphate of, <a href="#Page_352">352</a>-358;</li> + <li> value of, as a manure, <a href="#Page_352">352</a>.</li> + </ul> +</li> + +<li> Ammonium chloride in Chincha guano, <a href="#Page_305">305</a>.</li> + +<li> Ammonium-magnesium phosphate in Chincha guano, <a href="#Page_305">305</a>.</li> + +<li> Ammonium oxalate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Ammonium phosphate, in Chincha guano, <a href="#Page_305">305</a>; + <ul class="nest"> + <li> in concretionary nodules, <a href="#Page_328">328</a>.</li> + </ul> +</li> + +<li> Ammonium sulphate, <a href="#Page_352">352</a>-358; + <ul class="nest"> + <li> in Chincha guano, <a href="#Page_305">305</a>;</li> + <li> in concretionary nodules, <a href="#Page_328">328</a>.</li> + </ul> +</li> + +<li> Ammonium sulphocyanate, <a href="#Page_355">355</a>.</li> + +<li> Ammonium urate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Amphibole, potash in, <a href="#Page_220">220</a>.</li> + +<li> Analysis, of manures, <a href="#Page_539">539</a>-554;<span class='pagenum'><a name="Page_574" id="Page_574">[Pg 574]</a></span> + <ul class="nest"> + <li> of soils, value of, <a href="#Page_90">90</a>.</li> + </ul> +</li> + +<li> Anderson, Dr, analyses of minerals by, <a href="#Page_103">103</a>, <a href="#Page_105">105</a>-107; + <ul class="nest"> + <li> on nitrogen in soil, <a href="#Page_121">121</a>, <a href="#Page_124">124</a>.</li> + </ul> +</li> + +<li> Angamos, guano from, <a href="#Page_301">301</a>, <a href="#Page_329">329</a>.</li> + +<li> Animals, phosphoric acid in, <a href="#Page_205">205</a>; + <ul class="nest"> + <li> potash in, <a href="#Page_205">205</a>;</li> + <li> solid excreta of, <a href="#Page_224">224</a>;</li> + <li> urine of, <a href="#Page_228">228</a>.</li> + </ul> +</li> + +<li> Apatite, Canadian, <a href="#Page_201">201</a>, <a href="#Page_374">374</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_210">210</a>;</li> + <li> most abundant form of phosphoric acid, <a href="#Page_200">200</a>;</li> + <li> varieties of, <a href="#Page_200">200</a>.</li> + </ul> +</li> + +<li> Application of manures, <a href="#Page_474">474</a>-492.</li> + +<li> Arabian coast, guano deposits on, <a href="#Page_328">328</a>.</li> + +<li> Arable soil, absorptive power of, <a href="#Page_98">98</a>.</li> + +<li> Arbrohlos Island guano, <a href="#Page_309">309</a>.</li> + +<li> Arendt, experiments on oats by, <a href="#Page_503">503</a>.</li> + +<li> Aristotelian doctrine of chemical elements, <a href="#Page_4">4</a>.</li> + +<li> Artificial soil, <a href="#Page_54">54</a>.</li> + +<li> Aruba phosphate, <a href="#Page_308">308</a>, <a href="#Page_328">328</a>, <a href="#Page_379">379</a>.</li> + +<li> Ash, constituents of plants, <a href="#Page_53">53</a>-55; + <ul class="nest"> + <li> of rye, phosphoric acid in, <a href="#Page_204">204</a>;</li> + <li> of wheat, phosphoric acid in, <a href="#Page_204">204</a>;</li> + <li> of farmyard manure, composition of, <a href="#Page_287">287</a>, <a href="#Page_288">288</a>.</li> + </ul> +</li> + +<li> Ashes, an adulterant of guano, <a href="#Page_319">319</a>; + <ul class="nest"> + <li> mixed with manures, <a href="#Page_532">532</a>.</li> + </ul> +</li> + +<li> Asia, guano from, <a href="#Page_298">298</a>.</li> + +<li> Asparagin, nitrification in, <a href="#Page_182">182</a>.</li> + +<li> Atacama, nitrate of soda deposits at, <a href="#Page_342">342</a>.</li> + +<li> Atmosphere, ammonia in, <a href="#Page_48">48</a>, <a href="#Page_81">81</a>; + <ul class="nest"> + <li> relation of, to plants, <a href="#Page_39">39</a>.</li> + </ul> +</li> + +<li> Atwater on nitrogen in plants, <a href="#Page_44">44</a>.</li> + +<li> Augite, <a href="#Page_105">105</a>.</li> + +<li> Australia, guano from, <a href="#Page_298">298</a>; + <ul class="nest"> + <li> virgin soils of, <a href="#Page_133">133</a>.</li> + </ul> +</li> + +<li> Avenine in oats, <a href="#Page_503">503</a>.</li> + +<li> Aves guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +<br /></li> + + +<li> Bacilli, <a href="#Page_94">94</a>.</li> + +<li> Bacon, Lord, on salt as a manure, <a href="#Page_469">469</a>.</li> + +<li> Bacteria, in soil, <a href="#Page_92">92</a>; + <ul class="nest"> + <li> different classes of, <a href="#Page_93">93</a>-96.</li> + </ul> +</li> + +<li> Baker Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Ballestas, guano from, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Barilla, potash in, <a href="#Page_420">420</a>.</li> + +<li> Barley, farmyard manure not suited for, <a href="#Page_497">497</a>; + <ul class="nest"> + <li> fertilising ingredients removed from soil by, <a href="#Page_485">485</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_495">495</a>, <a href="#Page_498">498</a>;</li> + <li> nitrogen removed in crop of, <a href="#Page_145">145</a>;</li> + <li> Norfolk experiments on, <a href="#Page_497">497</a>;</li> + <li> period of growth of, <a href="#Page_495">495</a>;</li> + <li> period of ripening of, <a href="#Page_495">495</a>;</li> + <li> Rothamsted experiments on growth of, <a href="#Page_566">566</a>;</li> + <li> soils suited for, <a href="#Page_496">496</a>;</li> + <li> uniform manuring of, <a href="#Page_497">497</a>.</li> + </ul> +</li> + +<li> Barley soils, amount of nitrates and nitrogen in, <a href="#Page_158">158</a>.</li> + +<li> Barley-straw, composition of, <a href="#Page_238">238</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>.</li> + </ul> +</li> + +<li> Basalt, phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_210">210</a>.</li> + +<li> Bases fixed by soil, <a href="#Page_58">58</a>.</li> + +<li> Basic ammonium phosphate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Basic process of steel-smelting, <a href="#Page_400">400</a>.</li> + +<li> Basic silicates, <a href="#Page_103">103</a>.</li> + +<li> Basic slag, <a href="#Page_401">401</a>-417; + <ul class="nest"> + <li> after-effects of, <a href="#Page_412">412</a>;</li> + <li> application of, method of, <a href="#Page_416">416</a></li> + <li> —rate of, <a href="#Page_414">414</a>;</li> + <li> compared with other manures, <a href="#Page_410">410</a>-414;</li> + <li> composition of, <a href="#Page_404">404</a>, <a href="#Page_417">417</a>;</li> + <li> Darmstadt experiments with, <a href="#Page_410">410</a>;</li> + <li> discovery of value of, <a href="#Page_403">403</a>;</li> + <li> manufacture of, <a href="#Page_401">401</a>;</li> + <li> preparation of, processes for, <a href="#Page_406">406</a>;</li> + <li> relative activity of, <a href="#Page_411">411</a>;</li> + <li> soils best suited for, <a href="#Page_414">414</a>;</li> + <li> solubility of, <a href="#Page_408">408</a>;</li> + <li> Wagner's experiments with, <a href="#Page_408">408</a>-413.</li> + </ul> +</li> + +<li> Bat guano, <a href="#Page_320">320</a>, <a href="#Page_325">325</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_325">325</a>;</li> + <li> phosphoric acid in, <a href="#Page_325">325</a>.</li> + </ul> +</li> + +<li> Beans, fertilising ingredients removed from soil by, <a href="#Page_485">485</a>; + <ul class="nest"> + <li> good effect of gypsum on, <a href="#Page_526">526</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_525">525</a>-527;</li> + <li> phosphorus in, <a href="#Page_205">205</a>;</li> + <li> relative value of manurial ingredients to, <a href="#Page_526">526</a>;</li> + <li> source of nitrogen, <a href="#Page_153">153</a>.</li> + </ul> +</li> + +<li> Bean-straw, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Beatson, General, experiments of, with Peruvian guano, <a href="#Page_301">301</a>.</li> + +<li> Beddington meadows, irrigation at, <a href="#Page_432">432</a>.</li> + +<li> Bedfordshire, coprolites from, <a href="#Page_374">374</a>.</li> + +<li> Belgian phosphate, <a href="#Page_377">377</a>.</li> + +<li> Berthelot on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Biological properties of soil, <a href="#Page_92">92</a>-96.</li> + +<li> Blood corpuscles, potash in, <a href="#Page_217">217</a>.</li> + +<li> Blood, dried, <a href="#Page_424">424</a>;<span class='pagenum'><a name="Page_575" id="Page_575">[Pg 575]</a></span> + <ul class="nest"> + <li> composition of, <a href="#Page_424">424</a>;</li> + <li> manure for sugar-cane, <a href="#Page_425">425</a>;</li> + <li> potash in, <a href="#Page_217">217</a>, <a href="#Page_219">219</a>;</li> + <li> rate of nitrification in, <a href="#Page_192">192</a>;</li> + <li> source of nitrogen, <a href="#Page_152">152</a>;</li> + <li> suited for horticulture, <a href="#Page_425">425</a>.</li> + </ul> +</li> + +<li> Bohemia, phosphoric acid removed from, <a href="#Page_206">206</a>.</li> + +<li> Bolivia, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Bollaert on nitrate deposits, <a href="#Page_333">333</a>.</li> + +<li> Bone-ash, <a href="#Page_369">369</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_372">372</a>.</li> + </ul> +</li> + +<li> Bone-black, <a href="#Page_369">369</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_372">372</a>.</li> + </ul> +</li> + +<li> Bone-char, <a href="#Page_369">369</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_372">372</a>.</li> + </ul> +</li> + +<li> Bone-dust, <a href="#Page_360">360</a>.</li> + +<li> Bone-meal, <a href="#Page_361">361</a>, <a href="#Page_364">364</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_371">371</a>;</li> + <li> condition of nitrogen in, <a href="#Page_540">540</a>.</li> + </ul> +</li> + +<li> Bone-phosphate, <a href="#Page_385">385</a>.</li> + +<li> Bones, <a href="#Page_359">359</a>-372; + <ul class="nest"> + <li> action of, <a href="#Page_365">365</a>;</li> + <li> boiled, <a href="#Page_361">361</a>;</li> + <li> bruised, <a href="#Page_361">361</a>;</li> + <li> capable of nitrification, <a href="#Page_182">182</a>;</li> + <li> collected in Britain, <a href="#Page_353">353</a>, <a href="#Page_362">362</a>;</li> + <li> composition of, <a href="#Page_362">362</a>, <a href="#Page_371">371</a>;</li> + <li> compound, <a href="#Page_372">372</a>;</li> + <li> crops suited for, <a href="#Page_368">368</a>;</li> + <li> dissolved, <a href="#Page_368">368</a>, <a href="#Page_371">371</a>;</li> + <li> early use of, <a href="#Page_359">359</a>;</li> + <li> fermentation of, <a href="#Page_361">361</a>;</li> + <li> floated, <a href="#Page_365">365</a>;</li> + <li> forms of, <a href="#Page_360">360</a>;</li> + <li> grinding of, <a href="#Page_365">365</a>;</li> + <li> imports of, <a href="#Page_151">151</a>;</li> + <li> inorganic matter in, <a href="#Page_363">363</a>;</li> + <li> nitrogen in, <a href="#Page_151">151</a>;</li> + <li> organic matter in, <a href="#Page_363">363</a>;</li> + <li> putrefaction of, <a href="#Page_365">365</a>, <a href="#Page_366">366</a>;</li> + <li> raw, <a href="#Page_361">361</a>;</li> + <li> source of nitrogen, <a href="#Page_151">151</a>;</li> + <li> treatment of, <a href="#Page_364">364</a>.</li> + </ul> +</li> + +<li> Bonnet, Charles, discovery of source of plant's carbon by, <a href="#Page_11">11</a>.</li> + +<li> Boracic acid in <i>salinas</i>, <a href="#Page_335">335</a>.</li> + +<li> Bordeaux phosphate, <a href="#Page_379">379</a>.</li> + +<li> Boussingault, on dry matter in horse-manure, <a href="#Page_243">243</a>; + <ul class="nest"> + <li> early researches of,</li> + <li> in agricultural chemistry, <a href="#Page_21">21</a>;</li> + <li> experiments by, on nitrification, <a href="#Page_185">185</a>, <a href="#Page_198">198</a>;</li> + <li> on excrements of pig, <a href="#Page_250">250</a>;</li> + <li> on nitrates in guano, <a href="#Page_304">304</a>;</li> + <li> on nitrogen in plants, <a href="#Page_41">41</a>, <a href="#Page_42">42</a>;</li> + <li> on nitrogen in soil, <a href="#Page_124">124</a>;</li> + <li> on nitrogen in excreta, <a href="#Page_234">234</a>;</li> + <li> on nitrogen lost during fermentation, <a href="#Page_245">245</a>.</li> + </ul> +</li> + +<li> Bracken-fern, analyses of, <a href="#Page_283">283</a>; + <ul class="nest"> + <li> as litter, <a href="#Page_241">241</a>.</li> + </ul> +</li> + +<li> Bran, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Bretschneider on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Brewers' grain, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Bromine in ash of plants, <a href="#Page_55">55</a>.</li> + +<li> Browse Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Brüstlein and Peters on fixation of bases and acids by soil, <a href="#Page_59">59</a>.</li> + +<li> Buckland, Dr, discovery of coprolites by, <a href="#Page_373">373</a>.</li> + +<li> Buckwheat absorbs ammonia, <a href="#Page_352">352</a>.</li> + +<li> Bull River, phosphates from, <a href="#Page_376">376</a>.<br /><br/></li> + + +<li> Cabbages, benefited by saline manures, <a href="#Page_529">529</a>; + <ul class="nest"> + <li> manuring of, <a href="#Page_528">528</a>-529;</li> + <li> soils suited for, <a href="#Page_529">529</a>.</li> + </ul> +</li> + +<li> Caird, Sir James, experiments by, with Peruvian guano, <a href="#Page_301">301</a>.</li> + +<li> Calcareous earth, absorptive power of, <a href="#Page_98">98</a>; + <ul class="nest"> + <li> stones, phosphoric acid in, <a href="#Page_211">211</a>.</li> + </ul> +</li> + +<li> Calcium phosphate in Chincha guano, <a href="#Page_305">305</a>.</li> + +<li> Calcium sulphate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> <i>Caliche</i>, composition of, <a href="#Page_342">342</a>; + <ul class="nest"> + <li> occurrence of, <a href="#Page_341">341</a>.</li> + </ul> +</li> + +<li> California, guano deposits at, <a href="#Page_328">328</a>.</li> + +<li> Cambridgeshire, coprolites from, <a href="#Page_373">373</a>.</li> + +<li> Cameron, Sir Charles, on assimilation of urea by plants, <a href="#Page_46">46</a>.</li> + +<li> Canadian apatite, <a href="#Page_201">201</a>, <a href="#Page_374">374</a>.</li> + +<li> Cape Vert guano, phosphoric acid in, <a href="#Page_330">330</a>.</li> + +<li> Carbolic acid, action of, on nitrifying organisms, <a href="#Page_177">177</a>.</li> + +<li> Carbon, fixation of, by plants, <a href="#Page_37">37</a>; + <ul class="nest"> + <li> in plants, discovery of source of, <a href="#Page_11">11</a>.</li> + </ul> +</li> + +<li> Carbon bisulphide, effect of, on nitrification, <a href="#Page_166">166</a>, <a href="#Page_176">176</a>.</li> + +<li> Carbonate of ammonia formed in fermentation of dung, <a href="#Page_247">247</a>, <a href="#Page_258">258</a>.</li> + +<li> Carbonic acid, absorbed by plants, <a href="#Page_12">12</a> + <ul class="nest"> + <li> —by soil, <a href="#Page_81">81</a>;</li> + <li> in ash of plants, <a href="#Page_55">55</a>;</li> + <li> oxidation of, by bacteria, <a href="#Page_95">95</a>;</li> + <li> produced in decomposition of farmyard manure, <a href="#Page_258">258</a>.</li> + </ul> +</li> + +<li> Carbonising-works, ammonia from, <a href="#Page_353">353</a>, <a href="#Page_358">358</a>.</li> + +<li> Carburetted hydrogen, produced in decomposition of farmyard manure, <a href="#Page_258">258</a>.</li> + +<li> Caribbean phosphates, <a href="#Page_379">379</a>.</li> + +<li> Carnallite, <a href="#Page_420">420</a>.</li> + +<li> Carolina phosphate, <a href="#Page_376">376</a>.</li> + +<li> Carrots, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Catacombs, bones from, <a href="#Page_360">360</a>.</li> + +<li> Catch-cropping, <a href="#Page_138">138</a>, <a href="#Page_489">489</a>.</li> + +<li> Cattle foods, average composition of, <a href="#Page_557">557</a>.<span class='pagenum'><a name="Page_576" id="Page_576">[Pg 576]</a></span></li> + +<li> Caustic lime, <a href="#Page_453">453</a>.</li> + +<li> Cereals, manuring of, <a href="#Page_493">493</a>-504; + <ul class="nest"> + <li> nitrogenous manures benefit, <a href="#Page_494">494</a>;</li> + <li> potash in, <a href="#Page_217">217</a>;</li> + <li> silicates absorbed by, <a href="#Page_494">494</a>;</li> + <li> value of nitrate of soda as manure for, <a href="#Page_346">346</a>.</li> + </ul> +</li> + +<li> Chalk, an adulterant of guano, <a href="#Page_319">319</a>; + <ul class="nest"> + <li> lias, phosphoric acid in, <a href="#Page_211">211</a>.</li> + </ul> +</li> + +<li> Charcoal, a filter for sewage, <a href="#Page_437">437</a>.</li> + +<li> Charleston phosphate, <a href="#Page_376">376</a>.</li> + +<li> Chemical analysis of manures, interpretation of, <a href="#Page_539">539</a>; + <ul class="nest"> + <li> value of, <a href="#Page_539">539</a>.</li> + </ul> +</li> + +<li> Chemical composition of soil, <a href="#Page_87">87</a>-92.</li> + +<li> Cheshire, bones used in, <a href="#Page_360">360</a>.</li> + +<li> Chesterfield Island guano, <a href="#Page_309">309</a>.</li> + +<li> Chili and Peru, chief source of nitrate of soda, <a href="#Page_162">162</a>.</li> + +<li> Chincha Island guano, <a href="#Page_302">302</a>, <a href="#Page_303">303</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_305">305</a>;</li> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Chipana, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Chlorapatite, composition of, <a href="#Page_210">210</a>.</li> + +<li> Chlorine in ash of plants, <a href="#Page_55">55</a>.</li> + +<li> Chloroform prevents nitrification, <a href="#Page_166">166</a>, <a href="#Page_176">176</a>.</li> + +<li> Chlorophyll, organisms destitute of, <a href="#Page_169">169</a>; + <ul class="nest"> + <li> produced by nitrate of soda, <a href="#Page_347">347</a>;</li> + <li> relation of, to fixation of carbon by plants, <a href="#Page_37">37</a>.</li> + </ul> +</li> + +<li> Chuca, <a href="#Page_341">341</a>.</li> + +<li> Citrate of ammonia, solubility of phosphates in, <a href="#Page_408">408</a>.</li> + +<li> Clay, absorptive power of, <a href="#Page_68">68</a>; + <ul class="nest"> + <li> analysis of, <a href="#Page_107">107</a>;</li> + <li> grey, evaporation of water from, <a href="#Page_99">99</a>;</li> + <li> loamy, evaporation of water from, <a href="#Page_99">99</a>;</li> + <li> sandy, absorptive power of, <a href="#Page_98">98</a></li> + <li> —evaporation of water from, <a href="#Page_99">99</a>;</li> + <li> soils, benefited by basic slag, <a href="#Page_414">414</a></li> + <li> —puddling in, <a href="#Page_455">455</a>;</li> + <li> stiffish, evaporation of water from, <a href="#Page_99">99</a>;</li> + <li> strong absorptive power of, <a href="#Page_98">98</a>.</li> + </ul> +</li> + +<li> Clover-hay, fertilising ingredients removed from soil by, <a href="#Page_486">486</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_522">522</a>.</li> + </ul> +</li> + +<li> Clover-sickness, <a href="#Page_522">522</a>.</li> + +<li> Coal, nitrogen in, <a href="#Page_353">353</a>.</li> + +<li> Coke-works, ammonia from, <a href="#Page_353">353</a>, <a href="#Page_358">358</a>.</li> + +<li> Colloids, <a href="#Page_491">491</a>.</li> + +<li> Colour of soil, <a href="#Page_80">80</a>; + <ul class="nest"> + <li> difference in temperature due to, <a href="#Page_80">80</a>.</li> + </ul> +</li> + +<li> Columbia, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Composts, <a href="#Page_113">113</a>, <a href="#Page_445">445</a>-448; + <ul class="nest"> + <li> farmyard manure a typical, <a href="#Page_446">446</a>;</li> + <li> manufacture of, <a href="#Page_445">445</a>;</li> + <li> object of, <a href="#Page_445">445</a>;</li> + <li> purposes served by, <a href="#Page_445">445</a>;</li> + <li> substances used for, <a href="#Page_447">447</a>.</li> + </ul> +</li> + +<li> Compound bones, <a href="#Page_372">372</a>.</li> + +<li> Concretionary nodules, composition of, <a href="#Page_328">328</a>.</li> + +<li> Conglomerate, <a href="#Page_341">341</a>.</li> + +<li> Connecticut, experimental station at, <a href="#Page_33">33</a>.</li> + +<li> Cooke, F. J., on, farmyard manure, <a href="#Page_272">272</a>, <a href="#Page_277">277</a>; + <ul class="nest"> + <li> field experiments. <a href="#Page_547">547</a>;</li> + <li> manuring of barley, <a href="#Page_497">497</a></li> + <li> —of mangels, <a href="#Page_514">514</a></li> + <li> —of meadow-land, <a href="#Page_509">509</a></li> + <li> —of swedes, <a href="#Page_514">514</a></li> + <li> —of wheat, <a href="#Page_501">501</a>.</li> + </ul> +</li> + +<li> Copper, oxide of, in plants, <a href="#Page_55">55</a>.</li> + +<li> Copperas, as a fixer, <a href="#Page_246">246</a>, <a href="#Page_247">247</a>.</li> + +<li> Coprolites, <a href="#Page_373">373</a>; + <ul class="nest"> + <li> percentage of phosphates in, <a href="#Page_201">201</a>:</li> + <li> occurrence of, <a href="#Page_201">201</a>, <a href="#Page_373">373</a>.</li> + </ul> +</li> + +<li> Corcovado guano, nitrogen in, <a href="#Page_329">329</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Cordilleras, <a href="#Page_340">340</a>, <a href="#Page_341">341</a>.</li> + +<li> Costra, <a href="#Page_341">341</a>.</li> + +<li> Cotton-cake, decorticated, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Cotton-cake, undecorticated, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Cotton-seeds, imports of, <a href="#Page_153">153</a>.</li> + +<li> Cova, <a href="#Page_341">341</a>.</li> + +<li> Covered manure, potatoes grown with, <a href="#Page_289">289</a>; + <ul class="nest"> + <li> wheat grown with, <a href="#Page_289">289</a>.</li> + </ul> +</li> + +<li> Cow-dung, alkalies in, <a href="#Page_226">226</a>; + <ul class="nest"> + <li> composition of, in dry state, <a href="#Page_227">227</a>;</li> + <li> cool, <a href="#Page_225">225</a>;</li> + <li> nitrogen in, <a href="#Page_226">226</a>;</li> + <li> phosphoric acid in, <a href="#Page_226">226</a>;</li> + <li> water in, <a href="#Page_226">226</a>.</li> + </ul> +</li> + +<li> Cow-manure, <a href="#Page_247">247</a>; + <ul class="nest"> + <li> amount voided per day, <a href="#Page_248">248</a>;</li> + <li> amount voided per year, <a href="#Page_248">248</a>;</li> + <li> analysis of, <a href="#Page_286">286</a>;</li> + <li> dry matter in, <a href="#Page_248">248</a>;</li> + <li> fermentation in, slow, <a href="#Page_248">248</a>;</li> + <li> mineral matter in, <a href="#Page_248">248</a>;</li> + <li> mucilaginous matter in, <a href="#Page_248">248</a>;</li> + <li> nitrogen in, <a href="#Page_248">248</a>;</li> + <li> resinous matter in, <a href="#Page_248">248</a>.</li> + </ul> +</li> + +<li> Cow-urine, alkalies in, <a href="#Page_230">230</a>; + <ul class="nest"> + <li> composition of, in dry state, <a href="#Page_231">231</a>;</li> + <li> fertilising ingredients in, for food consumed, <a href="#Page_232">232</a>;</li> + <li> nitrogen in, <a href="#Page_230">230</a>;</li> + <li> phosphoric acid in, <a href="#Page_230">230</a>;</li> + <li> water in, <a href="#Page_230">230</a>.</li> + </ul> +</li> + +<li> Cows, percentage of food voided in excrements of, <a href="#Page_281">281</a>; + <ul class="nest"> + <li> solid excrements of, <a href="#Page_280">280</a>;</li> + <li> urine voided by, <a href="#Page_280">280</a>.</li> + </ul> +</li> + +<li> Cress, experiments with, <a href="#Page_41">41</a>.<span class='pagenum'><a name="Page_577" id="Page_577">[Pg 577]</a></span></li> + +<li> Crimea, bones from, <a href="#Page_360">360</a>.</li> + +<li> Cropped soils, nitrates in, <a href="#Page_157">157</a> + <ul class="nest"> + <li> —lost by drainage in, <a href="#Page_141">141</a>.</li> + </ul> +</li> + +<li> Crops, capacity of, for assimilating manures, <a href="#Page_486">486</a>; + <ul class="nest"> + <li> difference in root-systems of, <a href="#Page_488">488</a>;</li> + <li> manuring of common farm, <a href="#Page_493">493</a>-530;</li> + <li> period of growth of, <a href="#Page_489">489</a>;</li> + <li> potash removed in, <a href="#Page_218">218</a>;</li> + <li> suited for sewage, <a href="#Page_434">434</a>;</li> + <li> variation in composition of, <a href="#Page_490">490</a>.</li> + </ul> +</li> + +<li> Crusius on phosphoric acid removed from the farm, <a href="#Page_207">207</a>.</li> + +<li> Crust guanos, <a href="#Page_308">308</a>, <a href="#Page_379">379</a>.</li> + +<li> Crystalloids, <a href="#Page_491">491</a>.</li> + +<li> Curaçao phosphates, <a href="#Page_308">308</a>, <a href="#Page_330">330</a>, <a href="#Page_379">379</a>.<br /><br /></li> + + + +<li> Darmstadt experiments with basic slag, <a href="#Page_410">410</a>-413.</li> + +<li> Darwin on origin of nitrate-fields, <a href="#Page_335">335</a>.</li> + +<li> Daubeny on mineral sources of phosphoric acid, <a href="#Page_200">200</a>.</li> + +<li> Davy, Sir Humphry, lectures of, on agricultural chemistry, <a href="#Page_17">17</a>-19; + <ul class="nest"> + <li> on heat and water absorbing and retaining properties of soils, <a href="#Page_57">57</a>;</li> + <li> on hygroscopic power of soils, <a href="#Page_99">99</a>.</li> + </ul> +</li> + +<li> Dehérain, on nitrification, <a href="#Page_52">52</a>; + <ul class="nest"> + <li> on nitrification in sulphate of ammonia, <a href="#Page_191">191</a>;</li> + <li> on rate of nitrification, <a href="#Page_186">186</a>.</li> + </ul> +</li> + +<li> Denitrification, <a href="#Page_177">177</a>; + <ul class="nest"> + <li> conditions favourable for, <a href="#Page_178">178</a>;</li> + <li> effected by bacteria, <a href="#Page_178">178</a>.</li> + </ul> +</li> + +<li> Derby, Lord, introduction of Peruvian guano by, <a href="#Page_301">301</a>.</li> + +<li> Detmer on humus in soil, <a href="#Page_47">47</a>.</li> + +<li> Dew, action of, on guano, <a href="#Page_300">300</a>; + <ul class="nest"> + <li> explanation of, <a href="#Page_77">77</a>;</li> + <li> most abundant in summer, <a href="#Page_78">78</a>.</li> + </ul> +</li> + +<li> Dicalcic phosphate, <a href="#Page_387">387</a>; + <ul class="nest"> + <li> formula of, <a href="#Page_398">398</a>;</li> + <li> molecular composition of, <a href="#Page_398">398</a>;</li> + <li> percentage composition of, <a href="#Page_398">398</a>.</li> + </ul> +</li> + +<li> Digby, Sir Kenelm, on value of nitrates to plants, <a href="#Page_45">45</a>; + <ul class="nest"> + <li> theory of, on plant-food, <a href="#Page_6">6</a>-8.</li> + </ul> +</li> + +<li> Diorite, phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + +<li> Direct manures, <a href="#Page_113">113</a>.</li> + +<li> Dissolved-bone compound, <a href="#Page_372">372</a>.</li> + +<li> Dissolved bones, <a href="#Page_368">368</a>; composition of, <a href="#Page_371">371</a>.</li> + +<li> Dissolved guano, <a href="#Page_310">310</a>.</li> + +<li> Dolerite, phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + +<li> Dolomite, phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + +<li> Downton experiments on sewage-sludge, <a href="#Page_439">439</a>.</li> + +<li> Drainage, average of thirteen years, <a href="#Page_160">160</a>; + <ul class="nest"> + <li> nitrates in, <a href="#Page_160">160</a>;</li> + <li> nitrates lost by, <a href="#Page_140">140</a>;</li> + <li> phosphoric acid lost by, <a href="#Page_206">206</a>;</li> + <li> potash lost by, <a href="#Page_217">217</a>.</li> + </ul> +</li> + +<li> Drainings of manure-heaps, analysis of, <a href="#Page_290">290</a>.</li> + +<li> Dried blood, <a href="#Page_424">424</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_424">424</a>;</li> + <li> manure for sugar-cane, <a href="#Page_425">425</a>;</li> + <li> potash in, <a href="#Page_219">219</a>;</li> + <li> rate of nitrification in, <a href="#Page_192">192</a>;</li> + <li> source of nitrogen, <a href="#Page_152">152</a>;</li> + <li> suited for horticulture, <a href="#Page_425">425</a>.</li> + </ul> +</li> + +<li> Dried flesh, <a href="#Page_425">425</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_425">425</a>.</li> + </ul> +</li> + +<li> Dried leaves, as litter, <a href="#Page_242">242</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_242">242</a>;</li> + <li> nitrogen in, <a href="#Page_242">242</a>;</li> + <li> phosphoric acid in, <a href="#Page_242">242</a>;</li> + <li> potash in, <a href="#Page_242">242</a>.</li> + </ul> +</li> + +<li> Ducks' dung, analysis of, <a href="#Page_331">331</a>.</li> + +<li> Duhamel and Hales, theory of, on plant-growth, <a href="#Page_8">8</a>.</li> + +<li> Dundonald, Earl, treatise by, on agricultural chemistry, <a href="#Page_13">13</a>.</li> + +<li> Dung and urine, composition of, <a href="#Page_234">234</a>.</li> + +<li> Dutrochet on absorption of plant-food, <a href="#Page_55">55</a>.</li> + +<li> Dyer, Dr Bernard, analyses of stable manure by, <a href="#Page_283">283</a>; + <ul class="nest"> + <li> experiments on peat as litter, <a href="#Page_240">240</a>;</li> + <li> on nitrate of soda as manure for mangolds, <a href="#Page_349">349</a>.</li> + </ul><br /> +</li> + + +<li> Earth, an adulterant of guano, <a href="#Page_319">319</a>; + <ul class="nest"> + <li> composition of solid crust of, <a href="#Page_102">102</a>.</li> + </ul> +</li> + +<li> Ecuador, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Egyptian guano, nitrogen in, <a href="#Page_329">329</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Elbe, waters of, phosphoric acid in, <a href="#Page_206">206</a>; + <ul class="nest"> + <li> potash in, <a href="#Page_217">217</a>.</li> + </ul> +</li> + +<li> Elm-tree, water transpired by, <a href="#Page_71">71</a>.</li> + +<li> Enderbury Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_328">328</a>.</li> + </ul> +</li> + +<li> Endosmosis, <a href="#Page_55">55</a>.</li> + +<li> English farming, <a href="#Page_86">86</a>.</li> + +<li> Equalised guano, <a href="#Page_311">311</a>.</li> + +<li> Essex, coprolites from, <a href="#Page_374">374</a>.</li> + +<li> Estremadura phosphate, <a href="#Page_375">375</a>.</li> + +<li> Ethylamine, nitrification in, <a href="#Page_182">182</a>.</li> + +<li> Evaporation from soil, <a href="#Page_71">71</a>, <a href="#Page_72">72</a>, <a href="#Page_98">98</a>.</li> + +<li> Excreta, amount of nitrogen in, <a href="#Page_149">149</a>, <a href="#Page_292">292</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_226">226</a>, <a href="#Page_292">292</a>;</li> + <li> difference in amount of, for food consumed, <a href="#Page_279">279</a>;</li> + <li> liquid, in farmyard manure, <a href="#Page_224">224</a>;<span class='pagenum'><a name="Page_578" id="Page_578">[Pg 578]</a></span></li> + <li> solid, in farmyard manure, <a href="#Page_224">224</a>;</li> + <li> solid, undigested food in, <a href="#Page_224">224</a>;</li> + <li> solid, voided by cows, <a href="#Page_280">280</a>, <a href="#Page_292">292</a>;</li> + <li> solid, voided by horse, <a href="#Page_292">292</a>;</li> + <li> solid, voided by oxen, <a href="#Page_280">280</a>;</li> + <li> solid, voided by sheep, <a href="#Page_280">280</a>, <a href="#Page_292">292</a>.</li> + </ul> +<br /> +</li> + + +<li> Factors for calculating manurial ingredients + <ul class="nest"> + <li> into their different compounds, <a href="#Page_553">553</a>.</li> + </ul> +</li> + +<li> Falkland guano, <a href="#Page_308">308</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_330">330</a>;</li> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Fallow-fields, nitrates formed in, <a href="#Page_188">188</a>.</li> + +<li> Fanning Island guano, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Farmyard manure, <a href="#Page_223">223</a>-292; + <ul class="nest"> + <li> action of, on soils, <a href="#Page_273">273</a>;</li> + <li> ammonia in, <a href="#Page_258">258</a>;</li> + <li> amount produced on farm per year, <a href="#Page_252">252</a>;</li> + <li> analyses of, <a href="#Page_259">259</a>, <a href="#Page_286">286</a>;</li> + <li> application of, <a href="#Page_264">264</a>;</li> + <li> ash of, <a href="#Page_287">287</a>, <a href="#Page_288">288</a>;</li> + <li> carbonic acid gas in, <a href="#Page_258">258</a>;</li> + <li> classes of constituents of, <a href="#Page_224">224</a>;</li> + <li> compared with artificials, <a href="#Page_476">476</a>;</li> + <li> composition of, <a href="#Page_259">259</a>;</li> + <li> denitrification in, <a href="#Page_179">179</a>;</li> + <li> depth to plough to, <a href="#Page_267">267</a>;</li> + <li> effect of, on potatoes, <a href="#Page_520">520</a>;</li> + <li> fertilising matter in, <a href="#Page_270">270</a>;</li> + <li> fire-fang in, <a href="#Page_264">264</a>;</li> + <li> fresh, composition of, <a href="#Page_286">286</a>, <a href="#Page_288">288</a>;</li> + <li> functions of, <a href="#Page_268">268</a>;</li> + <li> heat in fermentation of, <a href="#Page_78">78</a>, <a href="#Page_253">253</a>;</li> + <li> humates in, <a href="#Page_259">259</a>;</li> + <li> humic acid in, <a href="#Page_258">258</a>;</li> + <li> inadequate source of nitrogen to soil, <a href="#Page_271">271</a>;</li> + <li> indirect influence of, <a href="#Page_273">273</a>;</li> + <li> influence of, on soil, <a href="#Page_475">475</a>;</li> + <li> Lawes, Sir John, on composition of, <a href="#Page_291">291</a>;</li> + <li> Lord Kinnaird's experiments with, <a href="#Page_289">289</a>;</li> + <li> marsh-gas in, <a href="#Page_258">258</a>;</li> + <li> mineral matter in, <a href="#Page_260">260</a>;</li> + <li> moisture in, <a href="#Page_260">260</a>;</li> + <li> nitric acid in, <a href="#Page_259">259</a>;</li> + <li> nitrogen in, <a href="#Page_260">260</a>;</li> + <li> ratio of, to ash ingredients, <a href="#Page_271">271</a>;</li> + <li> organic matter in, <a href="#Page_260">260</a>;</li> + <li> phosphoretted hydrogen in, <a href="#Page_258">258</a>;</li> + <li> phosphoric acid in, <a href="#Page_260">260</a>;</li> + <li> potash in, <a href="#Page_260">260</a>;</li> + <li> products of decomposition of, <a href="#Page_257">257</a>;</li> + <li> rate of application of, <a href="#Page_275">275</a>;</li> + <li> retrogression of nitrogen in, <a href="#Page_142">142</a>;</li> + <li> rotten, composition of, <a href="#Page_287">287</a>, <a href="#Page_288">288</a></li> + <li> —value of, <a href="#Page_261">261</a>;</li> + <li> rotting, effects of, on, <a href="#Page_262">262</a>;</li> + <li> solid excreta in, <a href="#Page_224">224</a>;</li> + <li> sulphuretted hydrogen in, <a href="#Page_258">258</a>;</li> + <li> supplemented with nitrogen, <a href="#Page_271">271</a>;</li> + <li> supplemented with phosphoric acid, <a href="#Page_272">272</a>;</li> + <li> temperature, effect of, on soil, <a href="#Page_79">79</a>, <a href="#Page_274">274</a>;</li> + <li> typical compost, <a href="#Page_446">446</a>;</li> + <li> ulmates in, <a href="#Page_259">259</a>;</li> + <li> ulmic acid in, <a href="#Page_258">258</a>;</li> + <li> unfavourable to certain crops, <a href="#Page_477">477</a>;</li> + <li> urine in, <a href="#Page_228">228</a>;</li> + <li> value of, <a href="#Page_268">268</a>;</li> + <li> variation in composition of, <a href="#Page_223">223</a>;</li> + <li> water in, <a href="#Page_258">258</a>.</li> + </ul> +</li> + +<li> Fatty acids in guano, <a href="#Page_305">305</a>.</li> + +<li> Felspars, <a href="#Page_103">103</a>; + <ul class="nest"> + <li> albite, <a href="#Page_103">103</a>;</li> + <li> composition of, <a href="#Page_103">103</a>;</li> + <li> labradorite, <a href="#Page_220">220</a>;</li> + <li> oligoclase, <a href="#Page_103">103</a>, <a href="#Page_214">214</a>, <a href="#Page_220">220</a>;</li> + <li> orthoclase, <a href="#Page_103">103</a>, <a href="#Page_214">214</a>, <a href="#Page_220">220</a>;</li> + <li> phosphoric acid in, <a href="#Page_211">211</a>;</li> + <li> potash manures, <a href="#Page_213">213</a>;</li> + <li> potash in, percentage of, <a href="#Page_213">213</a>, <a href="#Page_220">220</a>.</li> + </ul> +</li> + +<li> Ferment, aerobic, <a href="#Page_173">173</a>, <a href="#Page_255">255</a>; + <ul class="nest"> + <li> anaerobic, <a href="#Page_255">255</a>.</li> + </ul> +</li> + +<li> Fermentation, ammonium carbonate formed during, <a href="#Page_245">245</a>; + <ul class="nest"> + <li> in bones, <a href="#Page_365">365</a>;</li> + <li> heat of, <a href="#Page_79">79</a>;</li> + <li> of farmyard manure, <a href="#Page_253">253</a>;</li> + <li> of guano, <a href="#Page_299">299</a>;</li> + <li> temperature of, <a href="#Page_256">256</a>.</li> + </ul> +</li> + +<li> Fern, bracken, as litter, <a href="#Page_241">241</a>.</li> + +<li> Ferric chloride, test for sulphocyanates, <a href="#Page_355">355</a>.</li> + +<li> Fertilisers and Feeding Stuffs Act, <a href="#Page_543">543</a>.</li> + +<li> Fertilising ingredients, amount of soluble, in soil, <a href="#Page_90">90</a>; + <ul class="nest"> + <li> amounts removed by different crops, <a href="#Page_484">484</a>, <a href="#Page_485">485</a>;</li> + <li> chemical condition of, in soil, <a href="#Page_89">89</a>;</li> + <li> lodge in seed, <a href="#Page_491">491</a>;</li> + <li> in soil, <a href="#Page_87">87</a>.</li> + </ul> +</li> + +<li> Fertility, of the soil, <a href="#Page_65">65</a>-97; + <ul class="nest"> + <li> potential, of soil, <a href="#Page_214">214</a>, <a href="#Page_549">549</a>;</li> + <li> properties necessary for, <a href="#Page_66">66</a>;</li> + <li> supply of oxygen necessary for, <a href="#Page_81">81</a>.</li> + </ul> +</li> + +<li> Field experiments, <a href="#Page_545">545</a>, <a href="#Page_548">548</a>; + <ul class="nest"> + <li> educational value of, <a href="#Page_547">547</a>;</li> + <li> on rate of nitrification, <a href="#Page_187">187</a>.</li> + </ul> +</li> + +<li> Finger-and-toe prevented by lime, <a href="#Page_461">461</a>.</li> + +<li> Fire-fang in farmyard manure, <a href="#Page_264">264</a>.</li> + +<li> Fischer on absorption of plant-food, <a href="#Page_55">55</a>.</li> + +<li> Fish-guano, <a href="#Page_320">320</a>-323; + <ul class="nest"> + <li> application of, <a href="#Page_323">323</a>;</li> + <li> consumption of, <a href="#Page_152">152</a>;</li> + <li> manufacture of, <a href="#Page_321">321</a>;</li> + <li> nitrogen in, <a href="#Page_321">321</a>;</li> + <li> phosphoric acid in, <a href="#Page_321">321</a>;</li> + <li> production of, <a href="#Page_322">322</a>;</li> + <li> source of nitrogen, <a href="#Page_152">152</a>;</li> + <li> value of, <a href="#Page_322">322</a>.</li> + </ul> +</li> + +<li> Fixers, <a href="#Page_246">246</a>; + <ul class="nest"> + <li> chemical reactions with, <a href="#Page_284">284</a>.</li> + </ul> +</li> + +<li> Fleece, potash in, <a href="#Page_217">217</a>.</li> + +<li> Fleischer, Professor, on solubility of phosphates, <a href="#Page_408">408</a>.</li> + +<li> Flesh-guano, <a href="#Page_320">320</a>.</li> + +<li> Flint Island guano, <a href="#Page_309">309</a>.</li> + +<li> Flitcham experiments on growth of wheat, <a href="#Page_500">500</a>.<span class='pagenum'><a name="Page_579" id="Page_579">[Pg 579]</a></span></li> + +<li> Floated bones, <a href="#Page_362">362</a>, <a href="#Page_365">365</a>.</li> + +<li> Florida phosphate, <a href="#Page_378">378</a>.</li> + +<li> Fluorapatite, composition of, <a href="#Page_210">210</a>.</li> + +<li> Food, consumed by pigs, <a href="#Page_281">281</a>; + <ul class="nest"> + <li> dry matter of, voided in dung, <a href="#Page_228">228</a>;</li> + <li> percentage of, in excrements, <a href="#Page_281">281</a>.</li> + </ul> +</li> + +<li> Food-constituents, plant, necessary for nitrification, <a href="#Page_170">170</a>.</li> + +<li> Forbes, David, on nitrate-fields of Chili, <a href="#Page_334">334</a>.</li> + +<li> Forest-soils, absence of nitrification in, <a href="#Page_193">193</a>.</li> + +<li> Fowl-dung, <a href="#Page_320">320</a>, <a href="#Page_326">326</a>; + <ul class="nest"> + <li> analysis of, <a href="#Page_331">331</a>.</li> + </ul> +</li> + +<li> Fownes on phosphoric acid in rocks, <a href="#Page_202">202</a>.</li> + +<li> Frankland, P. F., experiments on nitrification, <a href="#Page_52">52</a>, <a href="#Page_167">167</a>, <a href="#Page_198">198</a>.</li> + +<li> Franklin, Benjamin, experiment of, with gypsum, <a href="#Page_462">462</a>.</li> + +<li> Frey Bentos, meat-meal guano from, <a href="#Page_324">324</a>.<br /><br /></li> + + +<li> Galapagos Islands, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Garden earth, absorptive power of, <a href="#Page_98">98</a>; + <ul class="nest"> + <li> ammonia in, <a href="#Page_128">128</a>.</li> + </ul> +</li> + +<li> Gas-liquor, ammonia in, <a href="#Page_353">353</a>.</li> + +<li> Gas-works, ammonia from, <a href="#Page_353">353</a>, <a href="#Page_358">358</a>.</li> + +<li> Gases, absorbed by soils, <a href="#Page_81">81</a>; + <ul class="nest"> + <li> present in soil, <a href="#Page_100">100</a>.</li> + </ul> +</li> + +<li> Gazzeri on retention by soil of plant-food, <a href="#Page_57">57</a>.</li> + +<li> Geese-dung, analysis of, <a href="#Page_331">331</a>.</li> + +<li> Geic acid in humus, <a href="#Page_47">47</a>.</li> + +<li> Gelatin, nitrification in, <a href="#Page_182">182</a>; + <ul class="nest"> + <li> from bones, <a href="#Page_364">364</a>.</li> + </ul> +</li> + +<li> Germany, agricultural research in, <a href="#Page_32">32</a>; + <ul class="nest"> + <li> bones imported from, <a href="#Page_360">360</a>;</li> + <li> manufacture of meat-meal guano in, <a href="#Page_324">324</a>.</li> + </ul> +</li> + +<li> Germination, influence of temperature on, <a href="#Page_76">76</a>; + <ul class="nest"> + <li> oxygen necessary for, <a href="#Page_81">81</a>.</li> + </ul> +</li> + +<li> Gilbert, Sir J. Henry, on barley-manuring, <a href="#Page_496">496</a>; + <ul class="nest"> + <li> on Liebig's mineral theory, <a href="#Page_28">28</a>;</li> + <li> on manuring of potatoes, <a href="#Page_520">520</a>;</li> + <li> Presidential address of, <a href="#Page_61">61</a>;</li> + <li> and see Lawes and Gilbert.</li> + </ul> +</li> + +<li> Glauber on artificial production of nitre, <a href="#Page_164">164</a>.</li> + +<li> Glue, <a href="#Page_364">364</a>.</li> + +<li> Glycin, assimilated by plants, <a href="#Page_47">47</a>.</li> + +<li> Glycocoll, experiments with, <a href="#Page_46">46</a>.</li> + +<li> Gneiss, <a href="#Page_106">106</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_207">207</a>.</li> + </ul> +</li> + +<li> Grandeau, Professor, on forms of plant-food in soil, <a href="#Page_107">107</a>; + <ul class="nest"> + <li> on loss of phosphoric acid, <a href="#Page_207">207</a>.</li> + </ul> +</li> + +<li> Granite, <a href="#Page_105">105</a>; + <ul class="nest"> + <li> in guano, <a href="#Page_303">303</a>;</li> + <li> phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>;</li> + <li> potash in, <a href="#Page_214">214</a>.</li> + </ul> +</li> + +<li> Grass, Bangor experiments on, <a href="#Page_508">508</a>; + <ul class="nest"> + <li> effect of manure on, <a href="#Page_505">505</a>;</li> + <li> influence of farmyard manure on, <a href="#Page_506">506</a>;</li> + <li> manuring of, <a href="#Page_504">504</a>-510.</li> + </ul> +</li> + +<li> Gray, Asa, on transpiration by plants, <a href="#Page_71">71</a>.</li> + +<li> Great Cayman guano, <a href="#Page_379">379</a>.</li> + +<li> Green manures, <a href="#Page_113">113</a>.</li> + +<li> Grouven on guano, <a href="#Page_313">313</a>.</li> + +<li> Guanape Island guano, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Guanine, <a href="#Page_304">304</a>; + <ul class="nest"> + <li> experiments with, <a href="#Page_46">46</a>.</li> + </ul> +</li> + +<li> Guano, <a href="#Page_293">293</a>-331; + <ul class="nest"> + <li> action of, as a manure, <a href="#Page_312">312</a>;</li> + <li> adulteration of, <a href="#Page_318">318</a>;</li> + <li> application of, <a href="#Page_315">315</a>;</li> + <li> bat, <a href="#Page_325">325</a>;</li> + <li> composition of, <a href="#Page_305">305</a>, <a href="#Page_329">329</a>;</li> + <li> crust, <a href="#Page_308">308</a>;</li> + <li> deposits of the world, <a href="#Page_327">327</a>;</li> + <li> dissolved, <a href="#Page_310">310</a>;</li> + <li> equalised, <a href="#Page_309">309</a>;</li> + <li> fermentation of, <a href="#Page_299">299</a>;</li> + <li> fertilising constituents in, <a href="#Page_314">314</a>;</li> + <li> fish, <a href="#Page_320">320</a>-323;</li> + <li> importance of, in agriculture, <a href="#Page_293">293</a>;</li> + <li> inequality in composition of, <a href="#Page_309">309</a>;</li> + <li> influence of, on farming, <a href="#Page_294">294</a>;</li> + <li> meat-meal, <a href="#Page_324">324</a>;</li> + <li> mode of application of, <a href="#Page_315">315</a>;</li> + <li> nitrification in, rate of, <a href="#Page_192">192</a>;</li> + <li> nitrogenous, <a href="#Page_300">300</a>-308;</li> + <li> origin of, <a href="#Page_297">297</a>;</li> + <li> Peruvian, <a href="#Page_300">300</a>-306;</li> + <li> phosphatic, <a href="#Page_308">308</a>;</li> + <li> quantity to apply, <a href="#Page_317">317</a>;</li> + <li> rectified, <a href="#Page_311">311</a>;</li> + <li> so-called, <a href="#Page_320">320</a>;</li> + <li> source of phosphoric acid, <a href="#Page_202">202</a>;</li> + <li> source of potash, <a href="#Page_219">219</a>;</li> + <li> value of, as a manure, <a href="#Page_296">296</a>;</li> + <li> variation in composition of, <a href="#Page_299">299</a>.</li> + </ul> +</li> + +<li> Gulf of Mexico, guano deposits at, <a href="#Page_328">328</a>.</li> + +<li> Gulls, guano from, <a href="#Page_297">297</a>.</li> + +<li> Gunning on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Gunpowder, exports of, <a href="#Page_149">149</a>; + <ul class="nest"> + <li> nitrogen lost in, <a href="#Page_149">149</a>;</li> + <li> production, annual, of, <a href="#Page_149">149</a>;</li> + <li> saltpetre in, <a href="#Page_149">149</a>, <a href="#Page_333">333</a>.</li> + </ul> +</li> + +<li> Gypsum, <a href="#Page_462">462</a>-464; + <ul class="nest"> + <li> absorptive power of, <a href="#Page_98">98</a>;</li> + <li> action of, mode of, <a href="#Page_462">462</a>—on nitrification, <a href="#Page_173">173</a>;</li> + <li> an adulterant of guano, <a href="#Page_319">319</a>;</li> + <li> as a fixer, <a href="#Page_246">246</a>, <a href="#Page_247">247</a>, <a href="#Page_285">285</a>;</li> + <li> decomposes double silicates, <a href="#Page_463">463</a>;<span class='pagenum'><a name="Page_580" id="Page_580">[Pg 580]</a></span></li> + <li> favourable to clover, <a href="#Page_464">464</a>;</li> + <li> as an oxidising agent, <a href="#Page_464">464</a>.</li> + </ul> +<br /> +</li> + +<li> Hales, Stephen, theory of, on plant-growth, <a href="#Page_8">8</a>.</li> + +<li> Hampe, Dr, on nitrogen in plants, <a href="#Page_46">46</a>.</li> + +<li> Harting on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Heat, of soils, <a href="#Page_76">76</a>-78; + <ul class="nest"> + <li> of fermentation, <a href="#Page_78">78</a>.</li> + </ul> +</li> + +<li> Heiden, Dr, on application of farmyard manure, <a href="#Page_265">265</a>; + <ul class="nest"> + <li> on fixation of bases and acids by soil, <a href="#Page_59">59</a>;</li> + <li> on loss of ammonia from dung, <a href="#Page_249">249</a>;</li> + <li> on percentage of food voided by animals, <a href="#Page_253">253</a>;</li> + <li> on straw as litter, <a href="#Page_244">244</a>, <a href="#Page_249">249</a>.</li> + </ul> +</li> + +<li> Hellriegel, on amount of water in soils, <a href="#Page_75">75</a>; + <ul class="nest"> + <li> on barley, <a href="#Page_498">498</a>;</li> + <li> on nitrogen in plants, <a href="#Page_44">44</a>.</li> + </ul> +</li> + +<li> Helmont, Van, theory of, on source of plant-food, <a href="#Page_4">4</a>.</li> + +<li> Henslow, Professor, on coprolites, <a href="#Page_374">374</a>.</li> + +<li> Heraüs on organisms in soil, <a href="#Page_95">95</a>.</li> + +<li> Herbage, effect of manure on, <a href="#Page_505">505</a>.</li> + +<li> Herrings as manure, <a href="#Page_321">321</a>.</li> + +<li> Hervé-Mangon, experiments on action of light on plants by, <a href="#Page_38">38</a>.</li> + +<li> Hilgenstock on tetracalcic phosphate, <a href="#Page_405">405</a>.</li> + +<li> Hippuric acid, experiments with, <a href="#Page_46">46</a>; + <ul class="nest"> + <li> in farmyard manure, <a href="#Page_257">257</a>.</li> + </ul> +</li> + +<li> Hire, De la, on evolution of gases by plants, <a href="#Page_11">11</a>.</li> + +<li> Hofmeister on horse excrements, <a href="#Page_243">243</a>.</li> + +<li> Hoof-guano, source of nitrogen, <a href="#Page_152">152</a>.</li> + +<li> Hoofs and horns, manure from, <a href="#Page_425">425</a>.</li> + +<li> Hops, manuring of, <a href="#Page_528">528</a>; + <ul class="nest"> + <li> potash removed by, <a href="#Page_217">217</a>;</li> + <li> slow-acting manures benefit, <a href="#Page_528">528</a>.</li> + </ul> +</li> + +<li> Horn, capable of nitrification, <a href="#Page_182">182</a>; + <ul class="nest"> + <li> as manure, <a href="#Page_425">425</a>;</li> + <li> nitrogen in, <a href="#Page_426">426</a>;</li> + <li> phosphoric acid in, <a href="#Page_426">426</a>.</li> + </ul> +</li> + +<li> Hornblende, <a href="#Page_105">105</a>.</li> + +<li> Horse-dung, alkalies in, <a href="#Page_226">226</a>; + <ul class="nest"> + <li> composition of, in dry state, <a href="#Page_227">227</a>;</li> + <li> hot, <a href="#Page_225">225</a>;</li> + <li> nitrogen in, <a href="#Page_225">225</a>, <a href="#Page_226">226</a>;</li> + <li> phosphoric acid in, <a href="#Page_226">226</a>;</li> + <li> water in, <a href="#Page_225">225</a>, <a href="#Page_226">226</a>.</li> + </ul> +</li> + +<li> Horse-manure, <a href="#Page_242">242</a>; + <ul class="nest"> + <li> amount produced per day, <a href="#Page_243">243</a>;</li> + <li> amount produced per year, <a href="#Page_243">243</a>;</li> + <li> analyses of, <a href="#Page_283">283</a>;</li> + <li> dry matter in, <a href="#Page_243">243</a>;</li> + <li> dry nature of, <a href="#Page_245">245</a>;</li> + <li> fermentation rapid in, <a href="#Page_245">245</a>;</li> + <li> mineral matter in, <a href="#Page_243">243</a>;</li> + <li> nitrogen in, <a href="#Page_243">243</a>, <a href="#Page_244">244</a>.</li> + </ul> +</li> + +<li> Horse-urine, alkalies in, <a href="#Page_230">230</a>; + <ul class="nest"> + <li> composition of, in dry state, <a href="#Page_231">231</a>;</li> + <li> fertilising ingredients in, <a href="#Page_232">232</a>;</li> + <li> nitrogen in, <a href="#Page_230">230</a>;</li> + <li> phosphoric acid in, <a href="#Page_230">230</a>;</li> + <li> water in, <a href="#Page_230">230</a>.</li> + </ul> +</li> + +<li> Hosäus on assimilation of ammonia, <a href="#Page_50">50</a>.</li> + +<li> Howland Island guano. <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Huanillos, guano from, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_330">330</a>;</li> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Huano, <a href="#Page_297">297</a>.</li> + +<li> Hueppe on organisms in soil, <a href="#Page_95">95</a>.</li> + +<li> Hughes, John, on bracken-fern as litter, <a href="#Page_241">241</a>; + <ul class="nest"> + <li> on composition of bracken, <a href="#Page_283">283</a>.</li> + </ul> +</li> + +<li> Humates in farmyard manure, <a href="#Page_259">259</a>.</li> + +<li> Humboldt, A., discovery of Peruvian guano by, <a href="#Page_300">300</a>.</li> + +<li> Humic acid in farmyard manure, <a href="#Page_258">258</a>; + <ul class="nest"> + <li> in humus, <a href="#Page_47">47</a>.</li> + </ul> +</li> + +<li> Humin in humus, <a href="#Page_47">47</a>.</li> + +<li> Humus, absorptive power of, <a href="#Page_68">68</a>, <a href="#Page_98">98</a>; + <ul class="nest"> + <li> evaporation from, <a href="#Page_99">99</a>;</li> + <li> nature of, in soil, <a href="#Page_47">47</a>;</li> + <li> soils improved by addition of, <a href="#Page_273">273</a>.</li> + </ul> +</li> + +<li> Huon Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Huxtable and Thompson on retention of plant-food by soil, <a href="#Page_57">57</a>.</li> + +<li> Hydrated silicates, <a href="#Page_107">107</a>, <a href="#Page_459">459</a>.</li> + +<li> Hydrochloric acid as a fixer, <a href="#Page_245">245</a>.</li> + +<li> Hydrogen, amount of, in plants, <a href="#Page_40">40</a>; + <ul class="nest"> + <li> source of, in plants, <a href="#Page_40">40</a>.</li> + </ul> +</li> + +<li> Hygroscopic power of soils, <a href="#Page_75">75</a>.<br /><br /></li> + + +<li> Ichaboe guano, <a href="#Page_307">307</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Independence Bay guano, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + + +<li> India, nitre soils of, <a href="#Page_162">162</a>.</li> + +<li> Indirect manures, <a href="#Page_113">113</a>, <a href="#Page_114">114</a>, <a href="#Page_449">449</a>-473.</li> + +<li> Ingenhousz, John, experiments by, on nitrogen in plants, <a href="#Page_41">41</a>; + <ul class="nest"> + <li> on oxygen evolved by plants, <a href="#Page_12">12</a>.</li> + </ul> +</li> + +<li> Insoluble phosphate, <a href="#Page_386">386</a>; + <ul class="nest"> + <li> value of, <a href="#Page_396">396</a>.</li> + </ul> +</li> + +<li> Iodine, in ash of plants, <a href="#Page_55">55</a>; + <ul class="nest"> + <li> in nitrate of soda, <a href="#Page_340">340</a>, <a href="#Page_342">342</a>.</li> + </ul> +</li> + +<li> Iquique, nitrate of soda from, <a href="#Page_333">333</a>.<span class='pagenum'><a name="Page_581" id="Page_581">[Pg 581]</a></span></li> + +<li> Iron in ash of plants, <a href="#Page_54">54</a>; + <ul class="nest"> + <li> necessary for plant-growth, <a href="#Page_55">55</a>;</li> + <li> reversion in superphosphates caused by, <a href="#Page_390">390</a>, <a href="#Page_399">399</a>.</li> + </ul> +</li> + +<li> Iron-works, ammonia from, <a href="#Page_353">353</a>, <a href="#Page_355">355</a>, <a href="#Page_358">358</a>.</li> + +<li> Irrigation, <a href="#Page_431">431</a>-433; + <ul class="nest"> + <li> intermittent, <a href="#Page_434">434</a>;</li> + <li> subsoil, <a href="#Page_432">432</a>.</li> + </ul> +<br /> +</li> + + +<li> Jamieson, Professor, experiments with coprolites, <a href="#Page_380">380</a>.</li> + +<li> Jarvis Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Jersey, manuring of potatoes in, <a href="#Page_521">521</a>.</li> + +<li> Johnson, Professor S. W., on application of superphosphate, <a href="#Page_395">395</a>; + <ul class="nest"> + <li> on Earl Dundonald, <a href="#Page_13">13</a>;</li> + <li> on nitrogen in buffalo-horn shavings, <a href="#Page_426">426</a>;</li> + <li> on nitrogen in soils, <a href="#Page_123">123</a>;</li> + <li> on solubility of basic slag, <a href="#Page_408">408</a>;</li> + <li> value of organic nitrogen to plant, <a href="#Page_46">46</a>.</li> + </ul> +</li> + +<li> Jürgensen on nitrogen in excreta, <a href="#Page_234">234</a>.<br /><br /></li> + + +<li> Kainit, as a fixer, <a href="#Page_247">247</a>; + <ul class="nest"> + <li> potash in, percentage of, <a href="#Page_214">214</a>, <a href="#Page_220">220</a>, <a href="#Page_421">421</a>;</li> + <li> rate of application of, <a href="#Page_423">423</a>.</li> + </ul> +</li> + +<li> Kaolin clay, analysis of, <a href="#Page_104">104</a>.</li> + +<li> Karmrodt, analysis of Chincha Island guano, <a href="#Page_305">305</a>; + <ul class="nest"> + <li> of concretionary nodules, <a href="#Page_328">328</a>.</li> + </ul> +</li> + +<li> Karnallite, potash in, <a href="#Page_220">220</a>.</li> + +<li> Kellner, experiments on nitrification by, <a href="#Page_52">52</a>.</li> + +<li> Kelp, potash in, <a href="#Page_420">420</a>.</li> + +<li> Kieserite, <a href="#Page_420">420</a>.</li> + +<li> Kinnaird, Lord, experiments by, with farmyard manure, <a href="#Page_289">289</a>.</li> + +<li> Kitchen-garden soil, nitrogenous matter in, <a href="#Page_122">122</a>.</li> + +<li> Knop on condition of nitrates in soil, <a href="#Page_138">138</a>.</li> + +<li> Koosaw River, phosphates from, <a href="#Page_376">376</a>.</li> + +<li> Kreatin assimilated by plants, <a href="#Page_47">47</a>.</li> + +<li> Kuria Muria guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>.<br /><br /></li> + + +<li> Labrador, guano deposits at, <a href="#Page_328">328</a>.</li> + +<li> Labradorite, <a href="#Page_214">214</a>; + <ul class="nest"> + <li> potash in, <a href="#Page_220">220</a>.</li> + </ul> +</li> + +<li> Lacepede Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Lahn phosphate, <a href="#Page_379">379</a>.</li> + +<li> Lava, phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + +<li> Lawes, Sir J. B., and Gilbert, early researches of, at Rothamsted, <a href="#Page_34">34</a>; + <ul class="nest"> + <li> experiments with farmyard manure, <a href="#Page_271">271</a>;</li> + <li> experiments with Peruvian guano, <a href="#Page_301">301</a>;</li> + <li> inauguration of Rothamsted experiments by, <a href="#Page_33">33</a>;</li> + <li> on composition of farmyard manure, <a href="#Page_291">291</a>;</li> + <li> on manuring of wheat, <a href="#Page_483">483</a>;</li> + <li> on motion of plant's sap, <a href="#Page_56">56</a>;</li> + <li> on percentage of food in excreta, <a href="#Page_233">233</a>;</li> + <li> on rate of nitrification, <a href="#Page_186">186</a>;</li> + <li> on sources of plant-nitrogen, <a href="#Page_43">43</a>;</li> + <li> on sulphate of ammonia, <a href="#Page_356">356</a>;</li> + <li> on unexhausted manures, <a href="#Page_550">550</a>, <a href="#Page_557">557</a>-559.</li> + </ul> +</li> + +<li> Lawes, Sir J. B., experiments with guano by, <a href="#Page_301">301</a>; + <ul class="nest"> + <li> manufacture of superphosphate by, <a href="#Page_382">382</a>;</li> + <li> on application of superphosphate, <a href="#Page_395">395</a>;</li> + <li> on bones, <a href="#Page_359">359</a>;</li> + <li> on composition of farmyard manure, <a href="#Page_291">291</a>;</li> + <li> on farmyard manure, <a href="#Page_477">477</a>;</li> + <li> on loss of nitrates, <a href="#Page_142">142</a>;</li> + <li> on sources of nitrogen, <a href="#Page_154">154</a>.</li> + </ul> +</li> + +<li> Leather, as manure, <a href="#Page_428">428</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_428">428</a>.</li> + </ul> +</li> + +<li> Leaves, dried, as litter, <a href="#Page_242">242</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_242">242</a>;</li> + <li> phosphoric acid in, <a href="#Page_242">242</a>;</li> + <li> potash in, <a href="#Page_242">242</a>.</li> + </ul> +</li> + +<li> Legrange, Charles, on extent of nitrate-fields, <a href="#Page_343">343</a>.</li> + +<li> Leguminous plants, benefited by basic slag, <a href="#Page_414">414</a> + <ul class="nest"> + <li> —by potash, <a href="#Page_523">523</a>;</li> + <li> fixation of free nitrogen by, <a href="#Page_42">42</a>;</li> + <li> gain of nitrogen with, <a href="#Page_135">135</a>;</li> + <li> manuring of, <a href="#Page_522">522</a>-527, <a href="#Page_530">530</a>;</li> + <li> nitrogenous manures hurtful to, <a href="#Page_523">523</a>.</li> + </ul> +</li> + +<li> Lehmann on ammonia as plant-food, <a href="#Page_50">50</a>, <a href="#Page_352">352</a>.</li> + +<li> Leipzig, bones from, <a href="#Page_361">361</a>.</li> + +<li> Leones, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Leucite, potash in, <a href="#Page_220">220</a>.</li> + +<li> Lias chalk, phosphoric acid in, <a href="#Page_211">211</a>.</li> + +<li> Liebig, criticism of humus theory by, <a href="#Page_25">25</a>; + <ul class="nest"> + <li> dissolved bones discovered by, <a href="#Page_361">361</a>;</li> + <li> first report to British Association, <a href="#Page_24">24</a>;</li> + <li> manufacture of superphosphate from bones by, <a href="#Page_359">359</a>;</li> + <li> mineral theory of, <a href="#Page_26">26</a>-29;</li> + <li> on ammonia as a manure, <a href="#Page_352">352</a>;</li> + <li> on importation of bones by Britain, <a href="#Page_360">360</a>;</li> + <li> researches of, in agricultural chemistry, <a href="#Page_23">23</a>-32;</li> + <li> services of, to agricultural chemistry, <a href="#Page_31">31</a>;</li> + <li> theory of manures by, <a href="#Page_29">29</a>;</li> + <li> theory of, on rotation of crops, <a href="#Page_29">29</a>.</li> + </ul> +</li> + +<li> Light, action of, on plant-growth, <a href="#Page_38">38</a>.</li> + +<li> Lime, <a href="#Page_449">449</a>-461;<span class='pagenum'><a name="Page_582" id="Page_582">[Pg 582]</a></span> + <ul class="nest"> + <li> abundant occurrence of, <a href="#Page_452">452</a>;</li> + <li> action of, <a href="#Page_461">461</a></li> + <li> —contradictory, <a href="#Page_450">450</a></li> + <li> —not thoroughly understood, <a href="#Page_449">449</a></li> + <li> —on nitrogenous organic matter, <a href="#Page_460">460</a></li> + <li> —on soil's texture, <a href="#Page_455">455</a>;</li> + <li> antiquity of, as a manure, <a href="#Page_449">449</a>;</li> + <li> binding effect of, <a href="#Page_457">457</a>;</li> + <li> biological action of, <a href="#Page_459">459</a>;</li> + <li> caustic, <a href="#Page_453">453</a>;</li> + <li> chemical action of, <a href="#Page_457">457</a>;</li> + <li> decomposes minerals, <a href="#Page_458">458</a>;</li> + <li> different forms of, <a href="#Page_453">453</a>;</li> + <li> effect of, on soils, <a href="#Page_112">112</a>;</li> + <li> fixed by soils, <a href="#Page_58">58</a>;</li> + <li> in ash of plants, <a href="#Page_54">54</a>;</li> + <li> mechanical functions of, <a href="#Page_455">455</a>;</li> + <li> mild, <a href="#Page_453">453</a>;</li> + <li> necessary for nitrification, <a href="#Page_171">171</a>, <a href="#Page_459">459</a></li> + <li> —for plant-growth, <a href="#Page_55">55</a>, <a href="#Page_450">450</a>;</li> + <li> neutralises acidity in soils, <a href="#Page_458">458</a>;</li> + <li> phosphates of, <a href="#Page_385">385</a>-388;</li> + <li> pig excrements contain, <a href="#Page_281">281</a>;</li> + <li> prevents clay puddling, <a href="#Page_456">456</a>;</li> + <li> returned to soil, <a href="#Page_452">452</a>;</li> + <li> soils contain, <a href="#Page_450">450</a>-452.</li> + </ul> +</li> + +<li> Limestone, analyses of, <a href="#Page_106">106</a>; + <ul class="nest"> + <li> evaporation of water from, <a href="#Page_99">99</a>;</li> + <li> occurrence of, <a href="#Page_452">452</a>.</li> + </ul> +</li> + +<li> Linseed, imports of, <a href="#Page_153">153</a>; + <ul class="nest"> + <li> manurial constituents of, <a href="#Page_282">282</a>.</li> + </ul> +</li> + +<li> Linseed-cake, manurial constituents of, <a href="#Page_282">282</a>.</li> + +<li> Liquid manure, <a href="#Page_442">442</a>-444.</li> + +<li> Lithia in ash of plants, <a href="#Page_55">55</a>.</li> + +<li> Litter, loam as, <a href="#Page_239">239</a>; + <ul class="nest"> + <li> peat as, <a href="#Page_240">240</a>;</li> + <li> straw as, <a href="#Page_236">236</a>;</li> + <li> uses of, <a href="#Page_236">236</a>.</li> + </ul> +</li> + +<li> Lloyd on fattening animals, <a href="#Page_253">253</a>.</li> + +<li> Loam, as litter, <a href="#Page_239">239</a>; + <ul class="nest"> + <li> evaporation of water from, <a href="#Page_99">99</a>;</li> + <li> poor in fertilising matter, <a href="#Page_239">239</a>.</li> + </ul> +</li> + +<li> Lobos, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Lobos de Afuera guano, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>.<br /><br /></li> + + +<li> Macabi Island guano, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> Maercker, Professor, on destruction of nitrifying organisms, <a href="#Page_177">177</a>.</li> + +<li> Magnesia, fixed by soils, <a href="#Page_58">58</a>; + <ul class="nest"> + <li> in ash of plants, <a href="#Page_54">54</a>;</li> + <li> in pig excrements, <a href="#Page_281">281</a>;</li> + <li> necessary for nitrification, <a href="#Page_171">171</a>;</li> + <li> necessary for plant-growth, <a href="#Page_55">55</a>;</li> + <li> sulphate of, as a fixer, <a href="#Page_246">246</a>, <a href="#Page_285">285</a>.</li> + </ul> +</li> + +<li> Maize, absorbs ammonia, <a href="#Page_352">352</a>; + <ul class="nest"> + <li> fertilising ingredients removed from soil by, <a href="#Page_485">485</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> source of nitrogen, <a href="#Page_153">153</a>.</li> + </ul> +</li> + +<li> Malden Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Malpighi on importance of atmospheric air for germination, <a href="#Page_39">39</a>.</li> + +<li> Malt-dust, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Manganese, oxide of, in ash of plants, <a href="#Page_54">54</a>.</li> + +<li> Mangels, fertilising ingredients removed from soil by, <a href="#Page_485">485</a>; + <ul class="nest"> + <li> guano a manure for, <a href="#Page_318">318</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_346">346</a>, <a href="#Page_511">511</a>, <a href="#Page_513">513</a>, <a href="#Page_514">514</a>;</li> + <li> Rothamsted experiments on growth of, <a href="#Page_568">568</a>.</li> + </ul> +</li> + +<li> Manitoba soils, nitrogen in, at various depths, <a href="#Page_156">156</a>; + <ul class="nest"> + <li> rate of nitrification in, <a href="#Page_186">186</a>.</li> + </ul> +</li> + +<li> Manure, cow, <a href="#Page_247">247</a>; + <ul class="nest"> + <li> farmyard, <a href="#Page_223">223</a>-292;</li> + <li> horse, <a href="#Page_243">243</a>;</li> + <li> liquid, <a href="#Page_442">442</a>-444;</li> + <li> meaning of word, <a href="#Page_109">109</a>;</li> + <li> pig, <a href="#Page_250">250</a>;</li> + <li> sewage, <a href="#Page_430">430</a>-441;</li> + <li> sheep, <a href="#Page_251">251</a>;</li> + <li> stable, from peat-moss, <a href="#Page_283">283</a></li> + <li> —wheat-straw, <a href="#Page_283">283</a>.</li> + </ul> +</li> + +<li> Manures, action of, <a href="#Page_61">61</a>; + <ul class="nest"> + <li> analysis of, interpretation of, <a href="#Page_539">539</a>-544;</li> + <li> application of, <a href="#Page_474">474</a>-492;</li> + <li> method of, <a href="#Page_531">531</a>-538; cash prices of, <a href="#Page_555">555</a>;</li> + <li> equal distribution of, <a href="#Page_531">531</a>;</li> + <li> functions of, <a href="#Page_109">109</a>, increase soil-fertility, <a href="#Page_474">474</a>;</li> + <li> intrinsic value of, <a href="#Page_545">545</a>;</li> + <li> lasting effects of, <a href="#Page_483">483</a>;</li> + <li> methods of valuing, <a href="#Page_544">544</a>;</li> + <li> minor artificial, <a href="#Page_424">424</a>-429;</li> + <li> mixing of, <a href="#Page_531">531</a>-538;</li> + <li> nitrogenous, <a href="#Page_293">293</a>-359;</li> + <li> phosphatic, <a href="#Page_359">359</a>-417;</li> + <li> potassic, <a href="#Page_418">418</a>-423;</li> + <li> quantities of, applied to oats, <a href="#Page_504">504</a>;</li> + <li> unexhausted, <a href="#Page_549">549</a>-552, <a href="#Page_558">558</a>;</li> + <li> units for determining commercial value of, <a href="#Page_554">554</a>;</li> + <li> valuation of, <a href="#Page_539">539</a>-559;</li> + <li> value of, deduced from experiments, <a href="#Page_548">548</a>;</li> + <li> various classes of, <a href="#Page_111">111</a>-114.</li> + </ul> +</li> + +<li> Manurial constituents of various foods, <a href="#Page_282">282</a>.</li> + +<li> Manurial ingredients, unit value of, <a href="#Page_544">544</a>.</li> + +<li> Manuring of, barley, <a href="#Page_495">495</a>-498; + <ul class="nest"> + <li> beans, <a href="#Page_525">525</a>-527, <a href="#Page_530">530</a>;</li> + <li> cabbages, <a href="#Page_528">528</a>;</li> + <li> cereals, <a href="#Page_493">493</a>-504;</li> + <li> clover, <a href="#Page_524">524</a>;</li> + <li> common farm crops, <a href="#Page_493">493</a>-530;</li> + <li> grass, <a href="#Page_504">504</a>-510;</li> + <li> hops, <a href="#Page_528">528</a>;</li> + <li> leguminous crops, <a href="#Page_522">522</a>-528;</li> + <li> mangels, <a href="#Page_511">511</a>, <a href="#Page_513">513</a>, <a href="#Page_514">514</a>;</li> + <li> oats, <a href="#Page_493">493</a>-504;</li> + <li> peas, <a href="#Page_527">527</a>;</li> + <li> potatoes, <a href="#Page_517">517</a>-522;</li> + <li> roots, <a href="#Page_510">510</a>-517;</li> + <li> turnips, <a href="#Page_510">510</a>, <a href="#Page_511">511</a>, <a href="#Page_513">513</a>-517;</li> + <li> wheat, <a href="#Page_499">499</a>-501.</li> + </ul> +</li> + +<li> Maracaïbo guano, nitrogen in, <a href="#Page_330">330</a>;<span class='pagenum'><a name="Page_583" id="Page_583">[Pg 583]</a></span> + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Marl, phosphoric acid in, <a href="#Page_211">211</a>.</li> + +<li> Marsh-gas from farmyard manure, <a href="#Page_258">258</a>.</li> + +<li> Meadow-hay, fertilising ingredients removed from soil by, <a href="#Page_485">485</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> Rothamsted experiments on manuring of, <a href="#Page_570">570</a>.</li> + </ul> +</li> + +<li> Meadow-land, benefited by basic slag, <a href="#Page_414">414</a>, <a href="#Page_508">508</a>; + <ul class="nest"> + <li> manuring of, <a href="#Page_508">508</a>;</li> + <li> Norfolk experiments on, <a href="#Page_509">509</a>.</li> + </ul> +</li> + +<li> Meat-meal guano, <a href="#Page_320">320</a>, <a href="#Page_324">324</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_152">152</a>;</li> + <li> imports of, <a href="#Page_324">324</a>;</li> + <li> manufacture of, <a href="#Page_324">324</a>;</li> + <li> nitrogen in, <a href="#Page_324">324</a>;</li> + <li> phosphoric acid in, <a href="#Page_324">324</a>;</li> + <li> rate of nitrification in, <a href="#Page_192">192</a>;</li> + <li> source of nitrogen, <a href="#Page_152">152</a>;</li> + <li> value of, <a href="#Page_324">324</a>.</li> + </ul> +</li> + +<li> Mechi on liquid manure, <a href="#Page_442">442</a>.</li> + +<li> Mejillones guano, <a href="#Page_309">309</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Mène, on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Menhaddo, guano manufactured from, <a href="#Page_322">322</a>.</li> + +<li> Mexico phosphate, <a href="#Page_308">308</a>, <a href="#Page_328">328</a>.</li> + +<li> Mica, analysis of, <a href="#Page_105">105</a>; + <ul class="nest"> + <li> potash in, <a href="#Page_214">214</a>, <a href="#Page_220">220</a>.</li> + </ul> +</li> + +<li> Micro-organisms, convert ammonia into nitrous acid, <a href="#Page_167">167</a>; + <ul class="nest"> + <li> convert nitrous acid into nitric acid, <a href="#Page_168">168</a>;</li> + <li> effect fermentation, <a href="#Page_80">80</a>;</li> + <li> effect fixation of free nitrogen, <a href="#Page_44">44</a>;</li> + <li> effect nitrification, <a href="#Page_161">161</a>;</li> + <li> oxidising power of, <a href="#Page_197">197</a>.</li> + </ul> +</li> + +<li> Mild lime, <a href="#Page_453">453</a>.</li> + +<li> Milk, nitrification in albuminoids of, <a href="#Page_182">182</a>; + <ul class="nest"> + <li> nitrogen removed in, <a href="#Page_147">147</a>;</li> + <li> phosphoric acid removed in, <a href="#Page_207">207</a>;</li> + <li> potash removed in, <a href="#Page_218">218</a>.</li> + </ul> +</li> + +<li> Mineral phosphates, <a href="#Page_373">373</a>-381; + <ul class="nest"> + <li> value of, as a manure, <a href="#Page_380">380</a>.</li> + </ul> +</li> + +<li> Mineral salts necessary for nitrification, <a href="#Page_52">52</a>.</li> + +<li> Minor artificial manures, <a href="#Page_424">424</a>-429.</li> + +<li> Mixing manures, <a href="#Page_532">532</a>-538; + <ul class="nest"> + <li> ammonia lost in, <a href="#Page_533">533</a>;</li> + <li> nitric acid lost in, <a href="#Page_536">536</a>;</li> + <li> phosphates reverted in, <a href="#Page_536">536</a>.</li> + </ul> +</li> + +<li> Moisture, atmospheric, action on guano, <a href="#Page_300">300</a>; + <ul class="nest"> + <li> in farmyard manure, <a href="#Page_260">260</a>;</li> + <li> in manures, <a href="#Page_543">543</a>;</li> + <li> necessary for nitrification, <a href="#Page_52">52</a>, <a href="#Page_176">176</a>.</li> + </ul> +</li> + +<li> Molds, <a href="#Page_94">94</a>.</li> + +<li> Mona guano, <a href="#Page_309">309</a>.</li> + +<li> Mond, Ludwig, on nitrogen in coal, <a href="#Page_354">354</a>.</li> + +<li> Monks guano, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Monocalcic phosphate, <a href="#Page_386">386</a>; + <ul class="nest"> + <li> formula of, <a href="#Page_398">398</a>;</li> + <li> molecular composition of, <a href="#Page_398">398</a>;</li> + <li> percentage composition of, <a href="#Page_398">398</a>;</li> + <li> reversion of, with iron and alumina compounds, <a href="#Page_399">399</a></li> + <li> —with tricalcic phosphate, <a href="#Page_399">399</a>.</li> + </ul> +</li> + +<li> Mulder on humus in soil, <a href="#Page_47">47</a>, <a href="#Page_126">126</a>.</li> + +<li> Müller, A., on nitrogen in soil, <a href="#Page_121">121</a>, <a href="#Page_124">124</a>.</li> + +<li> Munro, Dr J. M. H., on nitrification, <a href="#Page_52">52</a>; + <ul class="nest"> + <li> on sewage-sludge as manure, <a href="#Page_439">439</a>;</li> + <li> on urine voided, <a href="#Page_292">292</a>.</li> + </ul> +</li> + +<li> Müntz, on ammonia in air, <a href="#Page_118">118</a>; + <ul class="nest"> + <li> on nitrifying organisms in soil, <a href="#Page_180">180</a>;</li> + <li> on oxidising power of micro-organisms, <a href="#Page_197">197</a>.</li> + </ul> +</li> + +<li> Muriate of potash, application of, <a href="#Page_423">423</a>; + <ul class="nest"> + <li> forms calcium chloride, <a href="#Page_422">422</a>;</li> + <li> harmful effects of, <a href="#Page_421">421</a>;</li> + <li> more concentrated than sulphate, <a href="#Page_422">422</a>.</li> + </ul> +</li> + +<li> Mustard, <a href="#Page_139">139</a>.<br /><br /></li> + + +<li> Navassa phosphate, <a href="#Page_308">308</a>, <a href="#Page_328">328</a>, <a href="#Page_379">379</a>.</li> + +<li> Nesbit on composition of guano, <a href="#Page_301">301</a>.</li> + +<li> New Granada, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> New Zealand, meat-meal guano from, <a href="#Page_324">324</a>.</li> + +<li> Nile, nitrates in waters of, <a href="#Page_159">159</a>.</li> + +<li> "Nitraries," <a href="#Page_163">163</a>.</li> + +<li> Nitrate-fields, appearance of, <a href="#Page_340">340</a>; + <ul class="nest"> + <li> origin of, <a href="#Page_334">334</a>.</li> + </ul> +</li> + +<li> Nitrate of soda, <a href="#Page_332">332</a>-351; + <ul class="nest"> + <li> amount exported from Chili, <a href="#Page_151">151</a>, <a href="#Page_332">332</a>, <a href="#Page_351">351</a>;</li> + <li> amount imported into Britain, <a href="#Page_151">151</a>, <a href="#Page_351">351</a>;</li> + <li> appearance of fields of, <a href="#Page_340">340</a>;</li> + <li> application of, <a href="#Page_347">347</a>;</li> + <li> Chili and Peru chief source of, <a href="#Page_161">161</a>;</li> + <li> composition of, <a href="#Page_343">343</a>;</li> + <li> crops suited by, <a href="#Page_346">346</a>;</li> + <li> discovery of deposits of, <a href="#Page_333">333</a>;</li> + <li> extent of deposits of, <a href="#Page_342">342</a>;</li> + <li> encourages deep roots, <a href="#Page_344">344</a>;</li> + <li> formation of fields of, <a href="#Page_334">334</a>-340;</li> + <li> method of applying, <a href="#Page_347">347</a>;</li> + <li> method of mining, <a href="#Page_341">341</a>;</li> + <li> nitric acid in, source of, <a href="#Page_337">337</a>;</li> + <li> nitrogen in, percentage of, <a href="#Page_343">343</a>;</li> + <li> not an exhausting manure, <a href="#Page_345">345</a>;</li> + <li> origin of fields of, <a href="#Page_334">334</a>;</li> + <li> properties of, <a href="#Page_343">343</a>;</li> + <li> quantity to apply, <a href="#Page_348">348</a>;</li> + <li> shipments of, <a href="#Page_351">351</a>;</li> + <li> soils benefited by, <a href="#Page_348">348</a>;</li> + <li> source of nitrogen, <a href="#Page_150">150</a>;</li> + <li> top-dressing with, <a href="#Page_344">344</a>.<span class='pagenum'><a name="Page_584" id="Page_584">[Pg 584]</a></span></li> + </ul> +</li> + +<li> Nitrates, amount lost by drainage, <a href="#Page_140">140</a>; + <ul class="nest"> + <li> amount produced at different times, <a href="#Page_189">189</a>;</li> + <li> amount in soil, <a href="#Page_129">129</a>;</li> + <li> conditions diminishing loss of, <a href="#Page_139">139</a>;</li> + <li> constantly formed in soil, <a href="#Page_138">138</a>;</li> + <li> in barley-soils, <a href="#Page_158">158</a>;</li> + <li> in cropped soils, <a href="#Page_130">130</a>, <a href="#Page_157">157</a>;</li> + <li> in drainage-waters, <a href="#Page_160">160</a>, <a href="#Page_188">188</a>;</li> + <li> in fallow-soils, <a href="#Page_129">129</a>;</li> + <li> in manured wheat-soils, <a href="#Page_131">131</a>, <a href="#Page_157">157</a>;</li> + <li> in soil, <a href="#Page_129">129</a>, <a href="#Page_162">162</a>;</li> + <li> lost by drainage, <a href="#Page_137">137</a>;</li> + <li> most formed in summer, <a href="#Page_139">139</a>;</li> + <li> nitrogen as, in Rothamsted soils, <a href="#Page_198">198</a>;</li> + <li> position of, in soil, <a href="#Page_188">188</a>;</li> + <li> quantity formed in fallow-fields, <a href="#Page_188">188</a>.</li> + </ul> +</li> + +<li> Nitre, beds, <a href="#Page_163">163</a>; + <ul class="nest"> + <li> occurrence of, <a href="#Page_162">162</a>;</li> + <li> soils of India, <a href="#Page_162">162</a>.</li> + </ul> +</li> + +<li> Nitric acid, amount of, supplied to soil by rain, <a href="#Page_155">155</a>; + <ul class="nest"> + <li> derived from sea weed, <a href="#Page_337">337</a>;</li> + <li> formed from ammonia, <a href="#Page_118">118</a>;</li> + <li> formed from nitrous acid, <a href="#Page_168">168</a>;</li> + <li> in farmyard manure, <a href="#Page_259">259</a>;</li> + <li> in soil, <a href="#Page_128">128</a>;</li> + <li> lost in mixing manures, <a href="#Page_536">536</a>;</li> + <li> most important nitrogen compound for plants, <a href="#Page_161">161</a>;</li> + <li> relation of, to plants, <a href="#Page_50">50</a>;</li> + <li> source of, in nitrate of soda, <a href="#Page_337">337</a>.</li> + </ul> +</li> + +<li> Nitrification, <a href="#Page_51">51</a>, <a href="#Page_52">52</a>, <a href="#Page_161">161</a>-198; + <ul class="nest"> + <li> action of gypsum on, <a href="#Page_173">173</a>;</li> + <li> alkalinity necessary for, <a href="#Page_172">172</a>;</li> + <li> in asparagin, <a href="#Page_182">182</a>;</li> + <li> bearing of, on agriculture, <a href="#Page_193">193</a>;</li> + <li> in bones, <a href="#Page_182">182</a>;</li> + <li> cause of, <a href="#Page_165">165</a>;</li> + <li> conditions favourable for, <a href="#Page_170">170</a>;</li> + <li> denitrification, <a href="#Page_177">177</a>-179;</li> + <li> effected by micro-organisms, <a href="#Page_51">51</a>, <a href="#Page_167">167</a>;</li> + <li> in ethylamine, <a href="#Page_182">182</a>;</li> + <li> in fallow-fields, <a href="#Page_184">184</a>;</li> + <li> food-constituents necessary for, <a href="#Page_170">170</a>;</li> + <li> field experiments on rate of, <a href="#Page_187">187</a>;</li> + <li> in gelatin, <a href="#Page_182">182</a>;</li> + <li> in horn, <a href="#Page_182">182</a>;</li> + <li> laboratory experiments on rate of, <a href="#Page_185">185</a>;</li> + <li> in manures, <a href="#Page_190">190</a>, <a href="#Page_192">192</a>;</li> + <li> in milk albuminoids, <a href="#Page_182">182</a>;</li> + <li> mineral salts necessary for, <a href="#Page_52">52</a>;</li> + <li> moisture necessary for, <a href="#Page_52">52</a>, <a href="#Page_176">176</a>;</li> + <li> old theories on, <a href="#Page_196">196</a>;</li> + <li> organic matter not necessary for, <a href="#Page_169">169</a>, <a href="#Page_196">196</a>;</li> + <li> oxygen necessary for, <a href="#Page_52">52</a>, <a href="#Page_173">173</a>;</li> + <li> plant-roots promote, <a href="#Page_181">181</a>;</li> + <li> in rape-cake, <a href="#Page_182">182</a>;</li> + <li> rate of, <a href="#Page_183">183</a>;</li> + <li> rotation of crops, bearing of, on, <a href="#Page_195">195</a>;</li> + <li> soil best suited for, <a href="#Page_192">192</a>;</li> + <li> in subsoils, conditions favourable for, <a href="#Page_181">181</a>;</li> + <li> substances capable of, <a href="#Page_181">181</a>;</li> + <li> in summer, <a href="#Page_183">183</a>;</li> + <li> sunlight, effect of, on, <a href="#Page_176">176</a>;</li> + <li> temperature necessary for, <a href="#Page_52">52</a>, <a href="#Page_175">175</a>;</li> + <li> in thiocyanates, <a href="#Page_182">182</a>;</li> + <li> in urea, <a href="#Page_182">182</a>;</li> + <li> in wool, <a href="#Page_182">182</a>.</li> + </ul> +</li> + +<li> Nitrifying organisms, depth found at in soil, <a href="#Page_180">180</a>; + <ul class="nest"> + <li> distribution of, in soil, <a href="#Page_179">179</a>;</li> + <li> effect of poisons on, <a href="#Page_176">176</a>;</li> + <li> organic matter not required by, <a href="#Page_169">169</a>.</li> + </ul> +</li> + +<li> <i>Nitrobaeter</i>, <a href="#Page_167">167</a>.</li> + +<li> Nitrogen, <a href="#Page_115">115</a>-160; + <ul class="nest"> + <li> absorbed by soil, <a href="#Page_81">81</a>, <a href="#Page_131">131</a>;</li> + <li> accumulates in pastures, <a href="#Page_134">134</a>;</li> + <li> in air, <a href="#Page_116">116</a>;</li> + <li> as ammonia in soils, <a href="#Page_127">127</a>;</li> + <li> amount of, in plants, <a href="#Page_40">40</a>;</li> + <li> amount of, in soil, <a href="#Page_123">123</a>;</li> + <li> artificial supply of, <a href="#Page_150">150</a>;</li> + <li> in bat guano, <a href="#Page_325">325</a>;</li> + <li> in bones, <a href="#Page_363">363</a>, <a href="#Page_364">364</a>;</li> + <li> combined, in air, <a href="#Page_118">118</a>;</li> + <li> combined, in rain, <a href="#Page_119">119</a>, <a href="#Page_155">155</a>;</li> + <li> condition of, in manures, <a href="#Page_540">540</a>;</li> + <li> converted into nitrates in soil, <a href="#Page_51">51</a>;</li> + <li> in cow-dung, <a href="#Page_226">226</a>-228;</li> + <li> in cow excrements, <a href="#Page_278">278</a>;</li> + <li> in cow-urine, <a href="#Page_230">230</a>;</li> + <li> difference between surface and subsoil, <a href="#Page_126">126</a>;</li> + <li> different forms of, <a href="#Page_45">45</a>, <a href="#Page_116">116</a>;</li> + <li> dissolved in rain, <a href="#Page_131">131</a>;</li> + <li> in dried blood, <a href="#Page_424">424</a>;</li> + <li> in farmyard manure, <a href="#Page_260">260</a>;</li> + <li> in fish-guano, <a href="#Page_321">321</a>;</li> + <li> fixation of free, <a href="#Page_136">136</a>;</li> + <li> forms of, in plants, <a href="#Page_491">491</a>;</li> + <li> free, relation of, to plant, <a href="#Page_117">117</a>;</li> + <li> gain of, with leguminous crops, <a href="#Page_135">135</a>;</li> + <li> in guanos, <a href="#Page_329">329</a>;</li> + <li> in hoofs and horns, <a href="#Page_426">426</a>;</li> + <li> in horse-dung, <a href="#Page_226">226</a>-228;</li> + <li> in horse-manure, <a href="#Page_243">243</a>;</li> + <li> in horse-urine, <a href="#Page_230">230</a>;</li> + <li> importance of, in soil, <a href="#Page_88">88</a>;</li> + <li> in lean flesh, <a href="#Page_424">424</a>;</li> + <li> in leather, <a href="#Page_428">428</a>;</li> + <li> least abundant of manurial ingredients in soil, <a href="#Page_271">271</a>;</li> + <li> loss of, artificial sources of, <a href="#Page_144">144</a>;</li> + <li> loss of, by crops, <a href="#Page_144">144</a>;</li> + <li> loss of, on farm, <a href="#Page_146">146</a>;</li> + <li> loss of, sources of, <a href="#Page_137">137</a>-150;</li> + <li> loss of, total amount of, <a href="#Page_142">142</a>;</li> + <li> lost in the arts, <a href="#Page_148">148</a>;</li> + <li> lost in free condition, <a href="#Page_141">141</a>;</li> + <li> lost in treating farmyard manure, <a href="#Page_146">146</a>;</li> + <li> lost in milk, <a href="#Page_147">147</a>;</li> + <li> lost by retrogression, <a href="#Page_142">142</a>;</li> + <li> in Manitoba soils, <a href="#Page_156">156</a>;</li> + <li> in meat-guano, <a href="#Page_324">324</a>;</li> + <li> nature of, in soil, <a href="#Page_124">124</a>;</li> + <li> as nitrates in soil, <a href="#Page_128">128</a>;</li> + <li> as nitrates in cropped soils, <a href="#Page_130">130</a>, <a href="#Page_157">157</a>;</li> + <li> as nitrates in Rothamsted soils, <a href="#Page_198">198</a>;</li> + <li> as nitrates in wheat-soils, <a href="#Page_157">157</a>;</li> + <li> in nitrate of soda, <a href="#Page_343">343</a>;</li> + <li> nitric, in soil, <a href="#Page_128">128</a>;</li> + <li> organic, absorbed by plants, <a href="#Page_47">47</a>;</li> + <li> organic, in soil, <a href="#Page_125">125</a>;</li> + <li> original source of, in soil, <a href="#Page_133">133</a>;</li> + <li> in oxen excrements, <a href="#Page_280">280</a>;<span class='pagenum'><a name="Page_585" id="Page_585">[Pg 585]</a></span></li> + <li> in pasture-lands, <a href="#Page_158">158</a>;</li> + <li> peat-soils richest in, <a href="#Page_123">123</a>;</li> + <li> in Peruvian guano, <a href="#Page_302">302</a>, <a href="#Page_306">306</a>, <a href="#Page_307">307</a>, <a href="#Page_329">329</a>;</li> + <li> in pig-dung, <a href="#Page_226">226</a>-227;</li> + <li> position of, in agriculture, <a href="#Page_115">115</a>-160;</li> + <li> relative manurial value of, <a href="#Page_556">556</a>;</li> + <li> Rothamsted experiments on, <a href="#Page_115">115</a>;</li> + <li> in scutch, <a href="#Page_427">427</a>;</li> + <li> in sewage, <a href="#Page_431">431</a>;</li> + <li> in sewage-sludge, <a href="#Page_439">439</a>;</li> + <li> in sheep-dung, <a href="#Page_226">226</a>-228;</li> + <li> in sheep excrements, <a href="#Page_280">280</a>;</li> + <li> in sheep-urine, <a href="#Page_230">230</a>;</li> + <li> in soil, <a href="#Page_120">120</a>;</li> + <li> in soil, portion of, easily nitrifiable, <a href="#Page_187">187</a>;</li> + <li> in soils at various depths, <a href="#Page_156">156</a>;</li> + <li> in soot, <a href="#Page_428">428</a>;</li> + <li> source of, in plants, <a href="#Page_15">15</a>, <a href="#Page_16">16</a>, <a href="#Page_40">40</a>-52;</li> + <li> sources of soil, <a href="#Page_131">131</a>-137;</li> + <li> in straw, <a href="#Page_237">237</a>, <a href="#Page_243">243</a>;</li> + <li> in subsoil, <a href="#Page_121">121</a>;</li> + <li> in surface-soil, <a href="#Page_121">121</a>;</li> + <li> in swine-urine, <a href="#Page_230">230</a>;</li> + <li> in woollen rags, <a href="#Page_427">427</a>.</li> + </ul> +</li> + +<li> Nitrogenous guano, <a href="#Page_300">300</a>-308, <a href="#Page_329">329</a>.</li> + +<li> Nitrogenous manures, application of, <a href="#Page_478">478</a>; + <ul class="nest"> + <li> benefit cereals, <a href="#Page_494">494</a>;</li> + <li> hurtful to leguminous crops, <a href="#Page_523">523</a>.</li> + </ul> +</li> + +<li> Nitrogenous organic substances, in Chincha guano, <a href="#Page_305">305</a>; + <ul class="nest"> + <li> in concretionary nodules, <a href="#Page_328">328</a>.</li> + </ul> +</li> + +<li> <i>Nitrosomonas</i>, <a href="#Page_167">167</a>.</li> + +<li> Nitrous acid, converted into nitric acid, <a href="#Page_168">168</a>; + <ul class="nest"> + <li> formed from ammonia, <a href="#Page_167">167</a>.</li> + </ul> +</li> + +<li> Nobbe, on fixation of free nitrogen, <a href="#Page_136">136</a>; + <ul class="nest"> + <li> on potash in soil, <a href="#Page_108">108</a>.</li> + </ul> +</li> + +<li> Nöllner on origin of nitrate-fields, <a href="#Page_339">339</a>.</li> + +<li> Norfolk, coprolites from, <a href="#Page_374">374</a>; + <ul class="nest"> + <li> experiments on barley, <a href="#Page_497">497</a></li> + <li> —on meadow-land, <a href="#Page_509">509</a></li> + <li> —on turnips, <a href="#Page_513">513</a>.</li> + </ul> +</li> + +<li> North America, guano from, <a href="#Page_298">298</a>, <a href="#Page_328">328</a>.</li> + +<li> Norwegian apatite, <a href="#Page_375">375</a>.<br /><br /></li> + + +<li> Oak-tree, water transpired by, <a href="#Page_71">71</a>.</li> + +<li> Oat-straw, composition of, <a href="#Page_238">238</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>.</li> + </ul> +</li> + +<li> Oats, Arendt's experiments with, <a href="#Page_503">503</a>; + <ul class="nest"> + <li> avenine in, <a href="#Page_503">503</a>;</li> + <li> fertilising ingredients removed from soil by, <a href="#Page_485">485</a>;</li> + <li> hardy crop, <a href="#Page_502">502</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_501">501</a>-504;</li> + <li> nitrogen removed in crop of, <a href="#Page_148">148</a>;</li> + <li> require mixed nitrogenous manures, <a href="#Page_502">502</a>;</li> + <li> source of nitrogen, <a href="#Page_153">153</a>;</li> + <li> Rothamsted experiments on growth of, <a href="#Page_567">567</a>.</li> + </ul> +</li> + +<li> <i>Oficinas</i>, <a href="#Page_342">342</a>.</li> + +<li> Ohlendorff, introduction of dissolved guano by, <a href="#Page_311">311</a>.</li> + +<li> Oilcakes, imports of, <a href="#Page_153">153</a>; + <ul class="nest"> + <li> source of nitrogen, <a href="#Page_153">153</a>.</li> + </ul> +</li> + +<li> Oil-seeds, source of nitrogen, <a href="#Page_153">153</a>.</li> + +<li> Oligoclase felspars, <a href="#Page_103">103</a>, <a href="#Page_214">214</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_103">103</a>;</li> + <li> potash in, <a href="#Page_220">220</a>.</li> + </ul> +</li> + +<li> Organic matter, in bones, <a href="#Page_363">363</a>; + <ul class="nest"> + <li> in dung, <a href="#Page_228">228</a>, <a href="#Page_260">260</a>;</li> + <li> in manures, <a href="#Page_543">543</a>;</li> + <li> not necessary for nitrifying organism, <a href="#Page_169">169</a>.</li> + </ul> +</li> + +<li> Orthoclase felspars, <a href="#Page_103">103</a>, <a href="#Page_214">214</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_103">103</a>;</li> + <li> potash in, <a href="#Page_220">220</a>.</li> + </ul> +</li> + +<li> Ox-dung, fertilising ingredients in, for food consumed, <a href="#Page_228">228</a>.</li> + +<li> Ox-urine, fertilising ingredients in, <a href="#Page_232">232</a>.</li> + +<li> Oxalic acid in guano, action of, <a href="#Page_330">330</a>.</li> + +<li> Oxen, excrements of, <a href="#Page_280">280</a>; + <ul class="nest"> + <li> food aided by, <a href="#Page_280">280</a>;</li> + <li> solid excreta voided by, <a href="#Page_280">280</a>;</li> + <li> urine voided by, <a href="#Page_280">280</a>.</li> + </ul> +</li> + +<li> Oxidation, <a href="#Page_79">79</a>; + <ul class="nest"> + <li> products of, <a href="#Page_79">79</a>, <a href="#Page_80">80</a>.</li> + </ul> +</li> + +<li> Oxygen, absorbed by plant-roots, <a href="#Page_81">81</a>; + <ul class="nest"> + <li> absorbed by soil, <a href="#Page_81">81</a>;</li> + <li> evolved by plants, <a href="#Page_11">11</a>;</li> + <li> necessary for fertility, <a href="#Page_81">81</a>;</li> + <li> necessary for nitrification, <a href="#Page_52">52</a>, <a href="#Page_173">173</a>;</li> + <li> percentage of, in plants, <a href="#Page_39">39</a>;</li> + <li> source of, in plants, <a href="#Page_39">39</a>.</li> + </ul> +<br /> +</li> + +<li> Pabellon de Pica, guano from, <a href="#Page_298">298</a>, <a href="#Page_302">302</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_330">330</a>;</li> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Pacific Islands, guano from, <a href="#Page_298">298</a>.</li> + +<li> Pacific Ocean, sea-weed in, <a href="#Page_339">339</a>.</li> + +<li> Palagonite as potash manure, <a href="#Page_213">213</a>.</li> + +<li> Palm-kernel meal, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Pasteur, on fermentation in urine, <a href="#Page_255">255</a>; + <ul class="nest"> + <li> on nitrification, <a href="#Page_166">166</a>.</li> + </ul> +</li> + +<li> Pastures, accumulation of nitrogen in, <a href="#Page_134">134</a>; + <ul class="nest"> + <li> benefited by basic slag, <a href="#Page_414">414</a>;</li> + <li> deficient in lime, <a href="#Page_451">451</a>;</li> + <li> effect of manure on herbage of, <a href="#Page_505">505</a>;</li> + <li> nitrogen in, <a href="#Page_158">158</a>;</li> + <li> permanent, <a href="#Page_138">138</a>, <a href="#Page_194">194</a></li> + <li> —manuring of, <a href="#Page_509">509</a>;</li> + <li> season influences, <a href="#Page_507">507</a>;</li> + <li> soil influences, <a href="#Page_507">507</a>.</li> + </ul> +</li> + +<li> Patagonian guano, <a href="#Page_308">308</a>, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_330">330</a>;</li> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Patent phosphate meal, <a href="#Page_405">405</a>.</li> + +<li> Patillos, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Patos Island, guano deposits at, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Patterson on superphosphate, <a href="#Page_399">399</a>.<span class='pagenum'><a name="Page_586" id="Page_586">[Pg 586]</a></span></li> + +<li> Payen and Boussingault on composition of dried flesh, <a href="#Page_425">425</a>.</li> + +<li> Peas, manurial constituents in, <a href="#Page_282">282</a>; + <ul class="nest"> + <li> manuring of, <a href="#Page_527">527</a>;</li> + <li> phosphorus in, <a href="#Page_205">205</a>;</li> + <li> source of nitrogen, <a href="#Page_153">153</a>.</li> + </ul> +</li> + +<li> Peat, absorbing properties of, <a href="#Page_239">239</a>; + <ul class="nest"> + <li> adulterant of guano, <a href="#Page_317">317</a>;</li> + <li> analysis of stable-manure from, <a href="#Page_281">281</a>;</li> + <li> litter, <a href="#Page_239">239</a>;</li> + <li> nitrogen in, <a href="#Page_240">240</a>;</li> + <li> retaining properties of, <a href="#Page_240">240</a>;</li> + <li> soils, <a href="#Page_123">123</a>.</li> + </ul> +</li> + +<li> Pelicans, guano from, <a href="#Page_297">297</a>.</li> + +<li> Penguin Island guano, <a href="#Page_330">330</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_330">330</a>;</li> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Penguins, guano from, <a href="#Page_297">297</a>.</li> + +<li> Percival on carbonic acid in plants, <a href="#Page_12">12</a>.</li> + +<li> Peru, guano deposits in, <a href="#Page_327">327</a>;</li> +<li> guano first used in, <a href="#Page_297">297</a>;</li> +<li> nitrate of soda from, <a href="#Page_161">161</a>, <a href="#Page_162">162</a>.</li> + +<li> Peruvian guano, <a href="#Page_300">300</a>-306;</li> +<li> appearance of, <a href="#Page_303">303</a>;</li> +<li> composition of, <a href="#Page_304">304</a>-306;</li> +<li> deposits of, <a href="#Page_301">301</a>;</li> +<li> imports of, <a href="#Page_151">151</a>, <a href="#Page_297">297</a>;</li> +<li> source of nitrogen, <a href="#Page_151">151</a>.</li> + +<li> Peters and Eichhorn on solvent power of salt, <a href="#Page_471">471</a>.</li> + +<li> Petzholdt on sources of plant's nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Pfeffer on action of light on plant-growth, <a href="#Page_38">38</a>.</li> + +<li> Phœnix Island guano, <a href="#Page_309">309</a>.</li> + +<li> Phosphate of iron in Chincha guano, <a href="#Page_305">305</a>.</li> + +<li> Phosphate of lime, in Algerian phosphate, <a href="#Page_379">379</a>; + <ul class="nest"> + <li> in apatite, <a href="#Page_374">374</a>;</li> + <li> in Belgian phosphate, <a href="#Page_377">377</a>;</li> + <li> in bones, <a href="#Page_364">364</a>;</li> + <li> in Cambridge coprolites, <a href="#Page_374">374</a>;</li> + <li> in Carolina phosphates, <a href="#Page_376">376</a>;</li> + <li> in crust guanos, <a href="#Page_379">379</a>;</li> + <li> in Estremadura phosphate, <a href="#Page_375">375</a>;</li> + <li> in Florida phosphate, <a href="#Page_378">378</a>;</li> + <li> in French phosphates, <a href="#Page_379">379</a>;</li> + <li> in Lahn phosphates, <a href="#Page_379">379</a>;</li> + <li> in Somme phosphate, <a href="#Page_378">378</a>;</li> + <li> reverted in mixing manures, <a href="#Page_537">537</a>.</li> + </ul> +</li> + +<li> Phosphates of lime, <a href="#Page_385">385</a>-388, <a href="#Page_398">398</a>; + <ul class="nest"> + <li> importance of mechanical condition of, <a href="#Page_542">542</a>.</li> + </ul> +</li> + +<li> Phosphates, mineral, <a href="#Page_373">373</a>-381; + <ul class="nest"> + <li> imports of, <a href="#Page_381">381</a>;</li> + <li> value as a manure, <a href="#Page_380">380</a>.</li> + </ul> +</li> + +<li> Phosphatic guano, <a href="#Page_308">308</a>, <a href="#Page_330">330</a>.</li> + +<li> Phosphatic manures, application of, <a href="#Page_480">480</a>.</li> + +<li> Phosphoretted hydrogen in farmyard manure, <a href="#Page_258">258</a>.</li> + +<li> Phosphoric acid, <a href="#Page_199">199</a>-211; + <ul class="nest"> + <li> in ash of plants, <a href="#Page_54">54</a>;</li> + <li> in basic slag, <a href="#Page_404">404</a>;</li> + <li> in bat guano, <a href="#Page_325">325</a>;</li> + <li> in bones, <a href="#Page_363">363</a>;</li> + <li> condition of, in soil, <a href="#Page_203">203</a>;</li> + <li> in cow-dung, <a href="#Page_226">226</a>-228;</li> + <li> in cow excrements, <a href="#Page_280">280</a>;</li> + <li> in cow-urine, <a href="#Page_230">230</a>;</li> + <li> in farmyard manure, <a href="#Page_260">260</a>;</li> + <li> in fish-guano, <a href="#Page_321">321</a>;</li> + <li> fixed by soils, <a href="#Page_58">58</a>;</li> + <li> gain of, <a href="#Page_208">208</a>;</li> + <li> in guano, percentage of, <a href="#Page_329">329</a>, <a href="#Page_330">330</a>;</li> + <li> guano a source of, <a href="#Page_202">202</a>;</li> + <li> in hoofs and horns, <a href="#Page_426">426</a>;</li> + <li> in horse-dung, <a href="#Page_226">226</a>-228;</li> + <li> in horse-urine, <a href="#Page_230">230</a>;</li> + <li> importance of, <a href="#Page_88">88</a>;</li> + <li> loss of, artificial sources of, <a href="#Page_206">206</a></li> + <li> —by drainage, <a href="#Page_206">206</a></li> + <li> —in farmyard manure, <a href="#Page_208">208</a></li> + <li> —in milk, <a href="#Page_207">207</a></li> + <li> —in sewage, <a href="#Page_208">208</a></li> + <li> —sources of, in agriculture, <a href="#Page_205">205</a>;</li> + <li> in meat-guano, <a href="#Page_324">324</a>;</li> + <li> mineral sources of, <a href="#Page_200">200</a>;</li> + <li> necessary for plant-growth, <a href="#Page_55">55</a>;</li> + <li> occurrence of, in animals, <a href="#Page_205">205</a></li> + <li> —in nature, <a href="#Page_199">199</a></li> + <li> —in plants, <a href="#Page_204">204</a></li> + <li> —in soil, <a href="#Page_203">203</a>;</li> + <li> in oxen excrements, <a href="#Page_280">280</a>;</li> + <li> in pig-dung, <a href="#Page_226">226</a>, <a href="#Page_227">227</a>;</li> + <li> in pig excrements, <a href="#Page_281">281</a>;</li> + <li> in pig-urine, <a href="#Page_230">230</a>;</li> + <li> position of, in agriculture, <a href="#Page_199">199</a>-211;</li> + <li> relative trade values of, in manures, <a href="#Page_400">400</a>;</li> + <li> in rocks, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>;</li> + <li> in sewage-sludge, <a href="#Page_441">441</a>;</li> + <li> in sheep-dung, <a href="#Page_226">226</a>-228;</li> + <li> in sheep excrements, <a href="#Page_280">280</a>;</li> + <li> in sheep-urine, <a href="#Page_230">230</a>;</li> + <li> statement of, in analyses of manures, <a href="#Page_541">541</a>.</li> + </ul> +</li> + +<li> Phosphorite, <a href="#Page_201">201</a>, <a href="#Page_374">374</a>.</li> + +<li> Phosphorus, in albuminoids, <a href="#Page_205">205</a>; + <ul class="nest"> + <li> in animals, <a href="#Page_205">205</a>;</li> + <li> in beans, <a href="#Page_205">205</a>;</li> + <li> in peas, <a href="#Page_205">205</a>;</li> + <li> in plants, <a href="#Page_204">204</a>;</li> + <li> in pig-iron, <a href="#Page_401">401</a>.</li> + </ul> +</li> + +<li> Physical properties of soils, <a href="#Page_66">66</a>-87.</li> + +<li> Pichard on action of gypsum on nitrification, <a href="#Page_173">173</a>.</li> + +<li> Pig-dung, composition of, <a href="#Page_226">226</a>; + <ul class="nest"> + <li> in dry state, <a href="#Page_227">227</a>.</li> + </ul> +</li> + +<li> Pig excrements, <a href="#Page_281">281</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_281">281</a>.</li> + </ul> +</li> + +<li> Pig-manure, <a href="#Page_250">250</a>; + <ul class="nest"> + <li> amount produced per day, <a href="#Page_251">251</a>;</li> + <li> mineral matter in, <a href="#Page_251">251</a>;</li> + <li> nitrogen in, <a href="#Page_251">251</a>;</li> + <li> poor in nitrogen, <a href="#Page_251">251</a>.</li> + </ul> +</li> + +<li> Pig-urine, composition of, <a href="#Page_230">230</a> + <ul class="nest"> + <li> —in dry state, <a href="#Page_231">231</a>.</li> + </ul> +</li> + +<li> Pigeon-dung, <a href="#Page_320">320</a>, <a href="#Page_325">325</a>; + <ul class="nest"> + <li> analysis of, <a href="#Page_331">331</a>.</li> + </ul> +</li> + +<li> Pigs, excrements of, <a href="#Page_281">281</a>; + <ul class="nest"> + <li> food consumed by, <a href="#Page_281">281</a>.</li> + </ul> +</li> + +<li> Pisagua, nitrate-fields at, <a href="#Page_340">340</a>.</li> + +<li> Plant, action of light on, <a href="#Page_38">38</a>; + <ul class="nest"> + <li> amount of hydrogen in, <a href="#Page_40">40</a><span class='pagenum'><a name="Page_587" id="Page_587">[Pg 587]</a></span></li> + <li> —nitrogen in, <a href="#Page_40">40</a></li> + <li> —oxygen in, <a href="#Page_40">40</a>;</li> + <li> ash constituents of, <a href="#Page_53">53</a>-55;</li> + <li> carbon fixed by, <a href="#Page_37">37</a>, <a href="#Page_38">38</a>;</li> + <li> food, absorption of, by, <a href="#Page_55">55</a>;</li> + <li> phosphoric acid in, <a href="#Page_204">204</a>;</li> + <li> potash in, <a href="#Page_216">216</a>;</li> + <li> proximate composition of, <a href="#Page_36">36</a>;</li> + <li> relation of ammonia to, <a href="#Page_48">48</a>-50;</li> + <li> source of hydrogen in, <a href="#Page_40">40</a></li> + <li> —nitrogen in, <a href="#Page_40">40</a>-52</li> + <li> —oxygen in, <a href="#Page_39">39</a>, <a href="#Page_40">40</a>.</li> + </ul> +</li> + +<li> Plant-food, absorption of, <a href="#Page_490">490</a>; + <ul class="nest"> + <li> amount of soluble, in soil, <a href="#Page_100">100</a>;</li> + <li> early theories on source of, <a href="#Page_4">4</a>;</li> + <li> retained by soil, <a href="#Page_57">57</a>.</li> + </ul> +</li> + +<li> Plant-roots, grow downwards, <a href="#Page_84">84</a>; + <ul class="nest"> + <li> nitrification promoted by, <a href="#Page_181">181</a>;</li> + <li> openness required by, <a href="#Page_83">83</a>;</li> + <li> room required by, <a href="#Page_85">85</a>;</li> + <li> soil in relation to, <a href="#Page_84">84</a>.</li> + </ul> +</li> + +<li> Pliny, on lime as a manure, <a href="#Page_449">449</a>; + <ul class="nest"> + <li> on salt as a manure, <a href="#Page_465">465</a>.</li> + </ul> +</li> + +<li> Pockets a source of phosphoric acid, <a href="#Page_202">202</a>.</li> + +<li> Poisons, effect of, on nitrifying organisms, <a href="#Page_176">176</a>.</li> + +<li> Polstorff on ash constituents of plants, <a href="#Page_53">53</a>.</li> + +<li> Polyhallite, potash in, <a href="#Page_220">220</a>, <a href="#Page_420">420</a>.</li> + +<li> Porphyry, in guano, <a href="#Page_303">303</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + </ul> +</li> + +<li> Potash, <a href="#Page_212">212</a>-220, <a href="#Page_418">418</a>-423; + <ul class="nest"> + <li> in ash of plants, <a href="#Page_54">54</a>;</li> + <li> in barilla, <a href="#Page_420">420</a>;</li> + <li> chloride of, <a href="#Page_218">218</a>;</li> + <li> condition of, in soil, <a href="#Page_216">216</a>;</li> + <li> in cows' excrements, <a href="#Page_280">280</a>;</li> + <li> in drainage-waters, <a href="#Page_217">217</a>;</li> + <li> in farmyard manure, <a href="#Page_260">260</a>;</li> + <li> in felspars, <a href="#Page_220">220</a>;</li> + <li> in fleece, <a href="#Page_217">217</a>;</li> + <li> fixed by soils, <a href="#Page_58">58</a>;</li> + <li> importance of, in soil, <a href="#Page_88">88</a>;</li> + <li> in kelp, <a href="#Page_420">420</a>;</li> + <li> less important than phosphoric acid, <a href="#Page_212">212</a>;</li> + <li> manures, <a href="#Page_218">218</a>, <a href="#Page_418">418</a>-423;</li> + <li> muriate of, <a href="#Page_218">218</a>, <a href="#Page_421">421</a>;</li> + <li> necessary for nitrification, <a href="#Page_171">171</a>;</li> + <li> necessary for plant-growth, <a href="#Page_55">55</a>;</li> + <li> occurrence of, <a href="#Page_213">213</a>;</li> + <li> in ocean, <a href="#Page_213">213</a>;</li> + <li> in oxen excrements, <a href="#Page_280">280</a>;</li> + <li> in pig excrements, <a href="#Page_280">280</a>;</li> + <li> in plants, <a href="#Page_216">216</a>;</li> + <li> position of, in agriculture, <a href="#Page_212">212</a>-220;</li> + <li> relative manurial value of, <a href="#Page_556">556</a>;</li> + <li> Scottish soils supplied with, <a href="#Page_419">419</a>;</li> + <li> in sheep excrements, <a href="#Page_280">280</a>;</li> + <li> soda replaces, <a href="#Page_466">466</a>;</li> + <li> sources of loss of, <a href="#Page_217">217</a>;</li> + <li> in Stassfurt salts, <a href="#Page_214">214</a>;</li> + <li> statement of, in analyses of manures, <a href="#Page_542">542</a>;</li> + <li> in sugar-beet refuse, <a href="#Page_219">219</a>;</li> + <li> sulphate of, <a href="#Page_218">218</a>, <a href="#Page_421">421</a>;</li> + <li> in wood-ashes, <a href="#Page_218">218</a>, <a href="#Page_220">220</a>, <a href="#Page_419">419</a>.</li> + </ul> +</li> + +<li> Potash manures, <a href="#Page_218">218</a>, <a href="#Page_418">418</a>-423; + <ul class="nest"> + <li> application of, <a href="#Page_422">422</a>, <a href="#Page_480">480</a></li> + <li> —rate of, <a href="#Page_423">423</a>;</li> + <li> barilla as, <a href="#Page_420">420</a>;</li> + <li> crops suited for, <a href="#Page_423">423</a>;</li> + <li> relative importance of, <a href="#Page_418">418</a>;</li> + <li> soils suited for, <a href="#Page_423">423</a>;</li> + <li> sources of, <a href="#Page_419">419</a>;</li> + <li> Stassfurt salts as, <a href="#Page_420">420</a>;</li> + <li> wood-ashes a source of, <a href="#Page_419">419</a>.</li> + </ul> +</li> + +<li> Potassium phosphate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Potassium sulphate, in Chincha guano, <a href="#Page_305">305</a>; + <ul class="nest"> + <li> in concretionary nodules, <a href="#Page_328">328</a>.</li> + </ul> +</li> + +<li> Potatoes, effect of farmyard manure on, <a href="#Page_520">520</a>; + <ul class="nest"> + <li> fertilising ingredients removed from soil by, <a href="#Page_485">485</a>;</li> + <li> grown with covered manure, <a href="#Page_289">289</a>;</li> + <li> Highland Society's experiments on, <a href="#Page_518">518</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_517">517</a>-522</li> + <li> —in Jersey, <a href="#Page_529">529</a></li> + <li> —influences composition of, <a href="#Page_521">521</a>;</li> + <li> potash removed in, <a href="#Page_217">217</a>;</li> + <li> Rothamsted experiments on, <a href="#Page_519">519</a>, <a href="#Page_571">571</a>.</li> + </ul> +</li> + +<li> Precipitated ammonium phosphate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Precipitated phosphate, <a href="#Page_330">330</a>, <a href="#Page_387">387</a>.</li> + +<li> Precipitation, treatment of sewage by, <a href="#Page_436">436</a>.</li> + +<li> Priestley, discovery of evolution of oxygen by plants, <a href="#Page_11">11</a>; + <ul class="nest"> + <li> on nitrogen in plants, <a href="#Page_40">40</a>.</li> + </ul> +</li> + +<li> Prussiate of potash, manufacture of, <a href="#Page_353">353</a>.</li> + +<li> Pugh on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Punta de Lobos guano, <a href="#Page_302">302</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_303">303</a>;</li> + <li> phosphoric acid in, <a href="#Page_303">303</a>.</li> + </ul> +</li> + +<li> Punta de Patillos, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Pyroxene, potash in, <a href="#Page_220">220</a>.<br /><br /></li> + + +<li> Quartz, evaporation of water from, <a href="#Page_99">99</a>.</li> + +<li> Queensland, meat-meal guano from, <a href="#Page_324">324</a>.</li> + +<li> Quercitan, experiments of, with roses, <a href="#Page_8">8</a>.<br /><br /></li> + + +<li> Rape-cake, capable of nitrification, <a href="#Page_182">182</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>.</li> + </ul> +</li> + +<li> Rape-seeds, imports of, <a href="#Page_153">153</a>.</li> + +<li> Raza Island guano, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Rectified guano, <a href="#Page_311">311</a>.</li> + +<li> Relative trade values of phosphoric acid, <a href="#Page_400">400</a>.</li> + +<li> Resin in guano, <a href="#Page_305">305</a>.<span class='pagenum'><a name="Page_588" id="Page_588">[Pg 588]</a></span></li> + +<li> Retentive power of soils for water, <a href="#Page_70">70</a>-73.</li> + +<li> Retrogression, nitrogen lost by, <a href="#Page_142">142</a>.</li> + +<li> Reverted phosphates, <a href="#Page_389">389</a>-391; + <ul class="nest"> + <li> determination of amount of, <a href="#Page_391">391</a>;</li> + <li> formation of, <a href="#Page_387">387</a>;</li> + <li> value of, <a href="#Page_391">391</a>.</li> + </ul> +</li> + +<li> Rhine, nitrates in waters of, <a href="#Page_158">158</a>.</li> + +<li> Rice-meal, an adulterant of guano, <a href="#Page_319">319</a>; + <ul class="nest"> + <li> manurial constituents of, <a href="#Page_282">282</a>.</li> + </ul> +</li> + +<li> Rocks, phosphoric acid in, <a href="#Page_202">202</a>.</li> + +<li> Roots, influence of manures on composition of, <a href="#Page_512">512</a>; + <ul class="nest"> + <li> manuring of, <a href="#Page_510">510</a>-522;</li> + <li> Norfolk experiments on, <a href="#Page_513">513</a>;</li> + <li> potash removed in, <a href="#Page_217">217</a>.</li> + </ul> +</li> + +<li> Rotation of crops, bearing of, on nitrification, <a href="#Page_195">195</a>.</li> + +<li> Rotations, phosphoric acid in, <a href="#Page_290">290</a>; + <ul class="nest"> + <li> potash removed in, <a href="#Page_290">290</a>.</li> + </ul> +</li> + +<li> Rothamsted, alternate wheat and bean rotation at, <a href="#Page_524">524</a>; + <ul class="nest"> + <li> ammonia in rain at, <a href="#Page_49">49</a>;</li> + <li> barley experiments at, <a href="#Page_566">566</a>;</li> + <li> Broadbalk Field, alteration in composition of, <a href="#Page_159">159</a></li> + <li> —manuring of, <a href="#Page_159">159</a></li> + <li> —produce of wheat on, <a href="#Page_159">159</a>;</li> + <li> early experiments at, <a href="#Page_33">33</a>-36;</li> + <li> experiments, <a href="#Page_560">560</a>-572;</li> + <li> experiments with nitrate of soda at, <a href="#Page_347">347</a>;</li> + <li> experiments on nitrogen question at, <a href="#Page_115">115</a></li> + <li> —mangel-wurzel, <a href="#Page_568">568</a></li> + <li> —oats, <a href="#Page_567">567</a></li> + <li> —potatoes at, <a href="#Page_519">519</a></li> + <li> —value of nitrogen in farmyard manure, <a href="#Page_271">271</a>;</li> + <li> increase of nitrogen with manures at, <a href="#Page_137">137</a>, <a href="#Page_513">513</a>;</li> + <li> nitrates in barley-soils of, <a href="#Page_158">158</a>;</li> + <li> nitrates in cropped soils of, <a href="#Page_130">130</a>, <a href="#Page_157">157</a>;</li> + <li> nitrates in drainage of, <a href="#Page_189">189</a>;</li> + <li> nitrates in wheat-soils of, <a href="#Page_131">131</a>, <a href="#Page_157">157</a>;</li> + <li> nitrogen as nitrates in soils of, <a href="#Page_129">129</a>, <a href="#Page_198">198</a>;</li> + <li> nitrogen, decrease of, in soils, <a href="#Page_159">159</a>;</li> + <li> nitrogen in pasture at, <a href="#Page_126">126</a>;</li> + <li> pasture, increase of nitrogen in, <a href="#Page_158">158</a>;</li> + <li> retrogression of nitrogen at, <a href="#Page_142">142</a>;</li> + <li> soil, nature of, <a href="#Page_561">561</a></li> + <li> —nitrogen in, at various depths, <a href="#Page_156">156</a>;</li> + <li> total amount of nitrogen lost at, <a href="#Page_142">142</a>;</li> + <li> turnip experiments at, <a href="#Page_568">568</a>;</li> + <li> unmanured fallow-land loses nitrogen by drainage at, <a href="#Page_141">141</a>;</li> + <li> wheat experiments at, <a href="#Page_500">500</a>, <a href="#Page_562">562</a>-565.</li> + </ul> +</li> + +<li> Roy on sources of plant-nitrogen, <a href="#Page_42">42</a>.</li> + +<li> Rubidia in ash of plants, <a href="#Page_55">55</a>.</li> + +<li> Ruffle, John, on superphosphate, <a href="#Page_388">388</a>.</li> + +<li> Rye, manurial constituents in, <a href="#Page_282">282</a>.</li> + +<li> Rye-grass suited for sewage, <a href="#Page_435">435</a>.</li> + +<li> Rye-straw, summer, composition of, <a href="#Page_238">238</a>; + <ul class="nest"> + <li> winter, composition-of, <a href="#Page_238">238</a>.</li> + </ul> +<br /> +</li> + + +<li> St Helena, experiments at, with Peruvian guano, <a href="#Page_301">301</a>.</li> + +<li> Saldanha Bay guano, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_329">329</a>;</li> + <li> phosphoric acid in, <a href="#Page_329">329</a>.</li> + </ul> +</li> + +<li> <i>Salinas</i>, <a href="#Page_335">335</a>.</li> + +<li> Salm-Horstmar, Prince, on water-culture, <a href="#Page_54">54</a>.</li> + +<li> Salt, <a href="#Page_465">465</a>-473; + <ul class="nest"> + <li> action of, on crops, <a href="#Page_472">472</a>;</li> + <li> adulterant of guano, <a href="#Page_319">319</a>;</li> + <li> amount applied, <a href="#Page_473">473</a>;</li> + <li> antiquity of use of, <a href="#Page_465">465</a>;</li> + <li> an antiseptic, <a href="#Page_468">468</a>;</li> + <li> application of, <a href="#Page_472">472</a>;</li> + <li> clarifies water, <a href="#Page_470">470</a>;</li> + <li> coagulates clay, <a href="#Page_470">470</a>;</li> + <li> decomposes minerals, <a href="#Page_470">470</a>;</li> + <li> a germicide, <a href="#Page_468">468</a>;</li> + <li> indirect action of, <a href="#Page_468">468</a>;</li> + <li> mechanical action of, <a href="#Page_470">470</a>;</li> + <li> nature of action of, <a href="#Page_465">465</a>;</li> + <li> not a necessary plant-food, <a href="#Page_466">466</a>;</li> + <li> occurrence of, <a href="#Page_467">467</a>;</li> + <li> prevents rapid fermentation, <a href="#Page_471">471</a>;</li> + <li> quantity to apply, <a href="#Page_473">473</a>;</li> + <li> solvent action of, <a href="#Page_470">470</a>;</li> + <li> sources of, <a href="#Page_468">468</a>.</li> + </ul> +</li> + +<li> Saltpetre, formation of, <a href="#Page_164">164</a>; + <ul class="nest"> + <li> occurrence of, <a href="#Page_215">215</a>;</li> + <li> plantations, <a href="#Page_163">163</a>.</li> + </ul> +</li> + +<li> Sand, absorptive power of, <a href="#Page_68">68</a>; + <ul class="nest"> + <li> an adulterant of guano, <a href="#Page_319">319</a>;</li> + <li> calcareous, absorptive power of, <a href="#Page_98">98</a>;</li> + <li> siliceous, absorptive power of, <a href="#Page_98">98</a>.</li> + </ul> +</li> + +<li> Sandy soils deficient in lime, <a href="#Page_451">451</a>.</li> + +<li> Sandwich Islands, guano deposits at, <a href="#Page_328">328</a>.</li> + +<li> Saragossa Sea, sea-weed in, <a href="#Page_339">339</a>.</li> + +<li> Saussure, De, on absorption of gases by soil, <a href="#Page_81">81</a>; + <ul class="nest"> + <li> on nitrogen in plants, <a href="#Page_41">41</a>;</li> + <li> researches on plant-food by, <a href="#Page_15">15</a>.</li> + </ul> +</li> + +<li> Sawdust an adulterant of guano, <a href="#Page_319">319</a>.</li> + +<li> Scheibler, Professor, on basic slag, <a href="#Page_404">404</a>.</li> + +<li> Schloesing and Müntz, on nitrification, <a href="#Page_51">51</a>, <a href="#Page_166">166</a>; + <ul class="nest"> + <li> experiments on rate of nitrification by, <a href="#Page_185">185</a>;</li> + <li> on denitrification, <a href="#Page_179">179</a>;</li> + <li> on ferments effecting nitrification, <a href="#Page_167">167</a>;</li> + <li> on fixation of free nitrogen, <a href="#Page_42">42</a>;</li> + <li> on ammonia in air, <a href="#Page_119">119</a>, <a href="#Page_132">132</a>;</li> + <li> on nitrogen absorbed by soil from air, <a href="#Page_132">132</a>;</li> + <li> on temperature favourable for nitrification, <a href="#Page_175">175</a>.</li> + </ul> +</li> + +<li> Schoenite, potash in, <a href="#Page_220">220</a>.</li> + +<li> Schübler, on absorptive power of soils, <a href="#Page_98">98</a>; + <ul class="nest"> + <li> on retentive power of soils, <a href="#Page_98">98</a>.</li> + </ul> +</li> + +<li> Schulze on fixers, <a href="#Page_246">246</a>.<span class='pagenum'><a name="Page_589" id="Page_589">[Pg 589]</a></span></li> + +<li> Scutch, <a href="#Page_427">427</a>; + <ul class="nest"> + <li> manufacture of, <a href="#Page_427">427</a>;</li> + <li> nitrogen in, <a href="#Page_427">427</a>.</li> + </ul> +</li> + +<li> Sea-weed, nitric acid in, <a href="#Page_339">339</a>.</li> + +<li> Seals, guano from, <a href="#Page_297">297</a>.</li> + +<li> Seed, fertilising ingredients lodge in, <a href="#Page_491">491</a>.</li> + +<li> Seine, nitrates in waters of, <a href="#Page_158">158</a>.</li> + +<li> Sénébier, Jean, on carbon in plants, <a href="#Page_12">12</a>; + <ul class="nest"> + <li> on nitrogen in plants, <a href="#Page_41">41</a>.</li> + </ul> +</li> + +<li> Sewage, <a href="#Page_430">430</a>-441; + <ul class="nest"> + <li> charcoal a filter for, <a href="#Page_437">437</a>;</li> + <li> crops suited for, <a href="#Page_434">434</a>;</li> + <li> denitrification in, <a href="#Page_179">179</a>;</li> + <li> dry matter in, <a href="#Page_431">431</a>;</li> + <li> effects of continued applications of, <a href="#Page_433">433</a>;</li> + <li> filters for, <a href="#Page_437">437</a>;</li> + <li> irrigation with, <a href="#Page_431">431</a>-433;</li> + <li> nitrification in, <a href="#Page_166">166</a>;</li> + <li> nitrogen lost in, <a href="#Page_149">149</a>;</li> + <li> phosphoric acid lost in, <a href="#Page_149">149</a>;</li> + <li> purified by soils, <a href="#Page_435">435</a>;</li> + <li> treatment of, by precipitation, <a href="#Page_436">436</a>;</li> + <li> value of, as a manure, <a href="#Page_430">430</a>.</li> + </ul> +</li> + +<li> Sewage-sick land, <a href="#Page_433">433</a>.</li> + +<li> Sewage-sludge, <a href="#Page_438">438</a>-441; + <ul class="nest"> + <li> as a manure, experiments with, <a href="#Page_438">438</a>;</li> + <li> nitrogen in, <a href="#Page_439">439</a>;</li> + <li> phosphoric acid in, <a href="#Page_439">439</a>;</li> + <li> profitable treatment of, <a href="#Page_441">441</a>;</li> + <li> value of, <a href="#Page_439">439</a>;</li> + <li> water in, <a href="#Page_438">438</a>.</li> + </ul> +</li> + +<li> Shale-works, sulphate of ammonia, from, <a href="#Page_358">358</a>.</li> + +<li> Shark's Bay guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>.</li> + +<li> Sheep, excrements of, <a href="#Page_280">280</a>, <a href="#Page_281">281</a>; + <ul class="nest"> + <li> solid excreta voided by, <a href="#Page_280">280</a>;</li> + <li> urine voided by, <a href="#Page_280">280</a>.</li> + </ul> +</li> + +<li> Sheep-dung, alkalies in, <a href="#Page_226">226</a>; + <ul class="nest"> + <li> composition of, in dry state, <a href="#Page_227">227</a>;</li> + <li> most valuable excrement, <a href="#Page_227">227</a>;</li> + <li> nitrogen in, <a href="#Page_226">226</a>;</li> + <li> phosphoric acid in, <a href="#Page_226">226</a>;</li> + <li> water in, <a href="#Page_226">226</a>.</li> + </ul> +</li> + +<li> Sheep-manure, <a href="#Page_251">251</a>; + <ul class="nest"> + <li> amount produced per day, <a href="#Page_251">251</a></li> + <li> —per year, <a href="#Page_252">252</a>;</li> + <li> dry matter in, <a href="#Page_252">252</a>;</li> + <li> mineral matter in, <a href="#Page_252">252</a>;</li> + <li> nitrogen in, <a href="#Page_252">252</a>.</li> + </ul> +</li> + +<li> Sheep-urine, alkalies in, <a href="#Page_230">230</a>; + <ul class="nest"> + <li> composition of, in dry state, <a href="#Page_231">231</a>;</li> + <li> most valuable urine, <a href="#Page_231">231</a>;</li> + <li> nitrogen in, <a href="#Page_230">230</a>;</li> + <li> phosphoric acid in, <a href="#Page_230">230</a>;</li> + <li> water in, <a href="#Page_230">230</a>.</li> + </ul> +</li> + +<li> Shoddy, <a href="#Page_427">427</a>; + <ul class="nest"> + <li> production of, <a href="#Page_152">152</a>, <a href="#Page_425">425</a>;</li> + <li> nitrogen in, <a href="#Page_152">152</a>, <a href="#Page_427">427</a>.</li> + </ul> +</li> + +<li> Sicily, bones from, <a href="#Page_360">360</a>.</li> + +<li> Sidney Island guano, phosphoric acid in, <a href="#Page_330">330</a>.</li> + +<li> Siemens, Dr, experiments by, with light on plants, <a href="#Page_38">38</a>.</li> + +<li> Silica, in ash of plants, <a href="#Page_55">55</a>; + <ul class="nest"> + <li> in Chincha guano, <a href="#Page_305">305</a>;</li> + <li> jelly, <a href="#Page_169">169</a>;</li> + <li> necessary for plant-growth, <a href="#Page_55">55</a>.</li> + </ul> +</li> + +<li> Silicates, <a href="#Page_102">102</a>; + <ul class="nest"> + <li> absorbed by cereals, <a href="#Page_494">494</a>.</li> + </ul> +</li> + +<li> Silicic acid fixed by soils, <a href="#Page_58">58</a>.</li> + +<li> Simon on humus in soil, <a href="#Page_47">47</a>.</li> + +<li> Slaked lime, <a href="#Page_454">454</a>.</li> + +<li> Slugs killed by lime, <a href="#Page_461">461</a>.</li> + +<li> Smut prevented by lime, <a href="#Page_461">461</a>.</li> + +<li> Soda, in ash of plants, <a href="#Page_54">54</a>; + <ul class="nest"> + <li> fixed by soils, <a href="#Page_58">58</a>;</li> + <li> necessary for plant-growth, <a href="#Page_55">55</a>;</li> + <li> nitrate of, <a href="#Page_332">332</a>-351;</li> + <li> in <i>salinas</i>, <a href="#Page_335">335</a>;</li> + <li> replaces potash, <a href="#Page_466">466</a>.</li> + </ul> +</li> + +<li> Sodium chloride in Chincha Island guano, <a href="#Page_305">305</a>.</li> + +<li> Sodium phosphate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Sodium sulphate in concretionary nodules, <a href="#Page_328">328</a>.</li> + +<li> Soil, <a href="#Page_65">65</a>-108; + <ul class="nest"> + <li> absorptive power of, for water, <a href="#Page_67">67</a>, <a href="#Page_98">98</a>;</li> + <li> acids fixed by, <a href="#Page_58">58</a>-60;</li> + <li> action of lime on, <a href="#Page_453">453</a>;</li> + <li> ammonia absorbed by, <a href="#Page_81">81</a>;</li> + <li> amount of soluble plant-food in, <a href="#Page_100">100</a>;</li> + <li> artificial, <a href="#Page_54">54</a>;</li> + <li> barley, nitrates in, <a href="#Page_158">158</a>;</li> + <li> bases fixed by, <a href="#Page_58">58</a>-60;</li> + <li> best suited for nitrification, <a href="#Page_192">192</a>;</li> + <li> biological properties of, <a href="#Page_92">92</a>-96;</li> + <li> capacity for heat, <a href="#Page_76">76</a>-78;</li> + <li> carbonic acid absorbed by, <a href="#Page_81">81</a>;</li> + <li> chemical composition of, <a href="#Page_87">87</a>-92, <a href="#Page_101">101</a>-107;</li> + <li> colour of, <a href="#Page_80">80</a>;</li> + <li> cropped, nitrates in, <a href="#Page_157">157</a>;</li> + <li> denitrification in, <a href="#Page_177">177</a>;</li> + <li> evaporation from, <a href="#Page_71">71</a>, <a href="#Page_72">72</a>;</li> + <li> farmyard manure, action of, on, <a href="#Page_272">272</a>;</li> + <li> fertilising ingredients in, <a href="#Page_87">87</a>;</li> + <li> fertility of, <a href="#Page_65">65</a>-108;</li> + <li> fineness of, <a href="#Page_69">69</a>-70;</li> + <li> gases in, <a href="#Page_100">100</a>;</li> + <li> hygroscopic power of, <a href="#Page_75">75</a>-76, <a href="#Page_99">99</a>;</li> + <li> improved by humus, <a href="#Page_272">272</a>;</li> + <li> influence of farmyard manure on, <a href="#Page_475">475</a>;</li> + <li> on nitrification, <a href="#Page_180">180</a>;</li> + <li> manures increase fertility of, <a href="#Page_474">474</a>;</li> + <li> nitrates in, amount of, <a href="#Page_128">128</a>-131;</li> + <li> nitrifying organisms in, <a href="#Page_179">179</a>;</li> + <li> distribution of, <a href="#Page_179">179</a>;</li> + <li> nitrogen absorbed by, <a href="#Page_81">81</a>, <a href="#Page_82">82</a>, <a href="#Page_131">131</a>;</li> + <li> nitrogen accumulates, <a href="#Page_133">133</a>;</li> + <li> nitrogen in, amount of, <a href="#Page_120">120</a>-128;</li> + <li> nitrogen least abundant of manurial ingredients in, <a href="#Page_270">270</a>;</li> + <li> nitrogen at various depths in, <a href="#Page_156">156</a>;</li> + <li> oxygen absorbed by, <a href="#Page_81">81</a>;</li> + <li> phosphoric acid in, <a href="#Page_203">203</a></li> + <li> —condition of, in, <a href="#Page_203">203</a></li> + <li> —occurrence of, in, <a href="#Page_203">203</a>;</li> + <li> peat, <a href="#Page_123">123</a>;<span class='pagenum'><a name="Page_590" id="Page_590">[Pg 590]</a></span></li> + <li> possesses power of fixing ammonia, <a href="#Page_57">57</a>;</li> + <li> potash in, <a href="#Page_215">215</a></li> + <li> —condition of, in, <a href="#Page_216">216</a>;</li> + <li> potential fertility of, <a href="#Page_549">549</a>;</li> + <li> power of, for absorbing gases, <a href="#Page_81">81</a>;</li> + <li> relation of, to plant-roots, <a href="#Page_84">84</a>;</li> + <li> retention of plant-food by, <a href="#Page_57">57</a>;</li> + <li> retentive power of, for water, <a href="#Page_70">70</a>-73;</li> + <li> sewage purified by, <a href="#Page_435">435</a>;</li> + <li> shrinkage of, <a href="#Page_74">74</a>;</li> + <li> variation in absorbing powers of, <a href="#Page_82">82</a>;</li> + <li> varieties of, <a href="#Page_67">67</a>;</li> + <li> virgin, <a href="#Page_133">133</a>;</li> + <li> water in, most favourable amount of, <a href="#Page_75">75</a>;</li> + <li> water-logged, <a href="#Page_179">179</a>;</li> + <li> wheat, nitrates in, <a href="#Page_157">157</a>.</li> + </ul> +</li> + +<li> Soluble phosphate, <a href="#Page_386">386</a>.</li> + +<li> Sombrero phosphate, <a href="#Page_308">308</a>, <a href="#Page_328">328</a>, <a href="#Page_330">330</a>, <a href="#Page_379">379</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Somme phosphate, <a href="#Page_378">378</a>.</li> + +<li> Soot, <a href="#Page_428">428</a>; + <ul class="nest"> + <li> application of, rate of, <a href="#Page_429">429</a>;</li> + <li> crops suited by, <a href="#Page_429">429</a>;</li> + <li> nitrogen in, <a href="#Page_428">428</a>.</li> + </ul> +</li> + +<li> South America, guano deposits in, <a href="#Page_327">327</a>; + <ul class="nest"> + <li> meat-meal guano from, <a href="#Page_324">324</a>.</li> + </ul> +</li> + +<li> Starbuck Island guano, <a href="#Page_309">309</a>, <a href="#Page_328">328</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_330">330</a>.</li> + </ul> +</li> + +<li> Stassfurt salts, <a href="#Page_214">214</a>; + <ul class="nest"> + <li> potash in, <a href="#Page_215">215</a>, <a href="#Page_420">420</a>.</li> + </ul> +</li> + +<li> Stead and Ribsdale on formation of basic slag, <a href="#Page_407">407</a>.</li> + +<li> Stoeckhardt, on composition of solid excreta, <a href="#Page_226">226</a>; + <ul class="nest"> + <li> on composition of urine, <a href="#Page_229">229</a>.</li> + </ul> +</li> + +<li> Storer, Professor, on composition of birds' dung, <a href="#Page_331">331</a>; + <ul class="nest"> + <li> on composition of leaves, <a href="#Page_242">242</a>;</li> + <li> on fish-guano, <a href="#Page_323">323</a>;</li> + <li> on nitrogen removed in milk, <a href="#Page_147">147</a>.</li> + </ul> +</li> + +<li> Straw, composition of, <a href="#Page_238">238</a>; + <ul class="nest"> + <li> imports of, <a href="#Page_153">153</a>;</li> + <li> as litter, <a href="#Page_236">236</a>, <a href="#Page_248">248</a>;</li> + <li> mineral matter in, <a href="#Page_238">238</a>, <a href="#Page_243">243</a>;</li> + <li> nitrogen in, <a href="#Page_237">237</a>, <a href="#Page_243">243</a>;</li> + <li> variation in composition of, <a href="#Page_237">237</a>.</li> + </ul> +</li> + +<li> Subsoil, conditions favourable for nitrification in, <a href="#Page_181">181</a>.</li> + +<li> Suffolk coprolites, <a href="#Page_374">374</a>.</li> + +<li> Sugar-beet refuse, potash in, <a href="#Page_219">219</a>.</li> + +<li> Sulphate of alumina, a precipitant of sewage, <a href="#Page_437">437</a>.</li> + +<li> Sulphate of ammonia, <a href="#Page_352">352</a>-358; + <ul class="nest"> + <li> ammonia in, <a href="#Page_355">355</a>;</li> + <li> application of, <a href="#Page_356">356</a>;</li> + <li> composition of, <a href="#Page_355">355</a>;</li> + <li> a concentrated nitrogenous manure, <a href="#Page_356">356</a>;</li> + <li> converted into nitrates, <a href="#Page_356">356</a>;</li> + <li> from gas-works, <a href="#Page_353">353</a>;</li> + <li> from iron-works, <a href="#Page_355">355</a>;</li> + <li> from shale-works, <a href="#Page_354">354</a>;</li> + <li> manure for cereals, <a href="#Page_356">356</a>;</li> + <li> most easily nitrifiable manure, <a href="#Page_191">191</a>;</li> + <li> production of, <a href="#Page_151">151</a>, <a href="#Page_358">358</a>;</li> + <li> properties of, <a href="#Page_355">355</a>;</li> + <li> source of nitrogen, <a href="#Page_149">149</a>;</li> + <li> sources of, <a href="#Page_353">353</a>, <a href="#Page_354">354</a>, <a href="#Page_358">358</a>;</li> + <li> sulphocyanate of ammonia in, <a href="#Page_355">355</a>.</li> + </ul> +</li> + +<li> Sulphate of lime a fixer, <a href="#Page_246">246</a>.</li> + +<li> Sulphate of magnesia, an adulterant of guano, <a href="#Page_319">319</a>; + <ul class="nest"> + <li> as a fixer, <a href="#Page_246">246</a>.</li> + </ul> +</li> + +<li> Sulphate of potash, application of, <a href="#Page_422">422</a> + <ul class="nest"> + <li> —rate of, <a href="#Page_423">423</a>;</li> + <li> compared with muriate, <a href="#Page_421">421</a>;</li> + <li> sources of, <a href="#Page_218">218</a>, <a href="#Page_420">420</a>.</li> + </ul> +</li> + +<li> Sulphuretted hydrogen from farmyard manure, <a href="#Page_258">258</a>.</li> + +<li> Sulphuric acid, action of, on bones, <a href="#Page_382">382</a> + <ul class="nest"> + <li> —on guano, <a href="#Page_311">311</a></li> + <li> —on tricalcic phosphate, <a href="#Page_398">398</a>;</li> + <li> in ash of plants, <a href="#Page_54">54</a>;</li> + <li> as a fixer, <a href="#Page_245">245</a>, <a href="#Page_285">285</a>;</li> + <li> necessary for plant-growth, <a href="#Page_55">55</a>;</li> + <li> superphosphate manufactured with, <a href="#Page_384">384</a>, <a href="#Page_388">388</a>.</li> + </ul> +</li> + +<li> Superphosphate, <a href="#Page_382">382</a>-400; + <ul class="nest"> + <li> action of, <a href="#Page_392">392</a>-395</li> + <li> —sometimes unfavourable, <a href="#Page_395">395</a>;</li> + <li> application of, <a href="#Page_395">395</a></li> + <li> —rate of, <a href="#Page_397">397</a>;</li> + <li> composition of, <a href="#Page_391">391</a>;</li> + <li> discovery of, <a href="#Page_382">382</a>;</li> + <li> hastens early growth, <a href="#Page_394">394</a>;</li> + <li> high-class, <a href="#Page_392">392</a>;</li> + <li> low-class, <a href="#Page_392">392</a>;</li> + <li> manufacture of, <a href="#Page_383">383</a>-385</li> + <li> —phosphates suitable for, <a href="#Page_384">384</a>;</li> + <li> medium-class, <a href="#Page_391">391</a>;</li> + <li> production of, <a href="#Page_382">382</a>;</li> + <li> reversion in, <a href="#Page_389">389</a>, <a href="#Page_399">399</a>, <a href="#Page_400">400</a></li> + <li> —causes of, <a href="#Page_389">389</a>, <a href="#Page_390">390</a>;</li> + <li> reverted in soil, <a href="#Page_392">392</a>.</li> + </ul> +</li> + +<li> Surprise Island guano, <a href="#Page_328">328</a>.</li> + +<li> Swan Island guano, <a href="#Page_328">328</a>.</li> + +<li> Swedes, fertilising ingredients removed from soil by, <a href="#Page_485">485</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_514">514</a>.</li> + </ul> +</li> + +<li> Swine-dung, alkalies in, <a href="#Page_226">226</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_227">227</a>;</li> + <li> nitrogen in, <a href="#Page_226">226</a>;</li> + <li> phosphoric acid in, <a href="#Page_226">226</a>;</li> + <li> water in, <a href="#Page_226">226</a>.</li> + </ul> +</li> + +<li> Swine-urine, alkalies in, <a href="#Page_230">230</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_231">231</a>;</li> + <li> nitrogen in, <a href="#Page_230">230</a>;</li> + <li> phosphoric acid in, <a href="#Page_230">230</a>;</li> + <li> water in, <a href="#Page_230">230</a>.</li> + </ul> +</li> + +<li> Sydney Island guano, <a href="#Page_309">309</a>.</li> + +<li> Syenite, <a href="#Page_106">106</a>; + <ul class="nest"> + <li> phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + </ul> +</li> + +<li> Sylvin, potash in, <a href="#Page_220">220</a>.</li> + +<li> <i>Symbiosis</i>, <a href="#Page_44">44</a>.<br /><br /></li> + + +<li> Tamarugal, Pampa de, nitrate deposit in, <a href="#Page_340">340</a>.</li> + +<li> Tarapaca, nitrate deposits in, <a href="#Page_340">340</a>.</li> + +<li> Temperature necessary for nitrification, <a href="#Page_52">52</a>, <a href="#Page_175">175</a>.</li> + +<li> Tetracalcic phosphate, <a href="#Page_387">387</a>;<span class='pagenum'><a name="Page_591" id="Page_591">[Pg 591]</a></span> + <ul class="nest"> + <li> occurrence of, <a href="#Page_387">387</a>, <a href="#Page_405">405</a>;</li> + <li> solubility of, <a href="#Page_387">387</a>.</li> + </ul> +</li> + +<li> Thaer on application of farmyard manure, <a href="#Page_275">275</a>.</li> + +<li> Thiocyanates, nitrification in, <a href="#Page_182">182</a>.</li> + +<li> Thomas-Gilchrist process of steel-smelting, <a href="#Page_402">402</a>.</li> + +<li> Thomas-slag. See Basic slag.</li> + +<li> Tillage increases number of plants, <a href="#Page_86">86</a>.</li> + +<li> Timor Island guano, <a href="#Page_309">309</a>.</li> + +<li> Tobacco, potash in, <a href="#Page_217">217</a>.</li> + +<li> Torrefied horn, <a href="#Page_426">426</a>.</li> + +<li> Torrefied leather, <a href="#Page_428">428</a>.</li> + +<li> Tortola guano, <a href="#Page_309">309</a>.</li> + +<li> Trachyte, phosphoric acid in, <a href="#Page_202">202</a>, <a href="#Page_211">211</a>.</li> + +<li> Transpiration, by elm-tree, <a href="#Page_71">71</a>; + <ul class="nest"> + <li> by oak-tree, <a href="#Page_71">71</a>.</li> + </ul> +</li> + +<li> Trees, as pumping-engines, <a href="#Page_76">76</a>; + <ul class="nest"> + <li> water transpired by, <a href="#Page_71">71</a>.</li> + </ul> +</li> + +<li> Tricalcic phosphate, <a href="#Page_386">386</a>, <a href="#Page_398">398</a>.</li> + +<li> Tubercles on roots of plants, <a href="#Page_44">44</a>.</li> + +<li> Tull, Jethro, theory of, on plant-growth, <a href="#Page_9">9</a>-11, <a href="#Page_69">69</a>, <a href="#Page_109">109</a>.</li> + +<li> Turkey, dung produced by, <a href="#Page_331">331</a>.</li> + +<li> Turnips, fertilising ingredients removed from soil by, <a href="#Page_485">485</a>; + <ul class="nest"> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_510">510</a>, <a href="#Page_511">511</a>, <a href="#Page_513">513</a>-517;</li> + <li> Rothamsted experiments on growth of, <a href="#Page_568">568</a>.</li> + </ul> +</li> + +<li> Twigs, potash in, <a href="#Page_217">217</a>.</li> + +<li> Tyrosin, assimilated by plants, <a href="#Page_47">47</a>.<br /><br /></li> + + +<li> Ulmates in farmyard manure, <a href="#Page_259">259</a>.</li> + +<li> Ulmic acid, in farmyard manure, <a href="#Page_258">258</a>; + <ul class="nest"> + <li> in humus, <a href="#Page_47">47</a>.</li> + </ul> +</li> + +<li> Ulmin in humus, <a href="#Page_47">47</a>.</li> + +<li> Uncovered farmyard manure, <a href="#Page_263">263</a>, <a href="#Page_289">289</a>.</li> + +<li> Unexhausted manures, valuation of, <a href="#Page_549">549</a>-552, <a href="#Page_558">558</a>.</li> + +<li> Unit value of manurial ingredients, <a href="#Page_544">544</a>.</li> + +<li> Units for determining commercial value of manures, <a href="#Page_554">554</a>.</li> + +<li> Urate of ammonium in Chincha Island guano, <a href="#Page_305">305</a>.</li> + +<li> Urea, assimilated by plants, <a href="#Page_46">46</a>; + <ul class="nest"> + <li> in farmyard manure, <a href="#Page_257">257</a>;</li> + <li> nitrification in, <a href="#Page_182">182</a>.</li> + </ul> +</li> + +<li> Uric acid, experiments with, <a href="#Page_46">46</a>; + <ul class="nest"> + <li> in Chincha Island guano, <a href="#Page_305">305</a>.</li> + </ul> +</li> + +<li> Urine, <a href="#Page_228">228</a>; + <ul class="nest"> + <li> amount voided, <a href="#Page_291">291</a>;</li> + <li> composition of, varies, <a href="#Page_228">228</a>;</li> + <li> contains digested manurial ingredients, <a href="#Page_228">228</a>, <a href="#Page_232">232</a>;</li> + <li> devoid of phosphoric acid, <a href="#Page_205">205</a>;</li> + <li> and dung, composition of, <a href="#Page_234">234</a>;</li> + <li> influence of food on, <a href="#Page_229">229</a>;</li> + <li> nitrification in, <a href="#Page_197">197</a>;</li> + <li> nitrogen in, <a href="#Page_292">292</a>;</li> + <li> potash in, <a href="#Page_292">292</a>;</li> + <li> voided by cows, <a href="#Page_280">280</a>;</li> + <li> voided by oxen, <a href="#Page_280">280</a>;</li> + <li> voided by pigs, <a href="#Page_281">281</a>;</li> + <li> voided by sheep, <a href="#Page_280">280</a>.</li> + </ul> +</li> + +<li> Uruguay, meat-meal guano from, <a href="#Page_324">324</a>.<br /><br /></li> + + +<li> Valuation of manures, <a href="#Page_539">539</a>-559.</li> + +<li> Vegetation, desirable to have soil covered with, <a href="#Page_194">194</a>.</li> + +<li> Venezuela, guano deposits at, <a href="#Page_327">327</a>.</li> + +<li> Ville, Georges, on assimilation of ammonia, <a href="#Page_50">50</a>; + <ul class="nest"> + <li> theory of, on source of plant-nitrogen, <a href="#Page_41">41</a>.</li> + </ul> +</li> + +<li> Vine, potash removed by, <a href="#Page_216">216</a>.</li> + +<li> Virgin soils, <a href="#Page_133">133</a>.</li> + +<li> Voelcker, Dr, analysis of apatite, <a href="#Page_210">210</a> + <ul class="nest"> + <li> —of farmyard manure, <a href="#Page_259">259</a>;</li> + <li> on action of superphosphate, <a href="#Page_395">395</a>;</li> + <li> on fresh and rotted dung, <a href="#Page_261">261</a>, <a href="#Page_286">286</a>;</li> + <li> on guano, <a href="#Page_316">316</a>;</li> + <li> on salt as a manure, <a href="#Page_473">473</a>.</li> + </ul> +</li> + +<li> Voss, Hermann, on manures used, <a href="#Page_152">152</a>.<br /><br /></li> + + +<li> Wagner, Professor, on, application of basic slag, <a href="#Page_416">416</a>; + <ul class="nest"> + <li> assimilation of organic nitrogen, <a href="#Page_46">46</a>;</li> + <li> experiments with basic slag, <a href="#Page_408">408</a>-413;</li> + <li> fineness of basic slag, <a href="#Page_409">409</a>;</li> + <li> manures, <a href="#Page_412">412</a>;</li> + <li> relative manurial value of nitrogen compounds, <a href="#Page_556">556</a>;</li> + <li> solubility of basic slag, <a href="#Page_408">408</a>.</li> + </ul> +</li> + +<li> Wallace, Dr, on sewage purification, <a href="#Page_436">436</a>.</li> + +<li> Walruses, guano from, <a href="#Page_297">297</a>.</li> + +<li> Warington, R,., on ammonia in rain, <a href="#Page_49">49</a>; + <ul class="nest"> + <li> on appearance of nitrous organisms, <a href="#Page_168">168</a>;</li> + <li> on conditions favourable for nitrification, <a href="#Page_181">181</a>;</li> + <li> experiments on rate of nitrification, <a href="#Page_186">186</a>;</li> + <li> on composition of farmyard manure, <a href="#Page_260">260</a>;</li> + <li> on manufacture of superphosphate, <a href="#Page_383">383</a>;</li> + <li> on manurial constituents of foods, <a href="#Page_282">282</a>;</li> + <li> on nitrification in alkaline solutions, <a href="#Page_197">197</a>;</li> + <li> on nitrogen in excrements, <a href="#Page_233">233</a>;</li> + <li> on nitrogen in soil, <a href="#Page_122">122</a>;</li> + <li> on potash in wool, <a href="#Page_227">227</a>;</li> + <li> researches of, on nitrification, <a href="#Page_35">35</a>, <a href="#Page_52">52</a>, 166-168, <a href="#Page_180">180</a>, <a href="#Page_186">186</a>.</li> + </ul> +</li> + +<li> Water, absorbed by plants, <a href="#Page_73">73</a>;<span class='pagenum'><a name="Page_592" id="Page_592">[Pg 592]</a></span> + <ul class="nest"> + <li> amount of, transpired by plant-leaves, <a href="#Page_56">56</a>;</li> + <li> an adulterant of guano, <a href="#Page_319">319</a>;</li> + <li> a carrier of plant-food, <a href="#Page_55">55</a>;</li> + <li> in cow-dung, <a href="#Page_226">226</a></li> + <li> —cow-urine, <a href="#Page_230">230</a>;</li> + <li> from decomposition of farmyard manure, <a href="#Page_257">257</a>;</li> + <li> in horse-dung, <a href="#Page_226">226</a></li> + <li> —horse-urine, <a href="#Page_230">230</a>;</li> + <li> necessary for plant, <a href="#Page_67">67</a>;</li> + <li> in pig-dung, <a href="#Page_226">226</a></li> + <li> —pig-urine, <a href="#Page_230">230</a></li> + <li> —sheep-dung, <a href="#Page_226">226</a></li> + <li> —sheep-urine, <a href="#Page_230">230</a>;</li> + <li> transpired by elm-tree, <a href="#Page_71">71</a></li> + <li> —oak-tree, <a href="#Page_71">71</a>.</li> + </ul> +</li> + +<li> Water-culture, <a href="#Page_54">54</a>.</li> + +<li> Water-logged soils, <a href="#Page_179">179</a>.</li> + +<li> Waterloo, bones from, <a href="#Page_360">360</a>.</li> + +<li> Way, Thomas, on retention of plant-food by soil, <a href="#Page_57">57</a>, <a href="#Page_59">59</a>; + <ul class="nest"> + <li> on sewage, <a href="#Page_437">437</a>.</li> + </ul> +</li> + +<li> West Indies, guano from, <a href="#Page_298">298</a>.</li> + +<li> Whales, guano from, <a href="#Page_322">322</a>.</li> + +<li> Wheat, fertilising ingredients removed from soil by, <a href="#Page_485">485</a>; + <ul class="nest"> + <li> Flitcham experiments on, <a href="#Page_500">500</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>;</li> + <li> manuring of, <a href="#Page_499">499</a>-501</li> + <li> nitrogen removed in crop of, <a href="#Page_145">145</a>;</li> + <li> requires nitrogenous manures, <a href="#Page_499">499</a>;</li> + <li> Rothamsted experiments on, <a href="#Page_500">500</a>, <a href="#Page_562">562</a>-565;</li> + <li> a source of nitrogen, <a href="#Page_153">153</a>.</li> + </ul> +</li> + +<li> Wheat soils, nitrates in, <a href="#Page_157">157</a>.</li> + +<li> Wheat-straw, analysis of stable manure made from, <a href="#Page_283">283</a>; + <ul class="nest"> + <li> composition of, <a href="#Page_238">238</a>;</li> + <li> manurial constituents in, <a href="#Page_282">282</a>.</li> + </ul> +</li> + +<li> White clover, growth of, promoted by lime, <a href="#Page_451">451</a>.</li> + +<li> Wiegmann on ash constituents of plants, <a href="#Page_53">53</a>.</li> + +<li> Wilfarth on nitrogen in plants, <a href="#Page_44">44</a>.</li> + +<li> Wilting, <a href="#Page_73">73</a>.</li> + +<li> Winogradsky, on nitrification, <a href="#Page_52">52</a>, <a href="#Page_167">167</a>, <a href="#Page_169">169</a>, <a href="#Page_197">197</a>; + <ul class="nest"> + <li> on organisms in soil, <a href="#Page_94">94</a>.</li> + </ul> +</li> + +<li> Wolff on, analysis of manure-heap drainings, <a href="#Page_290">290</a>; + <ul class="nest"> + <li> composition of fresh and rotten dung, <a href="#Page_288">288</a>;</li> + <li> assimilation of organic nitrogen by plants, <a href="#Page_47">47</a>;</li> + <li> relative manurial value of manurial compounds, <a href="#Page_556">556</a>;</li> + <li> urine, <a href="#Page_232">232</a>.</li> + </ul> +</li> + +<li> Wood-ashes as potash manure, <a href="#Page_218">218</a>, <a href="#Page_419">419</a>.</li> + +<li> Woodhouse, researches of, on nitrogen in plants, <a href="#Page_41">41</a>.</li> + +<li> Wool, capable of nitrification, <a href="#Page_182">182</a>; + <ul class="nest"> + <li> potash in, <a href="#Page_217">217</a>.</li> + </ul> +</li> + +<li> Wool-waste, <a href="#Page_427">427</a>; + <ul class="nest"> + <li> nitrogen in, <a href="#Page_427">427</a>.</li> + </ul> +</li> + +<li> Woolney, on organisms in soils, <a href="#Page_93">93</a>, <a href="#Page_95">95</a>; + <ul class="nest"> + <li> on water in soils, <a href="#Page_75">75</a>.</li> + </ul> +</li> + +<li> Wrightson, Professor, on application of basic slag, <a href="#Page_414">414</a>.<br /><br /></li> + + +<li> Yeast, <a href="#Page_94">94</a>.</li> + +<li> Yorkshire, bones first used in, <a href="#Page_359">359</a>.<br /><br /></li> + + +<li> Zeolites, potash in, <a href="#Page_220">220</a></li> +</ul> + +<br /> +<br /> +<br /> +<br /> +<p class="cen">PRINTED BY WILLIAM BLACKWOOD AND SONS.</p> + +<br /> +<br /> +<br /> +<br /> +<div class="tr"> +<p class="cen"><a name="TN" id="TN"></a>Transcriber's Note</p> +<br /> + +Typographical errors corrected in the text:<br /> +<br /> +Page 58 Eichorn changed to Eichhorn<br /> +Page 134 diferent changed to different<br /> +Page 464 superposphate changed to superphosphate<br /> +Page 553 biophosphate changed to biphosphate<br /> +Page 579 Gallopagos changed to Galapagos<br /> +</div> + + + + + + + + +<pre> + + + + + +End of the Project Gutenberg EBook of Manures and the principles of manuring, by +Charles Morton Aikman + +*** END OF THIS PROJECT GUTENBERG EBOOK MANURES, PRINCIPLES OF MANURING *** + +***** This file should be named 27274-h.htm or 27274-h.zip ***** +This and all associated files of various formats will be found in: + https://www.gutenberg.org/2/7/2/7/27274/ + +Produced by Steven Giacomelli, Barbara Kosker and the +Online Distributed Proofreading Team at https://www.pgdp.net +(This file was produced from images produced by Core +Historical Literature in Agriculture (CHLA), Cornell +University) + + +Updated editions will replace the previous one--the old editions +will be renamed. + +Creating the works from public domain print editions means that no +one owns a United States copyright in these works, so the Foundation +(and you!) can copy and distribute it in the United States without +permission and without paying copyright royalties. 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