How crops feed. A treatise on the atmosphere and the soil as related to the nutrition of agricultural plants

Front matter

A TREATISE ON THE

ATMOSPHERE AND THE SOIL

AS RELATED TO THE

Preface

The work entitled “How Crops Grow” has been received with favor beyond its merits, not only in America, but in Europe. It has been republished in England under the joint Editorship of Professors Church and Dyer, of the Royal Agricultural College, at Cirencester, and a translation into German is soon to appear, at the instigation of Professor von Liebig.

The Autlior, therefore, puts forth this volume — the companion and complement to the former — with tlie hope that j it also will be welcomed by those who appreciate the sci- ^tific aspects of Agriculture, and are persuaded that a • y true Theory is the surest guide to a successful Practice.

^ The writer does not flatter himself that he has produced , a popular book. He has not sought to excite the imagi- , nation with high-wrought pictures of overflowing fertility - as the immediate result of scientiflc discussion or experi- ^""^ent, nor has he attempted to make a show of revolutionizing his subject by bold or striking speculations. His ^ office has been to dis^est the cumbrous mass of evidence, m which the truths of Vegetable Nutrition lie buried out

VI

PREFACE.

of the reach of the ordinary inquirer, and to set them forth in proper order and in plain dress for their legitimate and sober uses.

It has cost the Investigator severe study and labor to discover the lav^s and many of the facts which are laid down in the following pages. It has cost the Author no little work to collect and arrange the facts, and develop their mutual bearings, and the Reader must pay a similar price if he would apprehend them in their true significance.

In this, as in the preceding volume, the Author’s method has been to bring forth all accessible facts, to present their evidence on the topics under discussion, and dispassionately to record their verdict. If this procedure be sometimes tedious, it is always safe, and there is no other mode of treating a subject which can satisfy the earnest inquirer.

It is, then, to the Students of Agriculture, whether on the Farm or in the School, that the Author commends his book, in confidence of receiving full sympathy for its spirit, whatever may be the defects in its execution.

CONTENTS,

Introducttion. .^17

DIVISION L

THE ATMOSPHERE AS RELATED TO VEGETATION, CHAPTER I,

Atmospheric Air as the Food of Plants.

§ 1. Chemical Composition of the Atmosphere .21

§ 2, Relation of Oxygen Gas to Vegetable Nutrition...^..,., 22

§ 3. “ “ Nitrogen Gas to “ “ 26

§ 4, ** “ Atmospheric Water to Vegetable Nutrition 34

§ 5, « Carbonic Acid Gas “ ** .....38

§ 6. * « Atmospheric Ammonia to ** .......49

§ 8. Compounds of Nitrogen and Oxygen in the Atmosphere 70

§ 9. Other Ingredients of the Atmosphere 91

§ 10. Recapitulation of the Atmospheric Supplies of Food to Crops 94

§ 11. Assimilation of Atmospheric Pood 97

§ 12. Tabular View of the Relations of the Atmospheric Ingredients to the Life of Plants 98

CHAPTER II. The Atmosphere as Physically Related to Vegetation

§ 1. Manner of Absorption of Gaseous Pood by Plants

DIVISION n.

THE SOIL AS RELATED TO VEGETABLE PRODUCTION. CHAPTER 1.

Introductory.

Tin

BOW CROPS PEED.

CHAPTER II.

Origin anif Formation op Soils 106

I 1. Chemical Elements of Rocks lOT

I 2. Mineralogical Elements of Rocks 108

0 § 3. Kocks^ their Kinds and Characters 117

I 4. Conversion of Rocks into Sk>il 122

i 5. Incorporation of Organic Matter with the Soil, and its Effects 135

CHAPTER III. Kinos of Soils, their Definition and Classification

I 1. Distinctions of Soils based upon the Mode of their Formation or Deposition 142

I 2. Distinctions of Soils based upon Obvious or External Characters 14^

Chapter IV

§ 1. Weight of Soils 158

§ 2. State of Division 159 ^

§ 3. Absorption of Vapor of Water,. . . 161

I 4. Condensation of Gases 165

§ 5. Power of Removing Solid Matters from Solution 171

§6. Perroeability to Liquid Water. Imbibition. Capillary Power 176

§ 7. Changes of Bulk by Drying and Frost 183

§ 8. Adhesiveness 184

§ 9. Relations to Heat 186

Chapter V

The Soil as a Source of Food to Crops : Ingredients whose Elements ARE OF Atmospheric Origin.

The Free Water of the Soil in its Relations to Vegetable Nutrition

The Air of the Soil !

Non-nitrogenous Organic Matters. Humus

The Ammonia of the Soil

Nitric Acid (Nitrates) of the Soil

Nitrogenous Organic Matters of the Soil. Available Nitrogen

Decay of Organic Matters.

Nitrogenous Principles of Urine

Comparative Nutritive Value of Animoni^-SaUs and Nitrates

,222

COJ^TENTS,

IX

Chapter VI

The Soil as a Source op Food to Crops : Ingredients whose Elements ARE Derived from Rocks.

§ 1. General View of the Constitution of the Soil as Related to Vegetable

Nutrition ; 305

§ .3. Solution of the Soil in Strong Acids 329

§ 4. Portion of Soil Insoluble in Acids . . 330

§ 5. Reactions by which the Solubility of the Elements of the Soil Is altered. Solvent Effects of Various Substances. Absorptive and

Fixing Power of Soils 331

Index

Absorption and displacement, law

Absorptive power of soils 333

“ “ “ significance

Acids in soil 223

“ absorbed by soils 355

Adhesion 165

Adhesiveness of soils 184

Air, atmospheric, composition of.. 21 “ within the plant, composition

of 45

Alkali-salts, solvent eflfect of 130

Allotropism 66

Alluvium 145

Aluminum, alumina 107

Amides 276

Amide-like bodies 277, 300

“ absorbed by clay 243, 267

“ condensed in soils 240

“ conversion of into nitric

acid 85

“ evolved from flesh decaying under charcoal 169

“ fixed by gypsum 244

“ in atmosphere 54

“ “ “ how formed.77, 85

“ of rain, etc 60

“ of the soil, formation of. 239

“ “ “ chemically

combined. 243

“ “ “ physically

condensed. 240 “ “ “ quantity of. .248

“ “ “ solubility of. 246

“ “ “ volatility of.. 244

Ammonia-salts and nitrates, nutritive value of 300

Amphibole 112

Analysis of soils, chemical indications of. 368

mechanical 147

Apatite 116

Apocrenates 231

Apocrenic acid 227, 229

Argillite 119

Ash-ingredients, quantity needful

for crops 363

Atmosphere, chemical composition.. 21, 22

“ physical constitution. . 99

Atmospheric food, absorb.ed 99

“ “ assimilated — 97

Barley crop, ash ingredients of. .364

Basalt 120

Bases, absorbed by soils. 335, 359

Bisulphide of iron 115

Burning of clay 185

Calcite 115

Capillarity 175, 199, 201

Carbohydrates in soil 222

Carbon, fixed by plants 43, 48

“ in decay 291

“ supply of 95

“ “ absorbed by soil 221

45, 98

“ “ exhaled by plants.. 43, 99

“ “ in the soil 218

“ “ “ water of soil. .220

“ “ quantity in the air.40,

47, 94

“ “ solubility in water. 40, 130

XII

HOW CROPS FEED.

Carbonic acid, solvent action of 128

Carbonic oxide 92

Cliabasite 115

“ action on saline compounds 845

“ formed in Roman masonry 351

Chalk soils 192

Charcoal, absorbs gases 165

‘‘ defecating action of. 174

Chili saltpeter 253

Chlorite 113

Chrysolite 114

“ absorptive power, 174

“ effect of, on urine 293

Clay-slate 119

Coffee, condenses gases 168

Color of soil -..190

Conglomerates. . 121

Crenates 231

Crenic acid 227, 229

Decay 289

Deliquescence 163

Deserts 197

Diffusion of gases 100

Diorite 120

Dolerite 120

Dolomite 115, 121

Draining 185

Drain water, composition of 312

Drift 144

Dye stuffs, fixing of 174

Earth-closet 171

Eremacausis 289

Evaporation, produces cold 188

“ amount of, from soil. 197

Exhalation 202, 206

Exposure of soil — 195

Feldspar 108

“ growth of barley in 160

Fermentation 290

Fixtation of bases in the soil 839

Frost, effects of, on rocks 124

Fumic acid 258

Gases, absorbed by the plant 103

“ “ “ porous bodies., 167

“ diffusion of 100

“ osmose of 102

Glaciers 124

Glycine 206

Glycocoll 296

Gneiss 119

Granite 118, 120

Gravel 152

“ warmth of 195

Guanin • 296

Gypsum 115

“ does not directly absorb

“ fixes ammonia 244

Hard pan 156

Heat, absorptioivand radiation of,.

188, 193

“ developed in flowering 24

“ of soil 187

Hippuric acid 295, 277

Hornblende 112

Hydration of minerals 127

Hydraulic cement 122

Hydrochloric acid gas 93

Hydrogen, supply of, to plants 95

“ in decay 291

Hydrous silicates, formation of 352

Hygroscopic quality 164

Huniates 230

Humic acid 226, 229

“ absorbent power for water. . 162 “ absorbs salts from solutions. 172

“ action on minerals 138

“ chemical nature of 138

“ does it feed the plant? 232

“ not essential to crops 2:18

“ value of 182

Iodine in sea-water. . . 322

Isomorphism Ill

Kreatin 196

Kaolinite 113, 132

Latent heat 188

Lawes’ and Gilbert’s wheat experiments 372

Leucite 113

Lime, effects of 184, 185

Loam 154

Lysimetcr 314

Magnesite 115

Marble 121

Marl 155

Marsh gas 91, 99

Mica 109

INDEX,

XIII

Mica slate ... .J 119

Minerals 106, 108

‘‘ hydration of. 127

“ solution of 127

“ variable composition of 110

Moisture, effect of, on temperature

of soil 195

Mold 156

Moor-bed pan . ... 157

Muck 155

Nitrate of ammonia 71, 73

“ in atmosphere. 89

Nitrates 252

“ as food for plants •. . . 271

“ formed in soil 171, 179

“ in water 270

“ loss of. 270

“ reduction of. 73, 82, 85

“ “ “ in soil 268

“ tests for 75

“ “ as plant-food 90, 98

“ “ deportment towards the

soil :157

“ “ in atmosphere £0

“ “ “ rain-water 86

“ “ “ “ sources of 256

Nitric oxide 72

Nitric peroxide 72

Nitrification 252, 286

“ conditions of 265, 292

Nitrogen, atmospheric supply to

“ combined, in decay. 291, 292

“ “ of the soil. , .275

“ combined, of the soil,

available 283

“ combined, of the soil,

inert 278

“ combined, of the soil,

quantity needed for crops.2S8 “ free, absorbed by soil. . .167

“ “ assimilated by the

soil 259

“ “■ in soil 218

“ “ not absorbed by

vegetation 26, 99

** “ not emitted by living plants 23

Nitrogen-compounds, formation of,

in atmosphere. 75, 77, 83

Nitrogenous fertilizers, effect on

cereals ... 83 Nitrogenous organic matters of soil. 274

Nitrous acid 72

Nitrous oxide 71, 93

Ocher 156

Oxidation, aided by porous bodies.

169, 170

Oxide of iron, a carrier of oxygen. .257 “ ‘‘ hydrated, in the soil. 350

Oxygen, absorbed by plants 98

“ essential to growth 23

“ exhaled by foliage 25, 99

“ function of, in growth 24

“ in soil 218

“ supply 94

“ weathering action of 131

“ concerned in oxidation of nitrogen 82

“ formed by chemical action. 60, 67 “ produced by vegetation. 67, 84, 99 “ relations of, to vegetable nutrition...*. 70

Pan, composition of 852

Parasitic plants, nourishment of. . .235

“ nitrogen of 274

Phosphate of lime 116

Phosphoric acid fixed by the soil . . .357 “ presence in soil

Phosphorite 116

Plant-food, concentration of. 320

maintenance of supply. 371

Platinized charcoal 170

Platinum sponge, condenses oxygenl70

Porphyry .120

Potash, quantity in barley crop 863

Provence, drouths of 198

Pyrites 115

Pyroxene 112

Pumice 120

Putrefaction. 290

Rain-water, ammonia in 60, 88

‘‘ nitric acid in 86

“ phosphoric acid in 94

Ree Ree bottom, soil of 160

Respiration of the plant 43

“ attacked by plants. 140

XIV

HOW CROPS PEED.

Rocks, conversion into soils 122

Roots, direct action on soil 32(i

Saline incrustations 179

Saltpeter 252

Salts decomposed or absorbed by

the soil 336

Sand filter ^ 172

Sandstone 121

Serpentine 114, 121

Schist, micaceous 119

“ talcose ..121

chlorite 121

Shales 122

Sherry wine region 192

Shrinking of soils 183

“ function in the soil 353

“ of soil, liberated by strong

acids 330

Silicates . . .109

“ zeolitic, presence in soils. .349

Silicic acid, fixed in the soil 358

Silk, hygroscopic 165

Soapstone 121

Sod, temperature of 199

Soil 104

“ absorptive power of 333

“ aid to oxidation 17Q

“ aqueous solution of 309, 323, 328

“ condenses gases 165, 166

“ capacity for heat 194

“ chemical action in 331

“ composition of. .362, 369

“ exhaustion of. 373

“ inert basis 305

“ natural strength of..., 372

“ origin and formation. .106, 122, 135

“ physical characters 157

“ porosity of. 176

“ portion insoluble in acids 330

“ relative value of ingredients 367

“ reversion to rock 332

“ solubility in acids 329

“ source of food to crops .305

“ state of division 159

Soils, sedentary 143

transported 143

“ weight of 158

Solubility, standards of 308

Solution of soil in acids .370

Steatite 121

Swamp muck 155

Sulphates, agents of oxidation 258

Sulphate of lime 115

Sulphur, in decay ..293

Sulphurous acid 94

Sulphydric acid 94

Syenite 120

Talc 113

Temperature of soil 186, 187, 194

Transpiration 202, 208

Trap rock 120

U1 mates 230

Uric acid 295, 277

Urine 293

preserved fresh by clay 293

its nitrogenous principles assimilated by plants 296

Vegetation, antiquity of 138

decay of. 137

action on soil 140

Volcanic rocks, conversion to soil.. 135

Wall fruits 199

Water absorbed by roots 202, 210

functions of, in nutrition of

plant 216

imbibed by soil 180

movements in soil 177

proportion of in plant, influenced by soil 213

“ bottom water 200

capillary ... 200

hydrostatic 199

hygroscopic 201

quantity favorable to crops. .214

Water-currents 124

Water-vapor, absorbed by soil. 161, 164

“ exhaled by plants 99

“ not absorbed by

“ of the atmosphere 34

Weathering 131-134

Wilting 203

Woc:-l, hygroscopic 164

Zeolitea 114, 349

HOAV CROPS FEED.

INTRODUCTIOJf*

In his treatise entitled How Crops Grow,” the author has described in detail the Chemical Composition of Agrb cultural Plants, and has stated what substances are indispensable to their growth. In the same book is given an account of the apparatus and processes by which the plant takes up its food. The sources of the food of crops are, however, noticed there in but the briefest manner. The present work is exclusively occupied with the important and extended subject of Vegetable Nutrition, and is thua the complement of the first-mentioned treatise. Whatever information may be needed as preliminary to an under standing of this book, the reader may find in ‘‘ How Cropa Grow.” *

That crops grow by gathering and assimilating food is a conception with which all are familiar, but it is only by following the subject into its details that we can gain hints that shall apply usefully in Agricultural Practice.

* It has been at least the author’s aim to make the first of this series of bookie prepare the way for the second, as both the first and the second are written tu make possible an intellij^ible account of the mode of action of Tillage and of Fertilizers, which will be the subject of a third work.

When a seed germinates in a medium that is totally destitute of one or all the essential elements of the plant, the embryo attains a certain development from the materials of the seed itself (cotyledons or endosperm,) but shortly after these are consumed, the plantlet cetises to increase in dry weight,^ and dies, or only grows at its ow n expense.

A similar seed deposited in or<lmary soil, watered with rain or spring water and freely exposed to the atmosphere, evolves a seedling which survives the exhaustion of the cotyledons, and continues without cessation to grow, forming cellulose, oil, starch, and albumin, increases many times — a hundred or two hundred fold — in weight, luns normally through all the stages of vegetation, blossoms, and yields a dozen or a hundred new seeds, each as perfect as the original.

It is thus obvious that A^V, W(xte}\ and Soil^ are capable of fe(*ding plants, and, under purely natural conditions, do exclusively nourish all vegetation.

In the soil, atmosphere, and water, can be found no trace of the peculiar organic principles of plants. We look there in vain for cellulose, starch, dextrin, oil, or albumin. The natural sources of the food of crops consist of various salts and gases which contain the ultimate elements of vegetation, but which require to be collected and worked over by the plant.

ITie embryo of the geiminating seed, like the bud of a tree when aroused by the spring warmth from a dormant state, or like the sprout of a potato tuber, enlarges at the expense of previously organized matters, supplied to it by the contiguous parts.

As soon as the plantlet is weaned from the stores of the

♦ Since vegetable matter may contain a variable amount of water, either that which belongs to the sap of the fresh X)lant, or that which is hygroscopically retained in the pores, all comparisons must be made on the rf/v/, i. water -free substance. See ’'How Crops Grow,” pi). 513-5.

INTilOtrlrCTION.

mother seed, the materials, as well as the mode of its nutrition, are for the most part completely changed. Henceforth the tissues of the plant and the cell-contents must be principally, and may be entirely, built up from purely inorganic or mineral matters.

In studying the nutrition of the plant in those stages of its* growth that are subsequent to the exhaustion of the cotyledons, it is needful to investigate separately the nutritive functions of the Atmosphere and of the Soil, for the important reason that tlie atmosphere is nearly constant in its composition, and is beyond the reach of human influence, while the soil is infinitely variable and may be exhausted to the verge of unproductiveness or raised to the extreme of fertility by the arts of the cultivator.

In regard to the Atmosphere, we have to notice minutely the influence of each of its ingredients, including Water in the gaseous form, upon vegetable production.

The evidence has been given in ‘‘ How Crops Grow,” which establishes what fixed earthy and saline matters are esstmtial ingredients of plants. The Soil is plainly the exclusive source of all those elements of vegetation which cannot assume the gaseous condition, and which therefore cannot exist in the atmosphere. The study of tlie soil involves a consideration of its origin and of its manner of formation. The productive soil commonly contains atmospheric elements, which are important to its fertility; the mode and extent of their incorporation with it are topics of extreme practical importance. We have then to examine the significance of its water, of its ammonia, and especially of its nitrates. These subjects have been i-ecently submitted to extended investigations, and our treatise contains a large amount of information pertaining to them, which has never before appeared in any publication in the English tongue.

Those characters of the soil that indirectly afifect the growth of plants are of the utmost moment to the farmer. It is through the soil that a supply of solar heat, with^ now CKOPS FEED.

out wliich no life is possible, is largely influenced. Water, whose excess or deflcieiicy is as pernicious as its proper quantity is beneficial to crops, enters the plant almost exclusively through its roots, and hence those qualities of the soil which are most favorable to a due supply of this liquid demand careful attention. The absorbent power of soils for the elements of fertilizers is a subject which is treated of with considerable fullness, as it deserves.

Our book naturally falls into two divisions, tlie first of which is devoted to a discussion of the Relations of the Atmosphere to Vegetation, the second being a treatise on the Soil.

DIVISION I

THE ATMOSPHERE AS RELATED TO VEGETATION.