Fertilizers; the source, character, and composition of natural, home made and manufactured fertilizers; and suggestions as to their use for different crops and conditions

Front matter

Cliap...p.._ Copyright No

UNITED STATES OF AMERICA.

5>

CHAPTER I The Natural Fertility of the Soil, and Sources op

Loss OF the Elements of Fertility 1-20

Soil Fertility— Chemical elements needed in plant growth— Fertility as influenced by water, climate and season— The influence of physical character of soil- Location of soil qualifies the term "fertility " —Practical fertility is usable potential fertility 2-7

What Becomes of Our Fertility ? 7-8

Sources of Natural Loss op Nitrogen— Importance of careful culture— Loss of nitrogen by drainage— Escape of nitrogen into the atmosphere 8-12

The Natural Loss op the Mineral Elements— Losses due to mechanical means 12-14

Artificial Losses op Fertility— A comparison of the prices received for the fertility elements in different crops- Fertility content of cereals and vegetables — Irrational farm practice— Losses in manures 14-20

CHAPTER II The Function of Manures and Fertilizers, and the

Need of Artificial Fertilizers 21-37

The Essential Elements op Fertilizers 21

Natural Manures and Artificial Fertilizers 22

(vii)

Ylii CONTENTS

Direct and Indirect Effect of Manures 23

Unavailable and Available Plant-food 24-26

Danger of Loss from the Use of Soluble Plant-food.. 26 The Usefulness of a Fertilizer Constituent Does not

Depend Upon Its Original Source 27

Use of Fertilizers 28, 29

The Need of Artificial Fertilizers— The cost of production per unit of income is increased— A greater demand for special crops — Farm manures are inadequate— The growing importance of fruit-growing 30-35

Will It Pay to Use Fertilizers? 35-37

CHAPTER III Nitrogenous Fertilizers 38-57

What Is Meant by Form of Nitrogen ? 39

Dried Blood 40, 41

Dried Meat or Meal, Azotin, Ammonite, or Animal

Matter 41

Hoof Meal 42

Dried and Ground Fish, or Fish Guano 42

King Crab 43

Tankage 43, 44

Garbage Tankage 44

Low-grade Nitrogenous Products — Leather meal— Wool

and hair waste 45

Vegetable Nitrogenous Products— Cotton-seed meal- Linseed meal— Castor pomace 46

Natural Guanos 47-49

Ammonia Compounds — Sulfate of ammonia 50, 51

Nitrate Nitrogen— Nitrate of soda 52

The Relative Availability of the Different Forms of

Nitrogen— Conditions which modify availability 53-57

CONTEXTS IX

CHAPTER IV Phosphates— Their Sources, Composition, and Relative Value ... 58-77

Phosphate of Lime, or Bone Phosphate— Animal Bone— Raw bone — Fine bone— Boiled and steamed bone— Bone tankage— Other organic products — Bone-black, or animal charcoal— Bone ash 59-66

Mineral Phosphates— South Carolina rock phosphates — Florida phosphates— Canadian apatite— Tennessee phosphate—Iron phosphate, or Thomas phosphate powder— Phosphatic guanos 66-71

Phosphates as Sources of Phosphoric Acid to Plants— The influence of source of phosphate upon availability — Influence of fineness of division— The character of soil as a factor influencing availability— Influence of kind of crop— General considerations 71-77

CHAPTER V Superphosphates— Potash 78-98

Insoluble Phosphoric Acid 78

Soluble Phosphoric Acid 79

Reverted Phosphoric Acid 80

How Superphosphates are Made— The difference in the superphosphates made from the different materials — Soluble phosphoric acid identical chemically, from whatever source derived 80-83

Phosphates and Superphosphates are not Identical . . . 83-87

Double Superphosphates 87

Chemical Composition of Superphosphates— Well-made superphosphates contain no free acid— Phosphoric acid remains in the soil until taken out by plants 88-91

Potash Salts— The importance of potash as a constituent of fertilizers — Forms of potash— Kainit—Sylvinit— Muriate of potash— High-grade sulfate of potash — Double sulfate of potash and magnesia— Fixation of potash , 92-98

X CONTENTS

CHAPTER VI Miscellaneous Fertilizing Materials 99-123

Tobacco Stems and Stalks 100, 101

Crude Fish Scrap 101-103

Wool and Hair Waste 103

Poultry and Pigeon Manures 104

Sewage 105

Muck and Peat 106

King Crab, Mussels and Lobster Shells 107

Seaweed 108

Wood Ashes and Tan-bark Ashes 109-111

Coal Ashes Ill

Cotton-hull Ashes Ill

Marl 112

Agricultural Salt 116

Powder Waste , 117

Green Manures— "Nitrogen gatherers " and "nitrogen consumers"— The most useful crops— Green manure crops that

consume the nitrogen in the soil 117-123

CHAPTER VII Purchase of Fertilizers 124-148

Standard High-grade Materials 125, 126

Fertilizing Materials Variable in Composition 126, 127

High-grade and Low-grade Fertilizers— The "unit" basis of purchase— The "ton" basis of purchase — The necessity of a guarantee— Laws alone do not fully protect— Method of statement of guarantee sometimes misleading- Discussion of guarantees — The advantages and disadvantages of purchasing raw materials and mixed fertilizers . . . 127-141

Home Mixtures— Formulas— A low-grade fertilizer— The cost

of handling " make-weight " 141-147

General Advice 147-148

CONTENTS XI

CHAPTER VIII Chemical Analyses of Fertilizers 149-166

The Interpretation of an Analysis 149-152

The Agricultural Value of a Fertilizer 152-153

The Commercial Value of a Fertilizer— Schedule of

trade values adopted by experiment stations for 1898 153-162

Calculation of Commercial Values 162-164

The Uniformity of Manufactured Brands 164-166

CHAPTER IX Methods of Use of Fertilizers 167-190

Conditions Which Modify the Usefulness of Fertilizers— Derivation of soil a guide as to its possible deficiencies— Physical imperfections of sandy soils — Physical imperfections of clay soils — The influence of previous treatment and cropping— The influence of character of crop— The kind of farming, whether "extensive" or "intensive " 167-177

Plants Vary in Their Power of Acquiring Food— Characteristics of the cereal group— Characteristics of grasses and clovers— Root crops— Market-garden crops— Fruit crops 177-182

Systems of Fertilizing Suggested— A system based upon the specific influence of a single element— A system based upon the necessity of an abundant supply of the minerals—A system based on the needs of the plants for the different elements as shown by chemical analysis— A system in which the fertilizer is applied to the "money orop" in the rotation— An irrational system 182-190

Summary 190

CHAPTER X Fertilizers for Cereals and Grasses 191-213

Experiments to Determine the Lacking Element— A

scheme for plot experiments— Results that maybe attained. 193-198

Xll CONTENTS

The Importance op System in the Use op Fertilizers— Indian corn exhaustive of the fertility elements— Oats- Wheat— Clover— Timothy— A gain of fertility by the system—The necessity of adding more plant-food than is requii-ed by a definite increase in crop— The system should

be modified if no farm manures are used 198-207

Fertilizers for a Single Crop Grown Continuously . . . 208-211

Fertilizers for Meadows 211

Will This System of Fertilizing Pay? 212,213

CHAPTER XI Potatoes, Sweet Potatoes, Tomatoes and Sugar Beets . 214-240

Fertilizers for Potatoes, Early Crop— The time and method of application— The amount to be applied— Form of the constituents 215-220

Late Potatoes 220, 221

Sweet Potatoes— Fertilizer constituents contained in an average crop- The application of fertilizers 221, 226

Tomatoes— Field experiments with fertilizers for tomatoes — Fertilizers for the early crop for different conditions of soil— The use of fertilizers with yard manures— Fertilizers for late tomatoes 226-235

Sugar Beets— The demands of the crop for plant-food— The influence of previous deep cultivation of soil 235-240

CHAPTER Xn Green Forage Crops 241-261

Maize (corn) forage— Silage corn— Wheat and rye forage- Spring rye— Oats— Oats and peas— Barley and peas -Millet.

Clovers and Other Legumes— Cow pea and soy bean- Alfalfa, or Lucerne— Need of lime for legumes — Scheme of soiling crops 249-257

Root Crops— Fertilizers for fodder beets, sugar beets and carrots — Turnips, Swedes and rape 257-261

Tuber Crops 261

CONTENTS XUl CHAPTER XIII

Market-garden Crops 262-281

The Yield and Quality Dependent upon Continuous

AND Rapid Growth 262-264

Asparagus— The use of salt— Fertilizers that have proved

useful— A basic fertilizer for market-garden crops 264-269

Peas and Beans 269, 270

Beets and Turnips 270-272

Cabbage, Cauliflower and Brussels Sprouts 272, 273

Cucumbers, Watermelons, Muskmelons, Pumpkins and

Squashes 273-275

Celery 275

Sweet Corn 276

Egg-plant, Spinach, Lettuce and Rhubarb 277-278

Onions, Onion Sets and Scallions 278-281

CHAPTER XIV

Orchard Fruits and Berries 282-304

Fruit Crops Differ from General Farm Crops 283

The Specific Functions of the Essential Fertilizing

Constituents 284

The Character of Soil an Important Consideration... 285-287

The General Character of the Fertilization 287, 288

The Application of Fertilizers for Fruits 289

The Fertilization op Apples and Pears— The amounts

to be applied 289-294

Peaches— The need of fertilizers— Methods of fertilization.. 294-299

Plums, Cherries and Apricots 299

. Citrous Fruits 299

Small Fruits in General 300

Strawberries 301

Raspberries and Blackberries 302

Xiv CONTENTS

Currants and Gooseberries 303

CHAPTER XV

Fertilizers for Various Special Crops 305-327

Cotton— Fertilizers for cotton — Formulas for cotton fertilizers—Method of application 305-312

Tobacco— The influence of fertilizers upon the quality of the crop — The conclusions from Connecticut experiments—Form of the constituents— Amounts to apply 312-317

Sugar-Cane — The needs of the plant as indicated by the Louisiana experiments— The application of fertilizers' 317-321

Miscellaneous Crops— Sorghum — Buckwheat— Peanut- Roses and other flowering plants — Lawn grasses — Forcing-house crops 321-327

Chapter I

NATURAL FERTILITY OF THE SOIL, AND SOURCES OF LOSS OF THE ELEMENTS OF FERTILITY

There is no one question of greater importance to the farming industry than that of soil fertility. In order that the industry may be successful, it is not enough to produce crops ; it is necessary that their production shall result in a genuine profit. That is, it is not enough to produce crops which bring more than they cost in the way of labor and manures, without taking into consideration the effect of their growth upon the future productive capacity of the soil. The relation of the outgo and income of the fertility elements is an important factor in determining profits, and must be considered. The farmer who secures crops that bring more than they cost, and who, at the same time, maintains or even increases the productive capacit}^ of his soil, is, other things being equal, the broadly successful farmer. Many farmers are able to accomplish this object because of the knowledge they have acquired through long years of experience, rather than because thej' possessed in the beginning of their work a definite knowledge of the fundamental principies involved in crop production, and upon the observance of which their success depended. One of the first needs, therefore, in the use of commercial fertilizers is a more or less definite knowledge of what constitutes fertility, and of the principles which underlie crop production.

SOIL FERTILITY

The full meaning of the term " soil fertility " is not easily expressed, since many conditions are involved, all of which exercise more or less influence. The potential fertility, which is measured by the total content of the food elements contained in a soil, is made practicable, or usable, in proportion as the conditions are favorable. The more important of these influencing conditions are here briefly discussed. In the first place, it is of the utmost importance that a soil should contain those elements found in the plant ; hence, it is almost self-evident that a fertile soil must contain a maximum quantity of those particular elements or constituents which are removed from the land in maximum amounts bj' the crops grown. The removal of crops rapidly exhausts the soil of these elements, and finally reduces the quantity contained in the soil to so low a point as to make profitable cropping impossible.

Chemical Elements Needed in Plant Growth

Careful studies and experiments have shown that plants actually take from the soil at least ten chemical elements which are required for their normal

TEH] CHEMICAL ELEMENTS NEEDED 3

growth and development: viz., nitrogen, potassium, phosphorus, magnesium, sulfur, sodium, iron, chlorin, silicon and calcium. Yet the number liable to rapid exhaustion is limited in many cases to three, and at most to four, which are, nitrogen, phosphoric acid (phosphorus), potash (potassium), and lime (calcium), the latter only in exceptional cases. These are liable to be exhausted because the}^ exist in larger amounts than the others in the plants that are grown, and in smaller amounts than the others in even the most fertile soils. It has also been proved that it is the one element of these which exists in the smallest amount which measures the crop -producing power, or fertility, in this respect, as one element cannot substitute or exert the full functions of another. That is, there may be a relative abundance in the soil of potash and of phosphoric acid, but practically no nitrogen, in which case good crops of cereals, for instance, could not be grown, because no other element can substitute the nitrogen required by the plant, and it can be obtained by it from no other source than the soil ; and the soil, for all practical purposes, is quite as unproductive, lacking in productive fertilitj^ as it would be if it contained much smaller amounts of the mineral elements mentioned, and thus be poorer in potential fertility.

Fertility as Influe^iced hy Water, Climate and

Season

In the second place, there are soils that are so rich in all of these elements that if productiveness depended upon them alone, maximum crops might be grown for centuries without exhausting them, while' actually they are now incapable of producing a single profitable crop of cereals, grasses, fruits, or other products of the farm, because certain other conditions which are essential, in order to bring them into activity, are absent. For example, it may be that water, which is absolutely essential both for the solution of these food elements in the soil, as well as for their distribution in the plant after they have been acquired-, cannot be obtained, or that the temperature of the soil and of the surrounding air is either too low or too high, thus preventing or interrupting the progress of those changes which must go on, both in the soil and in the plant, in order that normal growth and development may be accomplished. With a full supply of the fertility elements in the soil, the climatic and seasonal conditions exert an important influence upon its productive power.

It is evident, therefore, that the chemical elements of fertility in themselves are not sufficient to constitute what we understand by the term. Fertility is not measured by them alone ; associated with them there must be other conditions. That is, while crops cannot be grown without these elements, it is the conditions which surround them that, in a large degree, determine the power of the crop to secure them.

The Influence of Physical Character of Soil

In the third place, the physical character of a soil is also a factor in determining actual fertility. This

LOCATION QUALIFIES FERTILITY 5

has reference, first, to the original character of the rocks from which the soil particles were derived, whether hard and dense in their mineral character, thus resisting the penetration and the solvent effect of air and water and other agencies, or whether soft and friable, and freely permitting their entrance and action ; and secondly, whether, in the formation of the soil, the particles were so fine and so free from vegetable matter as to settle in hard and compact masses, impervious to water, air and warmth ; or whether they were coarse, and not capable of close compaction, thus giving rise to an open and friable soil, freely admitting the active natural agencies, such as we find to be the case in sandy soils. In addition to these properties of soils, which have a distinct place in determining fertility, there are many other minor ones which together constitute what is understood as "condition."

Location of Soil Qualifies the Term ^^ Fertility ^^

Furthermore, fertility, even in this true sense, may be useless because of the location of the soil which possesses it. For example, there are many places on this continent where sugar -producing plants will grow and develop perfectly, since the soils are ver}^ rich in the fertility elements, and since the surrounding conditions are most favorable for their culture, yet, because of their location, it is unprofitable to grow them for the manufacture of sugar. In the first place, the soils are so situated as to make it impossible, or at least impracticable, to provide the means necessary for converting the sugar -producing crop into actual sugar, and, in the second place, even if it were possible to do so, the great distance from shipping stations to markets so increases the cost of transportation as to make it unprofitable to compete in the market with the crops grown upon lands possessing true fertilitj' in a lower degree.

Practical Fertility is Usable Potential Fertility

Practical fertility is, therefore, dependent upon many conditions, and fortunately our own country possesses it in a marked degree ; that is, the utility of the potential fertility, as represented by the total mineral content of our soil, is such as to make us one of the greatest agricultural nations in the world, both in the quantity and variety of products grown. Our soils possess the essential elements in lavish amounts, and our climatic and seasonal conditions are such as to permit of their ready conversion into a wide series of valuable products, and our location and facilities for handling and distributing our staple crops are such as to enable us to compete in any market of similar commodities.

Notwithstanding the truth of this general statement, it is also true that in certain sections of our countrj^ profitable crops cannot be grown without the addition of commercial fertilizers, because the soils are either naturally poor, or they have become partially exhausted of their plant -food elements. That is, the amounts that become available to the plant

WHAT BECOMES OF FERTILITY 7

through the growing season are not sufficient to enable the plant to reach a maximum development, though other conditions are perfect.

Our future progress depends, therefore, upon how well we understand and apply the principles which are involved, both in the conservation and use of the fertility' stored up in our soils, and in the use of purchased fertility ; and in this connection it is important to consider the sources of loss of the essential fertility elements, or those which in the beginning measured our capabilities in crop production.

WHAT BECOMES OF OUR FERTILITY %

Since fertility is dependent upon so many conditions, or, in other words, since the essential elements of fertility are dependent upon their utilit}', and since, in this sense, fertility is largely determined by natural conditions, it is pertinent to inquire, first, whether under our present systems of management, or mismanagement, of the land, it is suffering any natural loss of fertility. As already pointed out, the most important function of fertility is to furnish nitrogen, phosphoric acid and potash, and since the content of these in our soil, together with the knowledge we have as to their use, measures, in a sense, our prosperity as an agricultural people, the possibilities of losing them from the soil is a matter of national concern, and is of vital interest to individual farmers, who, in the aggregate, make up that part of the nation directly affected by the results of such loss.

It would, perhaps, be possible, by a careful cbemical survey of our soils, to determine both the actual and potential fertility of our entire country, and this knowledge, together with an accurate measure of the intelligence exercised in its use, would enable a prediction as to our future development, if present methods were continued. That is, whether our land would become barren and worthless, as has been the case in many older countries which at one time were quite as productive, or whether it would constantly increase in productiveness, even with continuous and profitable cropping, — though, as already pointed out, the present barrenness or sterility of a country formerly fertile may not be due entirely either to the natural or to the artificial loss of these constituents.

SOURCES OF NATURAL LOSS OF NITROGEN

Of the essential constituent elements, nitrogen is, in one sense, of the greatest importance; first, because it is the one that is more liable to escape than the others, and secondh', because it is more expensive to supply artificially than are the minerals. It is the most elusive of all the elements : to-day it may be applied to the soil, to-morrow it may be carried in streams to the ocean. It is also unstable — which is not the least valuable of its characteristics if properly understood; — to-daj^ it is an element of the atmosphere, to-morrow it is a constituent part of a growing plant, the next day the same element may exist as an animal product, and the day following it may be

NATURAL LOSS OF NITROGEN 9

returned to the soil to feed the plant. It is more liable to escape than any of the others, because it is available as plant -food largely in proportion as it changes to a nitrate, and after it assumes that form it is seldom absorbed or fixed in the soil. Nitrogen in this form remains freely movable, and the probability of loss by leaching is increased in direct proportion to the lack of preventive measures used, or the presence of those conditions which favor leaching. The latter may be classified as follows: First, the amount and time of the rainfall; secondly, the absorptive and retentive power of the soil and subsoil, due to their mineral and physical character ; and thirdly, the amount of vegetable matter (humus) acquired by the soil, which retards the passage of water. While the amount and time of rainfall cannot be controlled, its effect upon our soils in this direction can be largely governed if proper attention is given to correcting the other conditions, and these may be largely modified, if not entirely controlled. In the matter of the absorptive and retentive power of soils, it has been shown that if they are well supplied with vegetable matter and carefully cultivated, thej^ retain and hold the plant -food constituents in a much greater degree than if devoid of humus and improperly managed, and also that the drainage water from soils upon which crops are growing seldom contains more than the merest trace of nitrates. The loss of nitrogen through the operation of the forces of nature may, therefore, be reduced by the careful management of the soil.

Importance of Careful Culture

The presence of suitable amounts of vegetable matter, and good cultivation, are conditions that are within the power of all farmers to provide, though it is sometimes impracticable to keep the land continuously covered with a crop ; and sometimes it is thought that the loss incurred through leaching because of the absence of a growing crop is more than balanced by the gain in other directions. For example, though losses of nitrates may occur, the gain in availability of the mineral constituents, phosphoric acid and potash, with the accompanying improvement in texture, due to the exposure of the soil to atmospheric influence, more than balances these losses, particularly during the winter, with its w^ide changes of temperature.

Loss of Nitrogeyi bij Drainage

It has been shown by carefully conducted experiments, both in this and other countries, that in a season of average rainfall the drainage waters carry away from one acre, from uncropped soils only fairly rich in plant food, as much as 37 pounds of nitrogen per year, while when continually cropped the drainage waters from the same soils contain practically no nitrogen. This difference in the loss of nitrogen under the two conditions may not seem a great matter at the first glance, but a careful study of the bearing of this loss in its relation to crop production shows

LOSS OF NITEOGEN BY DBA IN AGE H

that it is really a serious matter. In the first place, the amount of possible loss annually is practically equivalent in nitrogen to the amount contained in two tons of timothy hay, or in one ton of either wheat, rye, oats, corn or buckwheat, quantities nearly double the average yield per acre of these crops throughout our whole country; and in the second place, that the nitrogen which is carried away by the drainage water is in the very best form for feeding the plant, or it would not have been lost, and thus its loss leaves the soil not only poorer in this constituent element, but poorer in the sense that the remainder of it in the soil is in a less useful form.

Escape of Nitrogen into the Atmosphere

Another source of natural loss of nitrogen is its escape from the soil as gas into the atmosphere. This is due to the oxidation of the vegetable matter, or to "denitriflcation," which takes place very rapidly when soils rich in vegetable matter are improperly managed. The possibilities of loss in this direction are strongly shown by investigations carried out at the Minnesota Experiment Station on "the loss of nitrogen by continuous wheat raising."* The results of these studies show that the total natural loss of nitrogen annually was far greater than the loss due to the cropping. In other words, by the system of continuous cropping, which is universally observed in the great wheat

*University of Minnesota Agricultural Experiment Station, Bulletin 53, fields in the Northwest, there were but 24.5 pounds of nitrogen removed in the crop harvested, while the total loss per acre was 171 pounds, or an excess of 146 pounds, a large part of which loss was certainly due to the rapid using up of the vegetable matter by this improvident method of practice. Whereas, on the other hand, when wheat was grown in a rotation with clover, the gain in soil nitrogen far exceeded that lost or carried away by the crop. The continuous wheat- and corn -growing in the West, and of cotton and tobacco in the southern states, are responsible for untold losses in this expensive element of fertility, while in nearly every state of the Union, soils both rich and poor are suffering more or less from the effect of natural losses in this direction

THE NATURAL LOSS OF THE MINERAL ELEMENTS

In the case of the minerals, phosphoric acid and potash, which exist in fixed compounds in the soil, the actual losses are undoubtedly very much less than is the case with nitrogen, since only traces of these constituents are ever found in solution in the drainage waters under ordinary circumstances; yet, because of the large quantity of water that passes through many of our soils, the total amount of these rendered soluble and carried away hy this means is very great. Our great rivers carry in solution into the ocean tons upon tons annually of these elements of fertility, and it is an absolute loss, as there is no natural means by which these may be returned to the soil, as is the case with

MECHANICAL LOSSES OF FERTILITY 13

nitrogen; and it is true, as in the case of the former, that the soil is not only absolutely poorer by. virtue of the loss of its elements of fertility, but poorer in the sense that the immediate utility of those remaining is reduced. These silent and unseen forces constantly at work are reducing the content of these constituents in our soils to an alarming degree, and it is because they are unrecognized forces that the disastrous results of their activity are not fully appreciated, and, consequently, the best means for restoring them are not used.

Losses Due to Mechanical Means

A serious loss of all of the fertility elements is also due to mechanical means. Aside from the amounts that the rivers of water are carrying in solution into the seas, immense amounts are carried in them in suspension. The results of this kind of loss are painfully evident ; in many of the southern states, and in sections where the forests have been removed and the land abandoned, the soils have been washed and gullied until not onlj- the very best portions, but in some cases the largest portions, have been carried away.

It is not, however, in the abandoned parts of the country alone that these mechanical losses of constituents are of importance — they are more or less apparent on every farm, and are measured by the methods of management. Soils that are allowed to lie bare and fully exposed to the storms of wind and rain througnout the larger portion of the year suffer the greatest loss, while from those which, on the other hand, have crops growing during a large part of the year, and which hold the soil particles together and prevent their easy movement, the losses are reduced in both the directions mentioned. The beneficial results derived from the use of good methods are cumulative ; the benefit is not only immediate, but continuous.

ARTIFICIAL LOSSES OF FERTILITY

In addition to these natural losses of fertility, there are the artificial losses of the constituents, or those due to the removal of crops. These, of course, necessarily accompany all farming operations, and, provided that in the removal and sale of the constituents in the form of crops, the farmer has received a fair price for them, they are entirely legitimate.

The sale of farm products is really in the last analysis a sale of actual constituents, together with a certain portion of the " condition " of our land, which is not readily measurable. That is, it is the constituents in the soil, together with the conditions surrounding it, that the farmer buys when he bu3's land. If an acre of land, containing within the reach of the roots of the plant, say 3,000 pounds of nitrogen, 5,000 pounds of phosphoric acid and 6,000 pounds of potash, sells for $100, the seller receives the $100, not for so much dirt, but really for the constituents contained in it. The purchaser believes that, with the

ARTIFICIAL LOSSES OF FERTILITY 15

conditions surrounding them, he can convert them into products which he can sell and from which realize a profit. If in selling these amounts of the constituents in the form of land, a lower price per acre is received, it is because the natural conditions which surround them, and which influence their utilitj^, are less favorable, and a greater proportionate effort and expense are necessarj^ to secure them in the form of salable products. The difference in the price of land is not alwaj's due to the content of the constituents, but often to the conditions surrounding them. In many cases, the soil may serve simply as a medium in which plants can grow, and the content of the fertility elements is of minor importance. Such would be the case in the growing of market -garden crops near large cities, the location near the consumer being of greater importance, in the case of perishable crops of this sort, than the chemical character of the soil. In the large majority of cases, however, the natural fertility fairly measures the market price. At the price per acre, and for the quantity of constituents here assumed, the buyer would pay at the rate of 1% cents per pound for the nitrogen, and % cent per pound each for the phosphoric acid and potash, and it now constitutes his capital stock.