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Popular Science Monthly/Volume 60/April 1902/The Soil as an Economic and Social Factor

< Popular Science Monthly‎ | Volume 60‎ | April 1902



THERE is no part of the material world about us that is more intimately connected with the general welfare of the people than the soil. It has often been said, and well said, that it is the foundation of agriculture, in more senses than one. And the importance of agriculture in our present social systems is too well understood to justify any further comment here.

For practically a century the study of soils, and the phenomena they present, has received the attention of some of the ablest and most distinguished savants the ranks of science have held. Much is now known about soils from the point of view of the geologist, the physicist, the chemist and the bacteriologist. Much more is yet to be learned, and this perhaps is not the least interesting feature of the subject to one of a philosophic or scientific turn of mind. But when the geologist, the physicist, the chemist and the bacteriologist have brought together all the data and material of which they are capable, and have presented it to the world in accessible form, it is evident that but a very small part of the study of soils has been accomplished, or can be accomplished, by them.

It is necessary, as this paper will endeavor to show, that upon the labors of those investigators who have worked from the point of view of the natural sciences, the economist and the sociologist must build for the best development and use of the soil. They seem, up to the present, to have given very little attention to the subject, and the general knowledge of it seems to be summed up in the saying—*A poor soil, a poor people; a rich soil, a rich people.' This aphorism is in fact the immediate text of this paper. It implies what is apparently self-evident—that the soil is an economic factor because upon its character and the treatment of it depends the success of agricultural operations; and it is a social factor because the character of the soil in a very large measure determines the character of the people living upon it. The causal connection between the typical Yankee's well-known characteristics and his peculiar soils and environments has become almost classical in our literature. That which exists between some of the poor white communities in our Southern States and their soils is even more obvious. And just as striking are the opposite conditions on some of the rich limestone soils of our eastern states, or some of the intensely cultivated, rich, irrigated districts of the west.

Like all popular sayings, this one contains much truth. But it is sometimes untrue or at least misleading. For whether or not the soil be poor will depend entirely upon the point of view, and that there may be at least more than one point of view for any given soil will, it is believed, become evident from the following pages. Soils which are seemingly poor, and supporting but a poor population, may be in fact, or at least potentially, quite rich. But in order to make plain what is meant, it will be well to point out briefly some of the facts that are now known, and some of the views that are held by those who are making an especial study of soils. It will not be necessary to go into very much detail, for it will be sufficient to present the leading ideas in a general way in order to show that the work of the physical scientist touches, as a necessary consequence, both the field of economics and sociology. From these points of contact the effort will be made to indicate a few at least of the social and economic possibilities which a study of the soil presents, and to submit a plea that those to whom we look as leaders in these latter directions will find this subject of such importance and of so much interest that they will be impelled to do something towards the development of this side of it for the benefit of our country and possibly mankind at large. It would seem, as indicated above, that an almost virgin field for investigation is offered here, which can hardly fail to yield rich rewards to the student.

The soil is a very complex, heterogeneous mixture, or as one may say technically, material system. It is composed of three distinct parts or phases: First, the mineral and organic matters in a solid condition; second, the water, or water solution, which all soils contain; and third, the gaseous part, which fills the interstitial spaces between the solid components of the soil not occupied by the ground solutions. Furthermore, the soil is in contact with the atmosphere above it. It is probably from the ground solutions alone, or almost entirely alone, that the plants take their nutriment as far as the soil itself is concerned. Of course it is perfectly well known that the carbon and oxygen, which form so large a part of the plant tissues, are obtained mainly from the atmosphere above the soil and in contact with it. But the plant can derive its mineral foods from the soil solution only, and it is upon the concentration and composition of the solution that the well-being of the plant is primarily dependent. The nature of this soil solution is in turn dependent both upon the nature of the solid and of the gaseous components of the soil. Furthermore, it is intimately connected with the physical conditions of the soil—that is to say, with its texture, or the size of the solid particles, and the structure, or the arrangement of the particles, mainly because upon these factors depends the amount of water which the soil will hold under any given conditions of temperature, climate, etc. And upon the amount of water which it will hold will depend in turn the composition and nature of the soil solution. The soil, then, is composed of something more than the solid components alone, and this point of view is well worth accentuating, because it is not always recognized, and because upon it is dependent much of the modern development in soil studies.

The solid components of the soil are derived from two general sources. The mineral components are derived from the decomposition of the subsoil, or the underlying rocks. Or at least from rocks, although perhaps at some distance, when the soil has been carried to its present position by water, wind or other like agencies. Besides these mineral components of the soil, there are always more or less detritus and organic remains from the decomposition and breaking down of organic tissues from the present and former vegetation.

It is true that some of the components of the soil are so very little soluble as to be called in popular language insoluble. But there is, in reality, no such thing as an insoluble substance, and even those components of the soil which most nearly approach this condition are, to some extent at least, soluble in the ground water. And it is from these slightly soluble minerals and organic substances that the ground solution obtains its dissolved material, which serves in turn as food for the plant when presented in this available form. By the action of atmospheric agencies, oxidation, etc., by the solvent action of the water, by the action of dissolved gases, such as carbon dioxide for instance, and by the action of numerous microorganisms which exist in practically all soils, both the mineral and organic matters are broken down, decomposed, and part of them made more soluble. This is essentially the process known as weathering, and it is going on all the time. It may be checked, or it may be augmented, but it cannot be stopped entirely. It is nature's method for bringing the mineral nutriments in the soil into such forms as to be 'available' for plant nourishment, in contradistinction to that potential plant food which is present, but in such forms as to be unavailable. The distinction between available and non-available plant food, while now sufficiently obvious, was not recognized in the earlier studies, and marks in fact one of the first great steps forward in soil investigations.

Plants do not take from the soil solution the various dissolved substances which it contains in the same relative proportions in which they are present. Therefore by the continued growth of a particular kind of crop, and its periodic removal by cropping, it may happen that some one or more of the necessary plant nutrients in the soil may be removed more rapidly than others or than the normal weathering of the soil can furnish it to the soil solution. If this process is continued far enough, the plants fail to thrive and the soil becomes barren, or, as it is popularly phrased, exhausted. Much that is incorrect is popularly believed on this subject of exhaustion. There is probably no such thing, in a strict interpretation of the term, as an exhausted soil, for it is pretty thoroughly established that although a condition of the soil may have been brought about, as just described, in which it is not suited to the growth of a particular crop, it may be very well suited indeed to some other crop, and generally is suited to some other crop, and so the terra 'exhaustion' in this sense is really a relative one only. It has likewise been pretty thoroughly established now that plants, like animals, need a varied, and, as it is sometimes called, 'balanced' ration; that there is a particular combination or proportion of various constituents in the nutrients which is best adapted to a plant at any particular stage of its growth. For example, it is well understood that for the development of a grain crop, especially at the time when the grain is forming, a certain amount of magnesia is necessary. But if the ratio of the magnesia to the other necessary mineral elements is above a certain figure, the soil solutions become extremely toxic, with the results that the crops fail and the soil is barren. It has been found that the absolute amount of the magnesia which may be present and probably causing the barrenness of a given area is extremely small—so small, indeed, as to be difficult of accurate estimation. But if the ratio of other elements to the magnesia, for instance lime, be raised sufficiently high, the plants will do remarkably well, and, up to a certain limit, the more magnesia, the better they will do, so long as the ratio of the magnesia to the lime does not become too high. These views will explain what was meant when it was said above that the fertility or nonfertility of the soil is relative, and it is as a matter of fact, the explanation of the earlier remark that the expression 'a poor soil, a poor people, etc.,' may be misleading, if not positively untrue. For it is very probable that there is no soil which is cultivatable at all which could not be regarded as a fertile soil for some crop.

It is possible to modify the conditions as to the fertility in any given soil by tillage, which changes the physical condition of the soil and removes interfering growth from the crop we wish to cultivate; which, on the one hand, promotes capillary rise of water from the lower depths of the soil, or, on the other hand, cuts it off from the surface to prevent its too rapid escape; and which may improve the physical condition of the soil and further promote the natural rate of decomposition or weathering. Again it has been found in modern times that the rotation of crops, or change of crops, will aid the soil. And the reason for this probably lies in large part in the fact, as noted before, that one crop requires a different proportion of constituents in the soil from another, and if it is changed in the proportions of the constituents present, it is still adapted to the succeeding crop, giving time for those which became deficient through the growth of the first crop, to be again accumulated in sufficient quantity and relative proportion. Other factors enter of course into rotation, such as change of the texture of the soil produced by one crop making it better for another, the elimination of parasites, etc.

A third method is that of fertilizing, and a most complex group of phenomena is involved in this practice. The function of fertilizing is probably three-fold at least. The added material may change the texture, structure or other physical conditions of the soil, whether it be by mechanical mixture or by some other physical or physico-chemical process, such as is probably involved in the flocculation of clays by certain solutions. Its most obvious purpose, and the one which is the controlling idea among agriculturists at large, and perhaps to entirely too great an extent among the supposed scientific workers in this field, is the direct addition of plant food to the soil. It is not intended by this latter statement to minimize the importance of this function of fertilizers, but to insist in the most emphatic way that more attention should be given to the third function, that is—the changes in the solubility of the soil components already present induced by the addition of fertilizing materials, especially the so-called mineral fertilizers or salts. This is not the place for, nor would the space allotted to this paper permit of, a satisfactory discussion of the subject. Suffice it to say, for the present, that it is thoroughly well known, though not always generally recognized, that great changes in the solubility of the soil components already present may be brought about by the addition of foreign material, and in this sense the process of fertilizing is one of retarding or expediting the natural weathering of the soil components originally present.

Within the last few years, it has come to be recognized that bacteria or other microorganisms play a large part in the fertility of arable soils; that the development of some of these is desirable, that of others, not. And while this side of the subject is in hardly more than the preliminary stages of its development, yet a good deal is known as to the several conditions which make for the presence of the desirable organisms or vice versa, and these conditions are for the most part readily controlled. Furthermore, the point has been reached when we can actually inoculate the soil with desirable substances of this nature. There is no branch of soil study which is offering greater promise of advancement at the present time than this. And the opportunities it offers for increasing our control over soil conditions augurs much for improved agricultural practices. Here again it seems worth while to call attention to the fact that these organisms are valuable not only for themselves, or rather the immediate products of their activities, but also quite as much probably for their influence upon the soil components already present, either in breaking them down into simpler forms or in general in making them more soluble in the ground waters, and thus more available to plant nutrition.

It will thus be seen that it is possible to control, in a measure, the soil. In another way much has been done in controlling soil and soil conditions, and that is in controlling the climate above the soil. This climate, or condition of the atmosphere above the soil and in contact with it, is also a most important factor in the growth and development of plants, and any way in which this can be controlled, correspondingly can the development of the plants be controlled. This is familiar to every one in the use of frames, hot-houses and conservatories, and, in some of the modern structures of this kind, it can hardly be said that the method is one adapted to a small scale only. In illustration, attention might be called to an establishment in Rhode Island which has upwards of fourteen acres under glass for the cultivation of one crop alone. And this can hardly be regarded as an isolated instance. Many others as extensive, or perhaps even more extensive, might be cited. In the last few years an even more striking illustration, because much greater in extent, of this control of climate has been developed in this country. For this purpose as well as for some other reasons, enormous areas in Florida are covered with either slats or cloth tent-like arrangements. These are erected for the purpose of protecting the plants and developing abnormal or unusual growth in certain varieties of tobacco, and have proved immensely successful in prolonging the growing season, through a modification of the climate about the plant, keeping it moist and warm, not cutting off the light entirely, but partially, and preventing the great evaporation from the surface which would dry the soil, and hasten the ripening of the plant. The experiment has been repeated in Connecticut under the auspices of the Bureau of Soils, U. S. Department of Agriculture, in cooperation with the Connecticut Experiment Station, over a very considerable area, sometimes single fields of as much as eight acres in extent being now protected by these cloth coverings for the production of a high-grade wrapper leaf tobacco. The shading of one crop by another with a taller, umbrageous growth, is a similar procedure. And this is practiced quite extensively in some places, as in the shading of coffee trees by larger tree growths, or the more familiar nurse crops, common in some parts of the United States. Modifications of the climate in other ways, by planting of trees, erection of wind brakes, and devices of a similar nature, have been used with greater or less success in certain regions, and are all more or less well known.

It is thus possible to greatly modify the soil and the soil conditions. Nevertheless the fact remains that it is impossible to make one soil just like any other soil. Consequently characteristic differences do exist in them, and it follows that some soils are adapted to some purposes for which other soils, which are in themselves very good, are totally unsuitable. And this leads at once to the idea of the adaptation of special crops to special soils.

In a general way it has long been recognized that certain soils are unusually well adapted to the production of particular crops, as the celery soils of Kalamazoo, the wheat soils of the Red River valley, etc. But it is not generally recognized that each particular individual soil is best adapted to some particular crop or rotation of crops, and perhaps the greatest economic sin of the farmers of this country has been the almost general refusal to appreciate this cardinal, fundamental truth. Much improvement in this direction is to be noted within the last few years. It has come to be more and more recognized that at least some soils are more profitable when confined to the production of particular crops, as with the lettuce soils about Boston, the soils of the apple belt through the middle Western States, the soils of the sugar-beet areas, the sandy truck soils of the Atlantic seaboard, all coming into prominence for the particular crops cited.

Something more than merely empirical determinations on this subject can now be recorded; and perhaps the most striking illustration is a development of certain soils in the Connecticut Valley, which soils were generally regarded as very poor and practically valueless, until it was pointed out as the result of the soil survey of the Connecticut Valley by the Bureau of Soils, U. S. Department of Agriculture, that these very soils were markedly similar to those of Florida, on which the best Sumatra seed tobaccos were grown. The climate of the Connecticut Valley during the growing season is not very different from that of Florida, and by the use of the tent-like arrangements for shading, to which reference was made above, climatic conditions over the soils in both Connecticut and Florida can be made very similar indeed. This has actually been done, and there is now being grown in the Connecticut Valley a fine grade of cigar wrapper, which apparently equals in every respect the best product of Florida or of the Island of Sumatra itself. This is but one of the most striking of several similar developments for particular types of soil to which attention might be directed, where the possibilities have clearly been seen, before the introduction of a crop or dependent industry. Many thousands of dollars have thus been brought to the producers, and this, than which there could be no greater, is a powerful economic argument for the liberal support of soil studies on a broad, but systematic, basis.

With this idea of the adaptation of particular soils to particular crops, it becomes evident at once that the classification of the agricultural soils is not only desirable, but a fundamental necessity for the thorough scientific study of the soils of the country. This necessity is now so well recognized that the national government is supporting a large and growing bureau in the Department of Agriculture for the classifying and mapping of the soils in the principal agricultural areas, supporting these surveys with strong laboratories for the investigation of soil phenomena, its management and economic control. More interesting to note, is the growth of this work with some of the individual states which, either in cooperation with the surveys of the national government or individually, are now annually expending many thousands of dollars in this direction, with the firm conviction that in no other way could a surer investment be secured for ultimate large returns. But the work upon soils, thus hastily sketched, has been and is being done almost entirely upon the physical side. This has been, in the past, in accordance with the peculiar nature of the case. But there is another side, no less important, as difficult, possibly more difficult, to handle, giving justification for the title to this paper.

The results which are being obtained both by the national Department of Agriculture, by the many experiment stations, and other agricultural institutions connected with the American universities, are being freely disseminated among the people, and the major part of the results obtained abroad, not only in England, Germany and France, but in Russia, Sweden, Norway, Holland, Japan and elsewhere, are available to any intelligent farmer in this country who cares to take a little trouble and pains to obtain them. This being the case, the question naturally arises as to the reason why the practical agriculturists of this country make so little use of these results. For it is not to be doubted that the 'agricultural possibilities of the soils of the United States are very great—certainly much greater than has been realized thus far. The answer to this question is partly a psychological and wholly a sociological one. With some few exceptions, the farmers at large do not approach their occupation with the point of view connoted by the term 'business principles.' Perhaps this idea is best brought out in the yet current classification of man's occupations into the learned professions, farming and business. It is generally recognized by all professional men that their best success is obtained when the principles of business men are applied to their own affairs. As a matter of fact, what are usually called business principles are sound scientific methods. But this has not been recognized as yet by the main body of farmers in this country, and they seem to be actuated in the management of their farms largely by sentiment, much as some men take their religion or their politics, because their fathers managed in this way, therefore that is the way in which they should manage. Their forebears did well, under vastly different conditions and standards than those which obtain to-day, and the obvious fact that the descendants are not doing so well is met with all manner of explanations and excuses, which, just as obviously, have little or nothing to do with the case. Instead of studying a soil and its situation, and determining to what crop, or rotation of crops, it may be best adapted, the farmer continues to cultivate the same crops his predecessors grew, or he puts in one he may happen to wish for some fancied reason, possibly in some cases caprice. For example, a man may wish a grass farm, and instead of studying his soils to determine if they be adapted to this purpose, he may sink hundreds of dollars in a vain attempt, foreordained necessarily to failure, which might have been as surely foreseen. A good illustration is the tobacco crop in southern Maryland. In many ways, it is a fine crop to grow, making an attractive, handsome appearance in the field, pleasing to one's esthetic sense. Moreover, it has been grown in this region from time immemorial. But for various reasons, it can no longer compete successfully with tobaccos from some other regions, and now brings but very little money. Nevertheless, the people are accustomed to this crop, they like its cultivation, and consequently it remains a staple, although it is very well known that the soils devoted to it are much better adapted to certain other crops which would indubitably yield a vastly greater money return.

Over the wider areas of our country this seems to be about the spirit in which agricultural conditions are still viewed and met. Where intensive agriculture is practised, as in the truck soils, or in the irrigated soils of the West, this is not the case, or not so frequently the case, and can never be where intensive methods are practised, for it is a necessary corollary of the high prices which lands under the intensive system of cultivation command, that the crops for which they are best adapted must be raised, or absolute failure inevitably follows. But where the extensive methods of cultivation are practised, it is usually possible to drift along on half crops or third crops, and still keep matters going on a gradual decline until conditions are so bad that the land is abandoned as barren, and pastures new are sought elsewhere.

While the soil may be best adapted to some particular crop or rotation, other conditions enter, or may make it more desirable to substitute a different crop or rotation not so well suited. For questions of transportation, or supply and demand, and of available labor, inevitably enter into the business management of every farmer, and thus the soil is an economic factor in every community. In certain areas of Arizona, for instance, the soils, climatic conditions and general features indicate most strongly the advisability of raising fruits. But the transportation facilities up to the present have been so unsatisfactory that, it has been impossible for the Arizona horticulturists, even with earlier crops than California, to put their products on the Eastern markets at such figures as to compete satisfactorily with those from the latter state. Again a case comes to mind of a plantation in eastern North Carolina, with an unusually fine crop of peanuts, covering about 400 acres, at a time when the market was in a remarkably satisfactory condition. Yet this crop was a complete and disastrous failure because the unreliable labor conditions existing in that locality prevented the proprietor from securing more than a quarter of his crop, the greater part of it remaining on the ground to rot or to be devoured by birds, etc. Thus it is that the management of the soil, as in every other practical policy in this world, must be largely a give-and-take matter, or a question of double-entry bookkeeping, so to speak, and manifold considerations are involved. Where one gains in one way, he loses in another, and it is sound judgment or business sense which will determine what is the best thing to be done in any given case to get the most out of the soil under the conditions surrounding it.

Opportunities to get just such training as is necessary for the intelligent management of the soil are readily accessible in this country. Agricultural colleges and other colleges not professedly so, but giving courses in agriculture, both on the theoretical and on the practical side, are numerous. The necessary expense of attending them is certainly not great, and well within the means of a very large number of the youth in the rural districts. But it is an astonishing fact that they are not availed of, astonishing because to one of a philosophical or scientific cast of mind, there are few, if any, fields more interesting, or better adapted to the practical application of scientific methods than those of agriculture, and especially of soil management. Yet in our so-called schools of agriculture and mechanic arts it is indeed unusual when the number of students, presumably farmers' sons, who graduate in the mechanical arts as engineers, surveyors, etc., do not largely outnumber the students taking their degree in the strictly agricultural courses. This is even more astonishing' when we reflect that there is a demand, and a growing demand, in this country for skilled agriculturists to manage the estates either of rich individuals or of corporations, and the development of special crops for special industries. The demand for men of this description is at the present time greater than the supply, and such as have the proper training and qualifications can conmand salaries from $1,500 to $4,000 or $5,000 per year, possibly, in exceptional cases, much more. A case could be cited, where a fine house and grounds and $10,000 per year were offered to a certain expert to take charge of a large plantation devoted mainly to the production of a particular crop. These salaries are far above the average incomes of young men in other branches of professional life. The life is in other ways an attractive one; it requires more or less aptitude in the qualifications of the student, for, as in every other branch of professional life, the successful man is one that necessarily keeps up with modern developments along his line; but it must from the nature of the case be largely an out-of-door life, and attractive to any one who has the least spark of the love of nature in his soul.

It would unquestionably be a most interesting and fruitful line of investigation for the sociologist to study the causes which are apparently diverting men from this most attractive field of labor. There are some popular conceptions upon this subject, we know. It is generally admitted that there is a tendency for men to congregate in the cities or the towns in preference to remaining in the country, and various reasons are assigned for it. We hear much in this connection of the gregarious instinct of man, but this is hardly a sufficient reason. For the entire trend of modern scientific agriculture is towards intensive cultivation, and the gregarious instinct should be sufficiently gratified in populations where this method prevails. On the other hand, it is sometimes held that the chances for development in a social sense are greater in other professions or occupations, such as business life, and these are having their effect upon the youth of the country. This may be true to some extent, for it is as natural for man to prefer fine clothes as it is for birds to prefer fine feathers, and the accepted garb of the farmer is certainly not as attractive to mankind at large as the everyday costume of the physician, clergyman or clerk. But that it can be as potent as it is generally believed scarcely seems probable, unless one is to accept the notion that the farming class, speaking in a broad way, is no more intelligent than the class from which the average servant girl of the city comes.

The opportunities for the development of special lines in agriculture and soil management are certainly as great and should be as attractive as in other professions. There is as great an opportunity for the development of experts in sugar-beet-raising, apple-raising, rose-raising, as for the development of specialists in eye, ear and throat treatment, corporation law or criminal procedure, mechanical engineering or electrical engineering, etc., and with this unusual knowledge and unusual ability along specialized lines will come also the unusual pecuniary emoluments that are found in other professions.

Many problems of a sociological or economic nature suggest themselves in this connection, and it is certainly not from lack of subjects or material that the literature is nearly barren. But the object of this paper is to call attention to this subject, rather than to discuss it, which must be left for abler and better fitted pens. The development of new countries, as influenced by the soils, such as in the case of the westward movement from the tide-water regions of the Atlantic slope, along the limestone belt of Pennsylvania, Maryland, Virginia, Kentucky, Tennessee and Ohio; the differences which do, and must of necessity, exist between communities practising intensive or extensive methods of cultivation; the land-rich and money-poor man, and his status in the community; whether it is advisable in the general interest of the state, to encourage the development of large or small farms; whether the methods in vogue in some other industries, the combinations of resources and capital sometimes developing into 'trusts' can be successfully adapted and applied to agricultural pursuits; the building up of infant agricultural industries, by government aid, or the extension of the principle of protection to agricultural productions, and dependent industries; whether, on the whole, it would be better to make for a complete specialization, or whether it would be more advisable for each farming community to raise its own necessities—these are but some of the problems which are directly connected with the soil and the soil management, and are also social and economic questions. It therefore seems appropriate to those of us who are interested in this study from the point of view of the natural sciences, or applied science, as it is the fashion to call it now-a-days, to enter a strong plea that our efforts should be seconded by a more serious attention to this same subject from the professional economist and sociologist.