BRIEFLY, this book sets out to show that the mouldboard plough which is in use on farms throughout the civilized world, is the least satisfactory implement for the preparation of land for the production of crops. Perhaps this sounds like a paradox, in view of the fact that for nearly a century there has been a science of agriculture, and that agricultural scientists almost to a man have used and approved the use of the mouldboard plough. Nevertheless, the statement made above is true and capable of proof. Much of the proof, as a matter of fact, has come in a left-handed manner from scientists themselves. The truth is that no one has ever advanced a scientific reason for ploughing. Many learned teachers have had embarrassing moments before classes of students demanding to be shown why it would not be better to introduce all organic matter into the surface of the soil than to bury it as is done by the plough.
The entire body of "reasoning" about the management of the soil has been based upon the axiomatic assumption of the correctness of ploughing. But ploughing is not correct. Hence, the main premise being untenable, we may rightly question the validity of every popularly accepted theory concerned with the production of any crop, when the land has been ploughed in preparation for its growth. That brings virtually all of our soil theories up for critical examination; so, in this book, the whole gamut of theory we have evolved concerning the growing of crops will be brought into focus for examination in the light of the discovery that ploughing is wrong.
The discussion will be undertaken in language common to laymen, so far as this is possible, and throughout the text foot-notes will be introduced to explain whatever may be perhaps out of range of the thinking of the ordinary reader. The nature of the reasoning upon which this entire study is based makes it unnecessary to resort to any but the simplest of scientific terms. Moreover, there are few ideas which are not common knowledge — strange as that may seem. The vast amount of technical language created by scientific agriculture as a result of an early and fundamental mistake, has produced its own confusions. Indeed, the mistake originally made might justly be called the basis for most, if not all, of the technology connected with present-day agronomy.
An agricultural experiment station has its uses, but these obviously would not have embraced the problem presented in this book, if those who work the soil had not got off from a false start in the matter of ploughing. In brief, if a way had been found to mix into the surface of the soil everything that the farmer now ploughs under; if the implements used in planting and cultivating the crop had been designed to operate in a surface mixture of soil and plant residues that would have resulted from working rough straw, leaves, stalks, stubble, weeds, and briars into the surface — crop production would have been so automatic, so spontaneous that there might not have developed what we now know as agricultural science. Actually, we would scarcely have needed one. From one point of view, we have been creating our own soil problems merely for the doubtful pleasure of solving them. Had we not originally gone contrary to the laws of nature by ploughing the land, we should have avoided the problems as well as the expensive and time-consuming efforts to solve them. That we should also have missed all of the erosion, the sour soils, the mounting floods, the lowering water table, the vanishing wild life, the compact and impervious soil surfaces is scarcely an incidental consideration.
We have really had a fling in scientific agriculture. The fling, in fact, appears to be the scientific counterpart of what our grandfathers used to call "sowing wild oats." It is time we sobered up and began to apply to the growing of farm crops the same basic science we have for so long been using in the factories, mills and workshops of our reasonably progressive civilization.
We in the United States of America have equipped our farmers with a greater weight of machinery per man than those of any other nation. Our agricultural population has proceeded to use that machinery towards bringing destruction to the soil in less time than any other people in the world's history. This is hardly a record of which to be proud. It gains nothing in attractiveness, moreover, when we consider that our Chinese friends and the often despised peasantry of the so-called backward countries of the world can produce more per acre without machinery than the American farmer can with all his fine equipment. Any reasonably well-travelled person will confirm this statement.
One of the persistent puzzles has been the fact that an ignorant, poverty-stricken Egyptian who stirs his land with the ancient crooked stick can produce more per acre than the British farmer whose equipment is right up to the minute. The explanation is that the poor peasant cannot afford the equipment that would make it impossible for him to continue growing such high yields per acre. The full import of all this will be explained in due course.
There is double meaning in the statement that all of the trouble in producing crops seems to lie in the farmer's fields. The uncultivated fields and woodlands surrounding his land do not show any signs of trouble. Even the crops growing near the fence and in the hedgerows seem to thrive in drought and in rainy weather alike. Does that observation justify us in wondering whether the manner in which farmers handle their land may be responsible for the way crops grow under tillage? Certainly we should not overlook the possibility that a clue to the farmer's trouble may be found by a comparative study of cultivated and virgin soils.
Our conventional ideas of the processes of growth require drastic revision. Much thought and experimental work have been devoted to studies of plant growth, but comparatively little consideration has been paid to the part played in plant and animal growth by the actual transfer, more or less directly, of previously used plant food from a lifeless body to one that is living.
We often think and speak of growth as if it were a building process — which, indeed, it is — but we are likely to assume without sufficient thought that the best growth would result from the use of materials not previously used in organic tissues. We think of our farm crops as getting a mineral solution from the land; and we think of that solution as originating from soil minerals directly, or from the fertilizers which the farmer applies. We do not give much consideration to the biochemistry of the matter. We know that anything covered up in the soil is subject to rather prompt decay, if it is at all decayable, but we do not reason from that point to the position of regarding the products of decay as choice building material for crops growing in the immediate vicinity.
In our material civilization we have rightly learned to be suspicious of anything constructed of cast-off materials. Few people would buy a motor-car that was assembled from used parts. And a suit of clothes made of shoddy does not bring a very high price. Our basic distrust is transferred to our thinking about the materials essential to the development of a plant. This would not be true if we did some critical thinking on the subject; but we have not done it. We have left the whole subject to our scientific men. They have learned the facts, and in many instances have published their findings in books or pamphlets which anyone who cares to do so may read; but few have cared to wade through the technical language in which such studies usually have been expressed. Such writings seldom make the headlines or the front pages, so we do not bother to read them. This may be distinctly bad for us.
Much of our knowledge of nutritive relationship is what might be called academic: pigeon-holed after discovery and never developed into practical usefulness. Particularly is this true of our knowledge concerning plant nutrition. We know, of course, that no animal can subsist solely on mineral solutions in simple, inorganic form. We do not take our lime as lime water, or our iron as tincture — at least not to any great extent as a matter of nutrition. Our present knowledge indicates that the human race and the whole animal kingdom would disappear completely from the earth if deprived of that organic storehouse known as the plant kingdom. That being true, it is highly important that we should have a thoroughly practical understanding of the nutritive relationships between plants and the earth; for those relationships are necessarily fundamental to animal well-being, including, of course, the human race.
For purposes of this discussion, it will simplify our reasoning if we think of inorganic solutions, such as those that occur in the soil where water is in contact with mineral substances, as new, or primary plant foods; and the inorganic solutions that originate in the decay of plant or animal tissues as used, or second-hand plant foods. These are distinctly not the technician's terms for such concepts, but it will be shown herein that they are useful for the layman in understanding how plants can be made to grow best. It should be said, too, that in practice we should practically never find in the soil any organic solution entirely devoid of inorganic compounds. This is because the water which assists in the decay of organic tissues already carries a load of inorganic compounds when it is absorbed into the organic material.
The chief trouble with our farming is that we have concerned ourselves increasingly with the difficult techniques of supplying our farm crops with new materials for growth, when we could easily take full advantage of the almost automatic provisions of Nature for supplying plants with complete rations in second-hand form. We have made a difficult job of what ought to be an easy one.
Several circumstances have conspired to distort our point of view on the nutrition of plants. Thirty years ago, farmers had not become so familiar as they are now with the possibilities offered by inorganic minerals as fertilizers. But, as they have learned about them, and as the costs of such fertilizers have been reduced from time to time, it has been progressively easier to use mineral fertilizers. Meanwhile, the means of restoring organic matter to the soil has seemed at the same time to become progressively more difficult. The net result is that technical attention to the inorganic mineral supply has been more and more necessary; and the organic possibilities have simply vanished from consideration.
The last few paragraphs outline the basic nutritive concepts involved in this book. No new technical discoveries are to be aired here. The discussion is concerned wholly with reducing to practical terms, employable in anybody's back garden or on any farm, the scientific information possessed for decades but hitherto not put to any extensive use.
Green manures have been known and recommended for a good many years. For those to whom the idea is new, green manures are simply crops of any kind raised for use as decayable material in the soil where they grew. Farmers have been advised for years to make frequent and regular use of green manures to supplement the always inadequate supply of anima! manure. In keeping with this idea, as early as thirty years ago, officials responsible for advising farmers urged them to make the ploughing down of green manures the basis of their soil improvement programme for very thin land. Then, when the results of those early attempts were reported, trouble loomed. Ploughing down great masses of green manure proved such a colossal boomerang that subsequent attempts to improve growing conditions for plants have been cautious expedients rather than bold attempts to imitate the perfect example set by the natural landscape. It seems never to have occurred to anybody to question the effects of the universally approved mouldboard plough.
The prevalent and generally accepted doctrine concerning green manures has accordingly been modified to two comparatively ineffective recommendations: (1) plough down the green manure crop early, before it has become woody and difficult to rot, and (2) if the crop gets out of hand and becomes woody before it can be ploughed in, apply nitrogenous fertilizers to the crop itself before ploughing it down.
Even these recommendations have always been recognized as makeshift procedures. It is obvious that rye when tender or other green crops must contain less minerals than the same plants when allowed to reach their full growth. And, while the second recommendation is of more recent origin and is supposed to be more advantageous, it has a fundamental weakness for which there is no completely effective remedy in Nature. The purpose of adding the nitrogenous fertilizer is to hasten the decomposition of the mass, thus removing the organic matter as a bar to further rise in the soil of water from deep in the earth. (It should be mentioned here that the ploughing in of great quantities of absorbent material results in exhausting the water from the overlying soil layers.) The decay is hastened by this trick; but the products of decay released are necessarily subject to being leached out of the soil by the first rains that fall after their release. A relatively small percentage of such nutrients can be retained by colloids — in soil which have enough colloids that are not already holding all the plant nutrients possible. The rest must inevitably be lost, unless by lucky chance insufficient rain falls to carry them away before roots arrive to salvage them. It must be remembered, too, that in most soils few roots ever reach the ploughsole to do salvage work. The net effect, then, of this treatment is likely to be almost nil.
Later it will be shown that such use of nitrogen — any purchased nitrogen, in fact — is sheer waste of money, since Nature is perfectly organized to supply the right amount of nitrogen to every plant. Later, too, the universal use in Nature of the principle of direct transfer of organic compounds from the decaying dead to the growing living will be exemplified by illustrations from small-scale test work, supplemented by later fieldwork, done during the last ten years or so in a city backyard and on leased land in the country.
Most scientists probably are mentally unprepared to accept, without official tests, an idea apparently so new. An exception is Paul B. Sears, who in 'Deserts on the March' has pictured plant nutrition as follows:
The face of the earth is a graveyard, and so it has always been. To earth each living thing restores when it dies that which has been borrowed to give form and substance to its brief day in the sun. From earth, in due course, each new living being receives back again a loan of that which sustains life. What is lent by earth has been used by countless generations of plants and animals now dead and will be required by countless others in the future.... No plant or animal, nor any sort of either, can establish permanent right of possession to the materials which compose its physical body.
Thus, pointedly, Sears brings to our attention a principle of plant growth which has not hitherto been sufficiently utilized, though most scientists have been aware of its academic existence at least. He says by implication that life necessarily depends upon the snuffing out of other lives — of enormous populations, in fact. We dislike thinking of ourselves as murderous, but the fact that we must be, if we are to live, is difficult to refute. As civilized beings, so-called, we keep the slaughterhouse out of sight of the dining-room; but, unless we are vegetarians, our very existence depends upon keeping that slaughter house busy. Even the strictest vegetarian must snuff out many lives — those of plants — if he is to retain his own.
Such suggestions may sound like bits of philosophical quibbling; however, the ideas involved are so pertinent to the subject in hand that they need to be brought sharply into focus in our thinking. We have always accepted theoretically the interdependence of every form of life upon other forms; we have not so easily progressed to the thought that dead tissues contribute their substance to new living forms. This is the solemn, necessary truth; and the earlier it becomes a part of our thinking, the more quickly can we plan intelligently the necessary work of recreating the soils on our-farm lands. We have been too squeamish to visualize dead tissue being transformed into living, though with every mouthful we eat we demonstrate precisely that fact. Let us be practical, even if being so proves painful to our stomachs.
Plants establish intakes, in the form of roots, for nutritive materials in the decaying fragments of last year's plants; and, left to themselves, they will use without loss every atom of the material that previously had been used in the dead plants. As farmers, we have not left the bodies of last year's plants where the roots of this season's crops could invade them. Instead, we have buried those decaying remains so deep that few roots could reach them. We have, by ploughing, made it impossible for our farm crops to do their best. Obviously, it seems that the time has arrived for us to look into our methods of soil management, with a view to copying the surface situation we find in forest and field where the plough has not disturbed the soil. No crime is involved in plagiarizing Nature's ways. Discovering the underlying principles involved and carrying them over for use on cultivated land violates no patents or copyrights. In fact, all that it is necessary to do — if we want a better agriculture — is to recharge the soil surface with materials that will rot. Natural processes will do the rest. The plant kingdom is organized to clothe the earth with greenery, and, wherever man does not disturb it, usually the entire surface is well covered. The task of this book is to show that our soil problems have been to a considerable extent psychological; that, except for our sabotage of Nature's design for growth, there is no soil problem.
Science now knows that several times more plant food is carried away from farm land in the streams that drain the various watersheds than is absorbed by growing crops or grazed off by animals. Most of this loss is in an invisible form, that is, dissolved — an especially important consideration because it is in the only form in which plants are able to take food from the soil. The undissolved (visible), eroded portion of the loss makes the news, simply because it is visible; but it is relatively unimportant as a loss, since beneath where it lay there is an inexhaustible stock of the same material. The chief damage done by erosion is the filling in of stream channels, reservoirs, and natural lakes, along with the burial of downstream lands under a quite inert layer of miscellaneous mud. Fortunately, the necessary technique for preventing erosion is precisely what is required to make the land most productive. By restoring the conditions which prevailed upon the land when it was new, we shall cure erosion and restore productiveness in a single stroke.
For years scientific men have been aware that losses by leaching were in progress, but until the report of the National Resources Board was made in the United States in 1934, few had any conception of the staggering scale on which the mineral resources of America were going out to sea. To arouse general interest in this matter, the United States Department of Agriculture included on page 99 of its 1938 Yearbook a condensed table of the various kinds of losses. To clarify further the seriousness of the land waste, the department hired Russell Lord, an able agricultural writer, to advertise the American Government's efforts to stop erosion by co-operative watershed demonstrations in various parts of the United States. In his report Mr. Lord gives this concrete resume of the figures in the report of the National Resources Board:
Leached plant food is that part that percolates down through the soil and is lost by way of underground waters.... Of mineral losses (nitrogen, phosphorus, potash, calcium, magnesium, and sulphur) crops and grazing take off a total of 19,500,000 tons a year, while erosion and leaching whisk away nearly 117,000,000 tons. (2).
Incidentally, Mr. Lord became so impressed by the urgency of the situation reflected above that he wrote 'Behold Our Land', in which he presented further interesting material,and published it the same year.
Most of the dissolved plant food that escapes by way of streams originates from the decaying material ploughed in. This seems an inescapable conclusion from the known facts. This being true, by salvaging this waste, even though no other measures were taken for soil improvement, we should be able to realize greatly increased production from the land. So long as plant food continues to get away, both land and people become poorer and poorer; and people become more and more subject to ailments which we now know are caused by insufficiency of certain essentials in their diets. The drain tile and the mouldboard plough, therefore, become suspect of complicity in robbing our people of their birthright of vigorous health — by stealing away vital elements from the plough-sole before plant roots are able to salvage them. So logical does this inference seem that it is difficult to understand why it has never been investigated officially.
It seems a bit humorous, too, to suggest a need for investigating whether men could grow healthy crops if they copied the soil conditions which prevail in Nature where crops are universally healthy. It is a good deal like suggesting to the mother of a new-born baby to investigate the possibility of feeding her child naturally rather than by bottle as is done conventionally. In neither case is experiment necessary. We already know — by incontrovertible example — that wherever man does not interfere crops grow spontaneously. It follows of necessity that if man duplicates in his farming the soil conditions which in Nature produce such perfect results, he will be able to grow similarly perfect crops on cultivated land.
So, I introduce to you something so old in agriculture that it may justly be considered as new. The whole thesis is perhaps so clearly obvious that we have universally failed to see it. Seven years were required for me to break away from conventional ways of thinking about soil. Like all others trained in agriculture, I had vainly tried to piece the puzzle together, in order to make of agriculture a consistent science. Then I discovered, through certain tests, that the trouble lay in the operation which preceded all the tests, namely ploughing. It was as if one tried to assemble a picture puzzle with the pieces upside down. By simply correcting the basic error — by incorporating all the organic matter into the surface of the soil — the difficulties all disappeared as if by magic. The tests by which these conclusions were reached are briefly described in the pages that follow.