Soil fertility

“ Another line in which very great improvement is shown is in maintaining the fertility of the soil. The old method was to exhaust the fertility of a field and then clear a new one; and it is doubtful if one farmer in a hundred could have answered the question, “Why does land become sterile after long cultivation?” for they had no conception of what the chemical elements of the soil were which are necessary to its fertility. There are two theories of fertilizing and fertility: one, that the soil is a mine to be worked out, and which will inevitably become unproductive in the process ”

“ It is now necessary to consider more closely the true cause of the conversion of arable land to pasture—the declining productivity of the soil—and the cause of the restoration of this land to cultivation—the restoration of its fertility.
The connection between soil fertility and the system of husbandry has been explained by Dr. Russell, of the Rothamsted Experiment Station:
Virgin land covered with its native vegetation appears to alter very little and very slowly in composition. ”

“ One of the most important points to be emphasized is the fact that haphazard fertilization is not effective in maintaining soil fertility. If one starts out to establish a five-course rotation and build up his soil through a rational system of fertilization, he will obviously not obtain the full benefit of the rotation until he begins to get crops from the second round, which will be the sixth year from the beginning. ”

“ The very evident decrease in the fertility of those soils which have been under cultivation for a number of years, combined with the increased competition and the advanced price of labor, have convinced the intelligent farmer that the agriculture of the future must be based upon more rational practices than those which have been followed in the past. We have felt for some time that there was a place for a brief, and at the same time comprehensive, treatise on this important subject of Soil Fertility. ”

“ Fertility cannot be measured quantitatively. Any measure of soil fertility must be related to the quality of its produce. . . . the most simple measure of soil fertility is its ability to transmit, through its produce, fertility to the ultimate consumer."
Howard also tells of creating a super-healthy herd of work oxen on his research farm at Indore, India. After a few years of meticulous composting and restoration of soil life, Howard's oxen glowed with well-being. ”

“ So many consider that all the fertility in a soil is contained in the few top inches of soil, and in a measure this is true—the available fertility is right there—but there is a wealth of unused fertility in the lower strata, but lack of cultivation, lack of moisture and most of all, lack of the humus which makes the soil retentive of moisture, render it unavailable, but if it is broken up and gradually mixed with the humus of the upper soil it becomes available and the soil is increasing in fertility instead of growing thinner and poorer year by year. ”

“ His withering blight has fallen upon every living thing within his reach, himself not excepted; and his besom of destruction in the uncontrolled hands of a generation has swept into the sea soil fertility which only centuries of life could accumulate, and yet this fertility is the substratum of all that is living. It must be recognized that the phosphate deposits which we are beginning to return to our fields are but measures of fertility lost from older soils, and indices of processes still in progress. ”

“ Constant tillage hastens the decay of organic matter in the soil. Hence any method or system of cropping which does not occasionally return to the soil a new supply of humus tends to weaken the powers of the soil toward water.
All of the operations and practices which influence soil water also affect the other conditions necessary to root growth; namely, texture, ventilation, heat, and plant food, and those operations and practices which properly control and regulate soil water to a large degree control and regulate soil fertility. ”

“ The value of heavy sods to a soil cannot be overestimated. They not only give to a farm a prosperous appearance, but our country's agriculture would be on a much safer basis if heavy coverings of grass were more universal. We do not hold the legumes in too high esteem, but the emphasis placed upon their ability to appropriate nitrogen from the air has caused some land-owners to fail in appreciation of the aid to soil fertility that may be rendered by the grasses. One often hears the statement that they can add nothing to the soil, and this is serious error. ”

“ Fertilizer for Grass.—A fertile soil will make a good sod. A thinner soil should have a liberal dressing of complete fertilizer at seeding time, and the formula that has been suggested is excellent for this purpose. If a succession of timothy hay crops is desired, the problem of maintaining fertility is wholly changed. The nitrogen supplied by the clover is soon exhausted, and the timothy sod must be kept thick and heavy until broken, or the soil will not have its supply of organic matter maintained. ”

“ In this way a gradual diminution of the fertility of the soil takes place, until, after the lapse of a period, longer or shorter, according to its natural resources, it will become entirely incapable of maintaining a crop, and fall into absolute infertility unless the substances removed from it are restored from some other source in the form of manure. ”

“ By fostering the appropriate combination it has been possible to carry out successful afforestation of heathland so poor that ordinary cultural methods prove inadequate for the least exacting tree species. Satisfying the mineral requirements of the trees by direct application of fertilizers is not in itself sufficient treatment to ensure continued healthy growth; biological factors also play an essential role in promoting soil fertility. ”

“ If live stock cannot be kept on a dry-farm, the most direct method of maintaining soil-fertility is by the application of commercial fertilizers. This practice is followed extensively in the Eastern states and in Europe. The large areas of dry-farms and the high prices of commercial fertilizers will make this method of manuring impracticable on dry-farms, and it may be dismissed from thought until such a day as conditions, especially with respect to price of nitrates and potash, are materially changed. ”

“ Actually, faster-growing crops use much less soil moisture than slower-growing ones. As early as 1882 it was determined that less water is required to produce a pound of plant material when soil is fertilized than when it is not fertilized. One experiment required 1,100 pounds of water to grow 1 pound of dry matter on infertile soil, but only 575 pounds of water to produce a pound of dry matter on rich land. Perhaps the single most important thing a water-wise gardener can do is to increase the fertility of the soil, especially the subsoil. ”

“ Where these areas are privately held, the state might wish either to purchase the land from the owners or to provide incentives for its restoration.
Intensive agriculture may quickly exhaust the soil cover, causing its degradation, unless some special soil protection measures aimed at constant restoration and expanded reproduction of fertility are taken. The task of agriculture is thus not confined to obtaining the biological product but extends to constant maintenance and augmentation of soil fertility. ”

“ Any soil that is not virgin soil—soil that has never been used, and that sort of soil is not available in towns and villages if, indeed, it is anywhere in an old, settled country like ours—must have returned to it, year after year, an equivalent of the fertility extracted from it in growing the previous season's crop. It may be that the loss of many seasons must be made good, it may be that the soil was originally deficient in many, or only one, of the elements that make fertility;65 probably it will lack that most important element of productive soil—humus. ”

“ We do not use any fertilizer for our trees only as we crop the land. The virgin soil of our county does not need fertilizing if planted in orchard until the tree comes into bearing, except we crop the land. It is, however, a mistake to think we can grow an orchard and crop the ground at the same time, without any injury to the orchard, unless we restore the lost fertility in some way. ”

“ The crops should follow each other in such succession that each crop naturally paves the way for the next one in the succession, or at least does not place its successor at a disadvantage.
When it is feasible, a rather large proportion of the entire produce of the rotation should be feeding-stuff for livestock, as soil fertility is most easily guarded by livestock farming. ”

“ Nature stored plant-food in more or less inert form and, as availability has been gained, plants have grown. Our dependence continues.
Plant Constituents.—There are a few technical terms whose use cannot be evaded in the few chapters on the use of lime and fertilizers. A plant will not come to maturity unless it can obtain for its use combinations of ten chemical elements. Agricultural land and the air provide all these elements. If they were in abundance in available forms, there would be no serious soil fertility problem. ”

“ By fertility is meant the power of the soil to furnish plant-food. Fertile soil is "rich" soil. By tillage is meant frequent stirring of the soil. For example, Billy Boy and his chum each have a flower garden side by side of equal size. Each boy sows seeds from the same bag. The same sunshine and the same rains give vigor to each flower-bed alike. Billy Boy spades the soil deep and makes it fine. His chum stirs the top and leaves clods on the surface. ”

“ If the farmer could see his way clear to cut down the quantity of seed wheat or oats used on a fertile soil, the catch of grass would be better, but the small-grain crop is not very profitable at the best, and the owner does not like deliberately to limit it.
A greater amount of failure is due to an inadequate supply of fertility. The grass does not suffer so much from over-shading as it does from starvation, both during the growth of the grain and after harvest. The stronger grain plants appropriate the scanty stock of available fertility, and leave the grass and clover nearly helpless. ”

“ When the usual summer drouth is past, livestock can again be turned into the field. This method is suggested only for thin fields that have failed to make catches of grass, and that for some reason cannot well be given the fertility that all thin soils need. The application of lime before seeding to the rye is an expense that usually must be met in the case of such fields, and fertilizers should be used. ”

“ It is by many considered that irrigation helps to fertilize the soil. The spring and flood water contain great quantities of mud and humus, which when spread over the land will greatly increase its fertility. Even ordinary river water contains salts and other ingredients, which will fertilize the soil to no small degree. Another cause of the increased fertility of subirrigated soils is that the water which constantly evaporates carries with it salts, etc., from the lower strata up towards the surface, and makes them accessible to the roots of the vines. ”

“ But it must be borne in mind that the use of commercial fertilizers is not intended to replace that of barnyard manure, but rather to supplement it until the soil has regained what it has lost by poor management. Commercial fertilizers will of themselves produce a crop, but it is at the expense of the after-fertility of the land, just as the application of the whip will spur a jaded horse to one more final effort. Liberal applications of manure, leaf mould or muck and bone meal will bring any land that has soil at all, up to a satisfactory condition of fertility in a very few years. ”

“ By this means the soil below is left firm, and the rich vines are mixed with the surface soil, where most needed. It is always a mistake to bury fertility in the bottom of the furrow when a soil is thin and small seeds are to be sown. The infertile ground lying next the subsoil is not what is needed at the surface when preparing for a sod. ”

“ A very wet or very dry soil is known to nullify the benefit which might be expected of a fertilizer in a simply moist soil; but more than this, more than by the accident of external circumstances, it is a fact that each kind of soil has a special action of its own on fertilizers, so that if it were asserted of two soils, which, unmanured, were of equal fertility, that a given fertilizer applied to both, greatly improved the crop on one, and had little effect on the other, such a statement might not only be accepted as a fact, but an explanation might be given in general terms for such a fact. ”

“ It has become unsuited to deep-rooted crops; and where the natural soil, alone, would have perpetuated fertility for many years, fertilization becomes necessary within a short time. The injury becomes doubly great when, as is frequently the case, the rising bottom water brings up with it to the surface soil the alkali salts which previously were distributed throughout many feet of substrata, frequently rendering profitable cultivation impossible where formerly the most luxuriant crops were grown. ”