THE FARM THAT WON'T WEAR OUT
WAS FIRST published serially in THE COUNTRY GENTLEMAN, the privilege having been granted the author of subsequent publication. It is now issued in book form in response to numerous requests coming especially from the Central, Eastern, and Southern States.
CYRIL G. HOPKINS.
CHAMPAIGN, ILL.
"Population must increase rapidly, more rapidly than in former times, and ere long the most valuable of all arts will be the art of deriving a comfortable subsistence from the smallest area of soil."—Lincoln.
"It is not the land itself that constitutes the farmer's wealth, but it is in the constituents of the soil, which serve for the nutrition of plants, that this wealth truly consists."—Liebig.
IT IS an old saying that "any fool can farm," and this was almost the truth when farming consisted chiefly in reducing the fertility of new, rich land secured at practically no cost from a generous Government. But to restore depleted soils to high productive power in economic systems is no fool's job, for it requires mental as well as muscular energy; and no apologies should be expected from those who necessarily make use of technical terms in the discussion of this technical subject, notwithstanding the common foolish advice that farmers should be given a sort of "parrot" instruction in almost baby language instead of established facts and principles in definite and permanent scientific terms. The farmer should be as familiar with the names of the ten essential elements of plant food as he is with the names of his ten nearest neighbors. Safe and permanent systems of soil improvement and preservation may come with intelligence—never with ignorance—on the part of the landowners.
When the knowledge becomes general that food for plants is just as necessary as food for animals, then American agriculture will mean more than merely working the land for all that's in it. This knowledge is as well established as the fact that the earth is round, although the people are relatively few who understand or make intelligent application of the existing information.
Agricultural plants consist of ten elements, known as the essential elements of plant food; and not a kernel of corn or a grain of wheat, not a leaf of clover or a spear of grass can be produced if the plant fails to secure any one of these ten elements. Some of these are supplied to plants in abundance by natural processes; others are not so provided and must be supplied by the farmer, or his land becomes impoverished and unproductive.
Two elements, carbon and oxygen, are contained in normal air in the form of a gas called carbon dioxid, and this compound is taken into the plant through the breathing pores, which are microscopic openings located chiefly on the under side of the leaves. Some plants have more than a hundred thousand breathing pores to the square inch of leaf surface.
When plants or plant products are burned or decomposed the carbon of the combustible material—grass, wood, coal, and so forth—unites with the free oxygen of the atmosphere to re-form the carbon dioxid, which thus returns as a gas to the air. Even the food taken into the animal system, after being digested and carried into the blood, is brought, into contact with the oxygen of the air—which also passes into the blood through the cell walls of the lungs—and a form of combustion takes place, the heat generated serving to warm the body while the carbon dioxid passes back into the lungs and is exhaled into the open air.
By these circulation processes the supply of carbon dioxid in the atmosphere is renewed and maintained without any special effort on the part of man. Hydrogen is one of the elements of which water is composed. Water is taken into the plant through the roots, carried through the stems to the leaves, and there, under the influence of chlorophyll, sunlight and the life principle, the carbon, oxygen and hydrogen are made to unite into some of the most important plant compounds, such as the sugars, which are later transformed into starch and fiber.
Though these three elements constitute the larger part of the mature agricultural plant they are no more necessary for plant growth than the seven which are supplied by the soil. Iron is one of the essential elements of plant food; but the amount required by plants is so small and the amount contained in the soil is so large that soils have never been known to become deficient in iron. Though sulfur is found in plants in very appreciable amounts and is known to be essential to plant growth, it is evident that plants do not need so much sulfur as they often contain, some of it being taken up and merely tolerated, as is the case with all of the sodium and silicon found in plants, neither of these being required for normal growth, although commonly found in plants in very considerable amounts. The supply of sulfur in normal soils is not large; but, with the combustion and decay of organic materials—coal, wood, grass, leaves, and so forth—sulfur passes into the air and is brought back to the soil dissolved in rain or absorbed by direct contact of soil and air. Thus under normal conditions the supply of sulfur naturally provided is ample to meet the needs of the staple farm crops, although there are some plants, such as cabbage, for example, which may possibly be benefited by fertilizing with sulfur.
But there are five other essential elements of plant food, and these require special consideration in connection with permanent soil fertility. They are potassium, magnesium, calcium, phosphorus and nitrogen. There are also five important points to be kept in mind in relation to each of these elements: (1) the soil's supply, (2) the crop requirements, (3) the loss by leaching, (4) the methods of liberation, and (5) the means of renewal.
The neglect of one or more of these important points in relation to one or more of these five elements has reduced the fertility of most cultivated soils in the United States, has greatly impoverished the older farm lands, and has brought agricultural abandonment to millions of acres in the original thirteen states. On the other hand, intelligent attention to these same factors will bring restoration and high productive power to such lands.
Where these five elements were supplied regularly to land on the Rothamsted Experiment Station the average yield of wheat for the thirty years, 1852 to 1881, was 35.9 bushels an acre, while 13.6 was the average yield of similar unfertilized land; and during the next thirty years—1882 to 1911—the corresponding average yields were 38 bushels an acre on the fertilized land, and 11.7 bushels where no plant food was applied. These statements are not mere opinions, but determined facts whose accuracy stands unquestioned.
On another field at Rothamsted, England, the average yield of barley for the same sixty years was 43 bushels an acre where nitrogen, phosphorus and calcium were regularly applied, 42.6 where all five elements—including potassium and magnesium—were added, but only 14.3 on unfertilized land.