The Farm That Won't Wear Out by Cyril G. (Cyril George) Hopkins
page 4 of 55 (07%)
page 4 of 55 (07%)
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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. Foods That Plants Live On 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 |
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