Page:Popular Science Monthly Volume 79.djvu/500

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HE maintenance of the food supply is the basal problem of civilization. Before commerce or manufactures or mining can be carried on—before science or art or religion can flourish—man must be fed.

Hitherto, the people of the United States, thinly scattered over a country of vast extent and seemingly exhaustless fertility, have scarcely realized that there is such a thing as a food problem, but more and more frequently of late there are heard warnings of the danger of an inadequate food supply for our future millions and of the resultant peril to our democracy through the fostering of caste and class distinctions. That the problem is a serious one, even if it be not so immediately imminent as some would have us believe, admits of no reasonable doubt.

Now the problem of food supply is in essence a problem of energy supply. Food yields the energy which operates the bodily mechanism and upon the regularity and sufficiency of this energy supply depends absolutely all human endeavor. To produce those carriers of energy which we call foods is the chief function of the farmer. By means of the green leaves of his crops he entraps the energy of the sunlight and stores it up in the starches, fats and proteins of his wheat, corn, etc., to be liberated again in the body when these are used as food. The farmer as a food producer is the first link in the chain of human activities—the agent by whose labors the boundless stream of solar radiation is utilized for man's service—and the density of population which a country can support from its own resources is practically limited by the amount of solar energy which the farmer can recover in food products.

Clearly then in preparing to meet the future food problem the primary thing is to see to it that the farmer is taught how by means of tillage, fertilization, seed selection, crop rotation, and all the arts of good farming to accumulate as much as possible of the solar energy in his yearly crops. The proposition is sufficiently obvious and already commands popular support.

There is, however, another less evident aspect of the question. In order to feed the teeming millions of the future, it will not only be necessary to fix as much of the solar radiation as possible in the form of crops, but also to utilize the energy which the latter contain with the maximum of efficiency. When our population reaches half a billion, there will be little margin for waste.