Page:Tree Crops; A Permanent Agriculture (1929).pdf/36

 the hand of primitive woman. But we still depend chiefly on her crops.

We are now entering an age of science. At least we are scientific in a few respects. It is time that we made a scientific survey of the plant kingdom—still the source, as always, of a very large proportion of that which is necessary to the existence and comfort of man. We should carefully scrutinize types of agriculture in relation to environment. Agricultural America should scientifically test the plant kingdom in relation to potential human use and do it as carefully and patiently as industrial America has tested cement. We test cement in every possible way, make it of all possible materials, mix all possible combinations, test it by twisting it, pressing it, pulling it; test it thousands of times, hundreds of thousands of times, millions of times, and in a few years our whole physical equipment is made over by reënforced cement made possible by these millions of tests.

Testing applied to the plant kingdom would show that the natural engines of food production for hill lands are not wheat and other grasses, but trees. A single oak tree yields acorns (good carbohydrate food) often by the hundred weight, sometimes by the ton. Some hickory and pecan trees give us nuts by the barrel; the walnut tree yields by the ten bushels. There are bean trees producing good food for cattle, which food would probably make more meat or milk per acre than our present forage crops now make.

These wonders of automatic production are the chance wild trees of nature. They are to be likened to the first wild animal