eat much more than the two-footed population consumes. Their paunches receive the crop from about four-fifths of our farm acres.
When tree agriculture is established, chestnut and acorn orchards may produce great forage crops and other orchards may be yielding persimmons or mulberries, crops which pigs, chickens, and turkeys will harvest by picking up their own food from the ground. Still other trees will be dropping their tons of beans to be made into bran substitute. Walnut, filbert, pecan, and other hickory trees will be giving us nuts for protein and fat food.
Even this partial list of native tree products shows nearly all of the elements necessary to man's nutrition, and that without introducing a single new species from foreign countries where dozens of new crop trees are waiting for the time to come when they can be made useful in American agriculture.
This permanent agriculture is much more productive than mere pasture, or mere forest, the only present safe uses for the hill fields. Therefore, tree crops should work their way into the rolling and sloping lands of all sections. New crop trees need to be created. Extensive scientific work in the plant kingdom should begin at once.
DOUBLING THE CROP AREA
As the deep-rooting, water-holding trees show their superior crop producing power in dry lands, we may expect some of our now arid lands to become planted with crop trees. Thus by using the dry land, the steep land, and the rocky land, we may be permitted to increase and possibly double our gross agricultural production and that too without resort to the oriental miseries of intensive hand and hoe labor. Tree crops also have a special advantage in their adaptability to a field reservoir system of irrigation which is at the same time of great promise as a means of flood control. (See Chapter XXII.)
The great question is, how can we shift from the grain type
