Page:Tree Crops; A Permanent Agriculture (1929).pdf/333

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  1. Nitrate instead of cultivation,
  2. Irrigation from rain-fed water pockets,
  3. Hogging down the crops.

III. A NEW TECHNIQUE—CULTIVATION BY NITRATE

At the mere suggestion of an uncultivated tree the devotees of the plow will rise up and say that trees need to be cultivated. I will agree with them and quote back for their comfort a statement given me in France that the Persian walnut tree in the pasture bears only half as much as the tree that is cultivated.

The orthodox defenders of the plow and of cultivation were telling us twenty years ago that an apple orchard had to be cultivated. For the most of the clay lands of eastern United States this statement is now known to be merely a kind of fetishism, as some millions of Virginia and other eastern American apple trees yearly attest. The apple trees are fertilized. The theory of cultivation is that it increases the available food supply. I accept the theory. Facts seem to prove it. The same theory underlies the use of the commercial fertilizer. Experiments at numerous farms, and numerous experiment stations such as those in Ohio and Virginia, show apple trees that will bear two or three bushels in uncultivated, unfertilized sod and will bear perhaps ten, fifteen, or twenty bushels if given a few pounds of fertilizer, preferably nitrate of soda.

With an established tree in many soils and locations you may cultivate or you may fertilize, but in most naturally forested sections of the United States it is not necessary to do both. I claim that tree-crop experimenters can use fence rows and corners of land to grow trees without cultivating them, but please do not quote me as saying they can do this without fertilizing the trees. Furthermore young trees, if not cultivated, must be protected in the first years by mulch. I have proved in many cases, to my sorrow, that grass can rob