Pastures are excellent sites from another angle. The closely grazed sod furnishes an ideal place to rake the nuts together at harvest time. Anyone who has hunted for nuts in a dense ground cover will appreciate this factor.
While the walnut responds best to the deep, fertile soil of the river bottoms and flood plains, it will grow well on the lower portions of slopes if water is available and the site is not too exposed to the force of drying winds. Contour strips should be prepared by plowing several furrows downhill, each a little less in depth than the preceding, and the walnuts planted thereon. The walnut is a spreading tree and plenty of space should be allowed. Perhaps it may be wise to plant the walnuts at extended intervals and fill up the contour row with black locusts, for post wood, and honey locusts to produce succulent pods for cattle feed. In any event, it is better to allow too much, rather than too little space, as walnuts are long-lived trees and will thrive best where there is least competition. In Iowa, black walnuts are responding well to "basin culture" in sites which were prepared by "scalping" the sod from the upper portion of a slope and depositing it on a lower portion in order to catch and retain more water.
Nut trees are like all other trees in that they react favorably to good horticultural practice. Fertilizer, particularly nitrogen, is usually always helpful. The addition of lime when the soil is acid and of organic matter when humus becomes depleted will aid in better soil aeration and an increased moisture supply. This, in turn, will be reflected in more vigorous tree growth and greater nut production. Occasional spraying may be necessary to control the Datana caterpillar in the summer.
Chinese chestnuts seem to be admirably adapted for interplanting with mulberries, cherries, pears, and the like in poultry runs and hog lots where the pigs and chickens will control the weevils by gleaning the prematurely dropped and overlooked chestnuts which contain the grubs of the weevil. The fruit portion of the integrated planting will maintain a high carbohydrate ration during the season for the use of the livestock. Here, again, plenty of space should be allowed between trees to allow each its full measure of water, food, air and sunlight.
Careful and thorough research is needed to determine the full requirements of nut trees and to work out the interplanting relationships. In view of the vast potentialities for their use, investigational programs may soon be under way and much more definite information be made available to the farmer and landowner.
References
AIKMAN, J. M.—A Basin Method of Nut Tree Culture. Proc. Iowa. Acad.
Sci. 50:241-246. 1943
NEEL, L. R.—The Effect of Shade on Pasture. Tenn. Exp. Sta. Cir. 65, 1939
SMITH, R. M.—Some Effects of Black Locusts and Black Walnuts on
Southeastern Ohio Pastures Soil Sci. 53:385-398, 1942
Nut Work At the Mahoning County Experiment Farm, Canfield, Ohio