Lime and Fertilizers for Our Black Walnut Trees

By Seward Berhow, Iowa

In 1941-1942-1943 black walnut crops from trees growing in timberland in competition with other trees were nearly a total failure. The nuts were fair in number but not filled, the kernels badly shriveled, tough, lacking greatly in flavor and discolored. Some of these black walnut trees have been bearing for 50 years. Are they through, due to having used up all the soil fertility?

Wild or native black walnut trees, growing on good soil and not crowded have done better. It looks to me as if it is time our experiment stations, particularly those having black walnut trees on or near their grounds should start studying the cultural requirements of nut trees in the way of lime and fertilizer for better nuts. I have experimented by applying lime and fertilizer to a few bearing trees with very good results. But we need to know the proper amounts to be used for all sizes of trees from the transplants to the bearing trees of different sizes. Such investigations can best be conducted by our experiment stations.

There is a very substantial increased demand for grafted nut trees each year. This is evidence that we should make a study of our nut tree culture and care.