Date of this Version
Investigations of the development of root systems of native and crop plants have been pursued for a number of years at the University of Nebraska. The gradual intensification of this work has led to a type of experimentation designed to discover the nature of the activities of roots at great depths in relation to absorption of water and nutrients. In the present investigation the effects of absorption of nutrients from deep levels upon quantity and quality of yield were determined. Studies on the amounts of water and nitrates removed by crops from various soil levels were begun in i919, but little attention was then given to yield. Since the results of these earlier experiments have a direct bearing upon the present problem, however, the methods employed being essentially the same, the more important results will be briefly summarized (cf. WEAVER, JEAN, and CRIST 20).