Late Spring Applications of Nitrogen for Efficient Utilization and Enhanced Production of Grain and Grain Protein of Wheat1

Abstract

AbstractApplications of 56 and 112 kg N ha‐1 (as KNO3) on April 2 and 23 and May 9 and 224 kg N ha‐1 on April 23 to Arthur and Blueboy (soft red winter) and Parker (hard red winter) wheats increased yield of grain, grain protein and grain protein percentage without exception. The average increases for all treatments and varieties for grain yield, grain protein and percentage grain protein were 21, 63 and 36% over the respective control values. Based only on amino acid composition, quality of the grains was unaffected by the nitrogen treatments. Depletion of soil nitrogen estimated by removal of grain alone for all varieties occurred not only in the control plots but in plots receiving 56 and 112 kg N ha‐1. Only the 224 kg N ha‐1 treatment plots gave an estimated net gain in soil nitrogen.The favorable results obtained for grain and grain protein production, the increasing availability of lodgeresistant wheats, and the concern over nitrate pollution of ground water and streams, all indicate that the practice of split applications of nitrogen made late in the spring to wheat has merit.