Protein Content of Winter Wheat in Relation to Rate and Time of Nitrogen Fertilizer Application1

Abstract

AbstractThe effects of N fertilization in the northeastern states on percent protein in soft winter wheat (Triticum aestivum L.) need to be evaluated in relation to time and rate of application and variety as a basis for developing practices that achieve the desired range in wheat protein.Fall and spring applications of different N rates to ‘Blueboy’ and ‘Redcoat’ varieties of soft winter wheat were compared at five locations on limestone‐derived Pennsylvania soils. Average protein contents were increased from 10.9!)% with no N applied to 14.3% with N fertilizer. The optimum rate of N for maximum grain yield often resulted in higher protein content than is considered desirable in grain used for pastry making. Under comparable conditions, the average protein contents of Redcoat and Blueboy wheats, respectively, were 13.3 and 11.8%. Spring application consistently gave higher protein contents than fall application, although the average difference was small (0.6%).Yields of protein were higher for Blueboy than for Redcoat, despite higher percent protein in the latter, because grain yields of Blueboy were substantially greater than yields of Redcoat. The importance of soil N as a source of N in these experiments was illustrated by the significant correlation that existed between relative N mineralization rates of soils from zero‐N plots and corresponding protein yields.