Sulfur and nitrogen fertilizer effects on wheat. II. Influence on grain quality

Abstract

A wide range of grain quality tests (on both a large and a small scale) was performed on samples obtained from a factorial (5 sulfur x 3 nitrogen treatments) field experiment in which Olympic wheat responded in yield of grain to both sulfur and nitrogen. Grain nitrogen concentration responded mainly to nitrogen supply and ranged from 1.38 to 2.56%. Grain sulfur concentration responded to both sulfur and nitrogen supply and varied from 0.08 to 0.18%. Flour sulfur was highly correlated with, but lower than, grain sulfur. Compared with high sulfur grain, low sulfur grain was harder (higher pearling resistance) and the dough had a greater resistance to extension and a lower extensibility. In fact, a restricted supply of sulfur seriously affected grain quality, producing a dough that was excessively tough and umuitable for normal use. These changes in dough quality were accompanied by decreases in the proportions of albumins and of high mobility gliadins in the total protein in the low sulfur grain.