Effects of nitrogen rates on grain yield and quality of wheat in different soil fertility

Effects of nitrogen rates on grain yield and quality of wheat in different soil fertility were studied. The results showed that it was a quadratic regression equation between nitrogen rate and grain under high fertility soil, and the suitable rate was 193.0 and 211.4kg/hm2 for high yield of Jinan17(J17) and Lumai21(L21), respectively. The yield (increased) with the N rate, but efficiency decreased when the rate was over N 300kg/hm2 in low fertility soil. Application of nitrogen could increase protein of grain, wet gluten, sedimentation volume, improve the proportion of protein and starch component, water absorption of dough, prolong dough development, stability time and valorimeter value and (increase) of RVA profile of wheat flour. The effects above indices were high in high fertility than that in low fertility soil, and (indicated) that the high fertility soil was propitious to improve quality of strong gluten wheat.