Effects of sulphur application on accumulations of carbon, nitrogen and sulphur and grain yield of winter wheat under different irrigation conditions

Irrigation plays an important role in increasing crop production in China. However, sulphur (S) is another essential element in plant nutrition. Under some stress conditions, such as low mineral content in soils, soil erosion and high nutrient removal by crops may determine S deficiency in crops. Most of previous studies focused on effects of S on yield and quality for wheat. The aims of this study were to analyze the effects of S and irrigation (W) and their interaction on accumulation of dry matter during wheat growth period, and distributions of carbon(C), nitrogen (N) and S at the maturity, and grain yield and its main components at the harvest. Two medium-gluten wheat cultivars (a multiple spike Yunong 949 and a large spike Lankao Aizao 8) were used in field experiments with different S and W treatments in 20092010 wheat growing season. The results show that the dry matter accumulations of the two cultivars under the S60 treatments are significantly higher than those of the S0 treatments at the anthesis and maturity stages with the increasing of irrigation times. Comparing with S0, organ dry matter weights at the maturity are increased under the irrigation combined with S application, and the increased grain weight is higher than those of the other organs, but no significant differences in the dry matter distribution among the organs. The S application could increase the contents of N and S in grain, but the N contents of grain and vegetative organs are decreased with the increase of irrigation times. With the increase of irrigation times, the S application promotes grain-number per spike,1000-grain weight and grain yield, and their maximum values are reached under the S60W2 treatment. Especially, the grain yield of S60W2 is increased by 34.29% compared to the S0W0 treatment, and the yield of Yunong949 is significantly higher than that of Lankao Aizao8. In conclusion, S60W1 or S60W2 in the study could increase dry matter accumulations, the contents of C, N and S, and gain yields of two winter wheat cultivars, but some differences exist in the cultivars.