Effect of topdressing nitrogen ratio on yield, protein components and physiological characteristics of winter wheat

A 2-factors randomized block design fertilizer experiment was carried out to study the impacts of basal and topdressing nitrogen ratios on winter wheat yield, protein components and physiological index. There were three winter wheat cultivars, Zhongmai 8(A1), Zhongmai 175(A2) and Lunxuan 518(A3), and three N ratios for basal, jointing and flowering: B1 (5∶5∶0), B2 (5∶4∶1) and B3 (5∶3∶2). The results show that under the same amount of N fertilizer, appropriate increase of the N topdressing proportion at the flowering stage is useful to prevent the chlorophyll in wheat flag leaf from degradation at the late growth stage, increase leaf nitrogen content and extend the functional period of leaves. Higher grain yield, bulk density, 1000-grain weight and protein yield were obtained with B3 treatments than with B1 and B2 treatments, and the difference in 1000grain weight between the B3 and B2 was significant. Significant differences were also existed in the production factors among cultivars. Different proportion of nitrogen dressing affects the globulin contents significantly, while the contents of other protein components are not significant.