Effects of Nitrogen Application Techniques on Grain Yield and Quality in Winter Wheat

The test with Wanmai 19 in 2003-2004 showed that the application rate of nitrogen fertilizer was in relation of quadric curved lines with grain yield and grain protein content. A critical N quantity on grain protein content was more than that on grain yield. The nitrogen range from 0-233.1 kg/ha was the simultaneous increase period for both grain yield and grain protein content.The range from 233.1-271.4 kg/ha was the period for the increase of grain protein content but decrease of grain yield. The range over 271.4 kg/ha was the decrease period for both grain yield and grain protein content.The content of gliadin and glutenin,the ratio of glutenin and gliadin were improved by increasing nitrogen fertilizer applied. The gluten content, the dough stability time and the dough extension were also increased.Combination of base munure and top dressing could be favor to improve the yield and grain quality,with the bast effect at base,jointing and booting stages. With more nitrogen applied after mediumand late stage, the nutrient and industrial quality were improved significantly.