Effect of Fractional Nitrogen Fertilization on the Dry Matter Accumulation and Grain Yield in Winter Wheat

The objectives of this study were to determine the best nitrogen topdressing stage and nitrogen rate for profitable yield and high efficient nitrogen utilization in winter wheat in eastern of Hebei province.Field experiments were conducted to investigate the effects of nitrogen fertilizer timing on the dry matter accumulation and grain yield of winter wheat with the total pure N 240 kg/ha.The urea was used with different fractions being applied at planting,reviving,stem elongation and flag leaf.Four nitrogen treatments were applied among planting,reviving,stem elongation,and flag leaf:240-0-0-0(NⅠ),120-120-0-0(NⅡ),120-0-120-0(NⅢ) and 80-80-0-80(NⅣ) kg/ha.The results showed that the nitrogen fertilizer applied at planting and stem elongation not only established a reasonable of the group structure but also improved kernels per spike from 4.41% to 13.00% and thousand kernel weight from 3.04% to 14.97%.Thus the wheat yield was improved.The research has a conclusion that,on wheat nitrogen of a certain circumstance,half of the all nitrogen fertilizer using in sowing and half of the nitrogen fertilizer using in stem elongation is in favour of increasing the yield of wheat.