Effects of Nitrogen Application on Grain Yield,N Absorption and Utilization Rate in Winter Wheat with Two Spike-types

Effects of nitrogen application on grain yield,N-absorption and N-utilization rate in 'Lankaoaizao 8'(big-spike type) and 'Yumai 49-198'(many-spike type) was studied.The results indicated that shoot dry matter(except reviving and jointing),grain yield and grain protein yield of two cultivars firstly increased and then decreased with nitrogen application increased and the highest value obtained in N treatment(180 kg·hm-2).Shoot N accumulated increased while nitrogen levels increased at different growing stage.Compared with the control(0 kg·hm-2),nitrogen applied treatments reached 5% significance levels.Grain protein content had the same tendency.Nitrogen utilization ratio,soil nitrogen contribution ratio and N-harvest index all showed the same tendency,which of big to small is 180,90 and 360 kg·hm-2.The nitrogen treatments reached 1% significance levels.The above results indicated that the right nitrogen application(180 kg·hm-2) can increased grain yield,protein yield and N-harvest index.