Effects of Different Nitrogen Form Ratios on the Nitrogen Accumulation and Utilization of Winter Wheat

Two wheat varieties including Zhengmai 366and Aikang58were planted in the field conditions with different nitrogen form ratios application from 2010to 2012.The results indicated that at the flowering and maturing stages the total nitrogen content in winter wheat source organs were:Leafcobs and glumesheathsstem.Compared to the single nitrogen form treatment,the treatments with mixed nitrogen forms application improved the total nitrogen content in the leaf,stem,sheath and cobs and glume of Zhengmai366and Aikang58at the flowering stage,promoted the nitrogen transportation of source organs during grain filling stage,and decreased the total nitrogen content of source organs at the mature stage.The grain protein yield of Zhengmai366of N2treatment was highest,which was 17.83%and 24.15% higher than that of N1and N5treatment,respectively.The grain protein yield of Aikang58of N5treatment was significantly lower than that of N3treatment.With the N2treatment,the nitrogen utilization efficiency of Zhengmai336were19.15%,9.80%,10.89%and 21.74% higher than that with N1,N3,N4,and N5treatment,and that of Aikang58were 9.47%,0.65%,11.43% and 9.47%.In a word,different nitrogen form ratios practice could improve the source organs and grain nitrogen content,grain protein yield,the nitrogen harvest index and nitrogen use efficiency of winter wheat,and the N3treatment showed the best.