Effects of nitrogen fertilizer and its combination with different crop straws on growth and nitrogen utilization of wheat

The influences of N fertilizer and its combination with different crop straws on the biomass, grain yield and nitrogen uptake of winter-wheat were researched with pot experiment. There were eight treatments in the study:no fertilizer(CK), urea(U, 150 mg·kg- 1 soil), urea+ soybean straw(UB), urea+ maize straw(UM), 120% urea+maize straw(120%UM),110% urea+ soybean straw+ maize straw(110%UBM),100% urea+ soybean straw+ maize straw(100% UBM)and 80% urea+ soybean straw+ maize straw(80% UBM),inwhich the application ratesof soybean straw and maize strawwere equally 2 g·kg- 1 soil. The results showed that, at returning green stage, the wheat biomass in the Utreatmentwas significantly higher than that in the treatments of urea combined with different straws; at harvest stage, the wheat biomass in the treatments of urea combined with different strawswas higher than that in the urea treatmentswith the same application rate, however, the difference was not significant.The grain yield in both the UMtreatment and UBM treatmentwas higher than that in the Utreatment. There was no significant difference of grain yield between the 80% UBM treatment and Utreatment.The nitrogen use efficiency in the treatments of urea combinedwith single strawwas generally higher than that in the treatments of urea or urea combined with double straws. Itwas concluded that the application of urea combinedwith straw could increase the biomass and grain yield ofwheat aswell as the nitrogen use efficiency.