Effects of different cultivation methods and nitrogen fertilizer application on nitrogen accumulation and distribution in winter wheat on semi-dryland farming

【Objective】The aim of this experiment is to investigate the effects of cultivation methods and nitrogen fertilizer rates on nitrogen accumulation,distribution and utilization efficiency of winter wheat in manural loessial soils under the winter wheat-summer maize cropping rotation system.【Method】A completely randomized block design was conducted in the experiment with four different cultivation methods(CK:control,SI:supplementary irrigation,SM:straw mulching,FP:furrow planting),three nitrogen fertilizer rates(0,120,240 kg/hm2)and four replications.【Result】Compared with other three cultivation methods,the nitrogen residue in the leaf and stem of wheat after harvesting was lower in SI cultivation method,so was the rate of residue N to total N accumulation in the crop;however,the rate of the nitrogen residue in the grain to the nitrogen accumulated in shoot was increased.As the increasing of the application rates of nitrogen fertilizer,nitrogen accumulation in the leaf,stem,glume rachis,and grain of wheat was significantly increased.While the nitrogen application was increased from 120 to 240 kg/hm2,nitrogen accumulation in wheat leaf,stem,and glume rachis was increased after harvesting;however,nitrogen accumulation in wheat grain didn't increased significantly.The application of nitrogen fertilizer had not show significant effect on the distribution of N in different organs of wheat.As the increasing of the application rates of nitrogen fertilizer,nitrogen recovery,agronomic efficiency and physiological efficiency became lower and lower.Compared with other different cultivation methods,N recovery,N agronomic efficiency and N physiological efficiency of supplementary irrigation pattern were higher during the two continuous years;the changes of these nitrogen efficiency indices of the other three cultivation methods were various in different years.【Conclusion】It is concluded that as the application of nitrogen fertilizer,nitrogen accumulation in different organs of wheat was significantly increased at different growth stages,however,it had less effect on the distribution of N in different organs of wheat;in comparison with the application of nitrogen fertilizer,the effects of different cultivation methods had less effects on nitrogen accumulation and distribution in winter wheat at the different stages,and supplementary irrigation in winter tended to improve the nitrogen efficiency of wheat.