Effects of different cultivation patterns and nitrogen fertilizer on accumulation,distribution and use efficiency of nitrogen in winter wheat/summer maize rotation system on semi-dryland farming

A field experiment was conducted in the Guanzhong region of Shaanxi Province to study the effects of different cultivation patterns and N fertilization on the accumulation,partition and use efficiency of N in maize and winter wheat rotation.The results showed that the furrow planting pattern significantly increased the N accumulation in maize during its mature stage,whereas other cultivation patterns had no significant effects on the N accumulation in the maize and wheat.Different cultivation patterns had significant effect on the N accumulation in leaves of wheat,while had no effects on other organs of maize and wheat.The contribution of N from different organs to grain increased in the order: furrow planting conventional straw mulching water-controlled.Applying N fertilizer(including N 120 kg/ha and N 240 kg/ha)increased the N accumulation in the crop in comparison with the control.The N accumulation in treatment of N 240 kg/ha was significantly higher than that of N 120 kg/ha treatment.However,there were no significant differences in the N translocation from different organs to grains and partition between the two N fertilizer treatments during the anthesis stage.As the increasing of N fertilizer rates,the N use efficiency and N agronomic efficiency decreased.