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.