不同栽培模式及施氮对半旱地冬小麦/夏玉米氮素累积、分配及氮肥利用率的影响

在陕西关中地区进行田间试验，研究了不同栽培模式、施氮量对夏玉米和冬小麦地上部分氮素的累积、分配和利用效率的影响。结果表明: 垄沟栽培模式显著增加了成熟期夏玉米的氮素累积总量及各个器官的氮素累积量，其余处理下成熟期夏玉米和冬小麦的氮素累积量差异未达显著水平; 不同栽培模式下，小麦的各器官除叶片的氮素累积量差异达显著外，其余器官的氮素累积量均未达到显著水平; 不同栽培模式下，小麦各器官对子粒氮素的贡献为垄沟常规覆草控水; 与不施氮肥相比较，施氮处理（N 120 kg/hm2和N 240 kg/hm2）显著增加了作物氮素累积量; 两个施氮肥水平相比，高氮处理显著提高氮素累积量，但小麦花后营养器官氮素向子粒转运和分配两个水平间无显著差异; 随着氮肥用量的增加，氮肥利用效率和氮肥农学效率均呈现降低趋势。

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.