喷灌玉米氮素养分推荐施肥指标体系的研究

Recommendation Index System of Nitrogen Fertilizer for Corn under Sprinkler Irrigation

通过连续5年的试验，研究了大型喷灌条件下玉米的氮素养分吸收分配规律、施氮肥效应及氮肥合理施用原则。结果表明，玉米吸收氮素累积量呈Logistic生长曲线变化，出苗后40d之前，植株吸收氮素累积量较少，出苗后40～100d是氮素吸收累积最快时期，出苗后80d左右氮素积累最大。玉米生育前期，茎、叶的氮素吸收积累量较多，而成熟期仅有30％～45％的氮滞留在茎、叶，但却有60％以上的氮素集中于籽实中。喷灌玉米施用氮肥时，平均增产54．6％，氮肥的农学效率为13．3kg／kg，增产效果显著。氮肥利用率平均为36．0％，吸收氮素量为1．91kg／lOOkg。可用基于作物产量反应和农学效率的推荐施肥方法进行氮素养分推荐。

The accumulation and distribution of nitrogen in maize and the balanced applying nitrogen fertilizer under sprinkling irrigation were studied through five-year consecutive field experiments. The results showed that nitrogen was accumulated in maize with Logistic curve. The nitrogen was accumulated slowly in 40 days after emergence, the accumulating rate was the fastest in 40-100 days after emergence, and the accumulated nitrogen was the top after emergence for about 80 days. The nitrogen was accumulated mostly in the stems and leaves in early stage. Only 30%- 45% nitrogen was accumulated in the stems and leaves while the accumulated nitrogen in the seeds was above 60%in the maturity stage. The corn yield was improved by 54.6% with nitrogen fertilizer under sprinkler irrigation. The nitrogen use efficiency was 36.0%, nitrogen agronomic efficiency was 13.3 kg/kg and nitrogen productive efficiency was 1.91 kg/100kg. The nitrogen fertilizer application rate could be recommended by the crop yield response and agronomic efficiency.