摘要： 为探究春玉米花后营养器官氮再分配及氮素利用特性对不同生育时期补充灌溉的响应，以郑单958为材料，设置拔节期、大口期、吐丝期和吐丝后15 d 4个关键时期的灌水处理及不灌水对照，进行了2年大田试验研究。结果表明，春玉米生育前期灌水能够显著增加吐丝期叶片氮浓度和积累量，但茎秆中氮素增加相对不明显。大口期和吐丝期灌水显著促进了叶片和茎秆中氮素的再利用，叶片氮素再利用率达到34%~59%。灌水处理显著增加了单株籽粒氮积累量，但籽粒氮含量下降了3.6%~25.4%。各时期补充灌水有效改善了春玉米的氮利用特性，2年中受粉正常年份的氮肥偏生产力、氮素利用效率、氮收获指数分别提高了2.8%~11.2%，29.2%~59.4%，14.3%~25.0%。灌水促进了玉米植株氮的再利用，有效改善了玉米的氮利用特性，其中吐丝期灌水处理效果最为显著。

关键词: 春玉米, 补充灌溉, 氮素再利用, 氮素利用效率

Abstract: A two years' field experiment was conducted to investigate the effects of supplemental irrigation at different stages on plant nitrogen(N) remobilization and N use efficiency in spring maize. The maize hybrid Zhengdan 958 was used,and the no irrigation treatment(CK) and four irrigation treatments including irrigated 750 m³/ha at jointing stage(I_V6),12th leaf stage(I_V12),silking stage(I_S) and 15 days after silking(I_S15) were implemented. The results showed that irrigation at vegetative growth stages of spring maize could significantly increase N accumulation in leaf,but not obvious in stem. The treatments of I_V12 and I_S distinctly improved N remobilization efficiency of leaf by 34%-59%. The irrigation treatments significantly increased plant N accumulation of kernel,but the kernel N concentration declined by 3.6%-25.4%. All of the irrigation treatments obviously enhanced the characteristics of N utilization. The partial factor productivity of applied N,N utilization efficiency and N harvest index were improved by 2.8%-11.2%,29.2%-59.4% and 14.3%-25%,respectively,in the normal year. In general,supplemental irrigation enhanced plant N remobilization,improved the characteristics of N utilization,especially,the irrigation at silking stage was the optimal choice for single supplemental irrigation in spring maize.

Key words: Spring maize, Supplemental irrigation, N remobilization, Nitrogen utilization efficiency

中图分类号: 

• S311

• S143.1