施氮量与地膜覆盖对长江中游春玉米产量性能及氮肥利用效率的影响

以宜单629为试验材料，于2012-2013年在湖北武穴通过大田试验，研究施氮量和地膜覆盖对长江中游春玉米产量及其性能参数的调节效应以及氮肥利用效率的影响。结果表明，增施氮肥促进春玉米生长发育，抽雄期和吐丝期提前8~12 d，延长籽粒灌浆期2~6 d，全生育期减少2~7 d；地膜覆盖促进种子萌发和玉米植株发育，种子出苗提前7~8 d，抽雄期和吐丝期提前6~11 d，生理成熟期提前3~6 d。增施氮肥和地膜覆盖优化长江中游春玉米产量性能参数，增施氮肥使平均叶面积指数(MLAI)提高81.18%~112.38%，平均净同化率(MNAR)提高19.20%~25.82%，穗粒数(GN)和千粒重(GW)增加72.61%~95.30%和13.09%~21.26%；同等施氮条件下，地膜覆盖提高MLAI (11.12%~17.12%)、MNAR (0.80%~10.66%)、HI (0.44%~6.50%)、GN (7.02%~16.07%)和GW (5.64%~7.93%)；由于产量性能参数间的超补偿作用，增施氮肥和地膜覆盖使春玉米籽粒产量提高6.80%~24.66%和7.16%~22.19%。施氮量增加显著降低春玉米氮肥利用效率，氮肥偏生产力(PFPN)和氮肥农学利用效率(ANUE)分别降低31.34%~51.20%和30.39%~42.12%；地膜覆盖促进春玉米的氮素吸收能力，显著提高春玉米氮肥利用效率，PFPN和ANUE分别提高18.30%~31.67%和25.83%~56.80%。统筹考虑长江中游春玉米产量性能优化补偿增产机制和氮肥利用效率特征，可选用优化施氮量202.5 ~270.0 kg hm^-2和覆膜增温降渍，其产量可达8995~9220 kg hm^-2。

Effects of Nitrogen Application and Film Mulching on Yield Performance Parameters and Nitrogen Use Efficiency of Spring Maize in the Middle Reaches of Yangtze River

A two-year field experiment using maize hybrid Yidan 629 with nitrogen(N) application and film mulching was conducted in Wuxue, Hubei Province, during 2012–2013 growing season to study the characteristics of yield performance parameters and N use efficiency of spring maize in the middle reaches of Yangtze River. The results showed that film mulching could make an earlier seed germination times of 7–8 d, N application and film mulching could promote the vegetative growth of spring maize, the tasseling stage and silking stage were advanced 8–12 d and 6–11 d, respectively, the maturity stage advanced 2–7 d and the physilogical maturity stage advanced 3–6 d. Compared with the control, the yield performance parameters of spring maize such as mean leaf area index (MLAI), mean net assimilation rate (MNAR), harvest index (HI), grain number per ear (GN) and 1000-kernels weight (GW) increased by 81.18%–112.38%, 19.20%–25.82%, 72.61%–95.30%, and 13.09%–21.26% in N application treatment, and increase 11.12%–17.12%, 0.80%–10.66%, 0.44%–6.50%, 7.02%–16.07%, and 5.64%–7.93% in film mulching treatment. With the super compensative effect of yield performance parameters, the grain yield of spring maize increased by 6.80%–24.66% and 7.16%–22.19%, respectively, resulting from N application and film mulching. The N use efficiency was significantly reduced with increasing N application, the partial factor productivity (PFPN) and nitrogen agronomic efficiency (ANUE) were decreased 31.34%–51.20% and 30.39%–42.12%. Film mulching enhanced N absorbing ability of spring maize, and increased PFPN and ANUE 18.30%–31.67% and 25.83%–56.80%, respectively. Comprehensive considering the super compensative effect of yield performance parameters and the characteristics of N use efficiency, achieving high yield of 8995–9220 kg ha^-1 in spring maizeneeds the N application of 202.5–270 kg ha^-1 with film mulching in the middle reaches of Yangtze River.