摘要：

研究不同覆膜方式下,施氮量对春玉米产量、氮素积累和氮肥利用效率的影响,为贵州高海拔区春玉米覆膜种植高效施氮管理提供理论依据,于2018-2019年开展田间试验,采用裂区设计,主区为不同覆膜方式(宽膜和窄膜),副区为5个施氮水平 (0,80,160,240,320 kg/hm²),研究不同覆膜方式及施氮量对春玉米产量、氮素积累、转运特征及利用效率的影响。结果表明,覆膜方式和施氮量及其互作显著提高春玉米产量,宽膜覆盖使春玉米增产17.8%,且显著增加了氮素积累量,促进了吐丝前积累氮素的再转移,从而显著提高了籽粒氮素积累量,并使氮素利用效率(NUTE)、氮素吸收效率(NUPE)、氮肥农学效率(AEN)、氮肥偏生产力(NPFP)、氮肥利用率(NUE)分别增加4.9%,21.4%,23.5%,12.2%和4.23百分点。施氮实现了春玉米籽粒产量和植株氮素积累量的协同增长,且能够显著影响氮素吸收、积累和转运。增施氮肥能有效促进提高吐丝后氮素转运量及其对籽粒的贡献率,但降低了春玉米氮肥利用效率,NDGPE(氮素干物质生产率)、NHI(氮收获指数)、NUTE、NUPE、NUE、AEN、NPFP均随施氮量的增加而明显下降,达到极显著水平。通过回归分析不同覆膜方式下的最佳产量和施氮量,宽膜覆盖比窄膜覆盖处理减少施氮55 kg/hm²,产量增加12.3%。宽膜覆盖和适宜施氮量相结合,有利于植株氮素积累和吸收利用,从而实现高产和高氮肥生产力,达到节肥增产。综合考虑春玉米籽粒产量、氮素累积、转运及氮肥利用效率,贵州高海拔及类似生态区春玉米宽膜覆盖种植的合理施氮量为160 kg/hm²,其产量可达11 404.3 kg/hm²。

关键词: 春玉米, 覆膜方式, 氮素利用效率, 施氮量, 贵州, 产量

Abstract:

The objectives of this study were to investigate the effects of nitrogen application rate on the grain yield,nitrogen accumulation and use efficiency of spring maize under different film mulching methods,and to provide a theoretical basis for efficient nitrogen application management of spring maize film mulching in high altitude area of Guizhou.Field trials were carried out from 2018 to 2019.The plots were arranged in a split-plot design.The main plots were assigned to the film mulching methods(wide film and narrow film) to be studied and divided into subplots according to the five nitrogen application levels(0,80,160,240 and 320 kg/ha).To study the effects of different film mulching methods and nitrogen application rates on yield,nitrogen accumulation,transport characteristics and utilization efficiency in different organs of spring maize.Film mulching,nitrogen application rate and their interaction significantly increased the yield of spring maize.The results showed that compared to narrow film mulching,wide film mulching not only increased the yield of spring maize by 17.8%,but also significantly enhanced the nitrogen accumulation and the retransfer of nitrogen accumulated before silking,then significantly increased the grain nitrogen accumulation.Moreover,compared to narrow film mulching,wide film mulching achieved significantly higher NUTE,NUPE,AEN,NPFP and NUE values showing increases of 4.9%,21.4%,23.5%,12.2% and 4.23 percentage points,respectively.Nitrogen application realized the synergistic growth of grain yield and plant nitrogen accumulation of spring maize,and could significantly affect nitrogen absorption,accumulation and transport.As the N application rate increased,the N translocation and the contribution rate of nitrogen transfer from vegetative parts to grain after silking could be effectively promoted,as well as enhanced.However,the nitrogen use efficiency,including the NDGPE,NHI,NUTE,NUPE,NUE,AEN,NPFP of spring maize,significantly decreased by increasing of N application rate.The regression analysis had shown that the optimal yield and nitrogen application rate for wide film mulching were reduced nitrogen application by 55 kg/ha and increased yield by 12.3% compared with narrow film mulching.The combination of wide film mulching and suitable nitrogen application rate was beneficial to the plant accumulation and absorption of nitrogen,so as to achieve high yield and nitrogen productivity,and then achieve the purpose of saving fertilizer and increasing yield.Considering the grain yield,N accumulation,transport and N use efficiency of spring maize,the reasonable N application rate of wide film mulching for spring maize in high altitude and other similar ecological zones in Guizhou was 160 kg/ha,which yield could reach 11 404.3 kg/ha.

Key words: Spring maize, Film mulching method, Nitrogen use efficiency, Nitrogen application amount, Guizhou, Yield