施氮量对超高产夏玉米产量与氮素吸收及土壤硝态氮的影响

摘要

[目的]探讨超高产夏玉米(≥ 12 000 kg·hm-2)节肥增效的适宜氮肥用量.[方法]在夏玉米超高产区连续两年田间试验,研究不同氮肥用量对超高产夏玉米产量、氮代谢、氮素积累、氮肥效率及土壤硝态氮的影响.[结果]超高产区夏玉米施用氮肥两年增产幅度分别为6.76％-9.62％和5.21％-9.80％,夏玉米产量随氮肥用量增加呈先增加后降低趋势,以施氮量300 kg·hm-2产量和收益最佳,经济最佳施氨量为255.40 kg·hm-2;施氮量300 kg·hm-2有利于提高硝酸还原酶和蔗糖磷酸合成酶的活性,促进氮素吸收积累,可维持土壤硝态氮平衡,其氮肥利用率和农学效率两年平均值分别为16.12％和3.69 kg·kg-1.[结论]综合产量、收益、氮素吸收、氮肥利用效率及土壤氮素平衡等方面考虑,豫北地区黏壤质潮土超高产夏玉米合理的氮肥用量为255-300 kg·hm-2.%[Objective] The objective of this study is to provide a scientific and rational nitrogen fertilizer amount for super-high-yield summer maize (≥ 12 000 kg·hm-2).[Method] field experiments were conducted to study the effect of nitrogen fertilizer application on grain yield,nitrogen metabolism,nitrogen absorption,use efficiency of nitrogen fertilizer and soil nitric N on the farm of super-high-yield summer maize in 2007 and 2008.[Result] The results showed that,by applying nitrogen fertilizer,the yields increased by 6.76％-9.62％ and 5.21％-9.80％,respectively in 2007 and 2008.With the increased nitrogen levels,the production of summer maize increased at first and then decreased.Nitrogen applied at 300 kg·hm2 had the highest yield and incomes,increased the activity of nitrate reductase and sucrose phosphate synthase,and promoted the assimilation and accumulation of nitrogen to maintain soil nitrate nitrogen balance,and the recovery efficiency and agronomic efficiency of the applied N were 16.12％ and 3.69 kg·kg-1,respectively.The economic optimum nitrogen application rate was 255.4 kg·hm-2.[Conclusion] Considering the yield,economic benefits,nitrogen metabolism,nitrogen accumulation,nitrogen use efficiency and soil nitrogen balance,the proper nitrogen application rate for super-high-yield summer maize is about 255-300 kg·hm-2 in clay loam fluvo-aquic soil in north Henan province.