连续施氮对冬小麦-夏玉米轮作体系产量和氮素吸收与利用的影响

摘要

[目的]为冬小麦-夏玉米轮作体系高产、稳产,合理施用氮肥提供依据.[方法]研究了连续施氮对冬小麦-夏玉米产量、经济效益、氮肥吸收利用效率和土壤无机氮的影响.[结果]施氮使冬小麦-夏玉米轮作体系显著增产,2个轮作周期分别增产17.76％～30.32％、22.24％～46.63％；施氮量660.0 kg/hm2在2个轮作周期的产量均最高,分别为23 391.19和23 444.35 kg/hm2,经济效益和产投比较佳,氮肥利用率分别为22.2％和30.7％,农学效率分别为8.3 kg/kg和11.3kg/kg.施氮量540.0和660.0 kg/hm2的氮肥利用率和农学效率均无显著差异.2个轮作周期后,施氮量540.0 kg/hm2的0～40 cm土壤无机氮积累量与试验前基本平衡.[结论]该试验条件下,综合产量、效益、氮肥效率及土壤无机氮平衡考虑,高产冬小麦-夏玉米轮作体系适宜施氮量为625.3～660.0 kg/hm2.%This study aimed to achieve high yield and stable yield of winter wheat-summer maize rotation system and provide basis for rational application of nitrogen fertilizer.[Method] Effects of continuous nitrogen application on grain yield,economic profit,nitrogen uptake and utilization efficiency,and soil inorganic nitrogen accumulation in winter wheat-summer maize rotation system were investigated.[Result] Nitrogen application could significantly increase the yield of the winter wheatsummer maize rotation system,which increased by 17.76％-30.32％ and 22.24％-46.63％ in two rotation cycles,respectively.The yield of the winter wheat-summer maize rotation system was the maximum in two rotation cycles with nitrogen application amount of 660.0 kg/hm2,which reached respectively 23 391.19 and 23 444.35kg/hm2,the yield and economic benefit were the highest,the nitrogen fertilizer use efficiency was 22.2％ and 30.7％,the agronomic efficiency was 8.3 and 11.3 kg/kg.However,the nitrogen fertilizer use efficiency and agronomic efficiency between nitrogen application amount of 540.0 and 660.0 kg/hm2 showed no significant difference.After two rotation cycles,inorganic nitrogen accumulation in 0-40 cm soil with nitrogen application amount of 540.0 kg/hm2 was almost equal to that before experiment.[Conclusion] Under the experimental conditions,comprehensively considering the grain yield,economic profit,nitrogen fertilizer efficiency and soil inorganic nitrogen balance,the optimal nitrogen application amount was 625.3-660.0 kg/hm2 in high-yield winter wheat-summer maize rotation system.