持续氮素调控对小麦/玉米轮作系统氮素利用和表观损失的影响

Effects of Constant Nitrogen Regulation on the Nitrogen Utilization and Apparent Loss in the Rotation System of Wheat and Maize

为解决作物生产中氮肥过量施用问题,采用田间小区试验法,设置农民习惯施氮(FN)、优化减氮(ON)、优化减氮后再减氮20%配施不同氮素调控剂等处理,研究持续氮素调控对小麦/玉米轮作系统作物产量、氮素利用和表观损失及经济效益的影响。结果表明:与FN比,ON的小麦和玉米产量、氮素吸收量均未受影响,而氮素利用率、氮肥生产效率、氮肥农学效率均提高。ON的小麦和玉米两茬作物总N输入量较FN减少207.7kg/hm^2,N素表观损失减少119.1kg/hm^2,增收672.8元/hm^2,说明在农民习惯施氮肥基础上合理减少施氮量不但没有影响作物产量,反而促进作物氮素利用,减少氮素损失,降低氮肥生产成本,增加纯收益。与ON比,在优化减氮的基础上再减氮20%并配施硝化抑制剂(DCD),小麦和玉米两茬作物增产9.54%,氮素吸收量提高3.83%,氮素利用率提升5%以上,N素表观损失减少114.5kg/hm^2,增收3 292元/hm^2。综合考虑,各氮素调控措施中以ON80%+DCD效果较好,既能持续获得作物稳定高产,减少氮肥用量,又能减少氮素向环境中的损失,同时获得更高经济效益。

To solve the problem of excessive nitrogen fertilizer application in crop production,a field plot experiment was conducted,in which different fertilization treatments including farmer＇s traditional N fertilization（FN）,optimal fertilization with reduced nitrogen fertilizer based on FN（ON）,and fertilization with 20%nitrogen fertilizer reduction based on ON treatment combined with different nitrogen regulators were designed.Effects of different nitrogen sustainable regulations on the crop yield,N utilization,N apparent loss and economic benefits in the rotation system of wheat and maize were studied.The results showed that compared with the FN,ON did not significantly affect yields and N uptakes of wheat and maize,but increased N use efficiency,N production and agronomic efficiency.The total N input of wheat and maize in ON was 207.7kg/hm2 lower than that in FN,while in ON,N apparent loss was 119.1kg/hm2 lower and the net income was 672.8yuan/hm2 higher than those in FN.It indicated that optimal fertilization with reduced nitrogen fertilizer based on FN didn＇t influence crop yield,but improved the N utilization of crops,decreased the N apparent loss and the N fertilizer production cost,and enhanced the net income.At the same time,compared to ON,fertilization with 20% nitrogen fertilizer reduction based on ON combined with nitrification inhibitor DCD increased wheat and maize yields,N uptake and N use efficiency by 9.54%,3.83%and 5%,respectively,while decreased N apparent loss by 114.5kg/hm2 andincreased the net income by 3292yuan/hm2.Based on comprehensive consideration,we suggested that in the all N regulation measures,ON 80%＋DCD was the best,which can not only achieve sustainable high yields of crop,decrease N fertilizer rates,but also decrease N loss and make farmers obtain higher net income.