氮肥调控对小麦／玉米产量、氮素利用及农田氮素平衡的影响

摘要

为了实现小麦／玉米高产高效生产，采用田间小区试验方法，研究了不同氮肥管理措施对小麦／玉米产量、氮素利用及农田氮素平衡的影响。结果表明，小麦季在农民常规施肥的基础上适当减少追氮量不会对小麦产量产生明显影响，在施氮总量195 kg／hm 2基础上配施调控剂处理小麦增产8．3％～24．6％，氮肥偏生产力、表观利用率和农学效率及氮肥贡献率均得到相应提高。在玉米季，以一次性基施适量氮肥同时配施抑制剂的氮肥管理方案为最佳，在施氮240 kg／hm2水平上与不添加抑制剂等氮量一次性基施和基追结合处理相比，增产幅度分别为7．4％～9.6％和13．9％～16．2％，氮肥贡献率、肥料偏生产力和农学效率亦得到显著提高；经过一个轮作周期后，农田土壤氮素盈余量为63．94～126．83 kg／hm 2。在总施氮量435 kg／hm 2的情况下，与单施尿素相比较，配施氮素调控剂的氮素盈余量降低了27．4％～44．2％，其中脲酶与硝化抑制剂配施效果最佳。但在总施氮量480 kg／hm 2的情况下，即使施用了氮素调控剂，氮素平衡盈余率仍在20％以上，存在较大的环境风险。%In order to achieve high yield and high efficiency production in the wheat/maize rotation system, field experiments were conducted to investigate the effects of different nitrogen management practices on the crop yield,nitrogen utilization and N apparent balance.The results indicated that,based on the farmers routine fertiliza-tion,appropriately reducing the amount of nitrogen-dressing had no significant effect on wheat yield.The application of nitrogen regulators could increase the wheat yield by 8.3%-24.6% when nitrogen rate was 195 kg/ha,and thereby improve the N partial factor productivity,N use efficiency,N agronomic efficiency and N contribute rate.In the maize growing season,compared with the treatments applied equal amount nitrogen as basal fertilizer or base-topdressing fertilizer without the addition of nitrogen regulators,the combination of nitrogen with nitrogen regulators as basal fertilizer was the best nitrogen management practice,which increased the corn yield around 7.4%-9.6%and 13.9%-16.2% when nitrogen rate was 240 kg/ha.And the N contribute rate,N partial factor productivity and N agronomic efficiency were also increased.After a period of crop rotation,the surplus amount of soil nitrogen was 63.94 -126.83 kg/ha.When the total amount of nitrogen was 435 kg/ha,compared with the single application of urea,the surplus amount of nitrogen in the treatment with nitrogen regulators reduced by 27.4%-44.2%,and the application of urease inhibitor combined with nitrification inhibitor had the most obvious effect.However,when the total amount of nitrogen was 480 kg/ha in wheat/maize rotation system,N balance surplus rate was still more than 20% even combined with the application of nitrogen regulators,which might cause a serious environmental risk.