【摘要】 通过设置不同幅度的氮肥减量施用,研究其在整个稻季中的环境效益、肥料效益和产量效益差异,为地区氮肥的减施增效提供依据。结果表明:稻田施肥后7 d之内,田面水中氮素含量维持较高水平,须谨慎控制田面水外排。在太湖地区现有肥力水平的基础上,适当减少氮肥用量是可行的。减少20%的常规施氮量可以有效降低田面水中氮素含量,进而降低向自然环境中排放的总氮量;并通过作用于水稻产量构成因素和提高氮肥农学效率,适当提高产量,最终达到协调产量效益、肥料效益和环境效益的目的。更多还原

【Abstract】 A field experiment was carried out in the Taihu Region to study economic benefit,fertilizer use efficiency and environmental benefit of reducing nitrogen application rate throughout the entire rice growing season with the purpose of providing the local government with scientific basis in promoting reduction of nitrogen application rate.Results show that nitrogen content in the surface water of paddy fields would remain high for at least 7 days after fertilizer application,which calls for prudence in draining the fields within the period.In view of the current nitrogen application rate in the Taihu area,it is practically feasible to reduce the rate somewhat.Reduction by 20% can not only effectively lower nitrogen content in the surface water,and hence total nitrogen in the runoff into the environment,but also improve agronomic efficiency of the nitrogen fertilizer and its effect on the factors affecting rice yield,thus leading to higher crop yield,and eventually harmonization of economic benefit,fertilizer utilization efficiency and environmental benefit of nitrogen application.更多还原