摘要
Excessivenitrogen(N)fertilizerapplicationtowinterwheatisacommonproblemontheNorthChinaPlain.TodeterminetheoptimumfertilizerNrateforwinterwheatproductionwhileminimizingNlosses,fieldexperimentswereconductedfortwogrowingseasonsateightsites,inHuiminCounty,ShandongProvince,from2001to2003.TheoptimumNrateformaximumgrainyieldwasinverselyrelatedtotheinitialsoilmineralNcontent(Nmin)inthetop90cmofthesoilprofilebeforesowing.TherewasnoyieldresponsetotheappliedNatthethreesiteswithhighinitialsoilmineralNlevels(average212kgNha-1).TheaverageoptimumNratewas96kgNha-1forthefivesiteswithlowinitialsoilNmin(average155kgNha-1)beforesowing.ResidualnitrateNinthetop90cmofthesoilprofileafterharvestincreasedwithincreasingfertilizerNapplicationrate.TheapparentNlossesduringthewheat-growingseasonalsoincreasedwithincreasingNapplicationrate.TheaverageapparentNlosseswiththeoptimumNrateswerelessthan15kgNha-1,whereasthefarmers'conventionalNapplicationrateresultedinlossesofmorethan100kgNha-1.Therefore,optimizingNuseforwinterwheatconsiderablyreducedNlossestotheenvironmentwithoutcompromisingcropyields.
出版日期
2006年06月16日(中国期刊网平台首次上网日期,不代表论文的发表时间)