03中国北京地区在污水灌溉条件下灌溉施肥管理制度的评价

EvaluationontheirrigationandfertilizationmanagementpracticesundertheapplicationoftreatedsewagewaterinBeijing,ChinaXiangpingWanga,b,GuanhuaHuanga,b,*aCenterforAgriculturalWaterResearch,ChinaAgriculturalUniversity,Beijing100083,PRChinabChinese–IsraeliInternationalCenterforResearchandTraininginAgriculture,ChinaAgriculturalUniversity,Beijing100083,PRChina1.IntroductionWinterwheatfollowedbysummercornisacommonlyuseddoublecroppingsystemintheNorthChinaPlain(NCP)(Liuetal.,2003;Zhangetal.,2003;Huang,2004;Huetal.,2006).Accordingtothestatistics(Anonymous,2006),thetotalcroppingareainBeijingis3.18105ha,withwhich1.197105haisusedforgrowingsummercorn,and5.33104haisusedforgrowingwinterwheat.Inordertoachievethehighgrainyield,farmerstendtooverusethechemicalfertilizer(RichterandRoelcke,2000;Liuetal.,2003;Juetal.,2007;Zhenetal.,2006).Asaresult,theincreaseingrainagriculturalwatermanagement95(2008)1011–1027articleinfoArticlehistory:Received17July2007Accepted30March2008Publishedonline21May2008Keywords:IrrigationwithtreatedsewagewaterNitrogentransportandtransformsIrrigationandfertilizationintegratedmanagementModelevaluationabstractIrrigationandfertilizationmanagementpracticesplayimportantrolesincropproduction.Inthispaper,theRootZoneWaterQualityModel(RZWQM)wasusedtoevaluatetheirrigationandfertilizationmanagementpracticesforawinterwheat–summercorndoublecroppingsysteminBeijing,Chinaundertheirrigationwithtreatedsewagewater(TSW).AcarefullydesignedexperimentwascarriedoutatanexperimentalstationinBeijingareafrom2001to2003withfourirrigationtreatments.Thehydrologic,nitrogenandcropgrowthcomponentsofRZWQMwerecalibratedbyusingthedatasetofonetreatment.Thedatasetsofotherthreetreatmentswereusedtovalidatethemodelperformance.Mostpredictedsoilwatercontentswerewithin1standarddeviation(S.D.)ofthemeasureddata.Therelativeerrors(RE)ofgrainyieldpredictionswerewithintherangeof26.8%to18.5%,whereastheREsofbiomasspredictionswerebetween38%and14%.Thegrainnitrogen(N)uptakeandbiomassNuptakewerepredictedwiththeREvaluesrangingfrom13.9%to14.7%,andfrom11.1%to29.8%,respectively.Theseresultsshowedthatthemodelwasabletosimulatethedoublecroppingsystemvariablesunderdifferentirrigationandfertilizationconditionswithreasonableaccuracy.ApplicationofRZWQMinthegrowingseasonof2001–2002indicatedthatthebestirrigationmanagementpracticewasnoirrigationforsummercorn,three83mmirrigationseachforpre-sowing,jointingandheadingstagesofwinterwheat,respectively.Andthebestnitrogenapplicationmanagementpracticewas120kgNha1forsummercornand110kgNha1forwinterwheat,respectively,undertheirrigationwithTSW.Wealsoobtainedthealternativeirrigationmanagementpracticesforthehydrologicyearsof75%,50%and25%,respectively,inBeijingareaundertheconditionsofirrigationwithTSWandtheoptimalnitrogenapplication.#2008ElsevierB.V.Allrightsreserved.*Correspondingauthor.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](G.Huang).availableat–seefrontmatter#2008ElsevierB.V.Allrightsreserved.doi:10.1016/j.agwat.2008.03.012yieldwasaccompaniedbyenvironmentalproblems.Fertilizernitrogen(N)isoneofthekeyfactorscontributingtograinyieldincrease.However,environmentalproblemsassociatedwithNcontaminationareamongthemostchallengingtasksforsustainableagriculture(RichterandRoelcke,2000;Linketal.,2006).Nitrate-N(NO3-N)pollutioninChinaisaseriousprobleminregionswithintensiveagriculturalpressure.Dingetal.(2007)hasreportedtheincreasingemissionofN2Otoenvironmentduetohumanactivities;NO3-NleachingattributedtoelevateNO3-NlevelingroundwaterhasbeenreportedinmanystudiesintheNCP(Zhangetal.,1996;Juetal.,2007).Waterisanotherfactoraffectinggrainproduction.AsrainfallintheNCPisbarelysufficienttosupportthecropgrowth,especiallyforwinterwheat,thegrainproductioninthisregionreliesheavilyonirrigationwithbothsurfaceandgroundwater(Sunetal.,2006;ShangandMao,2006).Inrecentyears,withrapiddevelopmentineconomy,competitionforwaterisbecomingmoreintensive,andgroundwatertableintheNCPisdecreasingsteadilybecauseofover-pumpingforcropirrigation(Huetal.,2002).Thus,forsustainableagriculture,itisnecessarytodevelopanappropriatewatermanagementstrategyforcropproductioninthisregion.Manyeffortshavebeenmadeoninvestigatingtherelationshipbetweenwater-savingandgrainproduction(Wangetal.,2001;Moetal.,2005;ShangandMao,2006;Sunetal.,2006).However,littleattentionhasbeenputonutilizingtreatedsewagewaterforcropproductioninthisregion.Sewagewaterisalargewaterresourcewhichcanbeusedforcropproductionafterappropriatetreatment.TheannualsewagewaterinBeijingareaisabout1.3billionm3(BCM),with53%beingsecondary-treatedforthecity,and12.5%foritssuburbs.AccordingtotheplanningofBeijingmunicipality,90%ofthetotalsewagewaterwillbetreatedbysecondarymethodswithinafewyears.And0.4BCMtreatedsewagewater(TSW),whichaccountsfor40%oftheirrigationwater,willbeusedforirrigation.Therefore,usingtheTSWtoirrigatethecropsisoneoftheeffectivemeasurestoalleviatethewatercrisisinBeijingareaatpresentandinthefuture.TheuseofTSWforirrigationhas