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《phosphorus load reductions under best management practices for sugarcane cropping systems in the everglades agricultural area：磷负荷降低的最佳管理实践在甘蔗种植系统在沼泽地农业区》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、AgriculturalWaterManagement56(2002)1739PhosphorusloadreductionsunderbestmanagementpracticesforsugarcanecroppingsystemsintheEvergladesAgriculturalArea*RonaldW.Rice,ForrestT.Izuno,RaymondM.GarciaInstituteofFoodandAgriculturalSciences,EvergladesResearchandE
2、ducationCenter,UniversityofFlorida,3200EastPalmBeachRoad,BelleGlade,FL33430-8003,USAAccepted13December2001AbstractStormwaterrun-offfromthe290,000haEvergladesAgriculturalArea(EAA)isdirectedintoSouthFloridasEvergladeswetlandecosystem.Concernsregardingrun-o
3、ffwaterqualityandenvironmentalimpactledtoa1992regulatoryprogramwhichrequiresPlevelsinbasinrun-offbereducedbyatleast25%relativetohistorictrends.Farmersmustcollectivelyachievethisannualbasin-leveltargetbyimplementingbestmanagementpractices(BMPs)toreducePle
4、velsinfarmdrainagewaters.Atthetime,proposedBMPstrategieswerelargelyuntested,andtowhatextenttheymightreducefarm-levelPdischargetrends(alsopoorlydocumented)wasunknown.Giventheseuncertainties,objectivesofthisstudywereto:(1)documentlong-termdrainagePtrendsfo
5、rEAAsugarcanesystemsand(2)quantifyBMPeffectson-farmdrainagePloading.Inlate-1992,dischargepumpsatfivefarmsites(croppedtosugarcane,sugarcanevegetables,and/orsugarcanerice)wereinstrumentedtocollectwatersamplesforPanalysisduringalldrainageeventsthroughoutbase
6、line(BL;pre-BMP)andBMPoperations.Highlyvariablerainfalldistributionsintheregionstronglyinfluencefarmdrainagerequirements,thus,meaningfulinterpretationsofwaterqualitytrendsrequirehydrologicadjustmenttoPloaddata.Fiverainfall-adjustmentanalyseswereappliedtot
7、he6-yearfarm-leveldatabases.TwoanalysismethodscomparedPloadtrendsfortheentireBLandBMPmonitoringperiods.InMethod1,unitareaPload(UAL)torainfallratios(UAL:R)duringBMPoperationswere20.447.3%smalleracrossallfivesitesthanthoserecordedduringBL.InMethod2,slopecoe
8、fficientsdescribingcumulativeUALversuscumulativerainfalltrendsduringBMPswere14.925.0%smallerthanBLslopes.Theremainingthreemethodsassesseddatatrendsacrossfiveconsecutivewateryears(WY).InMethod3,slopecoefficientsdescribingWY969
