简介：A5－yearexperimentonwaterbalancehasbeenconductedinaflatrainfedwheatfieldwithanareaof66×100m^2inFengqiu,HenanProvinceinChina.Basedontheanalysisofsemi-variancefunctionsconductedwithsoilmoisturesamplestakenfrom77nodesofa10×10m^2grid,thesoilmoisturedistributioninthefieldwasstructuralwithatemporalstability.Accordingtotheautocorrelationrangeofthesemi-variancefunction,6siteswereselectedforthedeterminationofsoilwaterconditions.Thecharacteristicofprobabilitydensityfunctionofthedifferencesofwaterstorageintwosetsofmeasurementsshowedthatthedistributionofthesevariablesinthefieldwasanormalone.Theerrorintheestimationoftheaverageof5randomsampleswas14%(α=0.10),andtheerrorsofwaterconsumptionbywheatduringtheexperimentswereestimatedtobe6-13%.Simetheexperimentalfieldwaslargeenoughtoavoidanyedgeeffect,theresultsobtainedshouldtallywiththeactualsituation.Yetthesoilsystemwasheterogeneous,sowemustfollowtheprinciplesofstatisticsandgeostatisticswhendescribingthesystem'sstatuswiththeaverageofthesamples.

简介：AnexperimentwasconductedinaredsoilderivedfromQuaternaryredclayintheEcologicalExperimentStationofRedSoil.theChineseAcademyofSciences,locatedinYingtan(28°15′30″N,116°55′30″E),JiangxiProvince,TheResultsshowthatthemajorwaysofnutrientlossareleachingandnitrogenvolatilization.Rationalizingcropdistribution,stimulatingnutrientrecycling,andimprovinginternalnutrientflowareeffectivemeasurestodecreasenutrientlossandtopromotenutrientutilizationefficiency.Theimportantwaysofregulatingnutrientcyclingandbalanceintheagroecosystemoftheredsoilaretoestablishoptimaleco-agriculturalmodels,practicebalancedfertilizationandcombinethecroppingsystemwiththelivestocksystem.