Storage and Spatial Variation of Phosphorus in Paddy Soils of China

(整期优先)网络出版时间:2009-06-16
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Duetothegrowingconcernabouttheagriculturalphosphorus(P)lossespollution,anin-depthunderstandingofPinpaddysoilsofChinawouldbehelpfulinprovidinganationalperspectiveoftheenvironmentalimpactofPcyclingandfertilityonChina'sfarms.Inthisstudy,weevaluatedthePstorageandthePdensityofpaddysoilsinChina,characterizedthespatialvariationsofPamongthesubgroupsofpaddysoilsandsoilregionsinChina,andevaluatedthePdatausingGIS-basedanalysis,whichincludedanewlycompiled1:1000000digitalsoilmapofChina,andusing1490soilprofiles.TheavailableandtotalPdensitiesofpaddysoilswere6.7and698.5gm-3,respectively.OverallinChina,thetotalPstoragewithin1mofpaddysoilswasestimatedtobe330.2Tg.ThePdensityofpaddysoilsvariedsubstantiallywithsubgroupsduetothedifferentsoilwaterregimessuchasgroundwatertableandsoildrainage.ThePavailabilityinpaddysoils,especiallyinsurfacelayer,washigherinhightemperatureandprecipitationareas.Furtherresearchisneededtoexaminemoreanthropogenicimpactfactors,suchasincreasinguseofchemicalfertilizer.