摘要
Incubation of two soils, a red soil derived from granodiorte and a fluvo-aquic soil from alluvial deposit,with rice straw, Chinese milk vetch and pig manure under submerged condition were conducted to study thespecies of Cu in soil solutions as affected by the organic materials. The organic materials increased totalsoluble Cu by raising dissolved organic carbon (DOC) in soil solution when the solution pH values were belowthe range in which Cu deposited quickly. When the solution pH rose to this range, the increase of DOCdid not raise total soluble Cu. Total soluble Cu in all the treatments dropped with incubation time. Afteradding organic materials labile Cu dropped with incubation time and decreased sharply in the pH range ofCu precipitation. Addition of organic materials enhanced slowly labile Cu but depressed the ratio of labileCu to total soluble Cu. Slowly labile Cu decreased with incubation time. Stepwise multiple linear regressionanalysis showed that total soluble Cu was positively correlated with Eh and DOC (P=0.0025), labile Cuwas negatively correlated with pH (P=0.011 8), and slowly labile Cu was positively correlated with Eh andDOC (P=0.002 2). Both the labile and slowly labile Cu were correlated with total soluble Cu at extremelysignificant levels.
INTRODUCTIONAddingorganicmaterialshasagreatimpactonthespeciationofheavymetalsinsoilsolutionbyalteringthecompositionandpropertiesofthesolidandliquidphasesofsoil.Thechemicalcompositionandpropertiesofsoilsolutionaremoreimportantthanthoseofthesolidphasei...
