Effect of Exogenous Rare Earths on Microbial Characteristics in Paddy Soil

(整期优先)网络出版时间:2004-02-12
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Anincubationstudywasperformedtoelucidateexogenousrareearthelements(RE)influencingonmicrobialbiomass,microbialecophysiologicalparameterscmic/corg,metabolicquotientqCO2andrespiratoryrateinrelationtotemporalavailabilityinpaddysoil.Sixsampleswereaddeddifferentconcentrationsbetween0and2000mg*kg-1REEsinsoil.ResultsshowthatexogenousREhaveslightstimulativeeffectsonmicrobialindicesinpaddysoilatlowconcentrationintheearlystageafteraddingRE,whilehavinginhibitoryeffectsathighconcentration.TheinhibitionisstrengthenedwithincreasingREconcentrationandisweakenedwithincreasingincubationtime.PrincipalcomponentanalysisoftheBIOLOGdataindicatesthatmicrobialcommunitystructureshavechanged,carbonsourcesconsumptionofmicroorganismsinpaddysoilbecomesmuchmorerapidafter8weeks,andunderREstress,thechangeofmicrobialcommunitystructuresisalong-termeffect.