简介：Carbonofhumusacids(HSAC)anddissolvedorganiccarbon(DOC)arethemostactiveformsofsoilorganiccarbon(SOC)andplayanimportantroleinglobalcarbonrecycling.WeinvestigatedtheconcentrationsofHSAC,water-solubleorganiccarbon(WSOC),hotwater-extractableorganiccarbon(HWOC)andSOCinsoilsunderdifferentvegetationtypesoffourcopperminetailingssiteswithdifferingvegetationsuccessiontimeperiodsinTongling,China.TheconcentrationsofHSAC,WSOC,HWOCandSOCincreasedwithvegetationsuccession.WSOCconcentrationincreasedwiththeaccumulationofSOCinthetailings,andalinearlypositivecorrelationexistedbetweentheconcentrationsofHSACandSOCinthetailings.However,thepercentagesofHSACandDOCintheSOCdecreasedduringvegetationsuccession.TherateofSOCaccumulationwashigherwhenthesuccessiontimewaslongerthan20years,whereasthespeedsofsoilorganicmatter(SOM)decompositionandhumificationwereslow,andtheconcentrationsofHSACandDOCincreasedslowlyinthetailings.Thepercentageofcarbonofhumicacid(HAC)inHSACincreasedwithvegetationsuccession,andthevaluesofhumificationindex(HI),HAC/carbonoffulvicacid,alsoincreasedwiththeaccumulationofHSACandSOCinsoilsofthetailingssites.However,theHIvalueintheeachofthetailingswaslessthan0.50.ThehumificationrateofSOMwaslowerthantheaccumulationrateofSOM,andthelevelofsoilfertilitywasstillverylowinthetailingsevenafter40yearsofnaturalrestoration.

简介：Integrationofsoilinformationsystem(SIS)andinteractiveself-organizingdata(ISODATA)wasstudiedtoestablishproperagriculturaldevelopingzonesinredsoilregionofsouthernChinawhichareofcrucialimportancetofarmers,researchers,anddecisionmaderswhileutilizingandmanagingredsoilresources.SIScreatedbyusingARC/INFOwasusedtoprovidedataacquisition,systematicmodelparameterassignment,andvisualdisplayofanalyticresults.Topography,temperature,soilcomponent(e.g.,organicmatterandpH)andconditionofagriculturalproductionwereselectedasparametersofISODATAmodel.TakingLongyouCounty,ZhejiangProvinceasthecasestudyarea,theeffectoftheintegrationandrecommendationsarediscussedforfutureresearch.

简介：Nutrient-poor,sandysoilsformtheprevailingsubstrateatpost-miningsitesoftheLusatianregion(Brandenburg,Germany)andpresentachallengeforvegetationdevelopment.Westudiedtheorganicacidquantityandcompositionofthreecommonlyoccurringpioneerplantspecies,thelegumesLotuscorniculatusL.andTrifoliumarvenseL.andthegrassCalamagrostisepigeios(L.)Roth,todetermineifplantgrowthandexudationdifferedwith(non-sterilizedsoil)andwithout(sterilizedsoil)anindigenoussoilmicrobialcommunity.Weinvestigatedwhetherorganicacidswerefoundintherhizosphereandsurroundingsoilandwhetherthisinfluencednutrientmobilization.Thisstudyconsistsoflinkedfieldinvestigationsandagreenhouseexperiment.Plantsweregrowninthegreenhouseineithersterilizedornon-sterilizedsandysoilfromareclamationsiteintheLusatianmininglandscape(WelzowSu¨d,EastGermany).Aftersevenmonths,theplantbiomass,rootmorphology,organicacids,andwater-solublenutrientsandrootcolonizationwitharbuscularmycorrhizalfungi(AMF)anddarkseptateendophytes(DSE)wereanalyzed.RootsofallthreeplantsinthefieldandgreenhouseexperimentswerehighlycolonizedwithAMF.CalamagrostisepigeiosandT.arvensehadasignificantlyhighercolonizationfrequencywithDSEthanL.corniculatus.Thequantityandcompositionoforganicacidsstronglydifferedamongplantspecies,withthehighestnumberoforganicacidsfoundforL.corniculatusandlowestforC.epigeios.Thequantityoforganicacidswasgreatlyreducedinallplantsundersterilizedsoilconditions.However,thecompositionoforganicacidsandplantgrowthinsterilizedsoilwerereducedforbothlegumes,butnotforC.epigeios,whichhadahigherbiomassundersterilizedconditions.Changesinnutrientconcentrationsinthefieldrhizospheresoilrelativetothoseinthecontrolweremeasurableaftersevenmonths.Whilethespectrumoforganicacidsandthegrowthoflegumesseemedtobedependentonahighly