简介：为了检验可降解生态覆盖垫在河滩地造林中抑制杂草生长的效果,分3个处理(有生态覆盖垫、无生态覆盖垫、空旷地对照)对北京延庆县中德合作项目示范区的油松、刺槐、元宝枫、蒙古栎、侧柏和铺地柏等树种下的杂草盖度等级进行了调查.结果表明:可降解生态垫的杂草抑制率超过82.1%;杂草生长越旺盛的林地,可降解生态垫的杂草抑制率越高;大苗和冠幅较大的树种,可降解生态垫抑制杂草的效果更为明显.

简介：在整理、分析黄土高原西峰等水土保持试验站径流、泥沙观测资料的基础上,研究了该地区水平梯田的蓄水保土效益.结果表明:其效益的平均值为86.7%和87.7%,但差异悬殊,主要是受暴雨、大暴雨质量的影响.次降雨综合参数PI、汛期降雨量和年产流降雨量分别小于20.0mm2/min、350mm和125mm时,蓄水保土效益均为100%,大于这些数值时,效益降低,两者呈负相关;同时,梯田的质量也影响蓄水保土效益.

简介：中世纪暖期是冰后期的又一次温暖期,研究表明,当时世界许多地区均出现不同程度的气温回升现象,而且气温回升与20世纪初气候变暖现象类似.为探讨该期中国东部沙地的气候环境状况,利用已有的研究成果,对中国东部沙地若干古土壤和河湖相沉积进行分析.结果表明,中世纪暖期,东部沙地普遍发育古土壤或河湖相沉积,气候温暖湿润,流沙固定,沙地面积缩小,植被盖度增加,沙地形成干草原-疏林草原景观.弄清中世纪暖期东部沙地气候状况,可为其未来气候环境演变趋势研究提供基础参考.

简介：TheimpactofpHchangesonmicrobialbiomasscarbon(Cmic)andmicrobialbiomassphosphorus(Pmic)wereexaminedfor3redsoilsundercitrusproductionwithdifferentlengthsofcultivation.SoilpHsignificantlyaffectedCmicandPmic.TheCmicandPmicchanges,asafunctionofsoilpH,appearedtofollowanormaldistributionwiththeoriginalsoilpHvalueattheapexandaspHincreasedordecreasedcomparedtotheoriginalsoilpH,CmicandPmicdeclined.Moreover,therewerecriticalpHvaluesatbothextremes(3.0ontheacidicsideand8.0to8.5onthealkalineside),beyondwhichmostofmicroorganismscouldneversurvive.TheeffectofpHonCmicandPmicwasalsorelatedtotheoriginalsoilpH.ThehighertheoriginalsoilpHwas,thelessCmicorPmicwereaffectedbypHchange.ItissuggestedthatsoilmicroorganismsthatgrowinasoilenvironmentwithamoreneutralsoilpHrange(I.e.pH5.5-7.5)mayhaveagreatertolerancetopHchangesthanthosegrowinginmoreacidicormorealkalinesoilpHconditions.

简介：ThereasonsfortheYangtzeRiverfloodcalamityin1998arebrieflyintroduced.Theauthorsbelievethatusinga'soilreservoir'conceptisanimportantmeanstohelpcontrolfloodingoftheYangtzeRiver.A'soilreservoir'hasalargepotentialstoragecapacityanditswatercanberapidly'discharged'intotheundergroundwaterinatimelyfashion.Theeroded,infertilesoilsoftheYangtzeRiverWatershedarecurrentlyanobstacletoefficientoperationofthe'soilreservoir'.Thestoragecapacityofthis'soilreservoir'hasbeenseverelyhamperedduetointensivesoilerosionandtheformationofsoilcrusts.Therefore,possiblemeasurestocontrolfloodsintheYangtzeRiverWatershedinclude:rehabilitatingthevegetationtopreservesoilandwaterontheerodedinfertilesoils,enhancinginfiltrationofthedifferentsoiltypes,andutilizingthelarge'soilreservoir'oftheupperreachesoftheYangtzeRiver.

简介：Undisturbedsoilcorewithmanymacroporesanddisturbedsoilcorewithonlyonemacropore(diameteris10mm)wereprobedbyx-raycomputedtomography(CT).Thesize,number,shapeandcontinuityofmacroporesinthetransverseandverticalsectionsofsoilwerecharacterizedusingCTscanningimages.TheprobabilitydensitiesofmacroporesinthetransversesectionofsoilcoreexhibitedalogarithmicΓdistribution.ResultsindicatedthatCTscanningwasapromisingnondestructivemethodforcharacterizingmacroporesinsoils.

简介：TwoecotypesofElsholtzia,ElsholtziasplendensandE.Argyi,aredominantplantsgrowingonCuandPb-Znsmelters,respectively.SamplesofthetwoecotypesandthecorrespondingsoilsfromfieldsofacopperminingareaandaPb-ZnminingareaofZhejiangProvince,China,wereanalyzedtoinvestigateCuorZntoleranceofthesetwoecotypes.EffectsofnineCulevels(0,5,10,20,40,80,160,240and320mgCuL-1asCuSO4@SH20)ongrowthanduptake,translocationandaccumulationofCuinthesetwoecotypeswereexaminedinasolutioncultureexperiment.Theexperimentalresultsshowedthatdryweights(DW)ofshootsandrootsweredepressed,andgrowthofE.SplendenswaslessdepressedthanthatofE.Argyiwhentreatedwith≥5mgCuL-1.ConcentrationsofCuinshootsofE.SplendensandE.Argyiexceeded1000mgkg-1DWat≥40mgCuL-x.ThemaximumCuaccumulatedintheshootsofGu-treatedE.SplendensandE.Argyireached101and142μgplant-1.Furthermore,analysisofplantsamplesfromthefieldsshowedthatthesetwoecotypescantolerantexcessheavymetalsandproducedhighdrymatter,andE.Splendenscanaccumulate11.7mgCuplant-1grownontheCusmelter.Therefore,E.SplendensandE.Argyicouldbegoodplantsforphytoremediation.

简介：Anincubationexperimentwasconductedtosimulatetheeffectoffloodingonwaterdeoxygenationinacidsulfatesoilfloodplainsystems.Theoriginallyoxygenated'floodwater'couldbedeoxygenatedimmediatelyfollowing'flooding'anditislikelythatthiswascausedmainlybydecompositionoforganicdebrisfromtheinundatedplants.Deoxygenationeventuallyledtothedepletionofdissolvedoxygen(DO)inthe'floodwater'anditishighlypossiblethatthisresultedinthetransformationsofferricFetoferrousFe,sulfatetohydrogensulfide,andorganicnitrogentoammonia(ammonification).Theaccumulationofthesereducedsubstancesallowsthe'floodwater'todevelopDO-consumingcapacity(DOCC).Whenthe'floodwater'ismixedwiththeintroducedoxygenatedwater,apartfromthedilutioneffects,thereducedsubstancescontainedinthe'floodwater'oxidizetofurtherconsumeDOcarriedbytheintroducedwater.However,itappearsthattheDOdropinthemixedwatercanonlylastforafewhoursifnoadditionalDO-depleted'floodwater'isadded.EntryofatmosphericoxygenintothewatercanraisetheDOlevelofthemixedwaterandlowerwaterpHthroughtheoxidationofthereducedsubstances.

简介：ExperimentswerecarriedoutonavegetablefieldwithPekingcabbage(Brassicapekinensis(Lour.)Rupr.),cabbage(Brassicachinensisvar.OleiferaMakinoandnemoto),greencabbage(BrassicachinensisL.),spinach(SpinaciaoleraceaL.)andrape(BrassicacampestrisL.)tostudytheeffectsofNformsandNratesontheirgrowthandnitrateaccumulation.Theresultsindicatedthatapplicationofammoniumchloride,ammoniumnitrate,sodiumnitrateandureasignificantlyincreasedtheyieldsandnitrateconcentrationsofPekingcabbageandspinach.Althoughnosignificantdifferencewasfoundintheyieldsafterapplicationofthe4Nforms,nitrateNincreasednitrateaccumulationinvegetablesmuchmorethanammoniumN.ThevegetableyieldswerenotincreasedcontinuouslywithNrateincrease,andoversupplyofNreducedtheplantgrowth,leadingtoayielddecline.Thistrendwasalsotruefornitrateconcentrationsinsomevegetablesandatsomesamplingtimes.However,asawhole,thenitrateconcentrationsinvegetableswerepositivelycorrelatedwithNrates.Thus,additionofNfertilizertosoilwasthemajorcauseforincreasesinnitrateconcentrationsinvegetables.Nitrateconcentrationsweremuchhigherinroots,stemsandpetiolesthaninbladesatanyNrate.

简介：InsouthernChina,collapsinggullyerosionproducesmassivedepositsofsedimentontheploughlayerofalluvialfanfarmland,leadingtoreducednutrients,increasederodibility,andevendesertification.Theaimofthisstudywastoinvestigatesoilerodibility(thefactorKintheUniversalSoilLossEquation,USLE)andphysicochemicalpropertiesofthealluvialfansofthemostseverecollapsinggullyerosionareas(Hubei,Jiangxi,Fujian,andGuangdongprovinces)insouthernChina.Thesoilsofthecollapsinggullyalluvialfanshadahigherbulkdensity,butalowertotalporosity,saturatedwatercontent,andsiltandclayfractionsthanthecontrol(CK)soilsfromthefarmlandwithoutdesertification.Soilqualitygraduallydecreasedfromfanedgetofanhead.SignificantdecreaseswerefoundinsoilpH,organicmatter,cationexchangecapacity,andtotalpotassium,nitrogen,andphosphorus,aswellasavailablenitrogen,phosphorus,andpotassium,resultinginagradualdecreaseinsoilnutrientsfromthefanedgetothefanhead.Soilerodibilitywasgreatestinthefanhead,andsoilerodibilityKvaluesofthealluvialfanswere53.71%,66.28%,67.53%,and71.68%greaterthanthatinthoseoftheCKsoilsofHubei,Jiangxi,Fujian,andGuangdong,respectively,indicatingasignificantcorrelationbetweenthesoilerodibilityKvaluesandphysicochemicalproperties,particularlysandfractionandorganicmattercontent.Theresultsprovidenewinsightsintotherelationshipbetweensoilphysicochemicalpropertiesanderodibilityofalluvialfans,andsuggestthatimprovingsoilstructuremightincreasesoilfertilityinthecollapsinggullyalluvialfanfarmland.

简介：Hydrolyzedleather,obtainedfromindustrialleatherwaste,isanorganicnitrogenousfertilizerwithahighchromium(Cr)content.SoybeancropscanbeadverselyaffectedbythepresenceofresidualCrinsoilafterapplicationofhydrolyzedleatherfertilizer.TheaimofthisworkwastoassesstheeffectofhydrolyzedleatheronCrabsorption,rootdevelopment,andsymbioticnodulationofsoybeanplantsgrownonthreedifferentsoilsincludingtwoLixisolsandaGleysol.Thesesoilswerepreviouslyfertilizedwithhydrolyzedleatheratthreedifferentrates(0.0,0.1,and0.8kgm-2).Soybeanshootheight,rootdevelopment,nodulation,andmineralnutrientconcentrationsinplanttissuesweredeterminedafter45dofcropgrowth.TheapplicationofhydrolyzedleathersignificantlyincreasedCrcontentinsoilandCruptakebyplants.Surprisingly,Crwasstoredmainlyintheaerialpartoftheplants.ThepresenceofCrhadanadverseimpactonshootdrymatter(41%reduction)andnumberofnodules(49%reduction)perplantgrownonthesoilwiththelowestcationexchangecapacity.However,noothersignificanteffectwasobservedinnoduleweight,diameter,oranyothermeasuredparameters.

简介：Organicamendmentssuchasvermicompostandbiocharhavebeenreportedtoenhancesoilfertilityandcropproductivity.However,whethertheco-applicationofbothamendmentshassynergisticeffectsorwhethersuchbenefitsareaccompaniedbytheriskofgaseousnitrogen(N)lossinanagroecosystemremainsunknown.Asoilcolumnexperimentwithafullyfactorialdesignwasconductedusingthreelevelsofvermicompost(nodose,lowdose(1%,weight:weight),andhighdose(3%,weight:weight))withoutorwithbiochar(1%,weight:weight)toinvestigatetheireffectsonricegrowthandgaseousNlossacrossthecropgrowingseason.Ourresultsdemonstratedthatsynergisticinteractionsexistedbetweenvermicompostandbiocharinpromotingcropyield.Comparedwithbiocharamendmentalone,biocharcombinedwithvermicompostsignificantly(P<0.01)increasedriceyieldby26.5%–35.3%.However,highdoseofvermicompostsignificantly(P<0.01)increasedthecumulativeammonia(NH3)andnitrousoxide(N2O)emissions.Inthepresenceofvermicompost,theincorporationofbiocharamendmentsignificantly(P<0.01)decreasedthecumulativeN2Oemissionby14.1%–18.6%.ThelowestemissionfactorvalueofNH3andN2Owasachievedusingbiocharincombinationwithlowdoseofvermicompost.Thisstudyrevealedthatthecombinationofbiocharandmoderatedoseofvermicompostoffersanovelapproachtopromotecropproductivitywhilereducingtheenvironmentalrisk.

简介：Prof.JamesM.Tiedje,UniversityDistinguishedProfessorandDirectoroftheCenterforMicrobialEcologyatMichiganStateUniversity,AcademicianoftheAmericanAcademyofSciences,hasbeenappointedasanHonoraryEditor-in-ChiefofPedosphere.Prof.

简介：Phosphorus(P)isalimitedresourcethatcouldbedepleted.Consequently,recyclingthePcontainedinsewagesludge,includingsewagesludgeincinerationash(SIA),fromwastewatertreatmentplantsisapossibilitytobeexplored.Agreenhouseexperimentusingannualryegrass(LoliummultiflorumL.)wasperformedwithanexperimentaldesignofthreecompletelyrandomizedblocksoftwosoilsand29treatments:onecontrolwithoutPandtwolevelsof9and26kgtotalPha-1from14differentsources:twelveSIAs(notcontaminatedbytracemetals)fromtheUSandCanada,onecommercialsyntheticfertilizer(triplesuperphosphate(TSP)),andonecommercialrockphosphate(RP).Higherryegrassbiomasslevelswereachievedatthehigherfertilizationrate(26kgtotalPha-1)andwhenusingtheSIAswiththehighestPsolubilitypercentage(PSP)(≥54%oftotalP).ThebiomassincreasesfollowingSIAapplicationwereashighas29%and59%morethanthecontrolforthesandyloamandclayeysoil,respectively,but40%lessthaninTSPforbothsoils.AsimilarbehaviorwasobservedforPuptake,withamaximumincreaseof26%fortheclayeysoil,and165%forthesandyloamsoil.TheryegrassbiomassandPuptakeincreasesduetoSIAapplicationwerelargerthanthoseduetoRPapplicationintheclayeysoil,butsimilartothoseinthesandyloamsoil.TheSIAswithaPSPof≥54%significantlyincreasedsoilavailablePstocksandsaturation.Accordingtoourfindings,weconcludethattheSIAsfrommunicipalandagrifoodindustrieshaveapotentialforPagriculturalrecycling,buttheirefficienciesvary.

简介：Anaerobicdigestionisaprocessthatiswidelyusedforthetreatmentoforganicwastes.Thedigestatecanbeusedasasoilamendmentorcropfertiliser.Theaimsofourworkweretoevaluate1)thephysicochemicalcompositionandpathogencontentinadigestatefrompoultrymanure,accordingtointernationalregulations,and2)theeffectofitssoilapplicationonthemajorchemicalandbiologicalsoilpropertiesandonthegrowthofLactucasativa.Theexperimentconsistedoftwogroupsofpots(withandwithoutcrop).Treatmentsappliedtoeachgroupwereasfollows:lowandhighdosesofdigestateandinorganicfertiliser,andnoapplication(control)(lowdose:70kgnitrogen(N)ha-1and21kgphosphorus(P)ha-1;highdose:210kgNha-1and63kgPha-1).Soilsamplesweretaken7and34d(harvest)aftertreatmentapplications.Heavymetalandpathogencontentsinthedigestatewerebelowtheupperlimitvalues.DespitethehighpHandelectricalconductivityvaluesofthedigestate,bothsoilparameterspresentedacceptablevaluesforcropgrowth.AlthoughtherewerenoinitialincreasesintotalinorganicNandavailablePinsoilwithdigestateapplication,anincreaseinthefreshweightofcropwasobservedwiththehighdoseapplication.Thisisprobablyassociatedwiththeslownutrientreleasefromthedigestateduringthedevelopmentofthecrop.Changesinthemicrobialcommunityweretemporaryandoccurredattheinitialsamplingstageoftheexperiment.

简介：Cadmium(Cd)ishighlytoxictoplants,animals,andhumans.Limitedinformationisavailableontheroleofnitricoxide(NO)and/or24-epibrassinolide(EBR)inresponseofplantstoCdstress.Inthisstudy,ahydroponicexperimentwasperformedtoinvestigatetheeffectsofNOand/orEBRonpeanutplantssubjectedtoCdstress(200μmolL-1)withsodiumnitroprusside(SNP,anexogenousNOdonor)(250μmolL-1)and/orEBR(0.1μmolL-1)addition.TheresultsshowedthatCdexposureinhibitedplantgrowth,andthisstresswasalleviatedbyexogenousNOorEBR,andespeciallythecombinationofthetwo.TreatmentwithCdinhibitedthegrowthofpeanutseedlings,decreasedchlorophyllcontent,andsignificantlyincreasedtheCdconcentrationinplants.Furthermore,theconcentrationofreactiveoxygenspecies(ROS)markedlyincreasedinpeanutseedlingsunderCdstress,resultingintheaccumulationofmalondialdehyde(MDA)andprolineinleavesandroots.UnderCdstress,applicationsofSNP,EBR,andespeciallythetwoincombinationsignificantlyreducedthetranslocationofCdfromrootstoleaves,increasedthechlorophyllcontent,decreasedtheconcentrationsofROS,MDA,andproline,andsignificantlyenhancedtheactivitiesofsuperoxidedismutase(SOD),peroxidase(POD),andcatalase(CAT)inpeanutseedlings.ExogenousNOand/orEBRalsostimulatedtheactivitiesofnitratereductase(NR)andnitricoxidesynthase(NOS)andincreasedthecontentsofantioxidants,suchasascorbicacid(AsA)andreducedglutathione(GSH).Furthermore,exogenousNOand/orEBRenhancedCdaccumulationinthecellwallandthusdecreasedCddistributionintheorganellesintheroots.Theconcentrationsofcalcium(Ca),iron(Fe),magnesium(Mg),andzinc(Zn)werealsoregulatedbyexogenousNOorEBR,andespeciallybythetwoincombination.TheseresultsindicatedthatSNPandEBR,aloneandparticularlyincombination,canmitigatethenegativeeffectsofCdstressinpeanutplants.

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

简介：Nitrogen(N)applicationmayleadtonichesegregationofsoilammonia-oxidizingarchaea(AOA)andbacteria(AOB),therebyreducingthecompetitiveinteractionsbetweenAOAandAOBduetohigherammoniumsubstrateavailability.However,theadaptivemechanismsofAOAandAOBunderNenrichmentremainpoorlyunderstood.Stableisotopeprobing(SIP)microcosmincubationwasemployedtorevealcommunitychangesofactiveAOAandAOBinaloesssoilfromafieldexperimentgrowingpotatoesthatreceivednoN(control,CK),lowN(LN,75kgNha-1),andhighN(HN,375kgNha-1).Theresultsshowedthatthesoilpotentialnitrificationrate(PNR)wasmeasuredbyculturingofthesoilsamplesfromthefieldexperiment.SoilPNRwassignificantlyincreasedinHNby87.5%and67.5%comparedwithCKandLN,respectively.ComparedwithCK,the13C-amoAgenesofsoilAOAandAOBinHNhad2.58×104and1.55×106copies,representing1.6-and16.2-foldincreaserespectively.ItwasindicatedthatAOBdominatedsoilammoniaoxidation.Aphylogeneticanalysisofthe13C-amoAgeneshowedthatNapplicationsignificantlyincreasedtheproportionof54d9-likeAOAupto90%inHN,whiletheNitrososphaeragargensis-likeandNitrososphaeraviennensis-likeAOAwereinhibitedandcompletelydisappeared.NitrogenapplicationalsoresultedinthecommunityshiftofactiveAOB-dominantgroupfromNitrosospirabriensis-liketoNitrosospirasp.TCH711-like.OurstudyprovidescompellingevidencefortheemergenceandmaintenanceofactivenitrifyingcommunitiesundertheintensifiedNinputtoanagriculturalecosystem.

简介：

简介：和田河流域属典型的内陆干旱区,根据和田河流域主要生态环境问题的形成机制,分析生态环境敏感性的区域分异规律,明确特定生态环境问题可能发生的地区范围与可能程度,并提出相应的保护建议,为流域未来区域发展规划、产业布局和区域生态环境整治规划提供参考,为生态环境保护与建设提供依据和指导。