简介：Withdevelopmentofmoderngeoscience,particularlydevelopmentofenvironmentalsciences,thecontemporarysoilscienceisundergoinggreatchangesinbothresearchcontentsandscope.Soilisnotonlyacertainsubstanceoracertainindependentnaturalhistoricalbodybutalsoasphericlayerwithpeculiarstructureandfunctionsintheearthsystem.Fromtheviewpointofthegeo-biospheresystemofearth,soilsciencedoesdealnotonlywiththesoilsubstancespersebutalsomoreimportantlywiththerelationshipsamongsoil,theotherspheresandthehumansurvivalenvironmentinviewofthe"pedosphere",Thisistheneworientationofsoilsciencetodayandwillaffectprofoundlythestudiesonthehumansurvivalenvironmentandglobalchanges,Tothrowmorelightonthissubject,thepresentpaperintendstoaddresstheconceptionofpedosphereanditsroleinglobalchanges,AlsoaddressedareseriesofenvironmentalissuesinChinaandtheirrelationstotheglobalchanges.Moreover,researchorientationandprioritiesareindicated,includingexploitationandprotectionofthesoilresources,soilfertilityandsustainableagriculturaldevelopment,constructionoftheecologicalenvironment,andthematerialcyclinginpedosphereanditsrelationtoglobalchanges.

简介：Thechangesofclaymineralassociationafterhigh-gradientmagneticseparation(HGMS)treatment,andtheeffectsofchemicalandphysicaltechnologiesonconcentratingFeoxidesformiansoilsincentralandsouthernChinawereinvestigatedbymeansofX-raydiffraction(XRD)andchemicalanalysismethods.ResultsindicatedthattheconcentratingtimesofFeoxidesbyHGMStreatmentwerethelargestfor0.2-2μmsizefractionintheexaminedsoils.Forthesoilsinwhich2:1phyllosilicatesweredominant,concentratingtimesofironoxidesbyHGMStreatmentwerelargerthanby5molL^-1NaOHtreatment.Phyllosili-catesweredecreasedafterHGMStreatment;however,thedecreasewaslessthanthatofkaolinite,Thegoethite/(goethite+hematite)valuesinFeoxidesofthesoilskeptvirtuallyconstantafterHGMStreatment.

简介：AsoneofthedevelopingcountriesChinahasanarablelandpercapitafarbelowtheworld'saveragelevel.Withahigh-densitypopulationanthequickdevelopmentofeconomyandurbaniztion,theYangtzeRiverDeltashowsthetypicalcharacteristicsoflanduseindevelopedregionsofChina,whichare:highlandreclamationrateandlowarablelandpercapita;intensivelanduseandhighoutputvalue;andrapidincreasingofconstructionlandareaandfastdiminishingofarableland.TheanalysisindicatesthattheprocessofthearablelandchangesintheYangtzeRiverDeltacouldbedividedintofourdifferentchangestagesoverthepast50years.

简介：Thesorption-desorptionbehaviorofdicyandiamide(DCD)isanimportantchemicalprocessthataffectsDCDfateandmobilityinsoils.Therefore,thisstudyquantifiedDCDsorption-desorptiononaphaeozem(Mollisol),aburozem(Alfisol),asoilwithorganicmatter-removedandpeathumususingthebatch-equilibrationprocedure,andidentifiedsoilpropertiesthatinfluencedDCDsorption.Thesorptiononpeathumuswashigherthanthatonthephaeozemandtheburozem,withmuchlowersorptionobservedonthesoilwithorganicmatter-removed,indicatingthatsoilorganicmatterwasthemaincarrierofDCDsorption.DuetoitsamphipathicpropertytheDCDmoleculesorptiononthephaeozemandtheburozemdecreasedaspHincreasedfromabout2to5,butafurtherincreaseinpHledtoariseinDCDsorption.TheDCDdesorptionhystereticeffectforpeathumuswasgreaterthanthatforthephaeozemandtheburozemusing0.01molL-1CaC12asthebackgroundelectrolyte,suggestingthatthehydrophobicdomainsoforganicmattermayplayanimportantroleinDCDsorption.

简介：Landscapechangesweretracedoverthe20yearsfrom1974to1995intheupperMinjiangRiverbasin,oneofthemostimportantforestregionsinChina,basedonsatelliteimageinterpretationtoprovidebasicdataforlocaldecision-makingaswellassustainablelandscapeuseandmanagement.Resultsrevealedthatlandscapefrom1974to1995changedattheregionalscaleastheareaofforestlanddecreased,whilecropland,shrubland,economicforest,grassland,andbuilt-uplandincreased.Landscapechangesmainlyoccurredinforestland,shrubland,grassland,economicforest,andbuilt-upland.Moreover,thechangesamongforestland,shrubland,andgrasslandwerethelargest,influencingthewholecharacteristicsofthechangesinthebasin.Analysisofthechangesbetween1974and1995inthestudyareaindicatedthatlandscapeheterogeneityandfragmentationincreased,whereaslandscapeconnectivitydecreased.Thereweremultiplereasonsforlandscapechanges.Aprincipalcomponentanalysis(PCA)wasusedtoquantitativelystudydrivingforcesoflandscapechanges.ThePCAresultsshowedthateconomicandpopulationfactorsweretheprincipaldrivingforcesoflandscapechangesfrom1974to1995intheupperMinjiangRiverbasin,andthatPCAwasasuitablemethodforinvestigatingdrivingforcesoflandscapechanges.

简介：TheintegratedeffectofirrigationandagriculturalpracticesonsoilsalinityintheJordanValley(JV),whereover60%ofJordan'sagriculturalproduceisgrown,wasinvestigatedinthisstudyduring2009-2010.Duetothedifferencesinagriculturaloperations,croppingpatterns,irrigationmanagement,andweatherconditions,206top-andsub-soilsamplesweretakenevery1to3kmfromrepresentativefarmsalonganorth-south(N-S)transectwith1to2kmlateralextents.Soilelectricalconductivityofsaturatedextract(EC_(se)),Ca,Mg,K,Na,Cl,andNaadsorptionratio(SAR)weredeterminedinsaturatedpasteextracts.Resultsindicatedthatabout63%ofsoilsintheJVareindeedsaline,outofwhichalmost46%aremoderatelytostronglysaline.AlongtheN-StransectoftheJV,EC_(se)increasedfrom4.5to14.1dSm~(-1)intop-soilsamples.Similarincreasewasobservedforthesub-soilsamples.Themajorchemicalcomponentsofsoilsalinity;i.e.,Ca,Mg,andCl,alsoshowedasimilarincreasealongtheN-Stransectofthevalley.Moreover,comparedtopreviousfieldsampling,resultsshowedthatchangesinsoilsalinityintheJVweredramatic.Inaddition,itwasfoundthatClimposedanexistingandpotentialthreattosensitivecropsin60%ofthesoilsintheJV,whereClconcentrationsweregreaterthan710mgL~(-1).UndertheprevalentaridMediterraneanconditions,improvingthemanagementofirrigationwater,crops,andnutrientinputsandincreasingwaterandfertilizeruseefficienciesshouldbeindispensabletoconserveandsustainthealreadyfragileagriculturalsoilsintheJV.

简介：Landusechangescangreatlyinfluencesoilphosphorus(P)dynamics,especiallywhenconvertingnativeforeststoagriculturalland.SoilsinXishuangbanna,whichisoneofsouthwestChina'stropicalareasthatmaintainfragmentsofprimaryforests,werestudiedtoa)evaluatetheeffectoftwocommonlandusechanges,conversionofforeststoagriculturallandorrubbertreeplantation,onthedynamicsofavailablePandtotalPinbulksoilsaswellastotalPinparticlesizefractions;b)assesstherelationshipbetweensoilPdynamicsandsoilorganiccarbon(SOC);andc)elucidatetherelationshipbetweensoilPcontentandsoilpropertiessuchaspHandtexture.Clearingsecondaryforestswithsubsequentshiftingcultivationandestablishmentofrubbertreeplantationcausedsignificantdecreases(P＜0.05)inavailablePat0-20cmsoildepths,whereasfortotalPtherewasasignificantdecrease(P＜0.05)whenconvertingtoshiftingcultivation,rubbertreeplantation,orfallowfieldatboth0-20and20-40cmdepths.Abandonmentoffieldsusedforshiftingcultivationledtosignificantincreases(P＜0.05)inavailablePat20-40cmdepth.Inaddition,therewasasignificantpositiverelationshipbetweensoilorganiccarbonandsoilPcontent.Comparedtosecondaryforests,theratiooforganiccarbontototalPinsurfacesoils(0-20cm)ofshiftingcultivationandrubbertreeplantationwassignificantlylower(P＜0.05).

简介：中国经历了使用在最近的十年改变的戏剧的土地，与显著环境、社会经济的后果。Hengshan县，在西北中国的风神黄土的区域定位了，被调查为环境、长期的农村经济开发说明陆地使用变化和他们的含意。在Hengshan县的农田显著地减少了在期间19902003，而森林土地和草地增加了。土地在不同时期之中显著地改变了的农田，果园陆地，森林陆地和建设的变换率：19901995，19952000和20002003。果园土地，草地和构造土地的变换是主导的在19901995，而到森林土地的农田的变换主要发生了在20002003。结果在机构的政策和陆地管理的政治经济建议了深刻转变，包括综合土壤侵蚀控制工程，面向市场的经济的采纳和‘Grain-for-Green'政策的实现，在在中国的这个时期期间。为了完成长期的持续土地，在Hengshan使用县，努力应该瞄准象建立节俭陆地的机制支持陆地生产率一样增加农村家庭的离开农场收入，除了保存措施。