简介：Inthisstudy,avariationalapproachtothesettlementanalysisofanaxiallyloadedpierem-beddedinamulti-layeredsoilprofileispresented.Inthismethod,thesoilprofileandtheembeddedpieraredividedintoanumberofsub-layersaccordingtotheactualnumberofsoillayersobservedinthefield.ThedisplacementshapefunctionofeachsoillayerisgivenasaproductofanexponentialequationalongthepierdepthandtheBessel’ssolutionintheradialdirection.Thedisplacementrelationshipamongthelayerscanbederivedthroughthetransformationmatrices.Oneofthemajorfeaturesofthismethodisthatthetotalnumberofpierelementsisthesameasthatofsoilsub-layers.Allthefieldcompontents,suchasthedisplacement,stress,andstraininthesoil,canbecalculatedbyclosed-formsolutionsexceptthattheonlyunknownvari-ableisthevalueβwhichcanbedeterminedbyiterationtechniques.Comparisonsweremadewiththeresultsoffiniteelementanalysisandthefieldobservationinpile-loadedtests.

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简介：Background:Soilorganiccarbon(SOC)isalargereservoirofterrestrialcarbon(C);itconsistsofdifferentfractionsofvaryingcomplexityandstability.PartitioningSOCintodifferentpoolsofdecomposabilityhelpbetterpredictthetrendofchangesinSOCdynamicsunderclimatechange.InformationonhowphysicalfractionsandchemicalstructuresofSOCarerelatedtoclimateandvegetationtypesisessentialforspatialmodelingofSOCprocessesandresponsestoglobalchangefactors.Method:Soilsampleswerecolectedfrommultiplerepresentativeforestsitesofthreecontrastingclimaticzones(i.e.cooltemperate,warmtemperate,andsubtropical)ineasternChina.MeasurementsweremadeonSOCcontentsandphysicalfractionsofthe0–20cmsoillayer,andthechemicalcompositionofSOCofthe0–5cmsoillayer,alongwithmeasurementsandcompilationofthebasicsiteandforeststandvariables.Thelong-termeffectsoftemperature,litterinputs,soilcharacteristicsandvegetationtypeontheSOCcontentsandfactionswereexaminedbymeansof"spacefortimesubstitution"approachandstatisticalanalysis.Result:Meanannualtemperature(MAT)variedfrom2.1℃atthecooltemperatesitesto20.8℃atthesubtropicalsites.TotalSOCofthe0–20cmsoillayerdecreasedwithincreasingMAT,rangingfrom89.2g·kg^-1incooltemperateforeststo57.7g·kg^-1insubtropicalforests,atanaveragerateof1.87%reductioninSOCwitha1℃increaseinMAT.WithincreasingMAT,theproportionsofaromaticCandphenolicCdisplayedatendencyofdecreases,whereastheproportionofalkylCandA/O-Avalue(theratioofalkylCtothesumofO-alkylCandacetalC)displayedatendencyofincreases.Overall,therewerenosignificantchangeswithMATandforesttypeineitherthephysicalfractionsorthechemicalcomposition.BasedontherelationshipbetweentheSOCcontentandMAT,weestimatethatSOCinthetop20soillayerofforestspotentiallycontribute6.58–26.3PgCgloballytotheat

简介：Availablewaterandfertilizerhavebeenthemainlimitingfactorsforyieldsofspringwheat,whichoccupiesalargeareaoftheblacksoilzoneinnortheastChina;thus,theneedtosetupappropriatemodelsforscenarioanalysisofcroppingsystemmodelshasbeenincreasing.ThecapabilityofCropSyst,acroppingsystemsimulationmodel,tosimulatespringwheatgrowthofawidelygrownspringcultivar,'Longmai19',intheblacksoilzoneinnortheastChinaunderdifferentwaterandnitrogenregimeswasevaluated.Fielddatacollectedfromarotationexperimentofthreegrowingseasons(1992-1994)wereusedtocalibrateandvalidatethemodel.Themodelwasrunfor3yearsbyprovidinginitialconditionsatthebeginningoftherotationwithoutreinitializingthemodelinlateryearsintherotationsequence.CropinputparametersweresetbasedonmeasureddataortakenfromCropSystmanual.Afewcultivar-specificparameterswereadjustedwithinareasonablerangeoffluctuation.TheresultsdemonstratedtherobustnessofCropSystforsimulatingevapotranspiration,abovegroundbiomass,andgrainyieldof'Longmai19'springwheatwiththerootmeansquareerrorsbeing7%,13%and13%oftheobservedmeansforevapotranspiration(ET),grainyieldandabovegroundbiomass,respectively.AlthoughCropSystwasabletosimulatespringproductionreasonablywell,furtherevaluationandimprovementofthemodelwithamoredetailedfielddatabasewasdesirableforagriculturalsystemsinnortheastChina.

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简介：这研究处理了土壤的分发特征器官的碳(SOC)和有在六个土壤剖面的深度的稳定的碳同位素组成(delta~(13)C价值)的变化，包括在西南中国的石灰岩地区常见的地形区域的二个土类和三植被型。植物主导的种类的delta~(13)C价值，叶发出，土壤被测量使用封口试管高温度的燃烧方法。玷污石灰石土壤剖面的内容都在11.4g/kg上面的器官的碳，与在表面土壤的71.1g/kg的最高的价值。然而，内容在三黄壤侧面在2.9g/kg和46.0g/kg之间变化。C土壤有机物(SOM)珍视的最大、最小的delta~(13)之间的差别为三黄壤侧面每千每千从2.2改变到2.9。但是它为石灰石土壤剖面每千每千从0.8改变到1.6。对比研究在器官的碳的垂直模式和在黄壤和石灰石土壤之间的SOM的delta~(13)C价值显示了那在那里存在的重要差别。这差别可以反映地点特定的因素，例如土类，植被型，土壤pH，和粘粒含量，等等，哪个控制在侧面包括SOM和土壤碳周转率的不同器官的部件的内容。在SOM的稳定的碳同位素的垂直变化模式有一不同地区性，在石灰岩地区常见的地形区域的特性。

简介：Thedynamicsofrhizospheremicrobialcommunitiesisimportantforplanthealthandproductivity,andcanbeinfluencedbysoiltype,plantspeciesorgenotype,andplantgrowthstage.ApotexperimentwascarriedouttoexaminethedynamicsofmicrobialcommunitiesintherhizosphereoftwosoybeangenotypesgrowninablacksoilinNortheastChinawithalonghistoryofsoybeancultivation.Thetwosoybeangenotypes,Beifeng11andHai9731,differinginproductivityweregrowninamixtureofblacksoilandsiliceoussand.Thebacterialcommunitieswerecomparedatthreezonelocationsincludingrhizoplane,rhizosphere,andbulksoilatthethirdnode(V3),earlyflowering(R1),andearlypod(R3)stagesusingpolymerasechainreaction-denaturinggradientgelelectrophoresis(PCR-DGGE)of16SrDNA.Theresultsofprincipalcomponentanalyses(PCA)showedthatthebacterialcommunitystructurechangedwithgrowthstage.Spatially,thebacterialcommunitiesintherhizoplaneandrhizosphereweresignificantlydifferentfromthoseinthebulksoil.Nevertheless,thebacterialcommunitiesintherhizoplaneweredistinctfromthoseintherhizosphereattheV3stage,whilenoobviousdifferenceswerefoundattheR1andR3stages.Forthetwogenotypes,thebacterialcommunitystructurewassimilarattheV3stage,butdifferedattheR1andR3stages.Inotherwords,somebacterialpopulationsbecamedominantandsomeothersrecessiveatthetwolaterstages,whichcontributedtothevariationofthebacterialcommunitybetweenthetwogenotypes.Theseresultssuggestthatsoybeanplantscanmodifytherhizospherebacterialcommunitiesintheblacksoil,andthereexistedgenotype-specificbacterialpopulationsintherhizosphere,whichmayberelatedtosoybeanproductivity.

简介：ShanghaiislocatedineasternChinaandisbuiltonoverburdensoillayers.ItcanbeseenfromtheMexicoMs=8.1earthquakeonSeptember19,1985andtheHanshinMs=7.4earthquakeonJanuary17,1995thatheavycasualtiesandpropertylosseshaveadirectrelationshipwithoverburdensoillayers.Groundmotionscausedbyearthquakesaresignifieantlyamplifiedwhenpassingthroughthesoillayers.Undertheinfluenceoftheseamplifiedmotions,buildingstructures,whosenaturefrequencyiswithinthefrequencybandofsoilamplificationresponse,willexperiencemoreseveredamagethanthosebuiltonbedrock.Therefore,engineeringseismologistshavepaidconsiderableattentiontheamplificationresponsesintheShanghaioverburdensoillayers.TheamplificationresponsesofsoilandsandlayersinthispaperaregivenbytheML=4.1earthquakeinNantong,JiangsuProvinceonDecember25,2001at31.8°N,120.9°E.Itcanbeseenthattheresponsesofsoilandsandlayersareverydifferent.Thatisimportant.

简介：Potexperimentswereconductedin2002and2003toinvestigatetheeffectsofsoilcopper(Cu)concentrationongrowth,developmentandyieldformationofricebyusingthejaponicacultivarWuxiangjing14andhybridricecombinationShanyou63.Theplantheight,leafnumber,elongatedinternodenumberandheadingdateofriceplantswerenotaffectedatsoilCulevelsbelow200mg/kg,butaffectedsignificantlyatabove400mg/kg.TheinhibitoryeffectsonricegrowthanddevelopmentwereincreasedwiththeincrementofsoilCulevels.ThegrainyieldsdecreasedsignificantlywithraisingsoilCulevels.ThemainreasonsforthegrainyieldreductionsunderlowersoilCulevels(100,200mg/kg)weremainlyduetothedecreaseofnumberofspikeletsperpanicle,however,underhighersoilCulevels(morethan400mg/kg),bothpaniclenumberandnumberofspikeletsperpaniclecontributedtotheyieldloss.ThedecreasesofpaniclenumberbyCustressweremainlyattributedtoslowrecoveryfromtransplanting,delayedtilleringandreducedmaximumtillernumbers.ThereductionofnumberofspikeletsperpanicleundersoilGustressresultedfromthedecreasesofbothshootdryweight(SDW)attheheadingdateandtheratioofspikeletstoSDW.TotalbiomassatmaturitydecreasedsignificantlywiththeincreaseofsoilCulevels,whileeconomiccoefficientshowednon-significantdecreaseexceptundersoilCulevelsabove800mg/kg.

简介：Becauseofthedistinctionofsoilpropertyandhumuscontent,soilwatercontentisnotidealtoindicatewhetheritissuitabletothegrowthofplant.MainlybasedonthePF-anumericalvaluedenotingthewaterregimeofsoilandconnectedwiththegrowthofplant,thestudycombinedthemoisturepercentageofsoilwithPFtoresearchinquantitytheinterrelationbetweenthemoisturepercentageandPFindifferentsuccessionphasesofsubalpinedarkconiferousforestinGonggaMountain.Theresultsshowedthat:(1)InthesamePFvalue,themoisturepercentageinhumushorizonincreasedgraduallywiththedevelopmentofthesuccessionofthedarkconiferousforest;Themoisturepercentageofover-matureforestwasthehighestand>matureforest>half-matureforest>younggrowthforest;(2)Withtheincreaseofsoildepth,thesoilbulkdensityincreasedandthemoisturepercentagedecreased,butthedifferenceinthepercentageofmoisturewasnotnotableindifferentsuccessionphases.(3)Indifferentsuccessionseries,thevegetationaffectedthesoilwatercharacteristicsbyincreasingthesoilorganicmatter,improvingthesoilconstruction,recedingthesoilbulkdensityandenhancingthesoilporosity;(4)Thehumushorizonofthedarkconiferousforestsoilhasthehighestwaterholdingcapabilityinthisregion.

简介：Thispaperhighlightspasteffortsindevelopingerosionprocessconceptsthatleadtothedevelopmentofthecurrentprocess-basederosionpredictionmodel,i.e.,WEPP.Recentprogressincludesthedevelopmentofamultiple-boxsystemthatcansimulatehillslopehydrologicconditions.Laboratoryproceduresenablethequantificationofnear-surfacehydrologiceffects,i.e.,artesianseepagevs.drainage,onthesoilerosionprocessandsedimentregime,flowhydraulics,andsedimenttransportanddepositionprocesses.Theserecentfindingsimprovesoilerosionscienceandprovidenewerosioncontrolstrategiesthatmayhaveadditionalenvironmentalbenefitsrelativetothetraditionalerosioncontrolpractices.Thepaperalsodiscussesthepotentialimpactsoftheerosionprocessonerosionmodeldevelopmentandfutureresearchdirectionsofsoilerosionprocessresearchandmodeldevelopment.

简介：Soilaggregatestability,animportantindexofthephysicalcharacteristicsofasoil,canprovideagoodindicationofasoil’serodibility,anddeservesspecialconsiderationinregionswithcoldclimate.Theobjectiveofthisstudywastostudytheeffectoffreeze-thawonsoilwater-stableaggregatesintheblacksoilregionofNortheastChina.Samplesofatypicalblacksoilintheregionwerecollectedtomeasurewater-stableaggregatesafterfreeze-thawunderdifferentconditions(i.e.,initialmoisturecontents,freezethawcyclesandfreezingtemperatures)bywet-sievingintoeightparticlesizegroups(>10,10–6,6–5,5–3,3–2,2–1,1–0.5,and0.5–0.25mm).Freeze-thawhadthemosteffectonaggregatestabilitywhenthesampleshadaninitialmoisturecontentof400gkg-1.Thewater-stableaggregatesofthefourlargerparticlesizegroups(>5,5–3,3–2,and2–1mm)reachedapeakstabilityvalue,butthoseofthetwosmallerparticlesizegroups(1–0.5and0.5–0.25mm)reachedaminimumvaluewhenthesoilmoisturecontentwas400gkg-1.Water-stableaggregatesofthefourlargerparticlesizegroupsdecreasedwhilethoseofthetwosmallerparticlesizegroupsincreasedwiththeincreaseoffreeze-thawcycles.Astemperaturesfell,thewater-stableaggregatesofthefourlargerparticlesizegroupsdecreasedwhilethoseofthetwosmallerparticlesizegroupsincreased.

简介：详细土壤调查包含昂贵、费时间的工作并且要求专家知识。因为土壤调查提供信息满足大量需要，新方法是必要的快速并且精确地印射土壤。在这研究，多层的视感控器人工的神经网络(ANN)被开发单位使用印射土壤数字举起模型(DEM)属性。几最佳的ANN基于很多个输入数据被生产并且隐藏单位。途径使用了测试和确认区域计算插入内推并且外推的数据的精确性。结果证明采用的土壤分类的系统和水平在结果的精确性上有直接效果。在底层，更小的错误比土壤分类(圣)系统与世界引用库(世界佛教徙联谊会)分类标准被观察，但是当使用圣时，更多的土壤类能被预言(在圣的情况中的7土壤对5与世界佛教徙联谊会)。训练错误为当测试错误(插值错误)和确认错误(推测错误)分别地象50%和70%一样高时，模型使用了的所有ANN低于11%。是期望，用分类的高水平的土壤预言介绍了精确性的更好全面的水平。获得更好的预言除了DEM属性，与是的地形或岩性学有关的数据形成土壤的因素，应该被用作ANN输入数据。

简介：Alaboratorylysimeterexperimentwasconductedtoinvestigatetheeffectsofforagecorn(ZeamaysL.)stalkapplicationontheCO2concentrationinsoilairandcalcareoussodicsoilreclamation.Theexperimentaltreatmentstestedweresoilexchangeablesodiumpercentage(ESP)levelsof1,11,and19,addedcornstalkcontentsof0to36gkg-1,andincubationdurationsof30and60days.TheexperimentalresultsindicatedthatcornstalkapplicationandincubationsignificantlyincreasedCO2partialpressureinsoilprofileandloweredpHvalueinsoilsolution,subsequentlyincreasednativeCaCO3mineraldissolutionandelectrolyteconcentrationofsoilsolution,andfinallysignificantlycontributedtoreductiononsoilsodicitylevel.Thereclamationeffciencyofcalcareoussodicsoilsincreasedwiththeaddedcornstalk.Whencornstalkswereaddedattheratesof22and34gkg-1intothesoilwithinitialESPof19,itsESPvaluewasdecreasedby56%and78%,respectively,afterincubationof60daysandtheleachingof6.5porevolumes(about48Lofpercolationwater)withdistilledwater.Therefore,cropstalkapplicationandincubationcouldbeusedasachoicetoreclaimmoderatecalcareoussodicsoilsorasasupplementofphytoremediationtoimprovereclamationeffciency.

简介：植物生长能力和土壤保护用三洪水容忍的长江河边种(Arundinellaanomala，Hemartriacompressa和Cynodondactylon)被调查。根和叶表面生长，植物生长能力和土壤流量的缓解用被5，10和18厘米盖住的potted植物被分析新沉积分别地。A。anomala从新沉积最慢慢地反应了到恢复，当时H。compressa有最高的恢复率。后者能生产起始的根长度24次，41在12个星期的生长时期期间预定它的原来的叶表面。C。dactylon没在与升起的沉积厚度的关系在生长显示出重要变化，它意味着甚至新沉积的18厘米被C容忍。dactylon。侵蚀测试证明所有三植物种能在超过63%减少土壤流量。比作另外的种类，一。anomala不太能够稳定新沉积。保护H的能力的土壤。compressa在超过10厘米新沉积以后减少了。C。dactylon与检验的另外的种类相比显示出最好的土壤保留，自从它能减少土壤流量直到87%。因而，C。dactylon被发现比A对土壤保护植物种类显著地更好。anomala和H。在三座峡水库给条件的compressa。

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简介：Afieldexperimentwasconductedfrom1999to2002tocompareandevaluatetheeffectsofnutrientandwaterregimesonpaddysoilqualitybyinvestigatingsoilchemicalandmicrobiologicalparameters.Fournutrientregimes,acontrol,chemicalfertilizersonly(CF),chemicalfertilizerswithswinemanure(SM),andchemicalfertilizerswithwheatstraw(WS),andtwosoilmoistureregimes,continuouswaterlogging(CWL)andalternatewettinganddrying(AWD),wereinvestigated.WithSMandWStotalorganiccarbonandtotalnitrogeninthepaddysoilweresignificantlyhigher(P＜0.05)thanthosewithCF.AsimilareffectfororganicamendmentswasobservedinthesoillightfractionorganicC(LFOC),water-solublecarbohydrates(WSC),andwater-solubleorganicC(WSOC).CWL,inparticularwhenswinemanurewasincorporatedintothepaddysoil,markedlydecreasedsoilredoxpotential(Eh)andincreasedtotalactivereducingsubstances(ARS).Meanwhile,ascomparedtoCF,SMandWSsignificantly(P＜0.05)increasedsoilmicrobialbiomassC(MBC)andmineralizablecarbon,withdifferencesinAWDbeinghigherthanCWL.Inaddition,SMandWStreatmentssignificantly(P＜0.05)improvedriceabove-groundbiomassandgrainyield,withAWDbeinggreaterthanCWL.Thus,forecologicallysustainableagriculturalmanagementofpaddysoils,long-termwaterloggingshouldbeavoidedwhenorganicmanurewasincorporatedintopaddysoil.

简介：Groundmotionsaresignificantlyinfluencedbydynamiccharacteristicsofoverburdensoillayersneargroundsurface,asthickandsoftsoillayerswouldobviouslyamplifythegroundmotionstrength.Theconventionalresearchmethodonsoilnonlineardynamiccharacteristicsunderstrongmotionsisbasedonexperimentsinlaboratoriesforthedeficiencyofobservationdata,butitisdifficulttoreliablysimulatethecomplexfactorsofsoilsinactualearthquakedurations,includingloadingpaths,boundaryconditions,anddrainageconditions.Theincrementaldataoftheverticaldownholeobservationarray,whichiscomprisedofatleastoneobservationpointongroundsurfaceandoneobservationpointinadownholerockbase,makesitpossibletostudysoilnonlineardynamicsaccordingtoinsituobservationdata,andprovidesnewbasicdataanddevelopmentopportunitiestosoilnonlineardynamicsstudies.

简介：Thedynamicshearmodulusratioanddampingratioofsandygravelareimportantparametersfortheseismicresponseanalysisofvalleygeomorphicsites,whichhaveanimportantimpactonthedeterminationofdesigngroundmotionparameters.Inthispaper,thedynamictriaxialtestofsandygravelshasbeenperformedbasedontheprojectoftheShangluoSeismicMicrozonation.Combinedwiththeotherresultsofsandygravel,therecommendedresultsofslightlydense,mediumdenseanddensesandygravelwereobtained.Bybuildingthetypicalsitemodel,theinfluenceofthedynamicshearmodulusratioandthedampingratiouncertaintyontheseismicresponseofthesiteisstudied.Theresultsshowthattheuncertaintyoftheaverageofthedynamicshearmodulusratioandthedampingratio±1timesthestandarddeviationhaslittleeffectonthepeakaccelerationofthesandygravelsite,andtherationalityofthegroupingandstatisticalresultsisexplained.Underdifferentprobabilitylevels,thechangeintheshearmodulusratioanddampingratioleadstoasignificantdifferenceinthehighfrequencyresponsespectrum.Theresponsespectrumof0.04-0.1srangesfromabout20%,butithaslittleeffectonthelongperiodspectrumofmorethan1.0s.Thestudyofdynamicshearmodulusratioanddampingratioofsandygravelhastheabilitytoimprovethereliabilityofthedesigninggroundmotionparameters.

简介：Traditionallyseismicdesignofstructuressupportedonpiledraftfoundationisperformedbyconsideringfixedbaseconditions,whilethepileheadisalsoconsideredtobefixedforthedesignofthepilefoundation.Majordrawbackofthisassumptionisthatitcannotcapturesoil-foundation-structureinteractionduetoflexibilityofsoilortheinertialinteractioninvolvingheavyfoundationmasses.Previousstudiesonthissubjectaddressedmainlytheintricacyinmodellingofdynamicsoilstructureinteraction(DSSI)butnottheimplicationofsuchinteractiononthedistributionofforcesatvariouselementsofthepilefoundationandsupportedstructure.ArecentnumericalstudybytheauthorsshowedsignificantchangeinresponseatdifferentelementsofthepiledraftsupportedstructurewhenDSSIeffectsareconsidered.Thepresentstudyisalimitedattemptinthisdirection,anditexaminessuchobservationsthroughshaketabletests.TheeffectofDSSIisexaminedbycomparingdynamicresponsesfromfixedbasescaleddownmodelstructuresandtheoverallsystems.Thisstudyindicatesthepossibilityofsignificantunderestimationindesignforcesforboththecolumnandpileifdesignedunderfixedbaseassumption.Suchunderestimationinthedesignforcesmayhaveseriousimplicationinthedesignofafoundationorstructuralelement.