简介：很多个基于过程的模型为确定被开发了在agro生态系统的碳(C)隐遁。DeNitrification分解(DNDC)模型被用来模仿并且确定长期(1980–2008)玷污器官的碳(SOC)在重要的生产大米的省的动力学，江苏，中国。在SOC存储的变化从在空间分辨率不同的二个土壤数据库被估计：由68个多角形和土壤组成的一个县数据库为在江苏的稻田的所有3.7Mha的701个多角形的基于补丁的数据库。分别地，当那与好决定估计数据库是201.6和216.2时，有粗糙的决定县数据库的模仿的SOC存储在2008在1980和170.3–305.1TgC在131.0–320.6TgC之间变化了在1980和2008的TgC分别地。建模，土壤数据库在空间分辨率不同的结果显示用土壤输入，有更高的分辨率的数据实质地增加了建模的结果的精确性；并且当缺乏详细土壤数据集时，DNDC模型，有最敏感的因素(MSF)的parameterized应付属性无常的方法，尽管，能仍然生产可接受的结果与为在这份报纸报导的案例研究的多达60%的偏差。

简介：Metalcontentandbioavailabilityareoftenthelimitingfactorsforapplicationofsewagesludgeinagriculturalfields.SewagesludgesampleswerecollectedfromfivetypicalurbanwastewatertreatmentplantsinChinatoinvestigatetheircontentsanddistributionofvariouschemicalfractionsofCu,Zn,Ni,Cr,PbandMobyusingtheBCR(CommunityBureauofReference)sequentialextractionprocedure.Thesludgescontainedconsiderableamountsoforganicmatter(31.8%-48.0%),totalN(16.3-26.4gkg-1)andtotalP(15.1-23.9gkg-1),indicatinghighpotentialagriculturalbenefitsoftheirpracticalapplications.However,totalZnandNicontentsinthesludgeexceededthevaluespermittedinChina'scontrolstandardsforpollutantsinsludgesfromagriculturaluse(GB4284-1984).TheresidualfractionwasthepredominantfractionforMo,NiandCr,theoxidizablefractionwastheprimaryfractionforCuandPb,andtheexchangeableandreduciblefractionswereprincipalforZn.Thedistributionofdifferentchemicalfractionsamongthesludgesamplesreflecteddifferencesintheirphysicochemicalproperties,especiallypH.ThesludgepHwasnegativelycorrelatedwiththepercentagesofreduciblefractionofCuandexchangeablefractionofZn.ThesludgesfromtheseplantsmightnotbesuitableforagriculturalapplicationsduetotheirhighcontentsofZn,NiandCr,aswellashighpotentialofmobilityandbioavailabilityofZn.

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。

简介：polyolefin涂的脲的有效性(Meister-5和Meister-10；CU)在小麦(TriticumaestivumL.)玉米(ZeamaysL.)旋转系统在为收割季节的三连续maize-wheat-maize位于北方中国平原的溶度计阴谋被学习。一个同位素的方法被用来把CU的命运比作非涂的脲(NCU)的，并且N申请0，100，150和225kgNha−1评价被评估。结果证明CU的氮使用效率(15NUE)是比为第一庄稼的NCU的大的13.3%–21.4%。或者，当差别方法被使用时(明显的NUE)，没有重要变化在所有三个季节在处理之中被观察。尽管无机的N从1.3m层沥滤，不到1%总数被使用N，15N的未辩别出的损失(=15N作为化肥–15N使用了的15N的损失由留在0–0.2m层–15N的庄稼–15N吸收了从1.3m层沥滤)在对待CU的阴谋是24.2%–26.5%比那些低对待NCU的阴谋。在在实验的结束的CU阴谋的0–1.3m层的硝酸盐集中是53%比对待NCU的阴谋的低。因此，CU从化肥增加了庄稼N举起并且减少了应用N的未辩别出的损失，它能减少地下水污染的风险。

简介：Aridsoilswherewaterandnutrientsarescarceoccupyover30%oftheEarth’stotalsurface.However,themicrobialautotrophyintheharshenvironmentsremainslargelyunexplored.Inthisstudy,theabundanceanddiversityofautotrophicbacteriawereinvestigated,byquantifyingandprofilingthelargesubunitgenesofribulose-1,5-bisphosphatecarboxylase/oxygenase(RuBisCO)formI(cbbL)responsibleforCO2fixation,inthearidsoilsunderthreetypicalplanttypes(Haloxylonammodendron,Cleistogeneschinensis,andReaumuriasoongorica)inNorthwestChina.Thebacterialcommunitiesinthesoilswerealsocharacterizedusingthe16SrRNAgene.Abundanceofred-likeautotrophicbacteriarangedfrom3.94×105to1.51×106copiesg-1drysoilandthoseofgreen-likeautotrophicbacteriarangedfrom1.15×106to2.08×106copiesg-1drysoil.Abundanceofbothred-andgreen-likeautotrophicbacteriadidnotsignificantlydifferamongthesoilsunderdifferentplanttypes.TheautotrophicbacteriaidentifiedwiththecbbLgeneprimerweremainlyaffiliatedwithAlphaproteobacteria,Betaproteobacteriaandanunculturedbacterialgroup,whichwerenotdetectedinthe16SrRNAlibrary.Inaddition,25.9%and8.1%ofthe16SrRNAgeneswereaffiliatedwithCyanobacteriainthesoilsunderH.ammodendronandR.soongorica,respectively.However,noCyanobacteria-affiliatedcbbLgenesweredetectedinthesamesoils.TheresultssuggestedthatmicrobialautotrophicCO2fixationmightbesignificantinthecarboncyclingofaridsoils,whichwarrantsfurtherexploration.

简介：在中国的三个峡区域，土壤侵蚀和结果的非点来源污染和生态的降级危及了农业生态系统和新鲜的水水库。尽管努力被承担了从斜坡土地减少土壤和水损失，为柠檬生产使用，管理的效果的信息在土壤富饶索引上练习也有限或不存在。这研究被进行比较10年各种各样的管理惯例的效果，柠檬与白苜蓿(WC)杂种，有稻草(SM)的柠檬mulched，柠檬与轮廓灌木篱墙(CH)杂种，有透不过的膜(IM)的柠檬果园土地，并且柠檬与小麦(Triticumaestivum)和花生(Arachrishypogaea)(WP)杂种，，土壤富饶上的处理与常规柠檬管理(厘米)的索引。结果证明器官的碳，全部、可得到的氮，可得到的钾，和水马厩聚集的土壤(>0.25公里)在0–5厘米深度的内容比CM处理为WC和SM处理是更高的。也在沿着WC和SM治疗的斜坡的土壤生育力有空间变化。土壤总数和可得到的氮，磷，和钾，和水马厩聚集(>0.25公里)在两个满足0–5和5–20厘米深度比CM处理为CH和IM处理是更高的。氮和可得到的钾满足的可得到的平均土壤比CM处理为WP处理是更高的，但是WP处理在器官的碳，全部的氮，和水马厩聚集的土壤上有小效果(>0.25公里)内容。这些建议白苜蓿杂种和稻草mulching是最有效的途径在三个峡区域的柠檬果园土地改进土壤富饶。

简介：Astudyonbalancedfertilizationwasconductedbymeansoflong-termfieldexperiments,andaconve-nienttableforbalancedfertilizationwascompiled.Theexperimentalresultsabouttheeffectoffertilizationonwateruseefficiencyofuplandwheatshowedthattheinputofinorganicfertilizershouldbereducedindryyears.

简介：Wetlandsoilqualitydegradationcausedbylarge-scaleagriculturalreclamationontheSanjiangPlainofNortheastChinahasbeenwidelyreported.Arelativesoilqualityevaluation(RSQE)modelandaprojectionpursuitevaluation(PPE)modelbasedonreal-codedacceleratinggeneticalgorithmwereintroducedtoevaluatequalityvariationsintoplayersofthemainwetlandsoilsontheSanjiangPlainin1999and2003,respectively.Assoilqualitydegradationboundarieswerevague,thisstudyestablishedtwofuzzysyntheticevaluation(FSE)modelsbasedontheoriginaldataandcriteriausedintheRSQEandPPEmodels.TheoutputsofthetwoFSEmodelswereobtainedbychoosingtwofuzzycompositeoperatorsM(∧,∨)andM(·,⊕).StatisticalanalysisshowedthattheresultsoftheFSE,RSQE,andPPEmodelswerecorrelated.Inparticular,outputsoftheFSEmodelusingM(·,⊕)weresignificantlycorrelatedwiththoseoftheRSQEmodelwithr=0.989atP<0.01.ComparedwithRSQEandPPEmodels,theFSEmodelmaybemoreobjectiveinshowingsoilqualityvariationsandwasclosertothenaturalsituation,showingthefeasibilityandapplicabilityoftheFSEmodelinevaluatingsoilqualitydegradation.However,thechoiceofcompositeoperatorwasofcriticalimportance.ThestudyofwetlandsoilqualitydegradationontheSanjiangPlainwasofscientificandpracticalsignificanceforprotectionandmanagementofsoilsandforsustainabledevelopmentofagricultureinthisareainthefuture.

简介：Fieldexperimentswereconductedinamaize(ZeamaysL.)fieldofacalcareousfluvo-aquicsoilinNorthChinaPlainforstudyingthefateandammonialossofurea-Nappliedatseedlingstage,aswellastheeffectivenessofcoatedcalciumcarbide(CCC)inreducingNlossandinimprovingtheyieldefficiencyofurea.Resultsshowthat:(1)Forthesurface-broadcasttreatmentammoniavolatilization(measuredwithmicro-meteorologicaltechnique)tookplacequickly,reachedthepeak20-26hrafterapplication,andthendeclinedgradually;thecumulativeammonialossapproachedthemaximum188hrafterapplication(30%oftheNapplied),andincreasedonlyto32%284hrafterapplication;thelatteraccountedfor71%ofthetotalloss(45%ofappliedN).(2)Inthecaseofpointplacementatadepthof5-10cm,ammonialoss188hrafterapplicationwasonly12%oftheNapplied,accountingfor40%ofthetotalloss.(3)Therewasnodifferenceintotallossbetweentheapplicationdepthsof6cmand10cm,thelossofthemwas30%and29%,respectively.(4)TotallossofNappliedatlowerrate(40kgN/ha)withpointdeepplacementat6cmdepthwasfoundonly4%oftheNapplied,itroseupto30%whentherateofapplicationincreasedto80kgN/ha.(5)Thenitrificationinhibitor,CCC,seemedtoenhanceNlossofurearatherthanreduceit,anddidnotshowanybenefiteffectinimprovingtheyieldefficiencyofurea,whichispresumablyduetothehighpotentialofammoniavolatilizationinthesoilandclimaticconditionsunderinvestigation.

简介：土壤有机物(SOM)的分解具有为在土壤和温度和潮湿被看作控制SOM分解的二个重要因素的土壤之间的公司2交换的重要性。在这研究，土壤样品在在东北中国在Changbai山上从753～2357m的5举起被收集，并且在不同温度下面孵化了(5，10，15，20，25，和30????ü

简介：AfieldexperimentwasconductedatKezuohouqiCounty,InnerMongoliaAutonomousRegionofChina,whichwaslocatedonthesoutheasternedgeoftheHorqinSandyLand,tostudythespatialvariabilityofsoilnutrientsforasmallscale,nutrient-poor,sandysiteinasemi-aridregionofnorthernChina;toinvestigatewhetherornottherewere'islandsoffertility'attheexperimentalsite;andtodeterminethekeynutrientelementsthatsustainedecosystemstability.Resultsobtainedfromgeostatisticalanalysisindicatedthatthespatialdistributionpatternofsoiltotalnitrogen(STN)wasfardifferentfromthoseofsoilorganicmatter(SOM),totalphosphorus(STP),andtotalpotassium(STK).ComparedtoSOM,STP,andSTK,STNhadalowerstructuralheterogeneityratioandalongerrange,whileotherelementswereallsimilar.Inaddition,STNhadanisotropicspatialstructure,whereastheothershadananisotropicspatialstructure.Thespatialstructurepatternsofherbagespecies,cover,andheightalsodiffered,indicatingthatspatialvariabilitywassubjectedtodifferentecologicalfactors.Differencesinthespatialvariabilitypatternsamongsoilnutrientsandvegetationpropertiesshowedthatsoilnutrientsforasmall-scalewerenottheprimarylimitingfactorsthatinfluencedherbagespatialdistributionpatterns.Incorporatingspatialdistributionpatternsoftreespecies,namely,Pinussylvestrisvar.mongolicaLitv.andshrubLespedezabicolorTurcz.inaresearchplotandusingfractaldimension,SOM,STP,andSTKwereshowntocontributetothe'islandsoffertility'phenomenon,howeverSTNwasnot,possiblymeaningthatnitrogenwasakeylimitingelement.Therefore,duringrestorationofsimilarecosystemsmoreattentionshouldbegiventosoilnitrogen.

简介：RemotesensingdatafromtheTerraModerate-ResolutionImagingSpectroradiometer(MODIS)andgeospatialdatawereusedtoestimategrassyieldandlivestockcarryingcapacityintheTibetanAutonomousPrefectureofGolog,Qing-hai,China.TheMODIS-derivednormalizeddifferencevegetationindex(MODIS-NDVI)datawerecorrelatedwiththeabovegroundgreenbiomass(AGGB)datafromtheabovegroundharvestmethod.RegionalregressionmodelbetweentheMODIS-NDVIandthecommonlogarithm(LOG10)oftheAGGBwassignificant(r2=0.51,P<0.001),itwas,there-fore,usedtocalculatethemaximumcarryingcapacityinsheep-unityearperhectare.Themaximumlivestockcarryingcapacitywasthenadjustedtothetheoreticallivestockcarryingcapacitybythereductionfactors(slope,distancetowater,andsoilerosion).Resultsindicatedthatthegrasslandconditionsbecameworse,withlowerabovegroundpalatablegrassyield,plantheight,andcovercomparedwiththeresultsobtainedin1981.Atthesametime,althoughtheactuallivestocknumbersdecreased,theystillexceededthepropertheoreticallivestockcarryingcapacity,andovergrazingratesrangedfrom27.27%inDarlagCountyto293.99%inBaimaCounty.Integratingremotesensingandgeographicalinformationsystemtechnologies,thespatialandtemporalconditionsofthealpinegrassland,trend,andprojectedstockingratescouldbeforecastedfordecisionmaking.

简介：降水在半干旱、干旱的区域是生态系统函数和进程的主要驱动程序。在如此的水有限生态系统，搏动了水输入直接通过弄干的一系列土壤和重新弄湿的周期控制地下的过程。在土壤CO2流出上调查水的分散的增加的效果，一个人工的降水事件(3公里)在亩被用于一个荒芜的灌木生态系统我们在中国的Ordos高原的沙土地。土壤呼吸率在在这块地里增加水以后立即增加了2.84.1次，然后它在48h以内回到了背景水平。在实验期间，土壤CO2生产在2047.0和7383.0mgm之间?2。在灌木陆地，土壤呼吸回答显示出空间变化，有在比在interplant空格的灌木下面的更强壮的脉搏效果。土壤呼吸回答的空间变化仔细与土壤底层可获得性的异质被联系。除了降水，玷污器官的碳和全部的氮水池也在荒芜的生态系统作为土壤CO2损失的决定因素被识别。

简介：在空气在农业土壤影响土壤质量和温室气体集中在土壤改变器官的碳(SOC)。干燥农田在中国盖住超过70%整个农田区域并且在减轻二氧化碳(CO2)起一个重要作用排出物。在这研究，4109个干燥农田土壤多角形用土壤层的空间覆盖分析被提取(1:500000)并且陆地使用层(1:500000)在安徽为干燥农田支持SOC动力学的世纪模型模拟省，从1980～2008的华东。就二个地确认地点而言，世纪模型在在省为干燥农田为SOC动力学建模相对表演了很好。模仿的结果证明区域加权的平均数玷污从18.77MgCha−增加的干燥农田的器官的碳密度(SOCD)；1在1980～23.99MgCha−；10.18MgCha−与平均隐遁在2008评价；1year−；1。约94.9%全部的干燥农田区域扣押了碳当5.1%有的碳输了时。在过去的29年，在省的干燥农田土壤的网SOC获得是19.37Tg，与0.67TgCyear−的平均隐遁率；1。SOC的扩大主要由于氮化肥和农家庭院粪肥的增加的消费。而且，SOC动力学高度在干燥农田土壤组之中被区分。有一条好规模的土壤数据库途径的世纪模型的集成能方便地在地区性的规模为SOC动力学的精确模拟作为一个工具被利用。

简介：