简介：Asimplemodelingapproachwassuggestedtosimulatepreferentialtransportofwaterandcontaminantsinsoil.AftersaturatedhydraulicconductivitywasinterpolatedbymeansofKrigeinterpolationmethodorscalingmethod,andthenzoned,thelocationswheresaturatedhydraulicconductivitywaslargerrepresentedregionswherepreferentialflowoccurred,becauseheterogeneityofsoil,oneofthemechanismsresultinginprefeentialflow,couldbereflectedthroughthedifferenceinsaturatedhydraulicconductivity,Themodelingapproachwasvalidatdthroughnumericalsimulationofcontaminanttansportinatwo-dimensionalhypotheticalsoilprofle.Theresultsofthenumericalsimulationshowedthattheapproachsuggestedinthisstudywasfeasible.

简介：Methaneoxidationbypaddysoilsinaclosedsystemcouldbesimulatedbytheequationx=k1xo/(k1+k2x0)exp(k2t)-k2x0wherex0andxaretheCH4concentrationsattimezeroandt,respectively;k1andk2areconstantsrelatedtotheconstantoffirst-order-kinetics.AccordingtotheequationthechangeofsoilabilitytooxidizeCH4couldbeestimatedbytheequationAc=k2/k1(x0-x)x0k2/k1-1.TheresultsshowedthatthesoilabilitytooxidizeCH4varied,dependingontheinitialCH4concentration.HighinitialCH4concentrationstimulatedsoilabilitytoconsumeCH4,whilelowconcentrationdepressedtheablility.Thischaracteristicofpaddysoilseemedtobeofconsiderablesignificancetoself-adjustingCH4emissionfromfloodedricefieldsifthereexistoxicmicrositesinthesoil.

简介：Boththeoreticalandfieldobservationswereexaminedtostudythecloserelationshipbetweensoildegenerationandtheevolutionofgrasslandvegetation.Ageneraln-speciesmodelofequalcompetitionunderdifferentdegreesofsoildegradationwasappliedtofielddatainordertoprobethedynamicprocessesandmechanismsofvegetationevolutionduetotheeffectsofthesoil'secologicaldeteriorationongrasslandvegetation.Comparisonsweremadebetweenthetheoreticalresultsandthepracticalsurveyswithsatisfactoryresults.

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。