学科分类
/ 1
15 个结果
  • 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.

  • 标签: 土壤质量退化 模糊综合评价 三江平原 湿地 中国 东北
  • 简介:Soilsalinityandhydrologicdatasetswereassembledtoanalyzethespatio-temporalvariabilityofsalinizationinFengqiuCounty,HenanProvince,China,inthealluvialplainofthelowerreachesoftheYellowRiver.Thesalinesoilandgroundwaterdepthdataofthecountyin1981wereobtainedtoserveasahistoricalreference.Electricalconductivity(EC)of293surfacesoilsamplestakenfrom2km×2kmgridsin2007and40soilprofilesacquiredin2008wasanalyzedandusedforcomparativemapping.OrdinarykrigingwasappliedtopredictECatunobservedlocationstoderivethehorizontalandverticaldistributionpatternsandvariationofsoilsalinity.Groundwatertabledatafrom22observationwellsin2008werecollectedandusedasinputforregressionkrigingtopredictthemaximumgroundwaterdepthofthecountyin2008.ChangesinthegroundwaterlevelofFengqiuCountyin27yearsfrom1981to2008wascalculated.Twoquantitativecriteria,themeanerrororbias(ME)andthemeansquarederror(MSE),werecomputedtoassesstheestimationaccuracyofthekrigingpredictions.Theresultsdemonstratedthatthesoilsalinityintheuppersoillayersdecreaseddramaticallyandthetaxonomicallydefinedsalinesoilswerepresentonlyinafewmicro-landscapesafter27years.Presently,thesoilswithrelativelyelevatedsaltcontentweremainlydistributedindepressionsalongtheYellowRiverbed.Thereductioninsurfacesoilsalinitycorrespondedtothelocationswithdeepenedmaximumgroundwaterdepth.Itcouldbeconcludedthatgroundwatertablerecessionallowedwatertomovedeeperintothesoilprofile,transportingsaltswithit,andthusplayedanimportantroleinreducingsoilsalinityinthisregion.Accumulationofsaltsinthesoilprofilesatvariousdepthsbelowthesurfaceindicatedthatsecondarysoilsalinizationwouldoccurwhenthegroundwaterwasnotcontrolledatasafedepth.

  • 标签: 土壤盐渍化 冲积平原 黄河下游 时空变异 普通克里格法 土壤盐碱化
  • 简介:PhysiographyandsoilinMaeRimwatershed,ChiangMaiProvince,Thailandwereinvestigatedbyusingaerialphotographsandsatelliteimageinconjunctionwithfieldwork,andsoilinfiltrationrateandsoilshearresistanceweremeasuredinfield.ManyfactorsaffectingrunoffwereanalyzedusigtheIntegratedLandandWaterInformaitonSystem(ILWIS).Asaresult,amodeldeterminingfloodhazarwassetup.Threempsincludingrunoffcurvenumbermap,runoffcoefficentmap,andfloodinumdationmapwerecreated,Inaddition,thetimeofconcentrationwaspredicted.

  • 标签: 洪水危害预报 遥感 地理信息系统 土壤性质 表面流失系数 泰国
  • 简介:Furfuralresidue,anindustrialwaste,isakindofstronglyacidicorganicmaterials.Itscomprehensiveutilizationinagricultureshowedasignificanteffectoncontrolofsoilalkaliztion,ameliorationofsolonetzandincreaseofcropyields.IndetailitmayadjustpH,depressalkalinity,reducebulkdensityandcompactnessandincreasewaterpermeabilityandretentionabilityofthesoil.Meanwhileagriculturaluseoffurfuralresidueprovidedaneffectivewaytoavoiditspollutionofthesoil,waterandair.

  • 标签: 糠醛废料 土壤碱性化 碱土改良 工业废渣 利用 酸性有机物
  • 简介:Effectofintermittentirrigationontheproductionofpaddyricewasstudiedinawell-puddledpaddyfieldwithfourtreatmentsand2replicates:continuoufloodingirrigation(CFI),andintermittentirrigationⅡ-0,Ⅱ-1andⅡ-2,inwhichplantswerere-irrigatedwhenthesoilwaterpotentialfellbelow0,-10,and-20toabout-10or-20kPadidnotsignificantlyaffectthenumberofgrainsandthepercentageofripenedgrains.While,alowercropgrowthrate(CGR)resultedfromadecreaseinthenetassimilationrate(NAR)duringintermittentirrigationⅡ-1andⅡ-2,andtherewasalsoareductionintheleafareaindex(LAI)durinindtermittentirrigationⅡ-2.SenescenceoflowerleavesonstemswaspromotedintreatmentsⅡ-1andⅡ-2attheripeningstage.Earlysenescenceatripeningstageandwaterstressaroundmiddaydecreasedtherateofphotosynthesisinleaves,causingthelowerNAR,Thesephysiologicalresponsesoftheplantswereresponsibleforthereductioninthedrymatterproductionandgrainyieldintheintermmittentirrigationtreatments.

  • 标签: 农作物生长速率 稻谷 间歇灌 水土保持 土壤 产量
  • 简介:Afieldexperiment,involvinglimeN(calciumcyanamide,CaCN2)fertilizationasacontrolmeasure,wasconductedtostudyenvironmentalproblemsinducedbylong-termheavyNapplicationinJapaneseteafields.Long-termteacultivationcausedserioussoilacidification.Seventy-sevenpercentofthe70teafieldsinvestigatedhadsoilpHvaluesbelow4.0,and9%below3.0,withthelowestvalueof2.7.Moreover,excessNapplicationinteafieldsputathreattoplantgrowth,inducedseriousnitratecontaminationtolocalwater,andcausedhighnitrousoxideloss.ComparedwiththeconventionalhighNapplicationtreatment(1100kgNha-1)withoutlimeN,thelowNapplication(400kgNha-1)withcalciumcyanamideeffectivelystoppedsoilacidificationaswellasachievedthesameorslightlyhigherlevelsinteayieldandintotalNandaminoacidcontentsofteashoots.Theapplicationofcalciumcyanamidecouldbeasuitablefertilizationforthepreventionofenvironmentalproblemsinteacultivation.

  • 标签: 土壤 酸化作用 水污染 氨腈
  • 简介:ThereasonsfortheYangtzeRiverfloodcalamityin1998arebrieflyintroduced.Theauthorsbelievethatusinga'soilreservoir'conceptisanimportantmeanstohelpcontrolfloodingoftheYangtzeRiver.A'soilreservoir'hasalargepotentialstoragecapacityanditswatercanberapidly'discharged'intotheundergroundwaterinatimelyfashion.Theeroded,infertilesoilsoftheYangtzeRiverWatershedarecurrentlyanobstacletoefficientoperationofthe'soilreservoir'.Thestoragecapacityofthis'soilreservoir'hasbeenseverelyhamperedduetointensivesoilerosionandtheformationofsoilcrusts.Therefore,possiblemeasurestocontrolfloodsintheYangtzeRiverWatershedinclude:rehabilitatingthevegetationtopreservesoilandwaterontheerodedinfertilesoils,enhancinginfiltrationofthedifferentsoiltypes,andutilizingthelarge'soilreservoir'oftheupperreachesoftheYangtzeRiver.

  • 标签: 土壤退化 土壤侵蚀 洪水控制 土壤蓄水 扬子江
  • 简介:Elovich,two-constant,parabolicdiffusion,exponential,second-order,first-orderandzero-orderequationswereusedtodescribethekineticcharacteristicsofpotassiumdesorptionfromsixpaddysoilsofZhejiangProvinceinaconstantelectricfield(44.4V/cm)ofEUF.Resultsshowedthatthesecond-orderandElovichequationscoulddescribethepotassiumdesorptionkineticsbest,asevidencedbythehighestcorrelationcoefficients(r)andtheloweststandarderrors(SE).Thefirst-order,two-constantandparabolicdiffusionequationsalsodescribedtheKdesorptionkineticswell,asshowedbytherelativelyhighcorrelationcoefficientsandrelativelylowstandarderrors.Thezero-orderequationdidnotdescribetheKdesorptionsatisfactorilywitharelativelylowcorrelationcoefficientandrelativelyhighstandarderror.However,theexponentialequationcouldnotbeusedtodescribetheKdesorptionkinetics,duetothelowestcorrelationcoefficientandthehigheststandarderror.

  • 标签: 土壤 钾释放 动力学方程式 水稻土 比较研究 解吸附作用
  • 简介:Soilswerecollectedfrom2-year(2-y)and3-year(3-y)oldred-pineseedlingplotsintwotreenurseries,HaywardinthenorthandWilsoninthesouthwesternpartofWisconsinStaterespectively,andequilibratedwith0.01MCa(NO3)2)forsoilsolutionZnandMn(solu-ZnandMn),andwith0.01MCa(NO3)2+0.005MEDTAforsoilabsorbedZnandMn(ad-ZnandMn).BufferingcapacityofsoilZnandMn(b-ZnandMn)wasobtainedfromtheratioofad-ZnandMntothesolu-ZnandMn.Theconcernedtracesinpineseedlingneedles(ndls),stems(sts)androots(rts)weresimultaneouslymeasured.Theresultsobtainedshowthat:About60%ofsolu-andad-Znrangedfrom0.2to0.4andfrom1to2μg/gsoilrespectively.About70%ofb-Znwaswithin3-10.Thehighestcontentofsolu-Zncomparedwiththelowestshowedadiscrepanceofmorethan10-fold.ThetwoformsofsoilZnwerecommonlyhigherinWilsonthaninHaywarkNursery.About80%ofsolu-,ad-andb-Mnwerewithin3-10,5-5.8μg/gsoiland1-2respectively.Influenceoflowbufferingcapacityonsolu-ZnandMnwasabout20timesstrongerthanthatofthehigh.TheE-value,aratioofaccumulatedZnandMninneedlestothoseinthesoilsolution,isprovedtobe:E-Zn>E-Mn;E-sts>E-ndlsorE-rts;andE-2y>E-3y.Curvilinearand/orlinearcorrelationsbetweensoilsolu-,ad-andb-ZnandMnandndls-,sts-,rts-ZnandMnwereatverysignificantorsignificantlevels.Forpredictingndls-ZnandMn,tworealizableandsimplemodelsfromtworegressionequationswereestablishedthroughtheselectionofrelatedparametersanddependentvariables.BinaryregressionanalysisbasicallyeliminatedtheinfluenceofsoilpHonthepredictionofZnandMninneedles.SoilpHwasthusthoughttobeexcludedfromthemodel.

  • 标签: 苗圃 红松苗 土壤 预测模式
  • 简介:土壤的理解在野火或控制灼伤以后的热电导率是重要的打管理和火以后的恢复努力。尽管玷污热电导率很好被学习了因为非火加热了土壤,全面数据评估在土壤上的从火的极端加热的长期的效果热电导率被限制。这研究的目的是由直接比较在土壤的有效热传导性上评估火的长期的影响加热火的,没有火控制通过一系列实验室研究玷污。热传导性在Manitou试验性的福雷斯特,以内从二个地点为十件土壤样品被测量科罗拉多,美国,为到浸透的剩余度的从浸透的水内容的一个范围。测量的热传导性与用文学用三个实验模型做的独立估计相比,包括坎贝尔等。(1994),C?t???????$

  • 标签: 土壤有效 森林火灾 热导率 实验室 模拟 经验模型
  • 简介:Basedontheconceptionoffluidmechanics,thepaperpropoundsamodelformonthlypotentialevapotranspirationETi(mm):ETi=22di(1.6+Ui^1/2)woi(1-hi)/Pi^1/2(273.2+ti)^1/4whereiisthenumberofamonth,Pithemeanmonthlyatmosphericpressure(hPa),tithemeanmonthlyairtemperature(℃),dithenumberofdaysinthemonth,Uithemeanmonthlywindvelocitymeasuredatheight10-12m(m/s),woithesaturatedwatervapourpressureatti(mmHg,1mmHg=133.322Pa),andhithemeanmonthlyrelativehumidity.TheannualaridityKis:K=12∑i=1ETi/rawhereraisthemeanannualprecipitation(mm).Baseduponthedataof669sitesinChinaduring1951-1980,therelationsamongthesoilmoistureregime,thevegetationandthevalueofKmaybeillustratedasfollows:KSoilmoistureregimeVegetationK<1UdicFOrest1≤K<2semi-udicFroest,froest-steppeandsteppe2≤K<3.5Semi-aridicAridsteppe3.5≤K<11AridecDesert-steppeK≥11VeryaridicDesert.

  • 标签: 中国 土壤水分状况 评估 潜性蒸散模型 干燥性
  • 简介:MicrometeorologicalandmicroplotexperimentswereconductedinthefieldoffreshlyharvestedgreencaneinQueensland,Australia.ResultsshowedthathighammonialossoffertilizerNcouldoccurunderrelativelydryconditionswhenureaorcommercialproductofmixtureofureaandmuriateofpotashwereappliedtothesurfaceofsugarcanetrash.ThemoisturecontentinthetrashandthepHoffertilizerweretwoimportantfactorscontrollingtheprocessesofureahydrolysisandammoniavolatilization.MostoftheNinthesoilwastransformedtothenitratel-nitritefromafter70daysoffertilizerapplication.Nosignificantleachingwasfound.Urea-freeNfertilizershadhigherNrecoveriescomparedtourea-containingfertilizers.

  • 标签: 甘蔗 氮肥 氮损失 氨挥发 微气象学实验
  • 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.

  • 标签: 土壤改良 玉米秸秆 钠含量 实验室 石灰性 应用
  • 简介:杆菌仙影拳X5的功效被在文化的增加下面检验秒阶段少年死亡和鸡蛋孵化率在vitro作为对根结线虫的一个潜在的生物控制代理人评估过滤并且在由与B提高的简历器官的化肥的申请的planta。仙影拳X5,B。thuringiensisBTG,或TrichodermaharzianumSQR-T037独自或一起在温室和领域试验。根结的biofumigation有器官的材料(鸡粪肥,猪粪肥和大米稻草)的大批出没于线虫的土壤独自或在有B的联合。仙影拳X5也在温室实验被进行。在实验室,B的filtrate。孵化的更有效地减少的鸡蛋有效地为14d和更多在潜伏期期间评估的仙影拳X5比B的在24h的潜伏期期间杀死了秒阶段少年。thuringiensisBTG。为温室西红柿和地甜瓜的一种的最高干燥的射击重量在两个被发现处理由与由仅仅与B提高的简历器官的化肥组成的三个biocontrol代理人和处理提高的简历器官的化肥组成。仙影拳X5。二简历器官的化肥比仅仅与B提高的那些完成了更好的nematicidal效果。thuringiensisBTG或T。harzianumSQR-T037。B。仙影拳X5也提高了biofumigation的效果,它导致了增加的植物生物资源并且在根和根围土壤减少了线虫计数。因此,这些结果在温室两个都建议了根结线虫的那生物控制,域能被使用B有效地完成。仙影拳X5和农业浪费。

  • 标签: 蜡样芽胞杆菌 生物有机肥料 生物控制剂 根结线虫 植物生物量 温室试验
  • 简介:Someelectrochemicalproperties,suchaspH,Eh,andvoltammetricbehavior.ofthedecompositionproductsofricestrawandtheinteractionsoftheseproductswithsoilswerestudied.ThepH,Eh,andamountsoforganicreducingsubstanceschangedmarkedlyduringthe6-dayanaerobicdecomposition.pHdecreasedsharplytopH5onthetenthdayandthenincreasedgraduallyto7onthe45rhday.Theamountsoforganicreducingsubstancesincreasedalmostsynchronouslywiththefallofredoxpotentialduringthefirst15days.Thedifferentialpulsevoltammetric(dpv)behaviorchangednotonlyinthepeakcurrentbutalsointhepeakpotential.Thefractionswithapparentmolecularweightslowerthan200daltonsappearedtobeactiveindpvbehavior.Theelectricchargeandpositivelycharged,respectively.Thegroupwithalowapparentmolecularweightandanegativechargewasthemaincomponentsresponsiblefortheloweranodicpeakpotentials.Theywereoxidizedfirstduringtheinteractionsoftheorganicreducingsubstanceswithsoils.

  • 标签: 水溶性有机还原物 稻草降解产物 电化学性质 土壤 相互作用