简介：Studiesonkineticsofadsorptionandreleaseofphosphorusbysoil,anewfieldinsoilchemistry,beganonlyovertenyearsago(Heetal.,1989;WangandZhu,1988;ZhangandZhang,1991;Lin,1989;LinandXue,1989;Jiang,1993;Xueetal.,1995;LUetal.,1997).

简介：Anewinorganicphosphorus(IP)fractionationschemedevelopedbyJiangandGuwasusedinanincubationexperimenttoinvestigatethetransformationofappliedPinacalcareousfluvisol.Theresultsshowthatafteradditionofcommonsuperphosphate(CSP),theCa2-PinthesoildecreasedgraduallyandtransformedlargelytothelessavailableFe-P,Al-PandCa8-P,ratherthantotheunavailableformsofCa10-PandO-P.ThedifferentIPfractionsrankedinthefollowingorderwithrespecttotheincrementbyadditionofCSPafter120daysofincubation:Fe-P>Al-P>Ca8-P>Ca2-P.Afteradditionofpigmanure,thecontentofCa2-Pinthesoilincreasedrapidlyatfirstandthendecreasedslowly,andtheamountofdifferentIPfractionsaccumulatedafter120daysofincubationrankedinthefollowingorder:Ca2-P>Fe-P>Ca8-P>Al-P.Evidently,thevariationincontentofCa2-PandtheorderofincreaseindifferentIPfractionsinincubationinducedbyapplicationofpigmanurewerequitedifferentfromthatofCSP.TheincreaseinIPfractionsintheincubationofbroadbeangreenmanure(BBGM)for120dayswasintherankofFe-P>Ca2-P>Ca8-P;butbecauseorganicphosphorus(OP)ofBBGMdegradedrelativelyslowly,theincrementinIPfractionswaslowerthanthatofpigmanure.WheatstrawwasdifficulttomineralizeandinducedastrongbiologicalfixationofsoilP,resultinginadecreaseofthecontentofCa2-P,evenCa8-P,Fe-PandAl-P.

简介：植物有多样的策略应付磷(P)缺乏。更好理解玉米怎么对P缺乏作出回应，有二P的一个地实验铺平，0和100kgP2O5ha1(P0和P100，分别地)，作为长期的P化肥地试用的部分被执行。植物和土壤分析证明那P缺乏的玉米减少了它的生长率，增加了P使用效率，并且形成了有在连接和silking的不到0.6公里上演的直径的更多的薄根，与与P100对待的植物相比。进一步，在每收获在在rhizospheric和体积土壤之间的主要无机的P部分(Ca2-P，Ca8-P，高山，Fe-P，堵塞P和Ca10-P)没有差别，甚至当土壤Olsen-P仅仅是1.38mgkg1时。这些结果建议那玉米由由在低碳的词法改变花费了的有利的根为生长和增加的P获得能力减少内部P需求对P缺乏作出回应。

简介：Withdecreasingavailabilityofwaterforagricultureandincreasingdemandforriceproduction,anoptimumuseofirrigationwaterandphosphorusmayguaranteesustainablericeproduction.Fieldexperimentswereconductedin2003and2004toinvestigatetheeffectofphosphorusandirrigationlevelsonyield,waterproductivity(WP),phosphorususeefficiency(PUE)andincomeoflowlandrice.Theexperimentwaslaidoutinrandomizedcompleteblockdesignwithsplitplotarrangementsreplicatedfourtimes.Mainplotconsistedoffivephosphoruslevels,viz.0(P0),50(P50),100(P100),150(P150),and200(P200)kg/hm2,whilesubplotscontainedofirrigationtimes,i.e.8(I8),10(I10),12(I12),and14(I14)irrigationlevels,eachwithawaterdepthof7.5cm.MeanvaluesrevealedthatP150incombinationwithI10producedthehighestpaddyyield(9.8t/hm2)andnetbenefit(1231.8US$/hm2)amongallthetreatments.PhosphorusenhancedWPwhenappliedinappropriatecombinationwithirrigationlevel.ThehighestmeanWP[13.3kg/(hm2?mm)]couldbeachievedatP150withI8anddecreasedwithincreaseinirrigationlevel,whilethehighestmeanPUE(20.1kg/kg)couldbeachievedatP100withI10anddiminishedwithhigherPlevels.TheoverallresultsindicatethatP150alongwithI10wasthebestcombinationforsustainablericecultivationinsiltyclaysoil.

简介：ChemicalformsofphosphorusinthesedimentsoftheDayaBay,theZhujiangRiverestuary,andtheXiamenBayaremeasuredwithextractionsolutionsofMgCl2,NaOH,andHCl.TheiravailabilitiestoChlorellasp.andlsochrysisgalbanaareestimatedbyusingsedimentsasthesolesourceofPinthebioassays.Theresultsshowthatthecontentsoftotalphosphorus(TP)inthesesedimentsare449.3,650.1and643.9mg/kg,respectively.ThecontentsofnonapatiteinorganicP(NAIP)extractedwithMgCl2andNaOHfrom3sedimentsare168.8,146.6and118.1mg/kg,respectively,andaccountfor18.3%～32.6%ofTP.ThephosphorusextractedwithHClsolutionisgreaterthanthatextractedwithNaOHsolutionandthelowestextractedPisMgCl2-extractableP.ThegreatestrelativegrowthratesofChlorellasp.andIsochrysisgalbanaculturedwithsedimentsareintherangeof4.3%～26.9%.TheincreasingbiomassesofthesealgaecorrespondtoNAIPandAAPP(theestimatedalgal-availableparticulateP).AAPPaccountsfor42.4%～78.2%ofNAIP,21.1%～27.1%oftotalinorganicP,and11.8%～20.3%ofTP,respectively.

简介：Themechanismswhichcontrolsthefixationand/orreleaseofPinsedimentofanextremelyacidiclake(pH=2.0to3.0)anditsresponsetotheinfluenceofeutrophicurbanwastewaterwereinvestigated.Theresults,inthechemicalcomposition,inthemineralogyofthesedimentandinthematerialasobtainedfromsedimenttraps,showthatthelakesedimentsaremainlyvolcanicmaterialreflectingvolcanicfeaturesofthebasin.Thesedimentationratecalculatedforthelake(2.5×10~(-2)mgm~(-2)day~(-1))washigherthanthatobservedinothersimilarglaciallakesinbothAndeanPatagoniaandalsoelsewhereintheworld.TheTotalPhosphorusconcentrationinsedimentswashigherthanfiguresreportedbyotherauthorsforminingacidlakes,andthemainfractionofPwasfoundassociatedwithorganicmatter.TherewasnocontrolbyFeorAlonP,becausebothareinsolutionatpH<3.0.Itwasconcludedthatchangesinthenaturalinputofnutrients(derivativesofCopahuevolcanofluid,thedischargeofsewage,orbasinrun-off)areresponsibleforahighconcentrationofSRPandN-NH_4~+inthelake.LaboratoryexperimentsshowedthatsedimentshavenoabilitytoretainphosphorusandacontinuousreleaseofPfromthesedimentsintothewatercolumnwasobserved.TheassayswherethepHwasartificiallyincreasedshowedthatthePstillremainsinsolutionuntilatleastpH7.0.Itwasconcludedthatchangesinthenaturalinputofnutrientsdueto:1)thevolcanicfluids,2)theincreaseinsewagecharges,or3)surfacerunoffupstream,maintainahightrophicstatewithhighconcentrationsofdissolvedPandN-NH_4~+,althoughthethresholdofneutralpHinthelakeisexceeded.Thisstudywillenableabetterunderstandingaboutofthemechanismofrelease/fixationofphosphorusinacidicsedimentsinordertoassistinmakingdecisionsregardingtheconservationandmanagementofthisnaturalenvironment.

简介：PterocarpusindicusWilld是抓住为种植园林地答应的热带木质的荚。二个温室实验在二种土壤类型上被承担在强调P、健康的植物的叶子决定磷(P)集中范围，并且为缺乏和毒性的诊断定义批评P集中。处于P化肥的率有一个狭窄的范围，作为Ca供应了(H2PO4)2睳湩吗？

简介：ThestudiesonthedistributionandvaratiationofthespecificationofphosphorusinthesouthernpartoftheYellowSeaaremade.ThebiogeochemistryofphosphorusintheYellowSeaisdiscussed.ThephosphorusisslightlyhigherinthebottomthaninthesurfacewatersinthesouthernpartoftheYellowSeaandthedissolvedorganicphosphorusisthemainform.Thetransferpatternsbetweenvariousformsofparticulateanddissolvedphosphorusaredifferentinthebottomandsurface,probablyduetothecontributionofdissolvedorganicphosphorus.Thedistributionsofdissolvedinorganicphosphorusanddissolvedorganicphosphorusaremainlyaffectedbythebiologicalprocessesandcouldactasapredictionfactorfortheredtide.ThesupplyofNandPinmostoftheareasinthesouthernpartoftheYellowSeaissufficient,withoutapparentlimitationofNorP.

简介：Duetothegrowingconcernabouttheagriculturalphosphorus(P)lossespollution,anin-depthunderstandingofPinpaddysoilsofChinawouldbehelpfulinprovidinganationalperspectiveoftheenvironmentalimpactofPcyclingandfertilityonChina'sfarms.Inthisstudy,weevaluatedthePstorageandthePdensityofpaddysoilsinChina,characterizedthespatialvariationsofPamongthesubgroupsofpaddysoilsandsoilregionsinChina,andevaluatedthePdatausingGIS-basedanalysis,whichincludedanewlycompiled1:1000000digitalsoilmapofChina,andusing1490soilprofiles.TheavailableandtotalPdensitiesofpaddysoilswere6.7and698.5gm-3,respectively.OverallinChina,thetotalPstoragewithin1mofpaddysoilswasestimatedtobe330.2Tg.ThePdensityofpaddysoilsvariedsubstantiallywithsubgroupsduetothedifferentsoilwaterregimessuchasgroundwatertableandsoildrainage.ThePavailabilityinpaddysoils,especiallyinsurfacelayer,washigherinhightemperatureandprecipitationareas.Furtherresearchisneededtoexaminemoreanthropogenicimpactfactors,suchasincreasinguseofchemicalfertilizer.

简介：ThetransformationoforganicP(Po)fromorganicmanuresintwotypesofsoils(ultisolandentisol)andtheinfluencesofexternaladditionoforganicsubstanceorinorganicP(Pi)onPoundertheconditionofthe60%maximumwatercapacitywereinvestigated.TheresultsobtainedfromPofractionationexperimentsindicatedthatallthePofractionsexceptforthehighlyresistantPofractiondecreasedduringincubation.ApplicationofpigfecesandcowfecescouldlargelyincreaseeachfractionofPointhesoils.ImmediatelyafterapplicationoforganicmanureintothesoilsalargepartoflabileandmoderatelylabilePofromorganicmanurewastransferredintomoderatelyresistantPo,whichmightbeduetothefactthatCa-orMg-inositolPwasprecipitatedintoFe-inositolP.However,theavailabilityofPofromorganicmanureinthesoilswouldincreaseagainafterincubationbecauseofthetransformationofmoderatelylabileandresistantPofractionsintolabilePofractions.AdditionofcelluloseorPiintothesoilsshowedagoodeffectonincreasingallthePofractionsexceptforthehighlyresistantPo,andthiseffectwasmuchmorepronouncedwhencellulosewasappliedincombinationwithPi.Therefore,inviewoftheeffectoforganicmanureonimprovingPnutritiontoplant,attentionshouldbepaidtoboththePoandtheorganicsubstancesfromorganicmanure,ItissuggestedthatapplicationofPifertilizercombinedwithorganicmanuremaybereferredtoasaneffectivemeansofprotectingPifromchemicalfixationinsoil.

简介：ＣＬＩＮＩＣＡＬＩＮＦＯＭＡＴＩＯＮＡＮＤＭＥＴＨＯＤＳＴｈｅ４２ｏｒｇａｎｉｃｐｈｏｓｐｈｏｒｕｓｐｏｉｓｏｎｅｄ，１６ｍａｌｅａｎｄ２６ｆｅｍａｌｅ，ａｇｅｄ１８～６１，ｈａｖｅａｎａｖｅｒａｇｅｏｆ３４．６ｙｅａｒｓ．Ｔｈｅｔｏｘｉｃａｎｔａｒ...

简介：Athermostaticincubationexperimentwascarriedouttoestimatetheeffectsoffloodingperiods,stalkapplicationandPadditionofFetransformationandPavailabilityincalcareoussoils.SubmergenceincreasedamorphousFe,especiallyinthecaseofstalkapplication.ThenewlyformedamorphousFewithagreatsurfaceareaplayedanimportantroleinPsorption;andsubmergencealsostimulatedthedissolutionofinorganicP,thusincreasingtheavailabilityofsoilPincalcareoussoils.Meanwhile,apartofsolublePwasabsorbedandfixedagainonthesurfaceofnewlyformedamorphousFe,thusresultinginadecreaseofPavailability.SoilrapidlyavailablePincreasedafter150-dayincubation.ThereexistedsignificantlynegativecorrelationsbetweensoilamorphousFecontentandsoilFe-PandrapidlyavailablePcontents.SubmergedconditionspromotedthetransformationofinorganicPaddedtowardFe-Pincalcareoussoils,especiallyinthecaseofstalkapplication.

简介：Citricandmalicacidsatconcentrationsof0.1,1.0,10,and100mmol/LwereaddedtothreeUltisolsandoneOxisol,TheamountofPinsolutionincreasedwithincreasingorganicacidconcentrations,whiletheamountofFe-andAl-boundPdecreased.ThisresultsuggestedthatnaturallyoccurringproductsoforganicmatterdecompositioncouldincreasethePavailabilitytoplantsinsoilswherethereisarelativelylargepoolofFe-andAl-boundP.Theinteractionsbetweencitricandmalicacidsattheaboveconcentrations,andpaddedatratesof10,20,40,and80mg/kgweredetermined.Atzerolevelsoforganicacids,alladdedPbecameeitherlabileorbound,andgreaterproportionsremainedsolubleastheconcentrationoforgaicacidsincreased,whichsuggestedthatorganicacidsreducedfixationofdissolvedPinFe-andAL-richsoils.AgriculturalpracticeswhichincreaseorganicmatterinputonP-deficientacidsoildcoulddecreasePdeficiency,Thiswouldbeimportantinmanytropicalandsubtropicalregionswherethesesoilsarecommon,andwherethecostsoffertilizersandlimearerelativelyhigh.

简介：Amini-plotfieldexperimentwasconductedonaloamyclayOxisoltocompareandevaluatePabsorptionandtransferinplantorgansandPmovementinsoilprofileatthreePapplicationdepthsunderthesoybean-citrusintercroppingversusthemonocultureusinga32Ptracertechnique.TotalPabsorption(Pt)bysoybeanandPaccumulation(Pa)insoybeanorgansdecreasedsignificantly(P<0.05)undertheintercroppingincontrasttothemonoculture.Withintercropping,when32Pwasappliedintopsoil(15cmsoillayer),total32Pabsorption(32Pt)insoybeanswassignificantlylower(P<0.05),butwhen32Pwasappliedtodeepersoillayers(35or55cmsoillayer),32Ptinsoybeanswassignificantlygreater(P<0.05).ThepercentageofPinleavestototalP(Pa/Pt)and32Pinleavestototal32P(32Pa/32Pt)forsoybeanwere(?)25%andthoseofroot(?)12%.WhenPwasappliedintopsoiland55cmsoillayer,nosignificantdifferenceswerefoundbetweenintercroppingandmonocultureforPtofcitrus.ThePabsorbedbycitruswastransferredrapidlytothegrowingorgansofabovegroundduringtheexperiment,andthespeedoftransferringtothegrowingorgansslowedwhenPwasappliedtothedeepersoillayers.Inintercropping,Pmobilitywasheightenedinthesoilprofile,andPindeepersoillayersmoveduptotopsoilmorerapidly.

简介：Bythemethodofcomparisonandanalysis,thesuccessionpatternoftotalP,availablephosphorus,organicPtypesandinorganicPtypesinrhizosphereandnon-rhizospheresoilatdifferentdevelopmentstagesinLarch(Larixolgensis)plantationswasrevealed.Theresultshowed:whenstandageincreased,thecontentofavailablephosphorus,O-P,totalPandorganicPinrhizospheresoildecreasedgreatlyorsignificantly,thecontentofinorganicP,Ca-PandFe-Pinrhizospheresoilinrhizospheresoilincreasedgreatlyorsignificantly.ThecontentofCa-Pinnon-rhizospheresoilincreasedwithstandgrowing.ThecontentofFe-Pinhalf-maturestand,availablePandFe-Pinnearmaturestand,availablePandCa-Pinmaturestandinnonrhizospheresoilwasmorethanthatinrhizospheresoil.

简介：ThesegregationandinteractionofREM,phosphorusandtinongrainboundariesofα-FewereinvestigatedbyAugerspectrometryandSEM.TheresultsshowthatREM,PandSntendtosegregateongrainboundariesofα-Fe.AddingREMintoFe-SnalloywithlowS,PcontentscouldsuppressthesegregationofSnongrainboundaries.ThesegregationofSnwoulddecreasewithincreasingofREM.InFe-Sn-PalloyPwouldsuppressthesegregationofSn.ThesegregationofPwouldbesuppressedbysegregationofREM.ThetrendofPsegre-gationdecreaseswithincreasingofREM.WithincreasingofREMthesegregationofSnatfirstisloweredbutthenfollowedwithanincreasing.AddingREMintoFe-SnandFe-Sn-Palloyscouldsuppressintercrystallinefractureofα-Featlowtemperatures.

简介：Asequentialextractionmethodforthefractionationofphosphorus(P)inlakesedimentswasusedtoanalyzephosphorusfractionsofsedimentstakenfromthreelarge,shallow,eutrophicfreshwaterlakesofChina-TaihuLake,ChaohuLake,andLongganLake.AllthreelakesarelocatedinthelowerreachesoftheChangjiangRiver(YangtzeRiver).InTaihuLakeandChaohuLake,algaebloomsoccurredeveryyear,whileLongganLakewasamacrophyte-dominatedlake.Resultsshowedthatexchangeablephosphorusfractionsweremuchhigherintheeutrophiclakesedimentsthaninthemacrophyte-flourishinglakesediment.Also,theratioofFe:Pinthesedimentsofthealgae-predominantlakeswasgenerallymuchlowerthanthatinthemacrophyte-predominantlakes.Thus,thegeochemicalfractionsofphosphorusinsedimentshadacloserrelationshipwiththetypeofaquaticvegetation.

简介：Phosphorus(P)fractionsandtheirbioavailabilityinthesedimentsfromElMexBayandLakeMariutinEgyptwereinvestigatedusingdifferentchemicalextractionmethods.Sodiumbicarbonate(NaHCO3)extractableP(Olsen-P)wasthelargestfraction(14.42%),followedbyalgalavailableP(AAP)(3.56%),watersolubleP(WSP)(0.79%),andreadilydesorbableP(RDP)(0.06%)forElMexBay.WhileAAPcontributed9.94%tototalPinsedimentsfromLakeMariut,Olsen-P8.53%,WSP4.11%,andRDP0.92%.SummationofthebioavailablePfractionsdidn'texceedthesedimentqualityguidelines,and,therefore,Pdoesn'trepresentadangertomarineorganisms.CorrelationcoefficientsshowedthatnoapparentrelationsbetweentotalP(TP)andiron(Fe),aluminum(Al),andcalcium(Ca)inthesediments.Furthermore,Fe:Pratiowaslessthan15indictingthattherewasnotenoughFeinsurfacesedimentstobindtoPatmostofthesamplingsites.ThepositivecorrelationbetweenTPandorganicmatter(OM)forLakeMariutandElMexBaysedimentsindicatedthattheorganicmattercontentofthesedimentwasausefulpredictorofthetotalphosphoruscontent.DatafromthisstudyconstituteabaselineofphosphorusbioavailabilityinsedimentsfromElMexBayandLakeMariutandcouldbeusedasareferenceforfuturestudiesonthechangesofbioavailableandresidualphosphorusfractionsovertime.

简介：Objective:Toexplorechemicalcomponentchangesofdogboneatdifferentlengtheningtimeandindifferentboneregionsofinterest,andtoevaluatethemineralizationduringIiizarovlengtheningprocess.Methods:Theashweight,theconcentrationsofcalcium,phosphorusandthecalcium/phosphorusratioweremeasuredatdifferentintervals(2,4,6,8,12weeks)sincelengtheningandthelengthenedpartwascomparedwithacontrolareaateachinterval.Results:Theashweight,theconcentrationsofcalciumandphosphorusinthelengthenedareadifferedatalldevelopmenttime.Thecalcium/phosphorus(Ca/P)ratiointhelengthenedregionremainedsignificantlylowerthanthatinthecontrolregionupto12weeksafterthelengthening.Conclusions:Theseresultssuggestthatalsootherinorganicionsplayanimportantroleinthemineralizationprocessandthattheybecomerelativelymoreimportantsince8weeksafterthelengthening.

简介：期刊海藻的花蕾从沉积导致磷(P)的免职和版本进水。因此，当海藻的粒子开始安定到底部时，在季节的变化期间，在沉积理解行为和P的分发特征是最重要的钥匙管理Saemangeum水库的水质量。在这研究，水质量和沉积作文包括叶绿素的变化--一(Chl--一)并且P被调查决定在水和沉积之间的相互作用。学习首先集中了于影响P版本和沉积的矿化作用的海藻的粒子沉积。Chl--水里的集中在10月看了锋利的衰落水藻什么时候开始在秋天死了，并且后来，化学的氧需求(货到付款)的集中和在沉积的全部的P(TP)在11月由于腐烂的海藻的粒子的沉积增加了。在时间的一样的时期期间，在沉积的容易地简历可得到的P(敲击)在在哪儿的上面的区域显示出激烈的增加Chl--水的集中高。在顺序，高敲击地区在早冬季从上面的区域变了到更低的区域。敲击移动被认为从分解水藻在沉积的表面上从安定的overlying水的物理流动被发源。Saemangeum水库最近被构造；因此，除了可溶的反应的磷(SRP)的无机的P部分的所有类型在湖和沼泽地沉积层的底部表面上存在不是足够的显著地影响overlying水。在另一方面，从水藻的释放P对季节的变化不同、敏感。在结论，海藻的粒子沉积是重要的在Seamangeum水库从沉积表面层的使矿物化的无机的P控制超营养作用而非P版本。