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

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：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：Successionrulesofsoilacidityqualityoflarchplantationsinfirstrotationatdifferentdevelopmentstages,successionrulesofsoilacidityqualityofyoungstandoflarchplantationsinsecondrotationandtherelationshipbetweensoilacidityandvariousformsoforganicphosphorusandinorganicphosphoruswerestudiedinmountainousareaofeasternpartofNortheasternChina.Theresultsshowedthatactiveacidity(pHvalue)inrhizospheresoildecreasedcontinuallywithstandageincreasingfromyoungstand,half-maturestand,nearmaturestandtomaturestand,butactiveacidity(pHvalue)innon-rhizospheresoil,exchangeacidity,exchangeablealuminium,totalhydrolyticacidity,andtheratioofexchangeacidityandtotalhydrolyticacidityinrhizospheresoilandinnon-rhizospheresoilincreasedapparently;totalorganicP,moderatelyresistantorganicP,andhighlyresistantorganicPinsoildecreasedatallagestagesinlarchplantationswhensoilacidityadded.Forrhizospheresoilofallstandsoflarchplantationsatdifferentdevelopmentstages,therewaspositivecorrelationbetweenCa-P(exceptinyoungstand),Al-P(exceptinhalf-maturestand),Fe-P(exceptinnearmaturestandandmaturestand),O-P(exceptinyoungstand),andsoilactiveacidity,respectively;Forrhizospheresoil,therewasnegativecorrelationbetweenCa-P(exceptinhalf-maturestand),Al-P(exceptinyoungstand),O-P,andexchangeacidity,exchangeablealuminium,therewasalsonegativecorrelationbetweenCa-P,Al-P(exceptinyoungstandandhalf-maturestand),Fe-P,O-P,andtotalhydrolyticacidityrespectively.Forrhizospheresoil,thecorrelationcoefficientbetweenCa-P,O-Pandtotalhydrolyticaciditydecreased,respectively,asstandagesupandthatbetweenFe-Pandexchangeacidity,exchangeablealuminiumincreased,respectively,asstandagesgrew.Fornon-rhizospheresoil,therewasnotsignificantcorrelationbetweensoilacidityandvariousformsofinorganicphosphorusandorganicphosphorus,respective

简介：TheimmunomodulationofseveralChargedsyntheticpolymerscontainingphosphorusinthebackbonewasstudiedinvitrothroughexaminingtheirinhibitionorpromotioneffectontheproliferatioinofbothTandBlymphocytes,Itisfoundthatpolymersbasedonlongchainalkylesteroftyrosineexhibitimmunomodulativeactivity.NegativelychargedpolymersshowstimulativeactivityonLPS-inducedBlymphocytesproliferation.PositivelychargedpolymersexhibitinhibitoryactivityonbothConA-inducedTlymphocytesandLPS-inducedBlymplhyocytesproliferation.

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简介：TheimpactofpHchangesonmicrobialbiomasscarbon(Cmic)andmicrobialbiomassphosphorus(Pmic)wereexaminedfor3redsoilsundercitrusproductionwithdifferentlengthsofcultivation.SoilpHsignificantlyaffectedCmicandPmic.TheCmicandPmicchanges,asafunctionofsoilpH,appearedtofollowanormaldistributionwiththeoriginalsoilpHvalueattheapexandaspHincreasedordecreasedcomparedtotheoriginalsoilpH,CmicandPmicdeclined.Moreover,therewerecriticalpHvaluesatbothextremes(3.0ontheacidicsideand8.0to8.5onthealkalineside),beyondwhichmostofmicroorganismscouldneversurvive.TheeffectofpHonCmicandPmicwasalsorelatedtotheoriginalsoilpH.ThehighertheoriginalsoilpHwas,thelessCmicorPmicwereaffectedbypHchange.ItissuggestedthatsoilmicroorganismsthatgrowinasoilenvironmentwithamoreneutralsoilpHrange(I.e.pH5.5-7.5)mayhaveagreatertolerancetopHchangesthanthosegrowinginmoreacidicormorealkalinesoilpHconditions.

简介：DetailedanalysesofthemonitoreddataprovidedbytheYantaiOceanAdministrationOfficebetween1989and1996showthat,thefluctuationregularitiesofcontentoftheinorganicphosphorusareasfollows:thecontentofinorganicphosphorusfluctuatedneartheclass-1standardlinebasicallyfrom1989to1993,tendedtoincreaserapidlyfrom1993,andincreasedcontinuously,causingwaterqualitytobedeterioratedfromtheclass-2toclass-3standardby19%.Causesforincrementofthecontentofinorganicphosphorusarealsoanalyzed.Theresultsshowthat,thefluxofphosphorusenteringYantainearshoreseaareaincreasesatanannualrateof16.5percent,inwhichtheincrementratesofthephosphoruscontainedinwashingpowderandinphosphatefertilizerare12.9and17.5percentrespectively.Bothofthemkeptapositiveinterrelationshipwiththeirfluxesintothesea.Inaddition,themigrationandregenerationmechanismofthephosphoruswithinthenearshoreareaalsoleadtotheinorganic

简介：Landusechangescangreatlyinfluencesoilphosphorus(P)dynamics,especiallywhenconvertingnativeforeststoagriculturalland.SoilsinXishuangbanna,whichisoneofsouthwestChina'stropicalareasthatmaintainfragmentsofprimaryforests,werestudiedtoa)evaluatetheeffectoftwocommonlandusechanges,conversionofforeststoagriculturallandorrubbertreeplantation,onthedynamicsofavailablePandtotalPinbulksoilsaswellastotalPinparticlesizefractions;b)assesstherelationshipbetweensoilPdynamicsandsoilorganiccarbon(SOC);andc)elucidatetherelationshipbetweensoilPcontentandsoilpropertiessuchaspHandtexture.Clearingsecondaryforestswithsubsequentshiftingcultivationandestablishmentofrubbertreeplantationcausedsignificantdecreases(P＜0.05)inavailablePat0-20cmsoildepths,whereasfortotalPtherewasasignificantdecrease(P＜0.05)whenconvertingtoshiftingcultivation,rubbertreeplantation,orfallowfieldatboth0-20and20-40cmdepths.Abandonmentoffieldsusedforshiftingcultivationledtosignificantincreases(P＜0.05)inavailablePat20-40cmdepth.Inaddition,therewasasignificantpositiverelationshipbetweensoilorganiccarbonandsoilPcontent.Comparedtosecondaryforests,theratiooforganiccarbontototalPinsurfacesoils(0-20cm)ofshiftingcultivationandrubbertreeplantationwassignificantlylower(P＜0.05).