简介:Sulfurtransformationin3soilsmaintainedinaclosedincubationsystemanditsavailabilitytoplantswereinvestigatedusingcarrier-free^35S-SO4^2-and^35S-labeledryegrassstraw.Forcarrier-freeNa2^35SO4treatment,78%,70%and64%of^35SappliedwerefoundinCa(H2PO4)2-extractaleSfraction,4%,5%and7%inslowlysolubleinorganicS,11%,15%and18%inC-O-S,5%,7%,and6%inC-bondedS,and5%,7%and6%inunidentifiedorganicS120daysafterincubationinblacksoil,cinnamonsoilandchestnutsoil,respectively.Mostof35Suptakebyplantscamefromextractable35SO4^2-,andlittlefromC-O-^35SandC-bonded^35S,Inthetreatmentwith35S-labeledstraw,51%,46%and36%of35SincorporatedwerefoundinCa(H2PO4)2-extractableSfraction,7%,6%and7%inslowlysolubleinorganicS,13%,15%and18%inC-O-S,8%,8%and6%inC-bondedS,and18%,25%and35%inunidentifiedorganicSattheendofincubationinabove-mentonedthreesoils,respectively.HigheravailabilityofC-O-35S,C-bonded35Sandunidentifiedorganic35Sfrom35S-labeledstrawwasobservedin35S-labeledstrawtreatmentcomparedtocarrier-freeNa2^35SO4treatment.
简介:INTRODUCTIONSoilacidificationduetoaciddepositionhasbeenoneofthemajorenvironmentalprob-lemsconcernedbysoilscientistsandecologistsfortherecent20years(vanBreemen,1990).SoilacidificationwithamarkedpHdecreaseofforestsoilswithinvarioustimeintervalshasbeenreportedinGermany,Sweden,theNetherlands,AustraliaandtheUnitedStates(van
简介:Anewendophyticantagonisticfungus,ChaetomiumspiraleND35fromPopulustomentosa,wasreported.Thebio-controltrialsofC.spiraleND35againsttheValsaCankerofapplewerepreliminarilyinvestigated.TheresultsofdualcultureonPDAplateshowedthatC.spiraleND35wascapableofstrongantagonismagainstValsaceratosperma,andforinhibitingthemycelialgrowthofV.ceratosperma,.thecrudeextractofliquidcultureofcornsteeppowderbrothwasmoreeffectivethanthatoneofmaltextractbroth(MEB).Theresultsofbio-controlingreenhouseandfieldindicatedthatthediseaseincidenceofappletreetreatedwithC.spiraleND35waslowersignificantlythanthattreatedbyothermethods.There-isolationexperimentsuggestedthatC.spiraleND35couldcolonizeinstemsandbranchesofappletreessuccessfully,andtheND35colonizationrateofthetreatmentwithsolidwheatbranculturewashigherthanthatofcornsteeppowderbroth,butthefieldexperimentresultthecontroleffectofliquidcultureofC.spiraleND35wasbetterthanthatofsolidculture.