不同氮肥对水稻根圈微生物生物量及硝化反硝化细菌的影响李振高

(Soils),2003,35(6):490~494210008NCNNCNN711NNNNN-S154.31/21/5N[1]N30%~70%30%~41%[2]N-NN10%~65%[3]Nrhizosphere[4]N-N0~20cm1((NH4)2SO4)((NH2)2CO)12cm6cm15cm320300g500g238169-2270%3%2028Table1physicalandchemicalproperteiesofthetestedsoilCNNPPpH(H2O)41.012.080.0710.660.0088.043947002539770024DOI:10.13758/j.cnki.tr.2003.06.01064913020180mgN(NH4)2SO456.5%(NH2)2CO53.0%0371115(NH4)2SO413[5][6,7]MPN[8]C12NCC[9]CNC/NCNNN3N786g/g91.9g/gN3,4[10]NNH4+NC/NNNNNN21NH4NO2-12[11]5,6N[12]NNNH4+N71161103cfu/g55.5103cfu/gNNH4NO2-N7,811NNN1~2N2O[13]NNN[14]NNNN492356493N1,..,1998,30(6):291~2972..,2000,9(1):1~63VlekPLGandByrnesBH.TheEfficacyandLossofFertilizerNinLowlandRice.Fertilizerresearch.1986,9:131~1474RoviaADandDaveyCB.BiologyoftheRhizosphere.In:ThePlantRootanditsEnvironment.Virginia:UniversityPress.1974,153~2045..:,1999,1466BrookesPC,AndreaLandman,PrudenG,JenkinsonDS.ChloroformFumigationandtheReleaseofSoilNitrogen:ARapidDirectExtractionMethodtoMeasureMicrobialBiomasssNitrogeninSiol.SoilBiol.Biochem.,1985,12(6):837~8427VanceED,BrookesPC,JenkinsonDS.AnExtractionMethodforMeasuringSoilMicrobialBiomassC.SoilBiol.Biochem.,1987,19(6):703~7078.,:,1985,49~589,,,,,.,1995,18():51~5710,,,,.,1987,24(2):120~12511,..:,1986,11412,..:,1992,94~12013,,,,N2O.,2001,10(4):273~27614,,,N.,1996,33(1):28~35EFFECTSOFDIFFERENTNITROGENFERTILIZERSONTHEMICROBIALBIOMASSANDTHEPOPULATIONOFNITRIFYING-DENITRIFYINGBACTERIAINTHERICERHIZOSPHERELiZhengaoYuShenWuShengchunWangJunhuaPanYinghua(InstituteofSoilScience,ChineseAcademyofSciences,Nanjing210008)AbstractTherhizosphereisamicro-zoneneartheplantrootsurfaceswherethemicrobialactivityismuchhigherthannon-rhizosphericsoil.Inthispaper,theRhizosboxtechnologywasemployedtostudytheeffectofapplicationofnitrogenfertilizers(ureaand(NH4)2SO4)onthevariationofmicrobialbiomassCandN,andthechronicchangesofpopulationsizeofnitrifiersanddenitrifiersinsoil.TherkeyesultindicatedthatthemicrobialbiomassCandNinrhizosphereweregreaterthanthoseinnon-rhizosphericsoilanddeclinedgraduallywiththeexperimentlasting.Theureatreatmentresultedinahighermicrobialbiomasscomparedtoammoniasulfatetreatment.Ingeneral,asimilartrendofthechangeofmicrobialbiomassNwasobserved:thebiomassNbegantorisefromthe3rddayaftertheadditionofnitrogenfertilizersandgotthepeakvalueatthe7thdayandthendecreasedgraduallywhilethebiomassNinnon-rhizosphericsoildidnotchangesignificantly.Alargerpopulationofnitrifiersanddenitrifierswasdetectedintherhizospherethannon-rhizosphere.Thepopulationofnitrifierachievedthepeakvalueatthe7thand11thdaywithureaor(NH4)2SO4additionrespectivelyandthendeclinedrapidly.Thedenitrifierpropagatedchronicallywiththe49435applicationof(NH4)2SO4.Inthecontrast,thelargestpopulationofdenitrifierappearedatthe11thday.Theresultsmanifestedthatthericerootexhibitedanobviousrhizosphericeffectonthegrowthofnitriferanddenitrifiersinsoil,whichmightberegardedasagreatpotentialforresultinginnitrogenlossfromsoil,especiallyduringfertilizationperiod.Ureashowedahysteresiseffectanseemedtobeabletosupplynitrogentoplantconstantlyandlastinglycomparingtothe(NH4)2SO4.Itwassuggestedthattheapplicationofurealeadtoahigherfertilizerutilizationratioandasmallerrisktotheambientenvironment.KeywordsRicerhizosphere;Nitrogenfertilizers;Microbialbiomass;Nitrifying-denitrifyingbacteria************************************************************************************************“”20031110~165015613NGO161110“”WalterParham“”JamesParhamMichelleSteinauerEgbucheChrisToochi1111~167“”