Linking_N2O_emission_to_soil_mineral_N_as_estimate

ShortcommunicationLinkingN2OemissiontosoilmineralNasestimatedbyCO2emissionandsoilC/NratioZhijianMua,b,c,*,AiyingHuangd,SonokoD.Kimurae,TaoJinb,ShiqiangWeia,RyusukeHatanobaKeyLaboratoryofAgriculturalResourcesandEnvironment,CollegeofResourcesandEnvironment,SouthwestUniversity,Chongqing400716,ChinabGraduateSchoolofAgriculture,HokkaidoUniversity,Sapporo060-8589,JapancKeyLaboratoryofEco-environmentsinThree-GorgesRegion(MinistryofEducation),SouthwestUniversity,Chongqing400716,ChinadCollegeofAgronomyandBiotechnology,SouthwestUniversity,Chongqing400716,ChinaeGraduateSchoolofAgriculture,TokyoUniverstiyofAgricultureandTechnology,Tokyo183-8509,JapanarticleinfoArticlehistory:Received16May2009Receivedinrevisedform10September2009Accepted15September2009Availableonline29September2009Keywords:AgriculturalsoilCarbondioxideC/NratioNitrousoxideabstractBasedontheN2OandCO2emissiondataconcomitantlymeasuredfromagriculturaluplandfieldsaroundtheworld,wedevelopedanempiricalmodelasfollows:cumulativeN2Oemission¼aexp[b*(ECO2/ScnþFn)](R2adj¼0.85w0.87),whereECO2istherateofheterotrophicrespirationfromsoils,ScnisthesoilC/Nratio,andFnisthechemicalfertilizerNrate.Themodelparametersderivedfromthedatafromthesoilswithoutreceivingchemicalfertilizersweresignificantlydifferentfromtheonesfromthefertilizedsoils.ThismodelindicatesthatCO2emissionandsoilC/NratiocanbeusedasscalingparameterstoproduceregionalorglobalinventoriesofN2Oemissionfromagriculturalsoils.2009ElsevierLtd.Allrightsreserved.Nitrousoxide(N2O)playsanimportantroleintheglobalwarming(LashofandAhuja,1990)andthestratosphericozonedestruction(Rowland,1991).Soilsareestimatedtocontributeabout60%ofthetotalglobalannualemissionofN2O(Kroezeetal.,1999).N2OemissionfromsoilsisderivedfromsoilmineralNthroughtheprocessesofmicrobialnitrificationanddenitrification(Conrad,1996).SoilmineralNiscomposedofinorganicN(NH4þandNO3)fromfertilizationandmineralizationoforganicmatter.Murphyetal.(2003)suggestedthatitshouldbepossibletoestimategrossNmineralizationfromCO2productiondividedbytheC/Nratioofthedecomposingmaterials.Luxhøietal.(2006)demonstratedthatthegrossNmineralizationfromplantlitterscouldbepredictedbyrespirationratesandplantlitterC/Nratio.AcorrelationofNmineralizationwithN2Oemissionwasfoundinsomestudies(Matsonetal.,1989;Ambus,2005).Theconnectionsamongsoilrespiration,NmineralizationandN2Oemis-sionsuggestthatCO2emissionmightbeusedtoestimateN2Oemis-sion.Infact,McLainandMartens(2005)showedthatN2OemissionfromsoilincubationcanbepredictedbythecompositionandrespiredCofaminoacidsamended.Innaturalecosystems,Garcia-Montieletal.(2002)presentedanempiricalrelationshipbetweenN2OandCO2emissionsfromsoilsofAmazontropicalforest.Inagriculturalsoils,Muetal.(2008)haveattempedtoestimategrossmineralizedNthroughsoilCO2emissionandsoilC/Nratio,andrelatesoilmineralNtocumulativeN2Oemission.Sucharelationship,ifvalidalsoatlargerscales,willgreatlyimproveourabilitytoquantifyN2Oemissionfromagriculturalsoils.ToverifytherelationshipwecompiledandanalyzedthemeasurementsofN2OandCO2emissionsfromuplandcropfieldspublishedinpeer-reviewedjournals(Table1).Dataextractioncompliedwiththefollowingcriteria:(1)Weonlyconsideredstudiescarriedoutinmineralsoilsunderuplandcroppingsystemsforatleastonecroppingseason(5months);(2)BothofN2OandCO2fluxesweremeasuredandreportedinthepapers;(3)Ifsoilswereamendedwithmanureorcropresidue,informationontheC/Nratioandapplicationrateofthesematerialsshouldbeavailableandcontrolplotsshouldbeestablishedtobeabletoestimatetherelativecontri-butionoftheappliedmaterialsandsoilorganicmattertothetotalCO2flux.Thefinaldatasetcomprisedof116fieldmeasurementsfrom21uplandsites(Table1).Mostofthefluxmeasurementsweremadeusingclosedchambertechniquewithsamplingfrequencyvaryingfrom1to3timesperweekto1–3timespermonth.Thecumulativeperiodofgasemissionwas17monthsinthestudybyJacintheandLal(2004)andwasover5monthsto1yearinotherstudies.*Correspondingauthorat:CollegeofResourcesandEnvironment,SouthwestUniversity,Chongqing400716,China.Tel.:þ862368250484;fax:þ862368250444.E-mailaddresses:[e-mail],[e-mail](Z.Mu).ContentslistsavailableatScienceDirectSoilBiology&Biochemistryjournalhomepage:–seefrontmatter2009ElsevierLtd.Allrightsreserved.doi:10.1016/j.soilbio.2009.09.013SoilBiology&Biochemistry41(2009)2593–2597Table1MeasurementsofcumulativeN2OandCO2emissionsfromagriculturaluplandsoilsandestimatesofsoilgrossmineralizedN(Ng)andtotalsoilmineralN(Nt).ReferenceLocationSoiltextureSoilC/NCrop/treatmentCumulativeperiodAmountofchemicalN(kgNha1)CO2emission(kgCha1)N2Oemission(kgNha1)Nga(kgNha1)Ntb(kgNha1)Jacintheetal.(2002),JacintheandLal,2003CentralOhio,USASiltloam12.0Bareplot9months04370c0.69364364Jacintheetal.(2002),JacintheandLal,2003CentralOhio,USASiltloam11.6Bareplot;wheatresidue9months06510c1.19393393Jacintheetal.(2002),JacintheandLal,2003CentralOhio,USASiltloam11.8Bareplot;wheatresidue9months07730c1.39410410Jacintheetal.(2002),JacintheandLal,2003CentralOhio,USASiltloam10.2Bareplot9months2444370c2.41428672Jacintheetal.