Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry ...

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Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory Office of the Chief Economist Climate Change Program Office Technical Bulletin 1939 July 2014 United States Department of Agriculture

Transcript of Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry ...

  • Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory

    Office of the Chief Economist Climate Change Program Office Technical Bulletin 1939 July 2014

    United States Department of Agriculture

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    QuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventoryMarlenEve,DianaPape,MarkFlugge,RachelSteele,DerinaMan,MarybethRileyGilbertandSarahBiggar,Editors.

    USDATechnicalBulletin1939July2014Publishedby:U.S.DepartmentofAgricultureOfficeoftheChiefEconomistWashington,DC20250

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    HowtoObtainCopies:YoumayelectronicallydownloadthisdocumentfromtheU.S.DepartmentofAgricultureswebsiteat:http://www.usda.gov/oce/climate_change/estimation.htmSuggestedCitationReportCitationEve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,(Eds),2014.QuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939.OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.ChapterCitationsEve,M.,M.Flugge,D.Pape,2014.Chapter1:Introduction.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939.OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.Eve,M.,M.Flugge,D.Pape,2014.Chapter2:ConsiderationsWhenEstimatingAgricultureandForestryGHGEmissionsandRemovals.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.Ogle,S.M.,P.R.Adler,F.J.Breidt,S.DelGrosso,J.Derner,A.Franzluebbers,M.Liebig,B.Linquist,G.P.Robertson,M.Schoeneberger,J.Six,C.vanKessel,R.Venterea,T.West,2014.Chapter3:QuantifyingGreenhouseGasSourcesandSinksinCroplandandGrazingLandSystems.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.Ogle,S.M.,P.Hunt,C.Trettin,2014.Chapter4:QuantifyingGreenhouseGasSourcesandSinksinManagedWetlandSystems.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.Powers,W.,B.Auvermann,N.A.Cole,C.Gooch,R.Grant,J.Hatfield,P.Hunt,K.Johnson,A.Leytem,W.Liao,J.M.Powell,2014.Chapter5:QuantifyingGreenhouseGasSourcesandSinksinAnimalProductionSystems.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.

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    Hoover,C.,R.Birdsey,B.Goines,P.Lahm,GreggMarland,D.Nowak,S.Prisley,E.Reinhardt,K.Skog,D.Skole,J.Smith,C.Trettin,C.Woodall,2014.Chapter6:QuantifyingGreenhouseGasSourcesandSinksinManagedForestSystems.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.Ogle,S.M.,2014.Chapter7:QuantifyingGreenhouseGasSourcesandSinksfromLandUseChange.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.Breidt,F.J.,Ogle,S.M.,Powers,W.,Hover,C.,2014.Chapter8:UncertaintyAssessmentforQuantifyingGreenhouseGasSourcesandSinks.InQuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939,OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,Eds.

    Acknowledgements:TheDepartmentofAgriculturewouldliketoacknowledgethemanycontributorstothisreport,includingcontractors,universityresearchersandFederalGovernmentemployees.MarlenD.Eve,Ph.D.,EnvironmentalScientistintheClimateChangeProgramOffice,servedastheProjectManagerforthisreport.Heprovidedguidanceontheprocessfordevelopingthereport,insightsonthelevelofdetailprovidedforthemethods,andeditorialreviewofthedocument.WilliamHohenstein,DirectorfortheClimateChangeProgramOffice,providedoveralldirectionontheguidingprinciplesfordevelopingthemethodsandassociatedreport.Specifically,wewouldliketoacknowledgetheteamatICFInternationalthatplayedakeyroleincoordinatingtheworkandleadingthedevelopmentofeachchapterincludedinthereport.ThecoreteamatICFInternationalincludes:SarahBiggar,ICFInternationalMarkFlugge,ICFInternationalDerinaMan,ICFInternationalDianaPape,ICFInternationalMarybethRileyGilbert,ICFInternationalRachelSteele,ICFInternationalAdditionally,wewouldliketoacknowledgethetremendouseffortputintothereportbyourworkinggroupsandexpertauthorsforeachchapterofthereport,aswellasourothercontributors,subjectmatterexpertsandscientificreviewers.USDArecognizestheirsignificantinvestmentoftimeandexpertiseandappreciatesthecontributionofeachmember.

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    WorkingGroups:Croplands/GrazingLands:

    StephenM.Ogle,ColoradoStateUniversity(LeadAuthor)PaulR.Adler,USDAAgriculturalResearchServiceJayBreidt,ColoradoStateUniversityStephenDelGrosso,USDAAgriculturalResearchServiceJustinDerner,USDAAgriculturalResearchServiceAlanFranzluebbers,USDAAgriculturalResearchServiceMarkLiebig,USDAAgriculturalResearchServiceBruceLinquist,UniversityofCalifornia,DavisPhilRobertson,MichiganStateUniversityMicheleSchoeneberger,USDAForestServiceJohanSix,UniversityofCalifornia,Davis;SwissFederalInstituteofTechnology,ETHZurichChrisvanKessel,UniversityofCalifornia,DavisRodVenterea,USDAAgriculturalResearchServiceTristramWest,PacificNorthwestNationalLaboratory

    Wetlands:StephenM.Ogle,ColoradoStateUniversity(LeadAuthor)PatrickHunt,USDAAgriculturalResearchServiceCarlTrettin,USDAForestService

    AnimalAgriculture:WendyPowers,MichiganStateUniversity(LeadAuthor)BrentAuvermann,TexasA&MUniversityN.AndyCole,USDAAgriculturalResearchServiceCurtGooch,CornellUniversityRichGrant,PurdueUniversityJerryHatfield,USDAAgriculturalResearchServicePatrickHunt,USDAAgriculturalResearchServiceKristenJohnson,WashingtonStateUniversityAprilLeytem,USDAAgriculturalResearchServiceWeiLiao,MichiganStateUniversityJ.MarkPowell,USDAAgriculturalResearchService

    Forestry:CoeliHoover,USDAForestService(LeadAuthor)RichardBirdsey,USDAForestService(CoLeadAuthor)BruceGoines,USDAForestServicePeterLahm,USDAForestServiceGreggMarland,AppalachianStateUniversityDavidNowak,USDAForestServiceStephenPrisley,VirginiaPolytechnicInstituteandStateUniversity

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    ElizabethReinhardt,USDAForestServiceKenSkog,USDAForestServiceDavidSkole,MichiganStateUniversityJamesSmith,USDAForestServiceCarlTrettin,USDAForestServiceChristopherWoodall,USDAForestService

    AdditionalContributorsMarkEaster,ColoradoStateUniversityRobertGleason,U.S.GeologicalSurveyJ.BooneKauffman,OregonStateUniversityErnieMarx,ColoradoStateUniversityKeithPaustian,ColoradoStateUniversityTomWirth,U.S.EnvironmentalProtectionAgencyAndreDenisWright,UniversityofVermont

    AgroupofexpertswereconvenedinFebruary2012toreviewthesoilN2Omethodsinthecroplands/grazinglandssectionoftheReport.SoilN2OWorkshopOrganizationCommittee:

    StephenM.Ogle,ColoradoStateUniversity(CoChair)PhilRobertson,MichiganStateUniversity(CoChair)SteveDelGrosso,USDAAgriculturalResearchServiceJohanSix,UniversityofCalifornia,Davis;SwissFederalInstituteofTechnology,ETHZurichRodVenterea,USDAAgriculturalResearchService

    SoilN2OWorkshopParticipants:MartinBurger,UniversityofCalifornia,DavisRaymondDesjardins,AgricultureandAgriFoodCanadaRonGehl,NorthCarolinaStateUniversityPeterGrace,QueenslandUniversityofTechnologyPeterGroffman,CaryInstituteofEcosystemStudiesArdellHalvorson,USDAAgriculturalResearchServiceWilliamHorwath,UniversityofCalifornia,DavisCesarIzaurralde,JointGlobalChangeResearchInstitute;UniversityofMarylandChangshengLi,UniversityofNewHampshireNevilleMillar,MichiganStateUniversityKeithPaustian,ColoradoStateUniversityPhilippeRochette,AgricultureandAgriFoodCanadaWilliamSalas,AppliedGeosolutionsCliffSnyder,InternationalPlantNutritionInstitute

    ExpertReviewersUSDAwouldliketoacknowledgethefollowingexpertreviewers,whoreviewedallorpartsofthedocumentduringtheMarch2013ExpertReview:

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    BobAbt,NorthCarolinaStateUniversityLeonHartwellAllen,USDAAgriculturalResearchServiceBenBondLamberty,JointGlobalChangeResearchInstituteSandraBrown,WinrockInternationalDavidClay,SouthDakotaStateUniversityStevenDeGryze,TerraGlobalCapitalPeteEpanchin,AAASFellow,U.S.EnvironmentalProtectionAgencyErinFitzgerald,InnovationCenterforU.S.DairyRonGehl,NorthCarolinaStateUniversityAmrithGunasekara,CaliforniaDepartmentofAgricultureNoelGurwick,SmithsonianEnvironmentalResearchCenterLindaHeath,USDAForestServiceWilliamHorwath,UniversityofCalifornia,DavisCesarIzaurralde,JointGlobalChangeResearchInstitute;UniversityofMarylandJenniferJenkins,U.S.EnvironmentalProtectionAgencyKurtJohnsen,USDAForestServiceErmiasKebreab,UniversityofCalifornia,DavisWilliamLazarus,UniversityofMinnesotaDeanneMeyer,UniversityofCalifornia,DavisTimParkin,USDAAgriculturalResearchServiceCharlesRice,KansasStateUniversityNeilSampson,TheSampsonGroupKaramatSistani,USDAAgriculturalResearchServiceCliffSnyder,InternationalPlantNutritionInstituteBrentSohngen,OhioStateUniversityMarthaStevenson,WorldWildlifeFundRichardTodd,USDAAgriculturalResearchServiceMicheleWander,UniversityofIllinoisTomWirth,U.S.EnvironmentalProtectionAgency

    Photocreditsforcoverandeachchapter: ExecutiveSummary:Stripsandshelterbelts:USDANRCS;NRCSMT00001.tif

    http://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=4851&site=PhotoGallery

    Chapter1:Planting:USDANRCS;JeffVanuga;NRCSVA02001.tifhttp://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=6529&site=PhotoGallery

    Chapter3:Farmstead:USDANRCS;TimMcCabe;NRCSMD81005.tifhttp://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=4511&site=PhotoGallery

    Chapter4:Wetland;USDANRCS;LynnBetts; NRCSIA99470.tifhttp://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=3629&site=PhotoGallery

    Chapter5:Hogs:USDANRCS;LynnBetts;NRCSIA99210.tifhttp://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=3115&site=PhotoGallery

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    Chapter6:Forest:USDANRCS;NRCSNM02093http://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=5971&site=PhotoGallery

    Chapter7:ForestHWP:USDANRCS;JeffVanuga;NRCSNM02093http://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=5471&site=PhotoGallery

    Chapter8:Compost:USDANRCS;NRCSCA06008.tifhttp://photogallery.nrcs.usda.gov/netpub/server.np?find&catalog=catalog&template=detail.np&field=itemid&op=matches&value=961&site=PhotoGallery

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    TableofContentsExecutiveSummary1 Introduction...............................................................................................................................................13

    1.1 OverviewoftheReport...............................................................................................................................141.2 ReportObjectives..........................................................................................................................................151.3 ProcessfortheDevelopmentoftheMethods....................................................................................161.4 ContentsoftheReport................................................................................................................................191.5 UsesandLimitationsoftheReport......................................................................................................110Chapter1References.............................................................................................................................................114

    2 ConsiderationsWhenEstimatingAgricultureandForestryGHGEmissionsandRemovals .........................................................................................................................................................................23

    2.1 Scope...................................................................................................................................................................232.1.1 DefinitionofEntity........................................................................................................................232.1.2 DefinitionofSystemBoundaries.............................................................................................24

    2.2 ReviewofRelevantCurrentToolsandMethods............................................................................2122.3 SelectionofMostAppropriateMethodandMitigationPracticestoInclude......................2132.4 OverviewofSectors....................................................................................................................................214

    2.4.1 CroplandsandGrazingLands.................................................................................................2162.4.2 Wetlands..........................................................................................................................................2172.4.3 AnimalProduction.......................................................................................................................2192.4.4 Forestry............................................................................................................................................221

    2.5 LandUseChange.........................................................................................................................................2222.6 Uncertainty....................................................................................................................................................223Chapter2References.............................................................................................................................................224

    3 QuantifyingGreenhouseGasSourcesandSinksinCroplandandGrazingLandSystems..... .........................................................................................................................................................................34

    3.1 Overview...........................................................................................................................................................353.1.1 OverviewofManagementPracticesandResultingGHGEmissions.........................363.1.2 SystemBoundariesandTemporalScale............................................................................3103.1.3 SummaryofSelectedMethods/ModelsSourcesofData.............................................3103.1.4 OrganizationofChapter/Roadmap......................................................................................311

    3.2 CroplandManagement..............................................................................................................................3123.2.1 ManagementInfluencingGHGEmissionsinUplandSystems...................................3123.2.2 ManagementInfluencingGHGEmissionsinFloodedCroppingSystems.............3253.2.3 LandUseChangetoCropland................................................................................................328

    3.3 GrazingLandManagement......................................................................................................................3293.3.1 ManagementActivityInfluencingGHGEmissions.........................................................3303.3.2 LandUseChangetoGrazingLands......................................................................................336

    3.4 Agroforestry..................................................................................................................................................337

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    3.4.1 CarbonStocks................................................................................................................................3393.4.2 NitrousOxide.................................................................................................................................3413.4.3 Methane...........................................................................................................................................3413.4.4 ManagementInteractions.........................................................................................................342

    3.5 EstimationMethods...................................................................................................................................3423.5.1 BiomassCarbonStockChanges.............................................................................................3433.5.2 LitterCarbonStockChanges...................................................................................................3493.5.3 SoilCarbonStockChanges.......................................................................................................3493.5.4 SoilNitrousOxide........................................................................................................................3583.5.5 MethaneUptakebySoils...........................................................................................................3743.5.6 MethaneandNitrousOxidefromFloodedRiceCultivation.......................................3773.5.7 CO2fromLiming...........................................................................................................................3833.5.8 NonCO2EmissionsfromBiomassBurning......................................................................3863.5.9 CO2fromUreaFertilizerApplications.................................................................................390

    3.6 SummaryofResearchGapsforCropandGrazingLandManagement..................................392Appendix3A:SoilN2OModelingFrameworkSpecifications...............................................................397

    3A.1DescriptionofProcessBasedModels.....................................................................3993A.2EmpiricalScalarsforBaseEmissionRates.........................................................31063A.3PracticeBasedScalingFactors................................................................................3108

    Appendix3B:GuidanceforCropsNotIncludedintheDAYCENTModel....................................3113Chapter3References..........................................................................................................................................3116

    4 QuantifyingGreenhouseGasSourcesandSinksinManagedWetlandSystems................43

    4.1 Overview...........................................................................................................................................................434.1.1 OverviewofManagementPracticesandResultingGHGEmissions.........................444.1.2 SystemBoundariesandTemporalScale..............................................................................474.1.3 SummaryofSelectedMethods/ModelsandSourcesofData......................................474.1.4 OrganizationofChapter/Roadmap........................................................................................48

    4.2 ManagementandRestorationofWetlands........................................................................................484.2.1 DescriptionofWetlandManagementPractices................................................................484.2.2 LandUseChangetoWetlands................................................................................................413

    4.3 EstimationMethods...................................................................................................................................4144.3.1 BiomassCarboninWetlands..................................................................................................4144.3.2 SoilC,N2O,andCH4inWetlands............................................................................................417

    4.4 ResearchGapsforWetlandManagement.........................................................................................421Chapter4References.............................................................................................................................................423

    5 QuantifyingGreenhouseGasSourcesandSinksinAnimalProductionSystems..............55

    5.1 Overview...........................................................................................................................................................555.1.1 OverviewofManagementPracticesandResultingGHGEmissions.........................555.1.2 SystemBoundariesandTemporalScale............................................................................5125.1.3 SummaryofSelectedMethods/Models/SourcesofData............................................512

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    5.1.4 OrganizationofChapter/Roadmap......................................................................................5145.2 AnimalProductionSystems....................................................................................................................518

    5.2.1 DairyProductionSystems........................................................................................................5185.2.2 BeefProductionSystems..........................................................................................................5225.2.3 SheepProductionSystems.......................................................................................................5255.2.4 SwineProductionSystems.......................................................................................................5255.2.5 PoultryProductionSystems....................................................................................................528

    5.3 EmissionsfromEntericFermentationandHousing.....................................................................5305.3.1 EntericFermentationandHousingEmissionsfromDairyProductionSystems........ .............................................................................................................................................................5315.3.2 EntericFermentationandHousingEmissionsfromBeefProductionSystems.5445.3.3 EntericFermentationandHousingEmissionsfromSheep........................................5525.3.4 EntericFermentationandHousingEmissionsfromSwineProductionSystems....... .............................................................................................................................................................5535.3.5 HousingEmissionsfromPoultryProductionSystems.................................................5605.3.6 EntericFermentationandHousingEmissionsfromOtherAnimals.......................5645.3.7 FactorsAffectingEntericFermentationEmissions.......................................................5665.3.8 LimitationsandUncertaintyinEntericFermentationandHousingEmissions

    Estimates.........................................................................................................................................5735.4 ManureManagement.................................................................................................................................575

    5.4.1 TemporaryStackandLongTermStockpile.....................................................................5775.4.2 Source:U.S.EPA(2011).Composting...................................................................................5815.4.3 AerobicLagoon.............................................................................................................................5855.4.4 AnaerobicLagoon,RunoffHoldingPond,StorageTanks............................................5865.4.5 AnaerobicDigesterwithBiogasUtilization......................................................................5915.4.6 CombinedAerobicTreatmentSystems..............................................................................5935.4.7 SandManureSeparation..........................................................................................................5945.4.8 NutrientRemoval.........................................................................................................................5945.4.9 SolidLiquidSeparation............................................................................................................5955.4.10 ConstructedWetland..................................................................................................................5975.4.11 ThermoChemicalConversion................................................................................................5985.4.12 LimitationsandUncertaintyinManureManagementEmissionsEstimates......599

    5.5 ResearchGaps............................................................................................................................................51055.5.1 EntericFermentation..............................................................................................................51055.5.2 ManureManagement...............................................................................................................5106

    Appendix5A:EntericCH4fromFeedlotCattleMethaneConversionFactor(Ym)..............5109Appendix5B:FeedstuffsCompositionTable...........................................................................................5113Appendix5C:EstimationMethodsforAmmoniaEmissionsfromManureManagement

    Systems......................................................................................................................................51235C.1 MethodforEstimatingAmmoniaEmissionsUsingEquationsfromIntegrated

    FarmSystemModel................................................................................................................51235C.1.1RationaleforSelectedMethod...............................................................................51235C.1.2ActivityData..................................................................................................................5123

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    5C.1.3AncillaryData...............................................................................................................51245C.2 MethodforAmmoniaEmissionsfromTemporaryStack,LongTermStockpile,

    AnaerobicLagoons/RunoffHoldingPonds/StorageTanks,andAerobicLagoons........................................................................................................................................................5124

    5C.3 MethodforEstimatingAmmoniaEmissionsfromCompostingUsingIPCCTier2Equations....................................................................................................................................5128

    5C.3.1RationaleforSelectedMethod...............................................................................51285C.3.2ActivityData..................................................................................................................51295C.3.3AncillaryData...............................................................................................................5129

    5C.4 MethodforAmmoniaEmissionsfromComposting..................................................51295C.5 UncertaintyinAmmoniaEmissionsEstimates...........................................................5129

    Appendix5D:ManureManagementSystemsShapeFactors( )...................................................5131Appendix5E:ModelReview:ReviewofEntericFermentationModels.......................................5134Chapter5References..........................................................................................................................................5139

    6 QuantifyingGreenhouseGasSourcesandSinksinManagedForestSystems....................64

    6.1 Overview.........................................................................................................................................................656.1.1 OverviewofManagementPracticesandResultingGHGEmissions.........................666.1.2 SystemBoundariesandTemporalScale..............................................................................696.1.3 SummaryofSelectedMethods/Models..............................................................................6106.1.4 SourcesofData..............................................................................................................................6116.1.5 OrganizationofChapter/Roadmap......................................................................................612

    6.2 ForestCarbonAccounting......................................................................................................................6156.2.1 DescriptionofForestCarbonAccounting..........................................................................6156.2.2 DataCollectionforForestCarbonAccounting.................................................................6236.2.3 EstimationMethods....................................................................................................................6256.2.4 Limitations,Uncertainty,andResearchGaps...................................................................628

    6.3 Establishing,Reestablishing,andClearingForests....................................................................6296.3.1 Description.....................................................................................................................................6296.3.2 ActivityDataCollection.............................................................................................................6336.3.3 EstimationMethods....................................................................................................................6346.3.4 SpecificProtocolforComputation........................................................................................6376.3.5 ActualGHGRemovalsandEmissionsbySourcesandSinksfromForestClearing... .............................................................................................................................................................6436.3.6 LimitationsandUncertainty....................................................................................................644

    6.4 ForestManagement..................................................................................................................................6456.4.1 Description.....................................................................................................................................6456.4.2 ActivityData...................................................................................................................................6536.4.3 ManagementIntensityCategories........................................................................................6576.4.4 EstimationMethods....................................................................................................................6646.4.5 LimitationsandUncertainty....................................................................................................666

    6.5 HarvestedWoodProducts.....................................................................................................................6666.5.1 GeneralAccountingIssues.......................................................................................................666

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    6.5.2 EstimationMethods....................................................................................................................6686.5.3 ActivityDataCollection.............................................................................................................6696.5.4 Limitations,Uncertainty,andResearchGaps...................................................................670

    6.6 UrbanForests..............................................................................................................................................6716.6.1 Description.....................................................................................................................................6716.6.2 ActivityDataCollection.............................................................................................................6736.6.3 EstimationMethods....................................................................................................................6746.6.4 LimitationsandUncertainty....................................................................................................680

    6.7 NaturalDisturbanceWildfireandPrescribedFire...................................................................6826.7.1 Description.....................................................................................................................................6826.7.2 ActivityDataCollection.............................................................................................................6826.7.3 EstimationMethods....................................................................................................................6826.7.4 LimitationsandUncertainty....................................................................................................687

    Appendix6A:HarvestedWoodProductsLookupTables.....................................................................688Chapter6References..........................................................................................................................................6107

    7 QuantifyingGreenhouseGasSourcesandSinksfromLandUseChange.............................73

    7.1 Overview...........................................................................................................................................................737.2 DefinitionsofLandUse...............................................................................................................................747.3 Caveats...............................................................................................................................................................767.4 EstimatingGHGFluxfromLandUseChange.....................................................................................76

    7.4.1 CarbonPoolsinLiveBiomass,DeadBiomass,andSoilOrganicCarbon................787.4.2 ChangesinSoilCarbon................................................................................................................787.4.3 ChangesinotherGHGemissions...........................................................................................713

    Chapter7References.............................................................................................................................................7148 UncertaintyAssessmentforQuantifyingGreenhouseGasSourcesandSinks...................83

    ComponentsandInputstoanEntityScaleMonteCarloUncertaintyAssessment............848.1.1 ParameterUncertainty................................................................................................................858.1.2 SamplingMethodUncertainty..................................................................................................868.1.3 LargeDatasetUncertainty..........................................................................................................898.1.4 ModelUncertainty.......................................................................................................................816

    ResearchGaps...............................................................................................................................................820Appendix8A:ExampleOutputFilefromFVSSamplingUncertaintyBootstrappingApplicationFVSBoot(asprovidedinGreggandHummel,2002)................................................................................821Appendix8B:UncertaintyTables....................................................................................................................822Chapter8References.............................................................................................................................................855

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  • QUANTIFYINGGREENHOUSEGASFLUXESINAGRICULTURE ANDFORESTRY:METHODSFORENTITYSCALE INVENTORY

    Eve,M.,D.Pape,M.Flugge,R.Steele,D.Man,M.RileyGilbert,andS.Biggar,(Eds),2014.QuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventory.TechnicalBulletinNumber1939.OfficeoftheChiefEconomist,U.S.DepartmentofAgriculture,Washington,DC.606pages.July2014.

    ExecutiveSummary

    BackgroundProvisionsofSection2709oftheFood,Conservation,andEnergyActof2008directtheU.S.DepartmentofAgriculture(USDA)topreparetechnicalguidelinesandsciencebasedmethodstomeasureenvironmentalservicebenefitsfromconservationandlandmanagementactivities,initiallyfocusedoncarbon.Themethodscontainedinthisdocumentaddressgreenhousegas(GHG)emissionsandremovalsfromagriculturalandforestryactivities.Throughthedevelopmentofthisreport,USDAhaspreparedtwoprimaryproducts:1. Acomprehensivereviewoftechniques

    currentlyinuseforestimatingGHGemissionsandremovalsfromagriculturalandforestryactivities;and

    2. AtechnicalreportoutliningthepreferredsciencebasedapproachandspecificmethodsforestimatingGHGemissionsatthefarmorforestscale(i.e.,thisdocument).

    PurposeoftheReportTheobjectiveforthisreportistocreateastandardsetofGHGestimationmethodsforusebyUSDA,landowners,andotherstakeholderstoassisttheminevaluatingtheGHGimpactsoftheirmanagementdecisions.ThemethodspresentedinthereportaddressGHGemissionsandcarbonsequestrationfortheentireentityoroperationandalsoprovidetheopportunitytoassessindividualpracticesormanagementdecisions.Therefore,easeofuseiscritical.AcoobjectiveistodemonstratecapacitywithinUSDA,establishingastandardized,consensussetofmethodsthatbecomethescientificbasisforentityscaleestimationoftheGHGimpactsoflandownermanagementdecisions.Therefore,scientificrigorandtransparencyarealsocritical.

    UsesoftheReportandMethods:

    EstimatingincreasesanddecreasesinGHGemissionsandcarbonsequestrationresultingfromcurrentandfutureconservationprogramsandpractices;

    ProvidingmethodssuitableforGHGinventoryeffortsattheentity,farm,orforestscale,withpossibleimplicationsforregionalandnationalscaleassessmentsaswell;and

    EstimatingincreasesanddecreasesinGHGemissionsandcarbonsequestrationassociatedwithchangesinlandmanagement.

  • Executive Summary

    ES-2

    Becausethereportisintendedasameansofevaluatingmanagementpracticesacrossthefullscopeofthefarm,ranch,andforestmanagementsystem,themethodsinthereportneedtobeascomprehensiveaspossible.Researchanddatagapsexistthatresultinsomemanagementpracticesnotbeingaccountedfororarereflectedinhigherlevelsofestimateuncertainty.Completenessisimportant,though,andthereportattemptstoidentifythemostsignificantresearchgapsanddataneeds.ThisreportwillbeusedwithinUSDAandbyfarmers,ranchers,andforestlandowners,andwillbemadepubliclyavailable.Thesemethodsaredesignedto:

    1. Provideascientificbasisformethodsthatcanbeusedbylandownersandmanagers,USDA,andotherstakeholderstoestimatechangesinGHGemissionsandremovalsatthelocalentityscale;

    2. CreateastandardsetofGHGquantificationguidelinesandmethodsforusebystakeholders;3. Quantifyallsignificantemissionsandremovalsassociatedwithspecificsourcecategories;4. Quantifyemissionsfromlandusechangeandcarbonsequestrationfromlandmanagement

    practicesandtechnologies;and5. Supportthedevelopmentofentity,farm,orforestscaleGHGinventoriesthatwillfacilitate

    theparticipationoflandownersinpublicandprivateenvironmentalmarketregistriesandreportingsystems.

    ThereportalsoservesasinputintothedevelopmentofaUSDAGHGEstimationTool.ThereportandthemethodsarenotintendedasanadditiontoorreplacementofanycurrentFederalGHGreportingsystemsorrequirements.ProcessfortheDevelopmentoftheReportThisreportwasdevelopedbythreeauthorteams(i.e.,workinggroups)underthedirectionofoneleadauthorforeachteam(plusonecoleadauthorfortheforestrychapter).TheleadauthorswerechosenbasedontheirexperiencewithGHGinventoriesandaccountingmethodologiesandtheirprofessionalresearchexperience.Withinputfromeachleadauthor,USDAchose8to12workinggroupmembersperteamtowritethereport.TheseworkinggroupmemberseachhaddifferentbackgroundsthatfitwiththeanticipatedcontentofthedocumentandalsohadexperiencewithGHGaccountingand/orfieldresearchthatwasuniqueandaddressedoneormoreofthenichemethodsthatwereessentialforensuringthecomprehensivenessofthemethodsforeachsector.Theauthorteamswereprovidedwithapreliminaryoutlineoftheirchaptersandwithtwobackgroundreportsdevelopedaspartoftheproject.Onebackgroundreportwasananalysisofthescientificliteraturerelatedtoratesofcarbonsequestrationoremissionsreductionresultingfromvariousmanagementpracticesandtechnologies(Denefetal.,2011).Theotherreportwasacompilationofalloftheavailabletools,protocols,andmodels,withbasicinformationoneachone(Denefetal.,2012).Themethodsweredevelopedaccordingtoseveralcriteriainordertomaximizetheirusefulness.Inparticular,themethodsmust:

    1. Standontheirown,independentofanyotheraccountingsystem,yetmaintainconsistencywithotheraccountingsystemstothemaximumextentpossible;

    2. BescalableforuseatentityscalesitesacrosstheUnitedStates,withapplicabilityatcountyand/orStatelevelsaswell;

    3. FacilitateusebyUSDAinassessingtheperformanceofconservationprograms;

  • Executive Summary

    ES-3

    4. ProvideabroadframeworktoassessmanagementpracticestoevaluatetheGHGaspectofproductionsustainability;

    5. Maintainmaximumapplicabilityforuseinenvironmentalmarkets,includingpossiblefutureFederal,State,orlocalGHGoffsetsinitiatives;

    6. BescientificallyvettedthroughUSDA,U.S.Governmentandacademicexpertreview,andpubliccomment;

    7. Providereliable,real,andverifiableestimatesofonsiteGHGemissions,carbonstorage,andcarbonsequestration(themethodswillbedesignedsothatovertimetheycanbeappliedtoquantifyonsiteGHGreductionsandincreasesincarbonstorageduetoconservationandlandmanagementactivities);and

    8. Provideabasisforconsistencyinestimationandtransparencyinreporting.Developmentofthereporthasbeeniterativeasvariousdraftsofthedocumenthavebeenputthroughseveralreviewstages,includingaUSDAintraagencytechnicalreview,aFederalinteragencytechnicalreview,ascientificexpertreview,andapubliccommentperiod.OverviewofRecommendedGHGEstimationMethodsintheReportThissectionprovidesanoverviewofthecurrentestimationmethodsorapproachesanentitycouldusetoestimateGHGemissionsandsinksonhisorherproperty.ThisoverviewisfollowedbyasummaryofeachsectorsproposedmethodologiesforentityGHGestimations.Thereareseveralapproachesthatafarmer,rancher,orforestlandownercanusetoestimateGHGemissionsatanentityscale,andeachapproachgivesvaryingaccuracyandprecision.Themostaccuratewayofestimatingemissionsisthroughdirectmeasurement,whichoftenrequiresexpensiveequipmentortechniquesthatarenotfeasibleforasinglelandownerormanager.Ontheotherhand,lookuptablesandestimationequationsaloneoftendonotadequatelyrepresentlocalvariabilityorlocalconditions.Thisreportattemptstodelineatemethodsthatbalanceuserfriendliness,datarequirements,andscientificrigorinawaythatistransparentandjustified.Thefollowingapproacheswereconsideredfortheseguidelines: Basicestimationequations(cf.,IPCC[IntergovernmentalPanelonClimateChange]Tier

    1)involvecombinationsofactivitydata1withparametersanddefaultemissionfactors.2Anydefaultparametersordefaultemissionfactors(e.g.,lookuptables)areprovidedinthetext,orifsubstantialinlength,inanaccompanyingcompendiumofdata.

    Models(cf.,IPCCTier3)usecombinationsofactivitydatawithparametersanddefaultemissionfactors.Theinputsforthesemodelscanbeancillarydata3(e.g.,temperature,precipitation,elevation,andsoilnutrientlevelsthatmaybepulledfromanunderlyingsource),biologicalvariables(e.g.,plantdiversity)orsitespecificdata(e.g.,numberofacres,

    1Activitydataisdefinedasdataonthemagnitudeofhumanactivityresultinginemissionsorremovalstakingplaceduringagivenperiodoftime(IPCC,1997).2Emissionfactorisdefinedasacoefficientthatquantifiestheemissionsorremovalsofagasperunitofactivity.Emissionfactorsareoftenbasedonasampleofmeasurementdata,averagedtodeveloparepresentativerateofemissionforagivenactivitylevelunderagivensetofoperatingconditions(IPCC,2006).3Ancillarydataisdefinedasadditionaldatanecessarytosupporttheselectionofactivitydataandemissionfactorsfortheestimationandcharacterizationofemissions.Dataonsoil,croporanimaltypes,treespecies,operatingconditions,andgeographicallocationareexamplesofancillarydata.

  • Executive Summary

    ES-4

    numberofanimals).Theaccuracyofthemodelsisdependentontherobustnessofthemodelandtheaccuracyoftheinputs.

    Fieldmeasurementsactualmeasurementsthatafarmerorlandownerwouldneedtotaketomoreaccuratelyestimatethepropertiesofthesoil,forest,orfarmortoestimateactualemissions.Measuringactualemissionsonthelandrequiresspecialequipmentthatmonitorstheflowofgasesfromthesourceintotheatmosphere.Thisequipmentisnotreadilyavailabletomostentities,sofieldmeasurementsaremoreoftenincorporatedintoothermethodsdescribedinthissectiontocreateahybridapproach.Afieldmeasurementsuchasasamplemeantreediametercouldbeincorporatedintoothermodelsorequationstogiveamoreaccurateinput.

    Inference(cf.,IPCCTier2)usesState,regional,ornationalemissions/sequestrationfactorsthatapproximateemissions/sequestrationperunitoftheinput.Theinputdataisthenmultipliedbythisfactortodeterminethetotalonsiteemissions.Thisfactorcanhavevaryingdegreesofaccuracyandoftendoesnotcapturethemitigationpracticesonthefarmortheuniquesoilconditions,climate,livestockdiet,livestockgenetics,oranyfarmspecificcharacteristics,althoughtheycanbedevelopedwithspecificsoiltypes,livestockcategories,orclimacticregions.

    Hybridestimationapproach(cf.,IPCCTier2orIPPCTier3)anapproachthatusesacombinationoftheapproachesdescribedabove.Theapproachoftenusesfieldmeasurementsormodelstogenerateinputsusedforaninferencebasedapproachtoimprovetheaccuracyoftheestimate.

    Thetypesofapproachesthattheauthorsrecommendedinthisreportincludebasicestimationequationswithdefaultemissionfactors(cf.,IPCCTier1);geography,crop,livestock,technology,orpracticespecificemissionfactors(cf.,IPCCTier2);andmodifiedIPCC/empiricaland/orprocessbasedmodeling(cf.,IPCCTier2orIPCCTier3).4TableES1categorizesthesourcesofemissionswiththetypesofapproachesthatarerecommendedinthisreport.TableES2summarizesthesourcesofagriculturalandforestryGHGemissionsandremovalsdiscussedinthisreport,therecommendedmethodforestimatingemissionsandremovalsforeachsourcecategory,andthereference(s)usedforthedevelopmentofthemethod.

    4Atierrepresentsalevelofmethodologicalcomplexity.Usuallythreetiersareprovided.Tier1isthebasicmethod,Tier2intermediate,andTier3mostdemandingintermsofcomplexityanddatarequirements.Tiers2and3aresometimesreferredtoashighertiermethodsandaregenerallyconsideredtobemoreaccurate(IPCC,2006).

  • Executive Summary

    ES-5

    TableES1:SummaryoftheSourcesofEmissionsandTypesofApproachesinthisReport

    SourceBasicEstimation

    Equation(cf.,IPCCTier1)

    Inference(cf.,IPCCTier2)

    ModifiedIPCCorEmpiricalModel

    (cf.,IPCCTier2orIPPCTier3)

    ProcessedBasedModel

    (cf.,IPPCTier3)

    Croplands/GrazingLands DirectN2OEmissionsfrom

    DrainageofOrganicSoils

    CH4EmissionsfromRiceCultivation

    CO2fromUreaFertilizerApplication

    SoilOrganicCarbonStocksforOrganicSoils

    CO2fromLiming N2OEmissionsfromRiceCultivation

    NonCO2EmissionsfromBiomassBurning

    IndirectN2OEmissions

    BiomassCarbonStockChanges

    CH4UptakebySoils DirectN2OEmissionsfromMineralSoils

    SoilOrganicCarbonStocksforMineralSoils

    Wet

    lands BiomassCarbon

    SoilC,N2O,andCH4

    AnimalProduction5

    EntericCH4fromSwine

    EntericCH4fromOtherAnimals(Goats,AmericanBison)

    CH4fromPoultryHousing

    CH4 fromDairyCattle,BeefCattle,andSwineHousing

    CH4andN2OfromAerobicLagoons

    CH4andN2OfromTemporaryStackandLongTermStockpile

    CH4andN2OfromComposting

    Enteric CH4 fromDairyCattle,Sheep,BeefCowCalf,Bulls,Stockers,FeedlotCattle

    CH4fromManurefromBarnFloorsDairyCattle

    N2OfromDairyCattle,BeefCattle,Swine,andPoultryHousing

    CH4andN2OfromAnaerobicLagoon,RunoffHoldingPond,StorageTanks

    CH4andN2OfromCombinedAerobicTreatmentSystems

    CH4fromAnaerobicDigester

    Forestry Establishing,Re

    establishing,andClearingForest

    HarvestedWood

    ForestCarbonAccounting

    ForestManagement UrbanForests

    5Ammonia(NH3),asanimportantprecursortoGHGs,isincludedintheanimalproductionsystemsdiscussionwherenecessary,butisnotofprimaryfocus.Ifreadersareinterestedinmoretechnicalinformation,methodsforestimatingNH3emissionscanbefoundinAppendix5C.

  • Executive Summary

    ES-6

    SourceBasicEstimation

    Equation(cf.,IPCCTier1)

    Inference(cf.,IPCCTier2)

    ModifiedIPCCorEmpiricalModel

    (cf.,IPCCTier2orIPPCTier3)

    ProcessedBasedModel

    (cf.,IPPCTier3)

    Products NaturalDisturbanceWildfireandPrescribedFire

    LanduseChange

    AnnualChangeinCarbonStocksinDeadWoodandLitterDuetoLandConversion

    ChangeinSoilOrganicCarbonStocksforMineralSoils

    OrganizationoftheReportThereportislargelyorganizedbysector,witheachchapterprovidinganoverviewofmanagementpracticesandresultingGHGemissionsandremovals.Foreachsector,backgroundandinformationonmanagementpracticesarepresentedfirst,followedbythedetailedmethodsproposedforestimatingemissionsandremovalsforthosepractices. Chapter1providesanoverviewofthereport,reportobjectives,contentsofthereport,and

    usesandlimitationsofthereport. Chapter2describesthelinkagesandcrosscuttingissuesrelatingtosectorspecificand

    entityscaleestimationofGHGemissionsandremovals. Chapter3describestheGHGemissionsfromcropandgrazinglandsystems.Thechapter

    presentsmethodsforestimatingtheinfluenceoflanduseandmanagementpracticesonGHGemissions(andremovals)incropandgrazinglandsystems.Methodsaredescribedforestimatingbiomassandsoilcarbonstockschanges,directandindirectsoilnitrousoxide(N2O)emissions,methane(CH4)andN2Oemissionsfromwetlandrice,CH4uptakeinsoils,carbondioxide(CO2)emissionsorremovalsfromliming,nonCO2GHGemissionsfrombiomassburning,andCO2emissionsfromureafertilizerapplication.

    Chapter4providesguidanceforestimationofcarbonstockchangesandCH4andN2Oemissionsfromactivelymanagedwetlands.

    Chapter5describesonfarmGHGemissionsfromtheproductionoflivestockandmanuremanagement.ThechapterpresentsGHGestimationmethodsappropriatetotheproductionofeachcommonlivestocksector(beef,dairy,sheep,swine,andpoultry),withmethodsrelatedtomanuremanagementcombinedforalllivestocktypes.

    Chapter6providesguidanceonestimatingcarbonsequestrationandGHGemissionsfrommanagedforestsystems.Thechapterisorganizedtoprovideanoverviewoftheelementsofforestcarbonaccounting,includingdefinitionsofthekeycarbonpoolsandbasicmethodsfortheirestimation.

  • Executive Summary

    ES-7

    Chapter7providesguidanceonestimatingthenetGHGemissionsandremovalsresultingfromchangesbetweenlandtypesi.e.,conversionsintoandoutofcropland,wetland,grazingland,orforestlandattheentityscale.

    Chapter8presentstheapproachforaccountingfortheuncertaintyintheestimatednetemissionsbasedonthemethodspresentedinthisreport.AMonteCarloapproachwasselectedasthemethodforestimatingtheuncertaintyaroundtheoutputsfromthemethodologiesinthisreportasitiscurrentlythemostcomprehensive,soundmethodavailabletoassesstheuncertaintyattheentityscale.

    SummaryIndevelopingthisreport,theauthorshavesoughttooutlinethemoststateoftheartandsuitablesciencebasedapproachesandspecificmethodsforestimatingfarmorforestscaleGHGemissions(seeTableES2).Insomecases,theproposedmethodshavenotpreviouslybeenappliedinspecificallythewaythatisproposed.Forexample,theforestrysystemschapterdescribestheintegrationoftheForestVegetationSimulator(FVS)withinotherestimationtoolsforforestcarbonaccounting.ThisapplicationofFVS,whiletechnicallysound,willrequireadditionalefforttoimplement.Inothercases,theauthorshaveproposednewmethodsthatbuildonorenhancepreviouslyusedmethods.Forexample,anewhybridapproachisproposedforestimatingdirectsoilN2Oemissionsfrommineralsoilsoncroplandsandgrazinglands.Thehybridapproachusesmodelstoderiveexpectedemissionratesatthetypicalfertilizationrateforthemajorsoiltextures,weatherpatterns,andcroprotationsystemsineachUSDALandResourceRegionandusesametaanalysisofempiricalstudiestodevelopemissionscalingfactorsforcroplandandgrazinglandsystems.Themethodalsoappliespracticebasedscalingfactorsderivedfromametaanalysisofthemostrecentdata.ThishybridapproachistheresultofaworkshopheldinFebruary2012thatconvenedexpertsonN2OemissionsfromcroplandsinordertodevelopestimationmethodsthatwereinclusiveandbestmettheobjectivesofUSDA.Inadditiontoproposingsciencebasedmethods,theauthorsalsoacknowledgethatforcertainpracticesandtechnologies,adequatedatadonotcurrentlyexisttoaccuratelyestimateGHGemissionsand/orcarbonsequestration.Ineachsectorchapter,theauthorshaveincludedadiscussionofresearchgapsorpriorityareasforfuturedatacollectionthatareimportantinordertoimprovethecompletenessandaccuracyoftheestimationmethodsputforthinthisreport.EstimationofGHGemissionsfrommanagedwetlandsystemsisagoodexample.Whileamethodisputforwardthatreflectsthebestcurrentlyavailablescience,theauthorsstateinSection4.3thatthemethodsfortheselandsarenotaswelldevelopedasforothersectors.LaterinthatsamesectionthereistextdiscussingtheconsiderablelimitationstoestimatingGHGfluxesfromthesesystemsandthelargelevelsofuncertaintyaroundfluxestimates.InSection4.4,theauthorsoutlineasignificantlistofresearchanddataprioritiesthatwouldhelptorefineandstrengthentheestimationmethods.Inthecontinualefforttoadvancethescienceandimprovetheunderstandingofthesecomplexanddynamicsystems,thisreportprovidesthefoundationforentityleveltoolstoquantifytheGHGbenefitsfromconservationandlandmanagementactivities.ThereportalsoidentifiesprioritiesforfutureeffortinordertobroadenthescopeofentityscaleGHGfluxestimationandreduceestimationuncertainties.

  • Exec

    utive

    Sum

    mary

    ES-8

    TableES2:Sum

    maryofSourceCategories,Recom

    mendedMethods,andEmissionFactorsinthisReport

    Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    Croplands/GrazingLands

    Bioma

    ssCarbo

    nSto

    ckChanges

    Herba

    ceousbio

    massise

    stima

    ted

    withanem

    piricalm

    ethodusing

    entity

    specificda

    taasinp

    utinto

    theIPCC

    6 equationsdeve

    lopedby

    Lasco

    etal.(2006)andV

    erchotet

    al.(20

    06).W

    oodyplantgrow

    thandloss

    esinagr

    ofores

    tryor

    peren

    nialtreecro

    psare

    estim

    ated

    withasimula

    tionm

    odel

    (DAYCENT

    )usin

    gentityinp

    ut.

    Changes

    intheestima

    ted

    bioma

    sscar

    bonstoc

    kfor

    cropla

    ndan

    dgraz

    inglan

    difthereisa

    landu

    secha

    ngeorachangeinthe

    cro

    porfo

    ragespecies.

    U.S.sp

    ecificde

    faultv

    alues

    (West

    etal.,20

    10)areuse

    dfor

    estim

    atingbiom

    ass

    carbonforannualc

    ropsand

    grazin

    glands.T

    heIPCC

    defau

    ltisprop

    osedfor

    estimatingthecarb

    onfra

    ction

    value.Yi

    eldinun

    itsofdry

    mattercanbe

    estim

    atedb

    ythe

    entity

    ,oravera

    geval

    ues

    fromUSDA

    Natu

    ral

    Agricultura

    lStatisticsSer

    vice

    statisticscanbeused.

    Thism

    ethodwa

    schosen

    becau

    seit

    captur

    esthe

    influenceoflan

    duse

    changeandchanges

    incropor

    forage

    speciesonbiom

    asscarbo

    nsto

    cksby

    using

    U.S.spe

    cificd

    efault

    valuesw

    hereentity

    specificda

    taare

    notavai

    lable.

    6 IPCC=I

    ntergo

    vernm

    entalPa

    nelonC

    limate

    Change

  • Exec

    utive

    Sum

    mary

    ES-9

    Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    SoilO

    rganic

    Carbo

    nstoc

    ksforMine

    ral

    Soils

    TheD

    AYCENT

    modeli

    sused

    to

    estimate

    thesoilorgan

    iccarb

    onat

    thebe

    ginnin

    ganden

    dofth

    eyear

    formine

    ralsoils.Th

    estoc

    ksare

    enteredintothe

    IPCCeq

    uations

    devel

    opedby

    Lasco

    etal.(2006)

    andV

    erchotetal.(2006)to

    est

    imate

    carbo

    nstoc

    kchanges.

    Addition

    ofcarbo

    nin

    manureando

    therorga

    nic

    amendm

    ents;tillag

    eintensity;r

    esidue

    managem

    ent(r

    etentionin

    fieldwitho

    utinc

    orpora

    tion;retentionin

    thefie

    ldwith

    incorp

    oration;and

    removalw

    ithha

    rvest,

    burni

    ng,or

    grazing);

    influe

    nceofbare

    and

    vegeta

    tedfallows;

    irriga

    tione

    ffectson

    decom

    position

    incroplan

    dandg

    razing

    landsyst

    ems;

    settinga

    sidecrop

    land

    frompro

    duction;in

    fluence

    offire

    onoxida

    tiono

    fsoil

    organicm

    atter;an

    dwoody

    plantencro

    achme

    nt,

    agrofo

    restry

    ,and

    silvopast

    ureeffectso

    ncar

    boninputs

    ando

    utputs

    .TheDA

    YCEN

    Tmodel(

    Parto

    netal.,19

    87).

    DAYCEN

    Tmodelh

    asbeen

    demo

    nstratedtorepre

    sentth

    edynamicsofsoilorga

    niccarbo

    nand

    estimate

    soilo

    rganic

    carbo

    nstoc

    kcha

    ngein

    croplan

    dandgrass

    lands

    (Parto

    netal.,1

    993).Th

    ereha

    vebeenun

    certaintiesnoted

    inthe

    modelin

    Oglee

    tal.(2007).T

    he

    modelca

    ptures

    soilm

    oistur

    edynamics,plantprod

    uction

    ,and

    therm

    alcontro

    lsonn

    etpri

    mary

    productionan

    ddeco

    mpositionw

    ith

    atimestep

    ofam

    onthorless.

    SoilO

    rganic

    Carbo

    nStoc

    ksfor

    Organ

    icSoils

    CO2em

    ission

    sfrom

    drain

    ageof

    organics

    oils(i.e.,hi

    stosols)are

    est

    imate

    dwithan

    inference

    metho

    d(cf.,IP

    CCTier2)usi

    ngtheIPCC

    equationd

    evelop

    edby

    Aalde

    etal.

    (2006)andregio

    nspecific

    emission

    facto

    rsfromOglee

    tal.

    (2003).

    Cropla

    nddrain

    age

    Emission

    facto

    rsare

    from

    Oglee

    tal.(2003)andare

    region

    specificba

    sedon

    typ

    icaldrainagepatterns

    and

    climaticcontro

    ls(e.g.,

    temperature

    /prec

    ipitation

    )onde

    composition

    rates

    .

    Usesentity

    specifican

    nuald

    ataas

    inputintotheeq

    uationu

    sedinthe

    U.S.In

    ventor

    y.

  • Exec

    utive

    Sum

    mary

    ES-1

    0Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    Direct

    N 2O

    Emission

    sfrom

    MineralSoils

    Direct

    N 2Om

    ethodsareest

    imate

    dwithah

    ybridestim

    ationmeth

    od.

    Form

    ajorcom

    moditycrop

    s,(e.g.,

    corn,c

    otton,alfalfa)a

    combin

    ationofexperim

    entalda

    taandp

    rocess

    based

    modelingusing

    DA

    YCEN

    T7 andD

    Enitrific

    ation

    decom

    position

    (DND

    C)8areu

    sed

    toderiveexpect

    edba

    seem

    ission

    ratesfordifferen

    tsoiltext

    ure

    classe

    sineachUSDA

    Land

    Resou

    rceRe

    gion.F

    orminor

    commo

    ditycrop

    s(e.g.,barley,

    oats,peanuts

    )andincases

    where

    the

    reare

    insuf

    ficien

    temp

    irical

    datatoderiveaba

    seem

    ission

    rate,theba

    seem

    ission

    rateis

    based

    ontheIPCCd

    efaultfacto

    r(i.e

    .,0.01

    )multiplied

    bythe

    agronom

    icnitrogeninput(d

    eKle

    inetal.,20

    06).T

    heseem

    ission

    ratesare

    scale

    dwithpract

    ice

    based

    scalingfacto

    rstoest

    imate

    the

    influenceofma

    nagem

    ent

    changessuc

    hasapplica

    tiono

    fnitrifi

    cation

    inhib

    itorsorslow

    releas

    efertiliz

    ers.

    Nitrog

    enap

    plicat

    ionto

    crops.Inad

    dition

    ,specific

    managem

    entprac

    ticesare

    inc

    ludedasscalingfacto

    rstha

    tinfluenceap

    ortion

    or

    theen

    tirep

    oolofm

    ineral

    nitrog

    en.9 M

    anage

    ment

    practices

    thatinflue

    ncea

    portionoftheemission

    ratein

    clude:

    Useofslow

    release

    formu

    lation

    Nit

    rificat

    ioninhib

    itor

    applicat

    ion

    Ma

    nurenitrog

    endir

    ectlyd

    eposited

    on

    pastu

    re/range/p

    addock

    Managem

    entprac

    ticestha

    tinflue

    ncetheentirepoolof

    mineralnitro

    geninclu

    de:

    Tillag

    e

    Theb

    aseem

    ission

    facto

    rsare

    adjusted

    byscalingfacto

    rsrelate

    dtospecificc

    rop

    managem

    entprac

    ticestha

    tare

    derivedfro

    mexp

    erime

    ntaldata

    .

    Them

    ethodisbased

    onusing

    res

    ultsfr

    omproce

    ssbased

    models

    andm

    easure

    dN2Oem

    ission

    sin

    combin

    ationwi

    thsca

    lingfact

    ors

    based

    onU.S.spe

    cifice

    mpiric

    aldata

    onas

    easonalt

    imesc

    ale.10

    7 TheversionofDA

    YCEN

    Tcodedan

    dpara

    meterizedforthe

    most

    recen

    tU.S.nationalGHG

    inven

    tory(U.S

    .EPA,2013)w

    asuse

    dtod

    eriveexp

    ectedba

    seem

    ission

    rates

    .8 D

    NDC9.5c

    ompiledon

    Feb2

    5,2013w

    asuse

    dtod

    eriveexp

    ectedba

    seem

    ission

    rates

    .9 Prac

    ticeb

    asede

    missionscalingfacto

    rs(0to1)are

    usedtoad

    justth

    eport

    ionoftheemissionrateass

    ociate

    dwithslo

    wrele

    asefertilizers

    ,nitrificationinhib

    itors,an

    dpastu

    re/ran

    ge/paddock

    (PRP)m

    anure

    nitro

    genad

    dition

    s.Theslo

    wreleas

    efertiliz

    er,nitrificationinhib

    itor,a

    ndPR

    Pmanure

    scalingfacto

    rsare

    weigh

    tedsothatthe

    ireffect

    isonlyo

    ntheam

    ountofnitrog

    eninfluenced

    bythese

    pract

    icesrela

    tivetotheen

    tirep

    oolofnitrogen(i.e.,the

    amountofslowreleas

    efertiliz

    er,fertilize

    rwith

    nitrifi

    cation

    inhib

    itororPRPmanure

    nitro

    genad

    dedtothesoil).Incontr

    ast,sc

    alingfacto

    rsfor

    tillag

    eareuse

    dtoscaletheen

    tireemissionrateunderth

    eassu

    mption

    thatth

    isprac

    ticein

    fluences

    theentirepoolofmineralnitro

    gen.

    10Afulldesc

    riptiono

    fthem

    ethodisinc

    ludedinCh

    apter3a

    ndits

    appendix.Supplem

    entalda

    taoutpu

    tsfrom

    them

    odelr

    unsw

    illbeavailableo

    nlinetodo

    wnloa

    d.

  • Exec

    utive

    Sum

    mary

    ES

    -11

    Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    Direct

    N 2O

    Emission

    sfrom

    Drain

    ageof

    Organ

    icSoils

    Direct

    N 2Oe

    missionsfr

    om

    draina

    geoforg

    anics

    oils,i.e.,

    histos

    ols,ar

    eestima

    tedwi

    tha

    basicestim

    ationeq

    uation(cf.,

    IPCCT

    ier1)meth

    od(deK

    leine

    tal.,20

    06).

    Drain

    ageoforgan

    icsoils.

    Emission

    ratefor

    cropped

    histos

    olsba

    sedon

    anIPCC

    Tier1em

    ission

    facto

    rof

    0.008tonnesN 2On

    itrogenha

    1 yea

    r1 .

    Usesentity

    specifican

    nuald

    ataas

    inputintotheeq

    uationu

    sedinthe

    USDA

    Inven

    tory(USDA

    ,2011).

    IndirectN

    2O

    Emission

    s

    Indirects

    oilN 2

    Oemissionsare

    estimate

    dwithan

    inference

    (cf.,IP

    CCTier2)based

    onIPCC

    metho

    dolog

    y(deKlein

    etal.,

    2006).

    Irriga

    tion.

    IPCCd

    efaultsareuse

    dfor

    estimatingthep

    roport

    ionof

    nitrog

    enthatiss

    ubjectto

    leachi

    ng,ru

    noff,and

    volatiliz

    ation.W

    here

    cropping

    systems

    with

    legum

    inousandn

    on

    legum

    inouswinte

    rcover

    cropsare

    grow

    n,aU.S.

    specifice

    missionfacto

    ris

    provid

    ed.

    Thism

    ethodusesentity

    specific

    season

    aldata

    onnitro

    gen

    managem

    entprac

    tices.

    Metha

    ne

    Uptak

    eby

    Soils1

    1

    Metha

    neup

    takeb

    ysoil

    isest

    imate

    dwithan

    equationthat

    usesaver

    agevalue

    sform

    ethane

    oxida

    tioninn

    aturalveget

    ation

    wheth

    ergra

    ssland,c

    oniferou

    sforest

    ,orde

    ciduousforest

    attenuated

    bycurre

    ntlan

    duse

    practices

    .This

    appro

    achisan

    empir

    icalm

    odel(

    cf.,IPCCTier2

    orIPP

    CTier3).

    Landmanage

    ment

    includ

    ingcultiv

    ationfor

    cropp

    roduct

    ion,gr

    azingin

    grasslands,fores

    tharv

    est,

    grassland,o

    rfores

    tfertilizat

    ion.

    Annuala

    verage

    CH4oxid

    ation

    emission

    sandremo

    valsare

    fromthe

    dataset

    usedby

    Del

    Gross

    oetal.(2000).

    Thisn

    ewlyd

    evelop

    edmeth

    odolo

    gyma

    kesuseofrec

    entU.S.based

    res

    earchtha

    tisno

    taddres

    sedby

    IPC

    Corth

    eU.S.Inv

    entor

    y.The

    metho

    dinco

    rporatesentity

    specific

    annuald

    ata.

    11Meth

    aneu

    ptakeby

    soilsisa

    natur

    alproc

    essinun

    distur

    bedsoils.Pro

    cesses

    forrest

    oringmeth

    anotr

    ophic

    activityaren

    otwe

    llunders

    tood,a

    ndrequirede

    cadesto

    devel

    op.A

    meth

    odisoutlin

    edinthisr

    eport

    ,butadditio

    naldata

    andu

    nders

    tandin

    garereq

    uiredpriortouseorim

    pleme

    ntationinq

    uantificationtools.

  • Exec

    utive

    Sum

    mary

    ES-1

    2Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    Metha

    nean

    dNit

    rousO

    xide

    Emission

    sfrom

    Ric

    eCultiva

    tion

    Abasicestima

    tione

    quation(cf.,

    IPCCT

    ier1)isuse

    dtoestima

    teCH

    4,andan

    inference(cf.,IP

    CC

    Tier2)m

    ethodisuse

    dforN 2O

    emission

    sfrom

    floodedric

    epro

    duction(Akiy

    amaetal.,2

    005;

    deKlein

    etal.,20

    06;Lasc

    oetal.,

    2006;USDA,2011).

    CH4:s

    caling

    facto

    rsare

    differentiated

    by

    hydro

    logicalco

    ntext(e.g.,

    irriga

    ted,ra

    infed

    ,uplan

    d(i.e

    .,drysoil)

    allric

    efields

    intheU

    nitedState

    sare

    irriga

    ted),cultiva

    tion

    periodfloo

    dingregi

    me

    (e.g.,con

    tinuous,multiple

    aeration),timesinc

    elast

    flooding

    (priorto

    cul

    tivation;e.g.,mo

    retha

    n180d

    ays,lesstha

    n30

    days)

    andtypeoforga

    nic

    amendm

    ent(e

    .g.,comp

    ost,

    farmy

    ardmanure

    ).NO:addition

    sfrom

    mineralfertilize

    rs,organ

    icam

    endm

    ents,andcrop

    res

    idues.

    CH4:theba

    seline

    emission

    factor

    ortypic

    aldailyrate

    at

    which

    CH4is

    produce

    dper

    unito

    flandarearep

    resents

    fields

    thatare

    continuously

    floodeddu

    ringthecultiv

    ation

    period,n

    otfloodedatall

    durin

    gthe18

    0days

    priorto

    cultivationan

    drece

    iveno

    org

    anica

    mendme

    nts.CH

    4sca

    lingfact

    orstoaccou

    ntfor

    waterregim

    escom

    efrom

    Lasco

    etal.(2006).

    N 2O:em

    ission

    facto

    rsrelyo

    nLasco

    etal.(2006)andthe

    scalingfact

    ortoacc

    ountfor

    dra

    inageeffect

    s;com

    esfro

    mAkiya

    maetal.(2005;USDA

    ,2011).

    TheN

    2Ometh

    odusesthe

    IPCC

    (2006)equationwi

    ththe

    addition

    of

    ascaling

    facto

    rfordrainagefro

    mAkiya

    maetal.(2005).Th

    emeth

    od

    formeth

    aneemissionsuses

    entity

    spe

    cifica

    nnualdata

    asinputin

    tothe

    equationa

    ndiscon

    sisten

    twithU.S.

    Inventor

    ymeth

    od.

    CO2fr

    om

    Liming

    Aninference(cf.,IP

    CCTier2)

    metho

    disused

    toestim

    ateCO

    2em

    ission

    sfrom

    applicat

    ionof

    carbonatelim

    es(de

    Klein

    etal.,

    2006)w

    ithU.S.spe

    cifice

    missions

    factor

    s(adapted

    fromWe

    stand

    McBride

    ,2005).

    Theamo

    untoflime

    ,cru

    shedlimest

    one,o

    rdolom

    iteap

    pliedtosoils.

    U.S.sp

    ecificem

    ission

    sfacto

    rs(W

    estan

    dMcBride,2

    005).

    UsesU.S

    .specificem

    ission

    facto

    rsas

    annuali

    nputintotheIPCCequation,

    which

    iscon

    sisten

    twiththeU

    .S.Inv

    entor

    y.

    NonC

    O 2

    Emission

    sfrom

    Bio

    mass

    Burni

    ng

    NonC

    O 2GH

    Gemissionsfr

    om

    bioma

    ssburningofgrazinglan

    dveg

    etationo

    rcrop

    resid

    uesare

    estimate

    dwithan

    inference(cf.,

    IPCCT

    ier2)meth

    od(Aald

    eetal.,

    2006).

    Areaburne

    d.

    Emission

    facto

    rsare

    from

    valuesin

    theIPCCg

    uidelines

    (Aald

    eetal.,2

    006)andW

    est

    etal.(20

    10)fo

    rthe

    residu

    e:yieldratios.

    Usesentity

    specifican

    nuald

    ataas

    inputintotheIPCCeq

    uation.

  • Exec

    utive

    Sum

    mary

    ES-1

    3

    Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    CO2fr

    omUr

    eaFertilizer

    Applicat

    ion

    CO2emissionsfr

    omap

    plicat

    ionof

    ureaorurea

    based

    fertilizers

    to

    soilsa

    reest

    imate

    dwithab

    asic

    estimationequation(cf.,IPCCTier

    1)me

    t hod(deKlein

    etal.,20

    06).

    The amo

    untofurea

    fertilizer

    appliedtosoils.

    Emission

    facto

    rsare

    from

    valuesin

    theIPCCg

    uidelines

    (deKlein

    etal.,20

    06).T

    his

    metho

    dassu

    mesth

    atthe

    sou

    rceofCO

    2used

    to

    manufactur

    eurea

    isfos

    silfue

    lCO

    2captu

    reddu

    ringN

    H 3

    manufactur

    e.

    Usesentity

    specifican

    nuald

    ataas

    inputintotheIPCCeq

    uation,w

    hich

    isused

    forth

    eU.S.Inv

    entor

    y.

    Wetlands

    Bioma

    ssCarbo

    nin

    Wetlands

    Metho

    dsforestim

    ating

    forest

    veget

    ationan

    dshru

    bandg

    rasslandveget

    ation

    bioma

    sscar

    bonstoc

    ksuse

    acom

    binationoftheFore

    stVeget

    ationSim

    ulator

    (FVS)

    modelan

    dlookuptablesfor

    dominantshr

    uban

    dgra

    sslandv

    egetation

    types

    foundintheC

    roplan

    dand

    GrazingLandCh

    apter.If

    thereisa

    landu

    secha

    nge,

    metho

    dsforcroplan

    dherba

    ceousbio

    massare

    sug

    gested

    .

    ForestedWetlands:S

    ameasth

    ose

    descr

    ibedforuplan

    dfore

    stsin

    Section6

    .2.3.

    ShrubandGrasslandVegetation:

    Sameasth

    osede

    scribe

    dfortotal

    bioma

    sscar

    bonstoc

    kchanges

    presen

    tedintheC

    roplan

    dand

    GrazingLandCh

    apter,Se

    ction

    3.5.1.

    ForestWetlands:R

    egional

    varian

    tsareava

    ilable

    forFVS

    thatallowf

    orreg

    ionsp

    ecific

    focusonspeciesandfore

    stveg

    etationcom

    munities.The

    driver

    forprod

    uctivityist

    he

    availabilityofsit

    eindex

    curves

    ,andtheregio

    nal

    varian

    tsincl

    udem

    any

    wetlandtre

    especies.

    Howe

    ver,ifas

    peciesspecific

    curveisn

    otava

    ilable

    ,thena

    defau

    ltfunctionisuse

    dto

    estimate

    carbo

    nstoc

    kcha

    nges.

    ShrubandGrassland

    Vegetation:Same

    asthe

    Cropla

    ndsandGrazingLands

    Chapter,Se

    ction3.5

    .1.

    Usesentity

    specificseaso

    naldata

    .NoIPCCmeth

    odolo

    giescurr

    ently

    existf

    orthissource

    ;hence,thisisa

    newlyd

    evelop

    edmeth

    od.

    SoilC

    arbon,

    N 2O,andC

    H 4in

    Wetlands

    TheD

    eNitrific

    ation

    DeComp

    osition(DN

    DC)

    proces

    sbase

    dbio

    geoche

    micalmodeli

    sthe

    metho

    dused

    forestima

    ting

    soilca

    rbon,N

    2O,an

    dCH 4

    emission

    sfrom

    wetlands.

    Veget

    ationmanage

    ment,wa

    ter

    managem

    entre

    gime,s

    oil

    managem

    ent,fertiliz

    ation

    practices

    ,andlandu

    sehis

    tory.

    Proces

    sbase

    dmodeli

    sused

    ;hence

    ,noem

    ission

    sfacto

    rsare

    usedinthism

    ethod.

    Thism

    ethodlev

    erages

    theD

    NDC

    modelto

    simula

    tesoilca

    rbon,N

    2O,

    andC

    H 4em

    ission

    sfrom

    wetlandson

    aseas

    onalt

    imesc

    ale.

  • Exec

    utive

    Sum

    mary

    ES-1

    4Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    AnimalProductionSystem

    s

    EntericFerm

    entation

    Matur

    eDairy

    Cows

    Mits3

    equationd

    evelop

    ed

    byMills

    etal.(2003)and

    furthe

    rutilized

    by

    DairyGEM(Ro

    tzetal.,

    2011).M

    its3e

    quationis

    based

    primarilyo

    nme

    tabolizab

    leenergy

    intake.D

    ryma

    tterin

    take

    (DMI),starch,acid

    detergen

    tfiber,c

    rude

    protein,a

    ndtotaldiges

    tible

    nutrientsp

    rovide

    thein

    puts

    fortheequation.

    Dietarychanges:incr

    easing

    DMI,

    usingfib

    rousconcen

    traterather

    thanstarchcon

    centrate,feeding

    rap

    idlyd

    egradedsta

    rch(such

    as

    barley),an

    dadditio

    nofdietary

    fat.

    Activitychanges:c

    onfining

    cur

    rentlygrazingan

    imals,fewe

    rwo

    rkhours

    perday,fewe

    rdays

    onfeedpriortosla

    ughte

    r.

    Emission

    facto

    rscalcul

    ated

    withappro

    achde

    velopedby

    Millsetal.(20

    03)andRo

    tzet

    al.(20

    11).

    Useofth

    eDairyGEM

    /Mits3e

    quation

    isreco

    mmendedo

    vertheIPCCT

    ier

    2equation(2006)becau

    seith

    aspro

    ventobe

    more

    accur

    ate,in

    gen

    eral,fo

    rdairycow

    s.

    BeefCowCalf

    andB

    ulls

    IPCCT

    ier2a

    pproa

    ch(20

    06).T

    hecalcu

    lation

    con

    siders

    weigh

    t,weig

    htgai

    n,matu

    rewe

    ight,

    pregnancy,lac

    tation

    ,other

    activity(gr

    azing,co

    nfined,

    dailywo

    rk),an

    dtheen

    ergy

    conten

    tofth

    eanim

    als'

    diets.

    Dietarychanges:inc

    reasin

    gDMI,

    usingfib

    rousconcen

    traterather

    thanstarchcon

    centrate,feeding

    rap

    idlyd

    egradedsta

    rch(such

    as

    barley),an

    dadditio

    nofdietary

    fat.

    Activitychanges:c

    onfining

    cur

    rentlygrazingan

    imals,fewe

    rwo

    rkhours

    perday.

    Emission

    facto

    rsare

    determinedw

    iththeIPCC

    Tier2eq

    uation(2006).

    Metha

    neconvers

    ionfacto

    r(Ym

    )base

    dona

    nimalspe

    cific

    guida

    nceinU.S.E

    PA(2013).

    Theequationsutilized

    arethesame

    asexistinginven

    torym

    ethods;

    howe

    ver,th

    emeth

    odsutilizefarm

    specificfeed

    typesandutiliz

    emo

    nthly,ratherth

    anan

    nual,lev

    eldata(i.e

    .,acco

    untfo

    rseas

    onal

    variation

    inforag

    equality

    ).

    Stocke

    rs

    IPCCT

    ier2a

    pproa

    ch(20

    06).T

    hecalcu

    lation

    con

    siders

    weigh

    t,weig

    htgai

    n,matu

    rewe

    ight,

    pregnancy,lac

    tation

    ,other

    activity(gr

    azing,co

    nfined,

    dailywo

    rk),an

    dtheen

    ergy

    conten

    tofth

    eanim

    als'

    diets.

    Dietarychanges:inc

    reasin

    gDMI,

    usingfib

    rousconcen

    traterather

    thanstarchcon

    centrate,feeding

    rap

    idlyd

    egradedsta

    rch(such

    as

    barley),an

    dadditio

    nofdietary

    fat.

    Activitychanges:c

    onfining

    cur

    rentlygrazingan

    imals,fewe

    rwo

    rkhours

    perday,fewe

    rdays

    onfeedpriortosla

    ughte

    r.

    Emission

    facto

    rsare

    determinedw

    iththeIPCC

    Tier2eq

    uation(2006)ona

    nentity

    byen

    tityba

    sis.Ym

    based

    onan

    imalspe

    cific

    guida

    nceinU.S.E

    PA(2013).

    Theequationsutilized

    arethesame

    asexistinginven

    torym

    ethods;

    howe

    ver,th

    emeth

    odsutilizefarm

    specificfeed

    typesandutiliz

    emo

    nthly,ratherth

    anan

    nual,lev

    eldata(i.e

    .,acco

    untfo

    rseas

    onal

    variation

    inforag

    equality

    ).

  • Exec

    utive

    Sum

    mary

    ES

    -15

    Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    FeedlotCa

    ttle

    IPCCT

    ier2a

    pproa

    ch(20

    06).T

    hecalcu

    lation

    con

    siders

    weigh

    t,weig

    htgai

    n,matu

    rewe

    ight,

    pregnancy,lac

    tation

    ,other

    activity(gr

    azing,co

    nfined,

    dailywo

    rk),an

    dtheen

    ergy

    conten

    tofth

    eanim

    als'

    diets.

    Dietarychanges:inc

    reasin

    gDMI,

    usingfib

    rousconcen

    traterather

    thanstarchcon

    centrate,feeding

    rap

    idlyd

    egradedsta

    rch(such

    as

    barley),an

    dadditio

    nofdietary

    fat.

    Activitychanges:c

    onfining

    cur

    rentlygrazingan

    imals,fewe

    rwo

    rkhours

    perday,fewe

    rdays

    onfeedpriortosla

    ughte

    r.

    Emission

    facto

    rsare

    determinedw

    iththeIPCC

    Tier2eq

    uation(2006).Y

    mbased

    ongu

    idance

    devel

    oped

    byHa

    les(2012).

    Thecalcula

    tionconsid

    erswe

    ight,

    weigh

    tgain

    ,matu

    rewe

    ight,

    pregnancy,lac

    tation

    ,otheractivity

    (grazing,co

    nfined,d

    ailyw

    ork),a

    nd

    theen

    ergyconten

    tofth

    eanim

    als'

    diets.

    Sheep

    Howd

    eneq

    uation(Howd

    en

    etal.,19

    94),b

    asedo

    ndie

    taryD

    MI.

    Dietarychanges,bu

    tnow

    ell

    devel

    opedresea

    rchdu

    eto

    difficultyo

    fobta

    iningaccur

    ate

    feedinta

    keestim

    atesfo

    rgraz

    ing

    sheep.

    Theequationfro

    mHowd

    enet

    al.(19

    94)estima

    tes

    emission

    sbase

    dsole

    lyon

    DMI;h

    ence,em

    ission

    facto

    rsnotutilized

    .

    Thism

    ethodusesact

    ualm

    onthly

    estimate

    sofDMI,ra

    therth

    anhe

    ad

    count,asutiliz

    edby

    theIPCCT

    ier1

    equation(2006).

    Swine

    IPC

    CTier1a

    pproa

    ch(20

    06).

    None.

    UtilizesIPC

    CTier1e

    mission

    factor

    (IPCC,20

    06).

    None.

    OtherAnimals

    (Goats

    ,Am

    erican

    Bis

    on)

    IPCCT

    ier1a

    pproa

    chfor

    American

    bison

    (base

    don

    buffalo,modifie

    dbyaver

    age

    animalw

    eight)

    andg

    oats

    (IPCC,20

    06).

    None.

    UtilizesIPC

    CTier1e

    mission

    factor

    s(IPCC,2

    006).

    None.

    Housing

    Metha

    ne

    Emission

    sfrom

    Ma

    nureon

    BarnFlo

    orsfor

    DairyCa

    ttle

    DairyGEM(asub

    setofthe

    Integr

    atedF

    armSyste

    ms

    Model)isused

    toestim

    ate

    CH4emissions.

    None.

    Empiricalre

    lation

    shipa

    spro

    videdinCh

    ianese

    etal.

    (Chian

    eseetal.,20

    09).

    Utilizesclim

    atean

    dentity

    charac

    teristics.

    Metha

    ne

    Emission

    sfrom

    DairyCa

    ttle,

    BeefCattle

    ,and

    Swine

    Housi

    ngIPCCT

    ier2a

    pproa

    ch.

    Typean

    ddura

    tiono

    fmanure

    sto

    rage.

    Utilizesacom

    binationofIPCC

    andU

    .S.EPAInventor

    yem

    ission

    facto

    rs.

    None.

  • Exec

    utive

    Sum

    mary

    ES-1

    6Source

    MethodologyApproach

    PotentialM

    anagem

    ent

    Practices

    SourceofEmissionFactors

    Improvem

    entsCom

    paredto

    OtherGreenhouseGas

    Methodologies

    Nitrou

    sOxid

    eEm

    ission

    sfrom

    DairyCa

    ttle,

    BeefCattle

    ,Sw

    ine,an

    dPoultry

    Housi

    ng

    IPCCT

    ier2a

    pproa

    ch,using

    Am

    erican

    Societyof

    Agricultura

    lEngine

    ers

    (ASAE)equationsto

    estimate

    nitro

    genexcre

    tion

    andd

    efaultvalue

    sfor

    ammo

    nialosse

    st