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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
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QuantifyingGreenhouseGasFluxesinAgricultureandForestry:MethodsforEntityScaleInventoryMarlenEve,DianaPape,MarkFlugge,RachelSteele,DerinaMan,MarybethRileyGilbertandSarahBiggar,Editors.
USDATechnicalBulletin1939July2014Publishedby:U.S.DepartmentofAgricultureOfficeoftheChiefEconomistWashington,DC20250
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TheU.S.DepartmentofAgriculture(USDA)prohibitsdiscriminationagainstitscustomers,employees,andapplicantsforemploymentonthebasesofrace,color,nationalorigin,age,disability,sex,genderidentity,religion,reprisal,andwhereapplicable,politicalbeliefs,maritalstatus,familialorparentalstatus,sexualorientation,orallorpartofanindividualsincomeisderivedfromanypublicassistanceprogram,orprotectedgeneticinformationinemploymentorinanyprogramoractivityconductedorfundedbytheDepartment.(Notallprohibitedbaseswillapplytoallprogramsand/oremploymentactivities.)ToFileanEmploymentComplaint
IfyouwishtofileaCivilRightsprogramcomplaintofdiscrimination,completetheUSDAProgramDiscriminationComplaintForm,foundonlineathttp://www.ascr.usda.gov/complaint_filing_cust.html,oratanyUSDAoffice,orcall(866)6329992torequesttheform.Youmayalsowritealettercontainingalloftheinformationrequestedintheform.SendyourcompletedcomplaintformorlettertousbymailatU.S.DepartmentofAgriculture,Director,OfficeofAdjudication,1400IndependenceAvenue,S.W.,Washington,D.C.202509410,byfax(202)[email protected]
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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