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BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| surfaceorremovedafterharvestwithnodistinctionbetweenremovalproportions.Croprotationsweredividedintotwocategories:aseriesofdierenttypesofcropinthesameareaclassedas“rotation”,orcontinuousmonoculture,classedas“norotation”.2.2Meta-analysisTheresponseratio(R)ofCO2emissionstoSOCundertillage(T)andno-tillage(NT)5wascalculatedusingEqs.(2)and(3).Ascommonpractice,thenaturallogoftheR(lnR)hasbeencalculatedasaneectsizeofobservation(Hedgesetal.,1999)InR=In(CO2T=CO2NT)(2)InR=In(SOCT=SOCNT)(3)TheMetaWin2.1software(Rosenbergetal.,2000)wasusedforanalyzingthedata10andgeneratingabootstrapped(4.999iterations)tocalculate95%condenceintervals.Themeansofeectsizewereconsideredtobesignicantlydierentfromeachotheriftheir95%condenceintervalswerenotoverlappingandweresignicantlydierentfromzeroifthe95%leveldidnotoverlapzero(GurevitchandHedges,2001).3Results153.1GeneralstatisticsofsoilCO2emissionsfromtilledanduntilledsoilsOverall,theaveragesoilCO2emissionscomputedfromthe174pairedobservationswas1152gCO2-Cm�2yr�1fromtilledsoilscomparedto916gC-CO2m�2yr�1forthoseunderno-tillage(Table3),whichcorrespondstoa21%averagedierence,sig-nicantatP0.05.ThegreatestsoilCO2emissionamongsttheconsideredsiteswas209125gC-CO2m�2yr�1andwasobservedundertilledsoilswithbarleyinanaridareaatNessonValleyinwesternNorthDakota,USA(Sainjuetal.,2008).Thelowestsoil15503 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| SoiltextureDierencesinCO2emissionsbetweentilledanduntilledsoilswerelargestinsandysoilswheretilledsoilsemitted29%moreCO2thanuntilledsoils(Fig.3a).Inclayeysoilsthedierencesbetweentillageandno-tillageweremuchsmallerwithtilledsoilsemitting12%moreCO2thanuntilledsoils.Texturaldierenceswereonlyobserved5betweensandyandclaysoils.Ontheotherhand,SOCCundertillagewassignicantlylowerthanunderno-tillage:by17%undersandysoilsand9%inclayeysoils(Fig.3b).However,therewerenodierencesbetweenclayeyandloamysoils.CroptypeSoilCO2emissionsweresignicantlygreaterintilledcomparedtountilledsoilsforall10croptypeswiththeexceptionofpaddyricewheretherewerenosignicantdierencesbetweentilledanduntilledsoil(Fig.4a).ThegreatestpositiveCO2emissiondierencebetweentillageandno-tillagewasfoundinfallow,withavalueof34%.Groupingallcroptypestogether,SOCCundertillagewassignicantlylowerthanunderno-tillage.Amongthedierentcrops(rice,maize,soybean,wheatandbarley)a15signicantSOCcdierencebetweentilledanduntilledsoilwasonlyobservedformaize(15%)atonesiteandforrice(7.5%).Forfallow,SOCCunderno-tillagewasslightlygreaterthanundertillage,butthedierenceisnotsignicant(Fig.4b).HighestSOCCnegativedierencesbetweentilledanduntilledsoilswereobservedformaizewhereSOCCwasonaverage15%lowerundertillagecomparedtono-tillage.20Durationofno-tillageThedurationofno-tillage(i.e.,timesincetillagewasabandoned)hadnostatisticalas-sociationwithsoilCO2emissions.However,therewasatendencyforthedierencesbetweentillageandno-tillagetoincreasewithincreasingdurationoftheno-tillageregime,withanaverage18%dierenceforexperimentsoflessthan10years,buta2515505 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| rstPCAaxis(Axis1),whichdescribed35%ofthetotaldatavariance,washighlycor-relatedtolatitude(LAT),meanannualtemperature(MAT),SOCc,andsoilclaycontent(CLAY).LATandbshowedpositivecoordinatesonAxis1,whiletheothervariablesshowednegativeones.Axis1couldthereforeberegardedasanaxissettingclayeyorganicandwarmsoilsagainstcompacted,sandysoilsfromacoldclimate.Thesec-5ondPCAaxis,whichexplained21%ofthedatavariance,correlatedthemostwithsiltcontent.ThedierencesinCO2uxesbetweentillageandno-tillage(ÉCO2T-NT)showedpositivecoordinatesonAxis1,whichrevealedgreaterCO2emissionsundertillagecomparedtono-tillageundercoolsandyanddensesoilscomparedtowarmclayeyandorganicallyrichsoilfromawarmandhumidclimate.104Discussion4.1OverallinuenceoftillageonSOCCandsoilCO2emissionsOurmeta-analysisshowsthattillagehasasignicantimpactindecreasingtop-soil(0–0.03m)organiccarboncontent(SOCC)andincreasingCO2emissions,with10%lowerSOCCintilledthaninuntilledsoilsand21%greaterCO2emissionfromtilled15thanfromuntilledsoils.GreaterCO2emissionsundertillagereectedfasterorganicmatterdecompositionasaresultofgreatersoilaeration,breakdownofsoilaggregates,whichrenderstheorganicmaterialmoreaccessibletodecomposers,andthemixingofcropresiduesintothesoil(Reicosky,1997;Sixetal.,2002,2004).Resultsfromtheliteraturedidnotalwaysagree.Forexample,whileUssiriandLal(2009)observed31%20greaterCO2emissionundertillagethanunderno-tillageformaizegrowncontinuouslyfor43yearsatCharlestonFarminUSA,Cheng-Fangetal.(2012)found7–48%greaterSOCCundertilledriceinChina.Ahmadetal.(2009)observednosignicanteectsoftilllageonSOCC,whileLietal.(2010)reportednosignicanteectsoftillageonCO2emissions.Incontrast,Oortsetal.(2007)foundgreatersoilCO2emissionunder25no-tillage(4064kgCO2-Cha�1)comparedtotillage(3160kgCO2-Cha�1),whichthey15507 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| attributedtogreatersoilmoisturecontentandtheamountofcropresidueonthesoilsurface.4.2InuenceofclimateAlthoughtherewasnosignicantdierencebetweenaridandhumidclimates,CO2emissionsandSOCCchangesbetweenuntilledandtilledsoilstendedtobegreater5inaridthaninhumidclimates(Fig.1a).Insupport,Álvaro-Fuentesetal.(2008),whoinvestigatedtillageimpactonCO2emissionsfromsoilsinasemiaridclimate,attributedtheobservedlargedierencebetweentillageandno-tillagetodierencesinsoilwateravailability.Athumidsitesthedecompositionisfavoredbyhighsoilmoisturewithlittledierencebetweentilledanduntilledsoils,whileinaridclimateswithmuchlowersoil10watercontent,dierencesbetweenno-tillageandtillagecandevelop(Fortinetal.,1996;Feizieneetal.,2011).Thissupportstheideathatthesoilresponsetotillageisaectedbyclimatethresholds(FranzluebbersandArshad,1996).4.3Inuenceofsoilproperties4.3.1Soilorganiccarboncontent15ThedecreaseofCO2emissiondierencesbetweentillageandno-tillagewithincreas-ingSOCCismostlikelyduetodiminishinginter-aggregateprotectionsitesasSOCclevelincreases.Severalstudieshaveshownthatcarboninputsintocarbon-richsoilsshowlittleornoincreaseinsoilcarboncontentwithmostoftheaddedcarbonbeingreleasedtotheatmosphere,whilecarboninputsincarbon-depletedsoilstranslateto20greatercarbonstocksbecauseofprocessesthatstabilizeorganicmatter(Paustianetal.,1997;Solbergetal.,1997;Sixetal.,2002).Anotherreason,whichdoesn'tinvolvedstabilization,isthefactthatsoilsthathavebeendepletedincarbontendtorecoverandaccumulateSOCuntilequilibriumisreached(Carvalhaisetal.2007).Therefore,aban-doningtillageinsoilswithlowSOCCtendstooergreaterprotectionofSOCthanin2515508 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Amos,B.,Arkebauer,T.J.,andDoran,J.W.:Soilsurfaceuxesofgreenhousegasesinanirrigatedmaize-basedagroecosystem,SoilSci.Soc.Am.J.,69,387–395,2005.Aslam,T.,Choudhary,M.,andSaggar,S.:Inuenceofland-usemanagementonCO2emis-sionsfromasiltloamsoilinNewZealand,Agr.Ecosyst.Environ.,77,257–262,2000.Baggs,E.,Chebii,J.,andNdufa,J.:Ashort-terminvestigationoftracegasemissionsfollowing5tillageandno-tillageofagroforestryresiduesinwesternKenya,SoilTill.Res.,90,69–76,2006.Baker,J.M.,Ochsner,T.E.,Venterea,R.T.,andGris,T.J.:Tillageandsoilcarbonseques-tration–Whatdowereallyknow?,Agr.Ecosyst.Environ.,118,1–5,2007.Balesdent,J.,Chenu,C.,andBalabane,M.:Relationshipofsoilorganicmatterdynamicsto10physicalprotectionandtillage,SoilTill.Res.,53,215–230,2000.Barré,P.,Eglin,T.,Christensen,B.T.,Ciais,P.,Houot,S.,Kätterer,T.,vanOort,F.,Peylin,P.,Poulton,P.R.,Romanenkov,V.,andChenu,C.:Quantifyingandisolatingstablesoilorganiccarbonusinglong-termbarefallowexperiments,Biogeosciences,7,3839–3850,doi:10.5194/bg-7-3839-2010,2010.15Barreto,R.C.,Madari,B.E.,Maddock,J.E.L.,Machado,P.L.O.A.,Torres,E.,Franchini,J.,andCosta,A.R.:Theimpactofsoilmanagementonaggregation,carbonstabilizationandcarbonlossasCO2inthesurfacelayerofaRhodicFerralsolinSouthernBrazil,Agr.Ecosyst.Environ.,132,243–251,2009.Batjes,N.H.:Totalcarbonandnitrogeninthesoilsoftheworld,Eur.J.SoilSci.,47,151–163,201996.Bauer,P.J.,Frederick,J.R.,Novak,J.M.,andHunt,P.G.:SoilCO2uxfromanorfolkloamysandafter25yearsofconventionalandconservationtillage,SoilTill.Res.,90,205–211,2006.Bellamy,P.H.,Loveland,P.J.,Bradley,R.I.,Lark,R.M.,andKirk,G.J.:Carbonlossesfrom25allsoilsacrossEnglandandWales1978–2003,Nature,437,245–248,2005.Borenstein,M.,Hedges,L.V.,Higgins,J.P.,andRothstein,H.R.:Introductiontometa-analysis,JohnWiley&Sons,WestSussex,UK,2011.Brye,K.R.,Longer,D.E.,andGbur,E.E.:Impactoftillageandresidueburningoncarbondioxideuxinawheat–soybeanproductionsystem,SoilSci.Soc.Am.J.,70,1145–1154,302006.15515 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Dendooven,L.,Gutiérrez-Oliva,V.F.,Patiño-Zúñiga,L.,Ramírez-Villanueva,D.A.,Verhulst,N.,Luna-Guido,M.,Marsch,R.,Montes-Molina,J.,Gutiérrez-Miceli,F.A.,andVásquez-Murrieta,S.:Greenhousegasemissionsunderconservationagriculturecomparedtotradi-tionalcultivationofmaizeinthecentralhighlandsofMexico,Sci.TotalEnviron.,431,237–244,2012.5Dilling,L.andFailey,E.:Managingcarboninamultipleuseworld:Theimplicationsofland-usedecisioncontextforcarbonmanagement,GlobalEnviron.Chang.,23,291–300,2012.Dimassi,B.,Cohan,J.-P.,Labreuche,J.,andMary,B.:Changesinsoilcarbonandnitrogenfollowingtillageconversioninalong-termexperimentinNorthernFrance,Agr.Ecosyst.En-viron.,169,12–20,2013.10Dimassi,B.,Mary,B.,Wylleman,R.,Labreuche,J.,Couture,D.,Piraux,F.,andCohan,J.P.:Long-termeectofcontrastedtillageandcropmanagementonsoilcarbondynamicsduring41years,Agr.Ecosyst.Environ.,188,134–146,2014.Dlamini,P.,Orchard,C.,Jewitt,G.,Lorentz,S.,Titshall,L.,andChaplot,V.:ControllingfactorsofsheeterosionunderdegradedgrasslandsintheslopinglandsofKwaZulu-Natal,South15Africa,Agr.WaterManage.,98,1711–1718,2011.Don,A.,Schumacher,J.,andFreibauer,A.:Impactoftropicalland-usechangeonsoilorganiccarbonstocks–ameta-analysis,Glob.ChangeBiol.,17,1658–1670,2011.Drury,C.,Reynolds,W.,Tan,C.,Welacky,T.,Calder,W.,andMcLaughlin,N.:EmissionsofNitrousOxideandCarbonDioxide,SoilSci.Soc.Am.J.,70,570–581,2006.20Elder,J.W.andLal,R.:TillageeectsongaseousemissionsfromanintensivelyfarmedorganicsoilinNorthCentralOhio,SoilTill.Res.,98,45–55,2008.Ellert,B.andJanzen,H.:Short-terminuenceoftillageonCO2uxesfromasemi-aridsoilontheCanadianPrairies,SoilTill.Res.,50,21–32,1999.FAO:InvestinginSustainableAgriculturalIntensication,TheRoleofConservationAgriculture,25AFrameworkforAction,FoodandAgricultureOrganizationoftheUnitedNations,Rome,2008.Feiziene,D.,Feiza,V.,Vaideliene,A.,Povilaitis,V.,andAntanaiitis,’.:Soilsurfacecarbondioxideexchangerateasaectedbysoiltexture,dierentlong-termtillageapplicationandweather,Agriculture,97,25–42,2010.30Feiziene,D.,Feiza,V.,Kadziene,G.,Vaideliene,A.,Povilaitis,V.,andDeveikyte,I.:CO2uxesanddriversasaectedbysoiltype,tillageandfertilization,ActaAgr.Scand.-B-S.P.,62,311–328,2011.15517 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Flanagan,L.B.andJohnson,B.G.:Interactingeectsoftemperature,soilmoistureandplantbiomassproductiononecosystemrespirationinanortherntemperategrassland,Agr.ForestMeteorol.,130,237–253,2005.Fortin,M.C.,Rochette,P.,andPattey,E.:Soilcarbondioxideuxesfromconventionalandno-tillagesmall-graincroppingsystems,SoilSci.Soc.Am.J.,60,1541–1547,1996.5Franzluebbers,A.andArshad,M.:Soilorganicmatterpoolswithconventionalandzerotillageinacold,semiaridclimate,SoilTill.Res.,39,1–11,1996.Giller,K.E.,Witter,E.,Corbeels,M.,andTittonell,P.:ConservationagricultureandsmallholderfarminginAfrica:theheretics'view,FieldCrop.Res.,114,23–34,2009.Govaerts,B.,Verhulst,N.,Castellanos-Navarrete,A.,Sayre,K.,Dixon,J.,andDendooven,L.:10Conservationagricultureandsoilcarbonsequestration:betweenmythandfarmerreality,Cr.Rev.PlantSci.,28,97–122,2009.Grüneberg,E.,Schöning,I.,Hessenmöller,D.,Schulze,E.D.,andWeisser,W.:OrganiclayerandclaycontentcontrolsoilorganiccarbonstocksindensityfractionsofdierentlymanagedGermanbeechforests,ForestEcol.Manag.,303,1–10,2013.15Gurevitch,J.andHedges,L.:Meta-analysis;combiningtheresultsofindependentstudiesinexperimental,in:DesignandAnalysisofecologicalexperiments,editedby:Sceiner,S.M.andGurevitch,J.,2ndEdn.,OxfordUniversityPress,UK,347–369,2001.Halvorson,A.D.,Wienhold,B.J.,andBlack,A.L.:Tillage,nitrogen,andcroppingsystemeectsonsoilcarbonsequestration,SoilSci.Soc.Am.J.,66,906–912,2002.20Hedges,L.V.,Gurevitch,J.,andCurtis,P.S.:Themeta-analysisofresponseratiosinexperi-mentalecology,Ecology,80,1150–1156,1999.Hendrix,P.,Han,C.R.,andGroman,P.:Soilrespirationinconventionalandno-tillageagroe-cosystemsunderdierentwintercovercroprotations,SoilTill.Res.,12,135–148,1988.Hijmans,R.J.,Cameron,S.E.,Parra,J.L.,Jones,P.G.,andJarvis,A.:Veryhighresolution25interpolatedclimatesurfacesforgloballandareas,Int.J.Climatol.,25,1965–1978,2005.Hobbs,P.R.:Conservationagriculture:whatisitandwhyisitimportantforfuturesustainablefoodproduction?,J.Agr.Sci.-Cambridge,145,127–137,2007.Hovda,J.,Mehdi,B.B.,Madramootoo,C.A.,andSmith,D.L.:Soilcarbondioxideuxesfromoneseasonmeasuredinsilageandgraincornunderconventionalandnotillage,The30Canadiansociteyforengenerringinagriculutre,foodandbiologicalsystems,WrittenforpresentationattheCSAE/SCGR2003MeetingMontréal,Québec,6to9July2003,2003.15518 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Lee,J.,Six,J.,King,A.P.,VanKessel,C.,andRolston,D.E.:Tillageandeldscalecontrolsongreenhousegasemissions,J.Environ.Qual.,35,714–725,2006.Lee,J.,Hopmans,J.W.,vanKessel,C.,King,A.P.,Evatt,K.J.,Louie,D.,Rolston,D.E.,andSix,J.:TillageandseasonalemissionsofCO2,N2OandNOacrossaseedbedandattheeldscaleinaMediterraneanclimate,Agr.Ecosyst.Environ.,129,378–390,2009.5Li,C.,Kou,Z.,Yang,J.,Cai,M.,Wang,J.,andCao,C.:SoilCO2uxesfromdirectseedingriceeldsundertwotillagepracticesincentralChina,Atmos.Environ.,44,2696–2704,2010.Li,C.,Zhang,Z.,Guo,L.,Cai,M.,andCao,C.:EmissionsofCH4andCO2fromdoublericecroppingsystemsundervaryingtillageandseedingmethods,Atmos.Environ.,80,438–444,2013.10Liu,X.,Mosier,A.,Halvorson,A.,andZhang,F.:TheimpactofnitrogenplacementandtillageonNO,N2O,CH4andCO2uxesfromaclayloamsoil,PlantSoil,280,177–188,2006.López-Garrido,R.,Díaz-Espejo,A.,Madejón,E.,Murillo,J.,andMoreno,F.:Carbonlossesbytillageundersemi-aridMediterraneanrainfedagriculture(SWSpain),SpanishJ.Agr.Res.,7,706–716,2009.15López-Garrido,R.,Madejón,E.,Moreno,F.,andMurillo,J.:ConservationtillageinuenceoncarbondynamicsunderMediterraneanconditions,Pedosphere,24,65–75,2014.Luo,Z.,Wang,E.,andSun,O.J.:Canno-tillagestimulatecarbonsequestrationinagriculturalsoils?Ameta-analysisofpairedexperiments,Agr.Ecosyst.Environ.,139,224–231,2010.Lupwayi,N.,Rice,W.,andClayton,G.:Soilmicrobialbiomassandcarbondioxideuxunder20wheatasinuencedbytillageandcroprotation,Can.J.SoilSci.,79,273–280,1999.Madari,B.,Machado,P.L.,Torres,E.,deAndrade,A.S.G.,Valencia,andL.I.:NotillageandcroprotationeectsonsoilaggregationandorganiccarboninaRhodicFerralsolfromsouthernBrazil,SoilTill.Res.,80,185–200,2005.Mathews,B.andHopkins,K.SuperiorityofS-shaped(sigmoidal)yieldcurvesforexplaining25low-levelnitrogenandphosphorusfertilizationresponsesinthehumidtropics,JournalofHawaiianandPacicAgriculture,10,33–46,1999.McKyes,E.:Soilcuttingandtillage.Developmentsinagriculturalengineering,ElsevierSciencepublisher,Amsterdam,1985.Menéndez,S.,Lopez-Bellido,R.,Benítez-Vega,J.,Gonzalez-Murua,C.,Lopez-Bellido,L.,and30Estavillo,J.:Long-termeectoftillage,croprotationandNfertilizationtowheatongaseousemissionsunderrainfedMediterraneanconditions,Eur.J.Agron.,28,559–569,2008.15520 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Smith,D.,Hernandez-Ramirez,G.,Armstrong,S.,Bucholtz,D.,andStott,D.:Fertilizerandtillagemanagementimpactsonnon-carbon-dioxidegreenhousegasemissions,SoilSci.Soc.Am.J.,75,1070–1082,2011.Smith,K.,Watts,D.,Way,T.,Torbert,H.,andPrior,S.:Impactoftillageandfertilizerapplicationmethodongasemissionsinacorncroppingsystem,SoilScienceSocietyofChina,22,5604–615,2012.Smith,P.,Martino,D.,Cai,Z.,Gwary,D.,Janzen,H.,Kumar,P.,McCarl,B.,Ogle,S.,O'Mara,F.,andRice,C.:Greenhousegasmitigationinagriculture,Philos.T.R.S.B,363,789–813,2008.Tumusiime,E.,WadeBrorsen,B.,Mosali,J.,Johnson,J.,Locke,J.,andBiermacher,J.T.:10Determiningoptimallevelsofnitrogenfertilizerusingrandomparametermodels,J.Agr.Appl.Econ.,43,541–552,2011.UNEP,WorldAtlasofDesertication,UnitedNationsEnvironmentProgram,EdwardArnold,London,1997.Ussiri,D.A.N.andLal,R.:Long-termtillageeectsonsoilcarbonstorageandcarbondioxide15emissionsincontinuouscorncroppingsystemfromanalsolinOhio,SoilTill.Res.,104,39–47,2009.VanOost,K.,Quine,T.,Govers,G.,DeGryze,S.,Six,J.,Harden,J.,Ritchie,J.,McCarty,G.,Heckrath,G.,andKosmas,C.:Theimpactofagriculturalsoilerosionontheglobalcarboncycle,Science,318,626–629,2007.20Varvel,G.E.andWilhelm,W.:SoilcarbonlevelsinirrigatedwesternCornBeltrotations,Agron.J.,100,1180–1184,2008.West,T.O.andPost,W.M.:Soilorganiccarbonsequestrationratesbytillageandcroprotation,SoilSci.Soc.Am.J.,66,1930–1946,2002.Wilson,G.,Dabney,S.,McGregor,K.,andBarkoll,B.:Tillageandresidueeectsonrunoand25erosiondynamics,T.ASAE,47,119–128,2004.15523 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Table1.Referencesincludedindatabasewithlocations,meanannualprecipitation(MAP),meanannualtemperature(MAT),climate,landuse,no-tillagecomparisonsandaveragetillage(T)andno-tillage(NT)CO2emissions. SN.Author(s)CountryComparisonsMAPMATClimateLanduseNo-tillagevs.CO2emissionsmmCgCO2-Cm�2yr�1TNT 1Ahmadetal.(2009)China2272117HumidRice-rapeCT8578882Al-KaisiandYin(2005)USA488910HumidMaize-soybeanST&DT&CP&MP2922063Alluvioneetal.(2009)USA238311AridMaizeCT4905994Almarazetal.(2009a)Canada29796HumidSoybeanCT7475235Almarazetal.(2009b)Canada49796HumidMaizeCT126913746Alvarezetal.(2001)Argentina1102017HumidWheat-soybeanCT215415337Álvaro-Fuentesetal.(2008)Spain2441515AridWheat-barley-fallow-rapeCT&RT231118918Aslametal.(2000)NewZealand196313HumidMaizeMP230622819Baggsetal.(2006)Kenya2180024HumidMaize-fallowCT17121510Bryeetal.(2006)USA4128216HumidWheat-soybeanCT3264260411Carbonell-Bojolloetal.(2011)Spain347525AridWheat-pea-sunowerCT29810012ChatskikhandOlesen(2007)Denmark27047HumidBarleyCT&RT11710213Cheng-fangetal.(2012)China4136117HumidRice-rapeCT63669914Chevazetal.(2009)Brazil1175519HumidOots-soybean-wheat-maizeCT46457315Dattaetal.(2013)USA1101611HumidMaizeCT43863416Dendoovenetal.(2012)Mexico260014AridMaize-wheatCT10010017Druryetal.(2006)USA38769HumidWheat-maize-soybeanCT57555918ElderandLal(2008)USA1103711HumidMaize-wheatMT22518919EllertandJanzen(1999)Canada54005AridWheat-fallowCT&RT40618620Feizineetal.(2010)Lithuania2450018HumidWheat-rape-barley-peaCT&RT30229621Hovda,etal.(2003)Canada29796HumidMaizeCT1342127722Jabroetal.(2008)USA137314HumidSugarcaneCT3424224723Leetal.(2009)USA356416AridMaize-sunowers-peaST93391724Lietal.(2010)China4136117HumidRice-rapeCT28432825Lietal.(2013)China2136118HumidRiceCT2196153426Liuetal.(2011)China455013HumidMaizeRT&PT1340119427López-Garridoetal.(2009)Spain148417AridWheat-sunower-PeaCT108094328López-Garridoetal.(2014)Spain348417HumidWheat-pea-redcloverCT107588729Lupwayietal.(1998)Canada1336-1AridWheat-pea-redcloverCT62146430Morelletal.(2010)Spain843014AridBarleyCT&MP30022931Mosieretal.(2006)USA938211AridMaizeCT38735132Menendezetal.(2007)Spain235016AridWheat-sunowerCT18321433Omonodeetal.(2007)USA458819HumidMaizeMP&CP27326834Oortsetal.(2007)France265011HumidMaize-wheatCT47562035Pesetal.(2011)Brazil2172119Humidwheat-soybeanCT1387100436ReginaandAlakukku(2010)Finland65854HumidBarley-wheat-oatsCT1856200937ReicoskyandArcher(2007)USA13015HumidMaize-soybeanMP5807154538RuanandRobertson(2013)USA189010HumidSoybeanCT1825153339Sainjuetal.(2008)USA436814AridBarley-peaCT6726421740Sainjuetal.(2010a)USA635016HumidBarley-peaCT24020841Scalaetal.(2001)Brazil4138021HumidMaizeROT&CP&DO&HO126465742Scalaetal.(2005)Brazil4138021HumidMaizeCT75851843Scalaetal.(2006)Brazil2138021HumidSugarcaneRT&CT5435260444Smithetal.(2011)USA179617HumidMaize-soybeanCT14115245Smithetal.(2012)USA4137017HumidMaize-soybeanCT97093546UssiriandLal(2009)USA2103711HumidMaize-soybeanCT&MT721500 15524 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Table2.Categoriesusedindescribingtheexperimentalconditions. CategoricalvariableLevel1Level2Level3 SOCCLowMediumHigh(10gkg�1)(10–30gkg�1)&#x-167;(30gkg�1)ClimateAridHumidSoiltextureClayLoamSand&#x-167;(32%clay)(20–32clay)(20%clay)Experimentduration10years10yearsNitrogenfertilizerLowhigh(100kgNha�1)(100kgNha�1)CropresiduesRemovedReturnedCroprotationNorotationRotation 15525 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure1.Percentchangein(a)soilCO2emissionsand(b)SOCintillage(T)soilcomparedtono-tillage(NT)asafunctionofclimate(aridandhumid).Thenumbersintheparenthesesindicatethedirectcomparisonsofthemeta-analysis.Errorbarsare95%condenceintervals.15527 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure3.Percentchangein(a)soilCO2emissionsand(b)SOCintillage(T)soilcomparedtono-tillage(NT)asafunctionofsoilparticledistribution(clay,loamandsand).Thenumbersintheparenthesesindicatethedirectcomparisonsofthemeta-analysis.Errorbarsare95%condenceintervals.15529 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure4.Percentchangein(a)soilCO2emissionsand(b)SOCintillage(T)soilcomparedtono-tillage(NT)asafunctionofcroptype.Thenumbersintheparenthesesindicatethedirectcomparisonsofmeta-analysis.Errorbarsare95%condenceintervals.15530 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure5.Percentchangein(a)soilCO2emissionsand(b)SOCintillage(T)soilcomparedtono-tillage(NT)asafunctionofexperimentduration(yearsand10years).Thenumbersintheparenthesesindicatethedirectcomparisonsofthemeta-analysis.Errorbarsare95%condenceintervals.15531 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure6.Percentchangein(a)soilCO2emissions(b)andSOCintillage(T)soilcom-paredtono-tillage(NT)asafunctionofnitrogenfertilization(low100kgNha�1andhigh100kgNha�1).Thenumbersintheparenthesesindicatethedirectcomparisonsofthemeta-analysis.Errorbarsare95%condenceintervals.15532 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure7.Percentchangein(a)soilCO2emissionsand(b)SOCintillage(T)soilcomparedtono-tillage(NT)asafunctionofcropresidues(returnedandremoved).Thenumbersintheparenthesesindicatethedirectcomparisonsofthemeta-analysis.Errorbarsare95%con-denceintervals.15533 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure8.Percentchangein(a)soilCO2emissionsand(b)SOCintillage(T)soilcomparedtono-tillage(NT)asafunctionofcroprotation.Thenumbersintheparenthesesindicatethedirectcomparisonsofthemeta-analysis.Errorbarsare95%condenceintervals.15534 BGD12,15495–15535,2015 No-tillagelessenssoilCO2emissionsthemostunderaridandsandysoilconditionsK.Abdallaetal. TitlePage Abstract Introduction Conclusions References Tables Figures J I J I Back Close FullScreen/Esc Printer-friendlyVersion InteractiveDiscussion DiscussionPaper|DiscussionPaper|DiscussionPaper|DiscussionPaper| Figure9.Principalcomponentsanalysis(PCA)usingthedierentenvironmentalfactorsasactivevariablesandsoilCO2emissiondierencebetweenTandNT(CO2FT-NT)asthesup-plementaryvariable.15535