research article quantification of direct and indirect
TRANSCRIPT
![Page 1: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/1.jpg)
J.Viet.Env.2018,10(1):49-55DOI:10.13141/jve.vol10.no1.pp49-55
49
*CorrespondingauthorE-mail:[email protected]
http://dx.doi.org/10.13141/JVE/ISSN:2193-6471
R E S E A R C H A R T I C L E
Quantification of direct and indirect greenhouse gas emissions from rice field cultivation with different rice straw management practices – A study in the autumn - winter season in An Giang Province, Vietnam
Phát thải khí nhà kính trực tiếp và gián tiếp từ sản xuất lúa theo các biện pháp quản lý rơm rạ khác nhau – Một nghiên cứu ở vụ Thu Đông ở tỉnh An Giang, Việt Nam
NGO Th i T h anh T r u c 1 * ; HO Vu Khanh 2 ; T RAN S y Nam3 ; DUONG Van Ch i n 4 ; NGUYEN Van Cong 3 ; NGUYEN Van Hung 5 1DepartmentEnvironmentalandResourceEconomics,CollegeofEconomics,CanThoUniversity,CanTho,Vietnam;2FacultyofEnvironmentandNaturalResources,KienGiangUniversity,KienGiangProvince,Vietnam;3DepartmentofEnvironmentalScience,CollegeofEnvironmentandNaturalResources,CanThoUniversity,CanTho,Vietnam;4LocTroiGroup,AnGiangProvince,Vietnam;5InternationalRiceResearchInstitute,LosBaños,Philippines
Thisstudyresultedinacomparativeanalysisofgreenhousegasemissions(GHGE)forriceproductionwithdifferentin-fieldricestrawmanagementpracticesbasedonanexperimentconductedinAnGiangProvinceofVietnam,duringtheautumn-winterseasonof2016.DirectfieldGHGEwasanalyzedbasedonin-situmeasurementandthetotaldirectandindirectGHGEwereestimatedbyapplyingthelifecycleassessmentusingEcoinvent3databasewhichisincorpo-ratedinSIMAPROsoftware.Theexperimentwasconductedbasedonacompletelyrandomdesignwiththreetreat-mentsandthreereplications.Thethreetreatmentsare[T1]IncorporationofstrawandstubblestreatedwithTricho-derma;[T2]Incorporationofstubblesandremovalofstraw;and[T3]In-fieldburningstraw.Closedchamberprotocolandgaschromatography(SRI8610C)wasusedtomeasureandanalyseCH4andN2O.CH4emissionratewasnotsignif-icantlydifferent(p>0.05)amongthethreetreatmentsduringsamplingdatesexceptonthedays17and24aftersowing(DAS).N2Oemissionratewasnotsignificantlydifferent(p>0.05)either.However,therewerehighvariationsofN2Oemissionafterthedatesofureaapplied.DirectfieldemissionsofCH4,N2OandCO2equivalent(CO2eq)arenotsignifi-cantlydifferentamongthethreetreatments,buttheamountofCO2eqperkgstrawinT1ofincorporatingricestrawtreatedwithTrichodermaissignificantlyhigherthaninT3ofin-fieldburningstraw.LCAbasedanalysisresultedintotalGHGEintherangeof1.93-2.46kgCO2-eqkg
-1paddyproducedconsistingof53-66%fromdirectsoilemissions.Incor-porationofstrawtreatedwithTrichodermadidnotindicatetheimprovementofpaddyyield.However,theorganicmatter,N-NH4
+,andN-NO3-ofthistreatmentwashigherthanthoseoftheotherresearchedtreatments.Thisresearch
wasjustconductedinonecropseason,however,theresultshaveinitialimplicationsfortheothercropseasons.
NghiêncứunàyphântíchphátthảikhínhàkínhtừsảnxuấtlúatheocácbiệnphápquảnlýrơmrạkhácnhaudựavàothínghiệmđượcthựchiệnởvụThuĐôngnăm2016tạitỉnhAnGiang,ViệtNam.LượngphátthảikhínhàkínhtừđấtđãđượcphântíchdựavàokếtquảđođạttạiruộngvàtổnglượngphátthảikhínhàkínhtrựctiếpvàgiántiếpđượcướctínhbằngphươngphápvòngđờisửdụngcơsởdữliệuEcoinvent3gắnkếtvớiphầnmềmSIMAPRO.Thínghiệmđượcbốtríhoàntoànngẫunhiêngồm3nghiệmthứcvà3 lầnlặplại.Cácnghiệmthứcgồm[T1]vùirơmvàrạvớiTrichoderma,[T2]lấyrơmrakhỏiruộngvàvùirạvà[T3]đốtrơm.Kỹthuậtbuồngkín(closedchamberprotocol)vàmáysắckýkhí(SRI8610C)đượcsửdụngđểđođạtvàphântíchkhíCH4vàN2O.TốcđộphátthảikhíCH4khôngkhácbiệtgiữabanghiệmthức,ngoạitrừkếtquảởlầnlấymẫu17và24ngàysausạ.TốcđộphátthảiN2Ocũngkhôngcósựkhácbiệtgiữacácnghiệmthức.Tuynhiên,tốcđộphátthảibiếnđộngrấtlớnsaucácngàybónphânđạm.LượngphátthảitrựctiếptừruộngcủaCH4,N2OvàCO2tươngđương(CO2-eq)khôngcósựkhácbiệtgiữabanghiệmthức,nhưnglượngCO2-eq/kgrơmởnghiệmthứcvùirơmvàrạvớiTrichoderma(T1)caohơnnghiệmthứcđốtrơm(T3).KếtquảphântíchLCAchothấylượngphátthảikhínhàkínhdaođộngtrongkhoảng1,93–2,46kgCO2-eq/kglúavới53–66%lượngphátthảitrựctiếptừtrongđất.VùirơmrạvớiTrichodermachưacảithiệnđượcnăngsuấtlúa.Tuynhiên,phầntrămchấthữucơvàhàmlượngđạmhữudụngtrongđấtcủanghiệmthứcnàycaohơnsovớihainghiệmthứccònlạicủathínghiệm.Nghiêncứunàychỉmớiđượcthựchiệnmộtvụ,nhưngđãmanglạinhiềukếtquảcóthểứngdụngchocácvụsau.
Keywords: GHGE,methane,nitrousoxide,strawmanagementpractices
![Page 2: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/2.jpg)
J.Viet.Env.2018,10(1):49-55
50
1. Introduction Lowlandricecultivationisoneoftheimportantsourcesofgreenhousegasemissionsinagriculture(Bhattacharyyaetal.,2012).AccordingtoVSC(2014),Vietnamemittedap-proximately46thousandtonsofCO2eqfromriceproduc-tion,whichaccountedfor50.5%oftotalGHGEfromagri-culturalactivities.Causesofgreenhousegasemissions inriceproductionareirrigatedricecultivation,over-fertiliza-tion, unsustainable straw and water management, andhigh density of sowing (Wassmann, 2000; Trinh et al.,2013;Tinetal.,2015).MekongDeltaproducesabout24–26milliontonsofricestrawannually(GSO,2016;Araietal.,2015).However,themostcommonpracticeofricestrawmanagementisopenburning(54–98%)andincorporatingfreshricestraw(7-26%)(Nametal.,2014;Trucetal.,2012).Only2–13%ofricestrawisusedtoproducestrawmushroom(Volvariellavovaraceae)andfeedforcattle.Burningricestrawispop-ular due to intensification, limit of straw utilization, andlackofregulationonburningstraw(Trucetal.,2012and2013).Openburningricestrawcausesairpollutionandlossofnu-trients while incorporating fresh straw and stubble re-leasesgreenhousegasemissions,aswellasorganicpoisontotheyoungpaddy(Gaddeetal.,2009;Gaoetal.,2003;NguyenQuocKhangandNgoNgocHung,2014).Inordertorecommendthebetterpracticeofricestrawmanage-ment, an experiment on in-situ rice straw practice hasbeen conducted to estimate direct and indirect green-housegasemissions.ThefirsttreatmentwasincorporatingricestrawandstubblewithTrichoderma.Trichodermaactsasanactivatortospeedupthedecompositionprocessin15–25days,reducingorganicpoisonwhenincorporatedwithfreshstraworstubbletothepaddyfield;andsupple-mentingorganicnutrientsaswell(Sonetal.,2008;TuyenandTan,2001).Thetwoothertreatmentsareincorporat-ingfreshstubbledirectlytothefield,andin-fieldburningofricestrawwhichisthemostpracticedricestrawman-agement in theMekong Delta (Nam et al., 2014). Afterquantifyingin-situgreenhousegasemission,thisstudyalsocalculatedthetotalgreenhousegasemissionbylifecycleassessment.
2. Materials and methodologies 2.1 Experiment set up and materials
Materials:RicecultivationwasconductedduringAutumn-Winterseasonsof2016(AugusttoDecember)atDinhThanhAgricultural Research Center in AnGiang province of Vi-etnam(10018’45.19”N;105018’57.87”E).TheexperimentaldesignappliedwastheCompleteRandomizedDesign(CRD)with3treatmentsnamely[T1] Incorporationofstrawandstubbles treatedwithTrichoderma; [T2] Incorporationofstubbles and removal of straw; and [T3] In-field burningstraw.Theexperimentalplotof25m2andthreereplications
weredone.ThequantityofstrawandstubbleaddedintheexperimentislistedinTable1.Table 1: Quantity of straw and stubbles added in the experi-
ment
Treatment Strawmanagement
Quantity(kgha-1)Straw Stubble
T1 Incorporated 2,697±140a 3,852±201aT2 Removed 2,563±7.1a 3,660±10.1aT3 Burning 2,850±86.6a 4,071±124a
Note:Meansfollowedbythesameletterarenotsignificantlydifferentamongsamplingdaysat0.05levelasdeterminedbyDuncanAgronomicandchemical inputs for the three treatmentsaredescribed inTable2.Riceseedsweresownbydrumseeder.Fertilizerwasappliedat10,20,and50daysaftersowing(DAS)(panicleinitiationstage).Table 2. Agronomic and chemical inputs in the experiment
Unit:kgha-1Inputs Tradename QuantityVariety LocTroi1 100Trichoderma TRICO-DHCT-LUAVON 1*N Urea(46%N);DAP
(18%N-46%P2O5)90
P2O5 DAP(18%N-46%P2O5) 45
K2O KCl(46%K2O) 45
Note:onlyTrichodermawasaddedinT12.2 Measurement and analysis
Gasmeasurement: Gasmeasurement and analysis wereadoptedfromtheguidelineofMinamikawaetal.,(2015).Gas samples were collected based on closed chambermethodat0,10,20,and30minutes,thenstoredin30mlvacuumvials.
Figure 1. Chamber to collect a gas sample
The chamber contains two main parts namely, the gaschamberwithavolumeof120Landheight70cmheight(V1),andthebasewithadiameterof50cmandheightof30cm(V2)(Figure1).SamplingsofGHGEwereconductedafter10DAS.Thegassampleswerecollectedat9ameveryweekuntil45DASandeverytendaysuntil95DAS.CH4andN2Oconcentra-tionwereanalysedusinggaschromatography(ModelSRI8610C,HayeSept-N)withFIDandECDdetectors.
![Page 3: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/3.jpg)
J.Viet.Env.2018,10(1):49-55
51
Directfield-emissionformula:CH4andN2Orateswereesti-matedbythefollowingformula(Parkinetal.,2003):
)*08206.0(*10*24*60*TA
MVx
dtdC
F =
whereF:CH4orN2Oflux(mg.m-2.day-1);T:temperatureinthe chamber (°K); V: volume of chamber; M: molecularweight of CH4 or N2O; A: surface area of chamber (m2);
dtdC :rateofgasconcentrationinthechamber(ppm.h-1);
andV:volumeofchamber(V=V1+V2).Again,V1istheup-perpartofthechamber,V2isthelowerpartofthecham-ber(V2=A.h);whilehistheheightofwaterlevelfromthegroundsurfaceinsidethechamberandadjustedwhenthewaterlevelishigherthanthegroundsurface.Theaverageemissionrateiscalculatedby:
n
FF
n
iå=
-1
whereFi:CH4orN2Ofluxofsamplingdate(mg.m-2.day-1),andn:numberofgassampling(n=11).ThetotalquantityofCH4orN2Oemissionperseason(autumn-winterseason)
isequalto-
F multiplybythenumberofdaysperseason(100days).Indirectfield-emissionformula:GHGEconversionfactorsofallrelatedmaterialswerebasedonthedatabaseofEcoin-vent3incorporatedinSIMAPROsoftware.Dieselconsump-tion for mechanized operations and seed rate were as-sumed150litresand100kgperhabasedonthenormalpracticesobservedintheexperimentedareas.Indirectly calculated emissions of the fuel consumptionsandagronomicinputsusedtheconversionfactorsshowninTable3.Forstrawburning,weusedtheemissionfactorsofCH4andN2OreportedinRomasantaetal.(2017).Thisindicatedthatburning1tonofstraw(drymatter)causedtheemissionsof4.5and0.069gramofCH4andN2O,respectively.Table 3. GHGE conversion factors of fuel, agronomic inputs,
and products
Parameters GHGE SourceUnit Value
Seeds kgCO2-eqkg-1 1.12 a
Dieselconsumption kgCO2-eqMJ-1 0.08 aNitrogen(N) kgCO2-eqkg
-1 5.68 aP2O5 kgCO2-eqkg
-1 1.09 aK2O kgCO2-eqkg
-1 0.52 aCH4 kgCO2-eqkg
-1 30.5 bN2O kgCO2-eqkg
-1 265 b(Source:a=Ecoinvent,2016andb=IPCC,2013)
SoilandwatermeasurementsSoilsampleswerecollectedbeforeincorporatingstrawandstubbles, 30, 60 and 90 DAS for each plot. Soil samplesweretakenat0–20cmfromthesurfacetomeasureN-NH4
+/N-NO3-andorganiccontent.
Redoxwasmeasured inall nineplotswith three replica-tionsbySWC-201RPatthesamedateandtimeofgassam-plecollection(at9amonthegassamplingdate).Water management followed the alternate wetting anddrying (AWD) technology. However, it was not followedstrictlyduetotherainyseason.Thewater levelwasrec-ordedat8ameverydayattheexperimentplot.Cropmeasurement:Actualpaddyyieldwasestimatedbyharvestingyieldof5m2plotsinallninetreatmentplotsandestimateddryyield(at14%moisturecontent).2.3. Statistical analysis
MeansamongtreatmentsofCH4,N2OandCO2-eqandrelatedparametersweretestedbyanalysisofvariancewithDuncantestof95%confidence.Besides,correlationanalysisofwa-terlevelandredoxwasalsousedbyPearsontests.
3. Results and discussions 3.1 Water level and redox potential
Waterlevelsinthepaddyfieldvariedfrom–13cmto5cmduringexperimental95-day-period (Fig.1a).Waterman-agement in this experiment tried to follow the alternatewettinganddrying(AWD)technologyevenitwasinrainyseason.AccordingtoBharatietal.(2001),thewaterlevelinthepaddyfieldmayaffecttheoxidationprocessinthesoil, and thusmay affect the emissions of CH4 andN2O.However, there are no significant correlations betweenwaterlevelandredoxamongthreetreatments.In the first 45DAS, the redox potentialwas low rangingfrom -120 to -160mV in all treatments (period of 10-46daysinFig.2b).Itisindicatedthatthereductionprocessinthesoilwasthemainprocesswhichhappenedduringthisperiod.The reason for this trendwascausedby the fastdegradationofthestrawbiomassinthefirst45DAS.Thentheredoxincreasedgraduallyuntil95DASduetothelowwaterlevelandslowstrawdegradationattheendoftheseason.
![Page 4: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/4.jpg)
J.Viet.Env.2018,10(1):49-55
52
Figure 2. Water level (a) and redox potential (b)
3.2 Emissions of CH4 and N2O
3.2.1DirectlyemissionrateofCH4The average CH4 emission rates of T1, T2 and T3 treat-mentsfluctuatedfrom139.7–222.6mg.m-2.day-1(Fig.3).TheemissionrateofCH4inT1wasnotsignificantlydiffer-ent from T2 and T3 treatments (p>0.05) inmost of thesamplingdates,except in17and24DAS.Thestrongde-compositionprocessofT1duringthisperiodmaybethereason for the high CH4 emission in comparisonwith T2andT3.AccordingtoDuetal(2014),Trichodermacande-composeupto40%ofthestrawwithin20days.AnotherreportfromHoi(2008)concludedthatthedecompositionrateofricestrawwashighestinthefirst15days,thenthedecompositionrateslowsdowncausingthestrawweighttodecreaseslowly.TherearehighvariationsinCH4emissionratesamongpre-vious researches.Forexample,NeueandSass (1998) re-ported that theaverageCH4emission rate ina rice fieldranged from 240 to 520 mg.m-2 days-1. Meanwhile, thestudy conducted by Bhattacharyya et al. (2012) showedthat CH4 emission rates ranged from 45.6 - 137 mg.m-
2.days-1. The lowest emission rate was 85 DAS at 5.87mg.m-2.days-1inwhichwaterlevelwas-1cmandredoxwas-112mVinalltreatments(Fig3).
Figure 3. Direct emission rate of CH4
Note:Means followedby the same letter arenot significantly differentamongsamplingdaysat0.05levelasdeterminedbyDuncan3.2.2.DirectlyemissionrateofN2OTheemissionofN2Ointhreetreatmentsvariedfrom0–6.57 mg.m-2.day-1 and there were no N2O emissions inmostofthesamplingdates(Fig.4).Thedatashowedthatjust after applying chemical fertilizers, theN2O emissionwasincreasedlater.Whenfertilizerswereappliedon8,20,and55DAS,theN2Oemissionson10,24,and65DASweredramaticallyincreased(Fig.4).Snyderetal.(2007)alsore-ported that N2O emissions are closely related to theamount of nitrogen applied in the field. However, therewasnosignificantdifferenceamongthethreetreatmentsin terms of N2O emission (p>0.05). It seemed that N2Oemission is more closely related to fertilizer applicationthanstrawmanagementpractices.The knowledge and research on N2O emission from thepaddyfieldwerequite limitedcomparedtoCH4(Jiangetal.,2003).However,accordingtoLouetal.,(2007),incor-poratingricestrawincreasesN2Oemission,incomparisonwith removing the straw from the field. TheemissionofN2Oisincreasedwhenthesoilisfertilizedbyorganicmat-ter,duetotheincreasednitratereductionandnitrificationof NH4
+ in partly or full aerobic condition (Khuong andHung,2014).
Figure 4. Direct emission rate of N2O
3.2.3TotaldirectlyemissionofCH4,N2OandCO2eqa.TotalCH4andN2Oofdirectemissions
![Page 5: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/5.jpg)
J.Viet.Env.2018,10(1):49-55
53
Fig.5 illustratesthattheaveragetotalemissionofCH4 is179.1 ± 24.0 kg.ha-1.season-1 (T1, T2 and T3 are 222.6,174.9,and139.7kg.ha-1.season-1,approximately).Thesta-tisticalanalysisshowedthattherewasnosignificantdiffer-ence in CH4 emissions among the three treatments(p>0.05).This value ishigher than thevalue reportedbyLinquistetal.(2012)at100kgCH4.ha
−1.season-1.
Figure 5. Total emission of CH4
Note:Meansfollowedbythesameletterarenotsignificantlydifferentat0.05levelasdeterminedbyDuncanSimilarly,therewasnosignificantdifferenceinN2Oemis-sions among three treatments, and it highly fluctuatedfrom0.21–1.16kg.ha-1.season-1(Fig.6).TheN2Oemissionalsovariedinalltreatments(Fig.6).Studyingpaddyfields,Pittelkowetal.(2013)statedthatthetotalemissionswere0.2to0.4kgN2O.ha
-1,whichwaslowerthantheN2Oemis-
sionfoundinthisstudy.TheresultofN2Oneedstobecon-firmedbyrepeatingthisexperiment inbothdryandwetseasons.
Figure 6. Total emission of N2O
Note:Meansfollowedbythesameletterarenotsignificantlydifferentat0.05levelasdeterminedbyDuncanb.TotaldirectemissionsofCO2eqTheemissionofCO2eqwas4,330–7,097kgCO2eq.ha
-1andit was not significantly different among the three treat-ments(Table4).However,theemissionofCO2eqperkgofricestrawincorporatedtothericefieldwithTrichodermainT1 (2.63±0.24kgCO2eq.ha
-1.kg ricestraw-1)wassignifi-cantly higher than that of T3 treatment (1.52 ± 0.35 kgCO2eq.ha
-1.kg rice straw-1). The result of this study is inagreementwiththatreportedin2006IPCCguidelinesandotherstudiesforthesimilarstudiesofstrawincorporationwithTrichodermaorcompost(Truc,2011;Wassmannetal,2000).
Table 4. CO2 equivalent emission
TreatmentYields(kg.ha-1)
Ricestraw(kg.ha-1)
CO2eq(kgCO2.ha
-1.season-1)CO2eq
(kgCO2eq.kgpaddy-1.season-1)
CO2eq
(kgCO2.kgstraw-1.season-1)
T1 4,360±112a 2,697±140a 7,097±639a 1.62±0.15a 2.63±0.24aT2 4,400±97.0a 2,563±7.10a 5,390±743a 1.22±0.17a 2,10±0.29abT3 4,250±85.0a 2,850±86.6a 4,330±991a 1,02±0.23a 1.52±0.35bAverage 4,337±98.0 2,703±77.9 5,605±806 1.29±0.18 2.08±0.19Note:Mean±StandardError;Meansfollowedbythesameletterarenotsignificantlydifferentat0.05levelasdeterminedbyDuncan3.3 Yields and nutrients in the soil
RiceyieldsofT1,T2andT3treatmentswerefrom4.25to4.40 ton.ha-1 and therewasno significantdifferencebe-tweenthreetreatments(p>0,05)(Table4).Itneedsatleasttwo or even longer time to see the difference in yieldamong different rice strawmanagement (Surekha et al.2003;Sonetal,2008;KhuongandHung,2014;Duetal,2014).Besides,theyieldisbetterimprovedinSpring-Win-terSeasonratherthaninAutumnWinterseasonasinthisexperiment.Theresults inFig.7andFig.8showthator-ganiccarboncontentandnitrogenavailable (N-NH4
+andN-NO3
-)inthesoilintreatmentT1wassignificantlyhigherthaninT2andT3attheendoftheseason.Miletal.(2012)reportedthatstrawincorporationinsoilreturns40%ofN,30%ofPand80%ofK(whichisabsorbedbyrice);strawincorporationalsoincreasesorganicmatterinsoilaswell.Ontheotherhandstrawburningresultsinlosing70-80%ofCandNinstraw(Hilletal.,1999).Theimprovementof
carbonandnitrogencontentsavailableinsoilwasoneoftheevidencethatsoilandpaddyyieldcanbeimprovedinthelongterm.
Figure 7. Organic matter in the soil (%)
Note:Mean±StandardError;Meansfollowedbythesameletterarenotsignificantlydifferentat0.05levelasdeterminedbyDuncan
![Page 6: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/6.jpg)
J.Viet.Env.2018,10(1):49-55
54
Figure 8. N-NH4
+ and N-NO3
- concentration in soil
Note:Mean±StandardError;Meansfollowedbythesameletterarenotsignificantlydifferentat0.05levelasdeterminedbyDuncan3.4 Total greenhouse gas emissions (GHGE)
Figure9showsGHGE(kgCO2eq.ha
-1)ofthecomponentsconstituting to the total emissions for three treatments(i.e.T1,T2,andT3).TotalGHGEwasintherangeof8,187-10,739kgCO2eqha
-1,equalingto1.93-2.46kgCO2-eqkg-1
paddyproduced(moisturecontentofpaddywasat14%inwet basis). The results showed that incorporation of allstraw(T1)hadthehighestGHGEat10,739kgCO2-eqha
−1
season-1.ContributiontotheoverallGHGE,thehighestwasfrom direct field-emission during rice cultivation ranging53-66% of the total GHGE.Mechanized operations con-sumingfuelalsocontributedarangeof26-34%,whiletheagronomic inputscontributeabout7%of the totalemis-sions.
Figure 9. Total greenhouse gas emissions from three treat-
ments
4. Conclusions CH4andN2Oemissionrateswerenotsignificantlydifferentamong the treatments; however, therewere high varia-tionsofN2Oemissionafterthedateswhenureawasap-plied.DirectfieldemissionsofCH4,N2OandCO2equivalent(CO2eq)arenotsignificantlydifferentamongthethreetreat-ments,buttheamountofCO2eqperkgstrawinT1ofincorpo-rating rice straw treatedTrichoderma is significantly higherthan in T3of in-fieldburning straw. LCAbasedanalysis re-sulted intotalGHGE in the rangeof1.93-2.46kgCO2-eqkg-1paddyproducedconsistingof53-66%fromdirectsoil
emissions. Incorporation of straw treated with Tricho-derma didnot indicate the improvementofpaddy yield.However,theorganicmatterandN-NH4
+andN-NO3-ofthis
treatmentwerehigherthanthosefromotherresearches.Thisresearchwasjustconductedinonecropseason,how-ever,theresultshaveinitialimplicationsfortheothercropseasons.Toverifytheseresults,werecommendtoconductfurtherexperimentswithreplicationsofcropseasonsandextendingtootherseasonsandcroppingsystems.Acknowledgement.Thisresearchwasconductedincollab-orationwiththeInternationalRiceResearchInstitute(IRRI)throughtheBMZ-IRRIproject"Scalablestrawmanagementoptionsforsustainabilityandlowenvironmentalfootprintin rice-based production systems” (contract No.81194994).WewouldliketothankDr.NguyenThanhNghi(NLU)forsupportingthisstudy.Thankstoallthestudentsin CTU, especially Thi Quoc Phong, VuQuoc Tin andHoMinhNhut,andthestaffofDTARCforsupportingthedatacollectioninthisstudy.
5. References [1] Bharati, K., S.R.Mohanty, V.R. Rao and T.K. Adhya,
2001. Influence of flooded and non-flooded condi-tions on methane efflux from two soils planted torice.ChemosphereGlobalChangeScience,3:25-32.
[2] Bhattacharyya,P.,K.S.Roy,S.Neogi,T.K.Adhya,K.S.RaoandM.C.Manna,2012.Effectsofricestrawandnitrogen fertilization on greenhouse gas emissionsand carbon storage in tropical flooded soil plantedwithrice.SoilandTillageResearch,124:119–130.
[3] Gadde,B.,S.Bonnet,C.MenkeandS.Garivait,2009.AirpollutantemissionsfromricestrawopenfieldburninginIndia,ThailandandthePhilippines.EnvironmentalPollu-tion,157:1554–1558.
[4] Gao,S.,K.TanjiandS.C.Scadaci,2003. Incorporatingstrawmayinducesulfidetoxicityinpaddyrice.CaliforniaAgricultureJournal,57:55-59.
[5] Hill, J.D,G.M. Brandon, S.M. Broader andA.U. Eke,1999.Winterfloodingandstrawmanagement:Impli-cationforriceproduction.Agronomyprogressreport1994-1996,264:5-25.
[6] Tin,H.Q.,N.H.Cuc,N.VSanh,N.V.Anh,J.Hughes,T.THoaandT.T.Ha,2012.LowCH4emissionriceproduc-tioninAnGiangprovince–Dryseason2010-2011(inVietnamese).ScientificJournalofCanThoUniversity,23a:31-41.
[7] IPCC,2006.2006IPCCguidelinesfornationalgreen-housegasinventories.Volume4and5.Preparedbythe National Greenhouse Gas Inventories Pro-gramme.Eggleaston,H.S.,Buendia,L.Miwa,K.Ngara,T.andTanabe,K(Eds).
[8] Jiang,J.Y.Y.HuangandL.G.Zong,2003.Influenceofwater controlling and strawapplicationonCH4 andN2O emissions from rice field. China Environmental
0
2,000
4,000
6,000
8,000
10,000
12,000
T1 T2 T3
kg C
O2-
eq h
a-1se
ason
-1
Straw burning
Direct field-emissionK2O
P2O5
Nitrogen
Seed
Fuel-mechanizedoperations
![Page 7: RESEARCH ARTICLE Quantification of direct and indirect](https://reader030.vdocuments.us/reader030/viewer/2022020701/61f8aea23a0cf600b956940b/html5/thumbnails/7.jpg)
J.Viet.Env.2018,10(1):49-55
55
Science,23:552–556.
[9] Linquist,B.A.,M.A.A.Adviento-Borbe,C.Pittelkow,C.van Kessel and K.J. van Groenigen, 2012. Fertilizermanagement practices and greenhouse gas emis-sionsfromricesystems:aquantitativereviewanaly-sis.FieldCropsRes,135:10–21.
[10] Lou,Y.,Ren,L.,Li,Z.,Zhang,T.,Inubushi,K.2007.Ef-fectofriceresiduesoncarbondioxideandnitrousox-ideemissionsfromapaddysoilofsubtropicalchina.WaterAirSoilPollut,178:157-168.
[11] Trinh,M.V,T.V.TheandB.T.P.Loan,2013.PotentialtomitigateGHGemissionsfromriceproductioninVi-etnam (in Vietnamese). http://www.iae.vn/. Ac-cessedon16/2/2017.
[12] Neue,H.U. andR.L. Sass, 1998. TheBudget ofMe-thanefromRiceFields.IGACtivitiesNewsLetter,12:3-11.
[13] Truc,N.T.T,2011.ComparativeassessmentofusingricestrawforrapidcompostingandstrawmushroomproductioninmitigatinggreenhousegasemissionsinMekong Delta, Vietnam and Central Luzon, Philip-pines.PhDdissertation.UniversityofthePhilippinesLosBaños.
[14] Khuong,N.Q.andN.N.Hung,2014.Effectsofthericestrawcompostincorporationonmethaneandnitrousoxideemissionsandriceyieldinthegreenhousecon-dition (inVietnamese).Scientific JournalofCanThoUniversity,32:46–52.
[15] Hoi, N.T., 2008. Influences of fresh rice straw andstubbleincorporationinfloodedsoilsonricegrowthinMekongDelta (in Vietnamese). PhD dissertation.CanThoUniversity.
[16] Du,N.X.,T.TNgaandN.T.KPhuoc,2014.Ricestrawtreatmentonthefieldusingbio-productionsinSpring-SummercropatCaiBeDistrict,TienGiangProvince(inVietnamese).ScientificJournalofCanThoUniver-sity.SpecialIssueinAgriculture:81–86.
[17] Parkin,T.,A.Mosier,J.Smith,R.Venterea,J.Johnson,D.Reicosky,G.DoyleG.McCartyandJ.Baker,2003.Cham-ber-basedTraceGasFluxMeasurementProtocol.USDA-ARSGRACEnet
[18] Pittelkow,C.M.,M.A.A.Adviento-Borbe,C. vanKes-sel, J.E.Hill andB.A. Linquist, 2014.Optimizing riceyieldswhileminimizing yield-scaled globalwarmingpotential.Glob.Chang.Biol,20:1382–1393.
[19] Romasanta,R.R.,Sander,B.O.,Gaihre,Y.K.,Alberto,M.C., Gummert, M., Quilty,J., Nguyen, V.H., Casta-lone, A.G., Balingbing, C., Sandro, J., Correa,T.,Wassmann, R., 2017. How does rice straw burningcomparewithotherstrawmanagementpracticesintermsofon-fieldCH4andN2Oemissions?Acompar-ative field experiment, Agriculture, Ecosystems andEnvironment. Agriculture, Ecosystems and Environ-ment,239:143–153.
[20] Snyder,C.S.,T.W.BruulsemaandT.L.Jensen,2007.Greenhouse gas emissions from cropping systemsandtheinfluenceoffertilizermanagement—alitera-ture review. International Plant Nutrition Institute,Norcross,Georgia,U.S.A.
[21] Surekha,K.,A.P.P.Kumari,M.N.Reddy,K.Satyana-rayanaandP.C.StaCruz,2003.Cropresiduemanage-menttosustainsoilfertilityandirrigatedriceyields.Nutrient Cycling in Agroecosystems. Volume 67,Number2:145-154.
[22] Mil,T.T,P.N.M.TrungandV.T.Guong,2012.Effectofricestrawtreatedandorganicamendmentonsoilfertility and rice yield in Chau Thanh district, HauGiangprovince(inVietnamese).ScientificJournalofCanThoUniversity,22a:253-260.
[23] Son,TranThiNgoc,L.H.Man,C.N.Diep,T.T.A.ThuandN.N.Nam,2008.Bioconversionofpaddystrawandbio-fertilizer for sustainable rice based cropping systems.Omonrice16Journal,CuuLongRiceResearchInstitute,CanTho–Vietnam.pp57-70.
[24] Tuyen,TranQuangandP.S.Tan,2001.Effectsofstrawmanagement,tillagepracticesonsoilfertilityandgrainyield of rice. Omonrice 9 Journal, Cuu Long Rice Re-searchInstitute,CanTho–Vietnam.pp74-78.
[25] VietnamSecondCommunication(VSC),2014.Thein-itialupdatedreportofVietnamtotheUnitedNationsFramework Convention on ClimateChange.Wassmann,R.Latin,R.S.andNeue,H.U(Eds),2000.Methaneemissions fromrice field inAsia. III.Mitigationoptionsandfuturesearchneeds.NutrientCyclinginAgroecosystems,58:23–36.
[26] Nam,T.S,N.T.HNhu,N.H.Chiem,N.V.C.Ngan, L.H.VietandKjeldIngvorsen,2014.Toquantifythesea-sonal rice strawand its use indifferentprovinces intheVietnameseMekongDelta(inVietnamese).Scien-tificJournalofCanThoUniversity,32:87–93.
[27] Truc, N.T.T, Z. M. Sumalde, F. G. Palis and R.Wassmann, 2013. Farmers’ Awareness and FactorsAffectingFarmers’AcceptancetoGrowStrawMush-room inMekongDelta,VietnamandCentral Luzon,Philippines.InternationalJournalofEnvironmentandRuralDevelopment.Volume4.Number2.P.179-184.
[28] Truc.N.T.T,Z.M.Sumalde,M.V.O.Espaldon,E.P.Pacardo,C.L.RaperaandF.G.Palis,2012.Farmers’Awareness and FactorsAffectingAdoptionofRapidComposting inMekong Delta, Vietnam and CentralLuzon,Philippines.JournalofEnvironmentalScienceandManagement15(2):59-73.
[29] Minamikawa,K.,T.Tokida,S.Sudo,A.PadreandK.Yagi, 2015. Guidelines for Measuring CH4 and N2OEmissionsfromRicePaddiesbyaManuallyOperatedClosedChamberMethod.NationalInstituteforAgro-EnvironmentalSciences,Tsukuba,Japan.