Nghiên cứu xây dựng phương pháp luận và tính toán dấu vết các bon cho sản phẩm lúa gạo tại vùng đồng bằng sông hồng tt tiếng anh

MINISTRY OF NATURAL RESOURCES AND ENVIRONMENT INSTITUTE OF METEOROLOGY, HYDROLOGY AND CLIMATE CHANGE DAO MINH TRANG DEVELOPMENT OF A METHEODOLOGY FOR CALCULATION OF CARBON FOOTPRINT OF RICE PRODUCTS IN THE RED RIVER DELTA Major: Climate Change Code: 9440221 SUMMARY OF THE THESIS CLIMATE CHANGE Hanoi, 2019 The Thesis was completed at: Vietnam Institute of Meteorology, Hydrology and Climate Change Supervisor: Assoc Prof Dr Huynh Thi Lan Hương Assoc Prof Dr Mai Van Trinh Reviewer 1: Reviewer 2: Reviewer 3: The Thesis will be defended at Viet Nam Institute of Meteorology, Hydrology and Climate Change at: …hour….date…month…year The dissertation is available at: - National Library of Viet Nam - Library of Viet Nam Institute of Meteorology, Hydroogy and Climate Change INTRODUCTION RATIONALE According to Viet Nam’s greenhouse gas (GHG) inventory result, GHG emissions from agriculture has accounted for a large proportion, of which methane emissions from rice cultivation constituting 48-62% Recently, Viet Nam has become one of major rice exporting countries in the world Increasing the export value of the Vietnamese rice, including labeling low-carbon footprint, is important, so that trade barriers can be overcomed if any in future The Red River Delta (RRD) is one of the two major regions for rice production in Viet Nam The implementation of the research on “Development of a metheodology for calculation of carbon footprint of rice products in the Red River Delta” is the basis for the development of methodology and calculation of rice carbon footprint in other regions Based on the cresults, this study has identified activities with high mitigation potential and proposed prioritized mitigation options OBJECTIVES (1) To develop a methodology for calculation of carbon footprint of rice products in the Red River Delta; (2) To calculate the rice carbon footprint for the pilot area of Phu Luong commune, Dong Hung district, Thai Binh province; (3) To propose mitigation options to reduce GHG emissions from rice production in the study area SUBJECT AND SCOPE The study subject was GHG emissions during the rice life cycle in the spring and summer seasons according to three cultivation methods: convention (CM), wide-narrow row (WNR) and system of rice intensification (SRI) The pilot area was Phu Luong commune, Dong Hung district, Thai Binh province The study year was 2017 The thesis calculated key GHG emissions during the rice life cycle In the up-stream processes, GHG sources included: electricity generation for machinery operation and production of fertilizer, lime and pesticide In the "rice production" stage, GHG sources included: methane emissions from rice cultivation; CO2 emissions from the application of urea and NPK fertilizers; N2O emissions from agricultural soils; lime application and diesel combustion for on-farm operation of agricultural machinary In the "post-farm" stage, GHG emissions from transporting rice from fields to houses and on-field burning of rice stubble and straw were taken into account ARGUMENTS OF THE DISSERTATION The incorporation of the Life Cycle Assessment (LCA) of the International Organization for Standardization (ISO) and the 2006 Guidelines for National Greenhouse Gas Inventories (GL 2006) of the Intergovernmental Panel on Climate Change (IPCC) is a suitable methodology for calculating carbon footprint of rice products during its life cycle in the Red River Delta CH4 emissions from rice cultivation accounts for the largest proportion in the carbon footprint; followed by that from electricity generation and energy use for operation of agricultural machinery The expansion of WNR cultivation method in Phu Luong commune is a potential mitigation option that also brings back economic benefits, and hence should be prioritized SCIENTIFIC AND PRATICAL SIGNIFICANCE OF THE DISSERTATION This study has developed a methodology for calculating the rice carbon footprint in the RRD based on which future studies can be adjusted and developed to calculate for rice carbon footprint in other rice production areas, such as the Mekong River Delta The identification of prioritized mitigation options will support for the implementation of Viet Nam's NDC and contribute to removing trade barriers if any in the future CONTRIBUTION OF THE DISSERTATION ▪ Develop a methodology for calculating carbon footprint of rice products in the Red River Delta; ▪ Apply methodology for pilot calculation for the research area; ▪ Propose prioritized mitigation options during the rice life cycle, contributing to the review and updatte of the NDC STRUCTURE OF THE DISSERTATION In addition to Introduction and Conclusion, the thesis consists of 03 chapters Chapter presents an overview of studies on rice carbon footprint and the research area Chapter presents the content and research method Chapter presents the results of the research and discussion The appendix includes sample questionnaires, intermediate calculation results and images of the study area CHAPTER OVERVIEW OF STUDIES ON RICE CARBON FOOTPRINT AND RESEARCH AREA 1.1 Overview of product carbon footprint 1.1.1 Definition of “carbon footprint” “The quantity of GHGs expressed in terms of CO2-equivalent (CO2e), emitted into the atmosphere by an individual, organization, process, product, or event from within a specified boundary” [97] 1.1.2 Scope of product carbon footprint The scope of carbon footprint includes: Tier (on-site emissions), Tier (emissions embodied in purchased energy) and Tier (all other indirect emissions not covered under Tier 2) [30], [33], [106] 1.1.3 Guidelines on calculating product carbon footprint 1) Calculating product carbon footprint One of the guidelines for calculating GHG emissions using the activity-based approach is the IPCC’s GL 2006 [51] The three universally accepted PCF calculation guidelines are: Publicly Available Specification (PAS) 2050 of the British Standards Institute (BSI), the GHG Protocol of the World Resources Institute and the World Business Council for Sustainable Development (WRI/WBCSD) [106] and ISO 14067 2) Calculating carbon footprint of agricultural products Guidelines for calculating carbon footprint of agricultural products include: WRI/WBCSD’s GHG Protocol Agriculture Guidance [95]; PAS 2050-1:2012 - Assessment of life cycle GHG emissions from horticultural products of BSI [32] and FAO [47] 1.2 Overview of studies on rice carbon footprint 1.2.1 Sources of greenhouse gases emissions during rice life cycle ❖ Up-stream processes: Production of input materials (electricity, fertilizer, lime and pesticides); Production, amortisation and maintenance of agricultural machinery and equipment ❖ Rice production: Diesel combustion for on-farm operation of agricultral machinery; CO2 emissions from groundwater extraction for irrigation; Methane emissions from rice cultivation; N2O emissions from soils; GHG emissions from lime application; CO2 emissions from urea application ❖ Post-farm stage: Transporting rice from fields to houses; Onfarm burning of rice stubble and straw after harvest 1.2.2 International studies on rice carbon footprint A variety of studies applied the LCA of ISO such as Blengini and Busto [28], Gan et al [56], [57], Kasmaprapruet et al [80], Xu et al [109] Some studies combined LCA and the IPCC’s GL, such as Farag et al [48], Yodkhum and Sampattagul [110] Few studies calculated GHG emissions from the production of input materials 1.2.3 Studies in Viet Nam on rice carbon footprint Viet Nam has applied the IPCC’s GL to calculate the national GHG emissions from agriculture in 1994, 2000, 2005, 2010, 2013 and 2014 Several studies used the LCA to assess the impact of rice cultivation techniques such as Le Thanh Phong and Pham Thanh Loi [15] and Le Thanh Phong and Ha Minh Tam [14] Some other studies used empirical methods to measure GHG emissions from rice cultivation and agricultural soils such as: Nguyen Viet Anh and Nguyen Van Tinh (23), Nguyen Huu Thanh et al [17] and the Institute for Agricultural Environment (IEA) [65] 1.2.4 Existing gaps in current research Studies on rice carbon footprint are limited and didnot adequately calculated GHG emissions during the rice life cycle 1.3 Overview of the research area Phu Luong Commune is located in the North of Dong Hung district in Thai Binh province, with the area of 298 hectares for rice cultivation, of which the cultivation area according to the conventional method is 148 hectares, according to the WNR method is 90 hectares and the SRI method is 60 hectares The activities during the rice life cycle in Phu Luong commune are typical for Thai Binh province in particular and the Red River Delta in general 1.4 Conclusion of Chapter In Viet Nam, very few studies on rice carbon footprint were conducted and most of them have not yet fully calculated the GHG GHG emissions during the rice life cycle The main methodology used is LCA of ISO Very few studies have calculated GHG emissions from the production of input materials for rice production CHAPTER RESEARCH CONTENT AND METHODS 2.1 Research content ▪ Overview of studies on rice carbon footprint on the world and in Vietnam; ▪ Develop a methodology for calculating carbon footprint of rice products in the Red River Delta; ▪ Calculate rice carbon footprint of the pilot area of Phu Luong commune, Dong Hung district, Thai Binh province; ▪ Propose prioritized options to mitigate GHG emissions from activities during the rice life cycle in the study area 2.2 Research methods 2.2.1 Method of data collection and synsthesis 1) Method of collecting secondary data: is implemented on the basis of inheriting, analyzing and synthesizing relevant data 2) Method of field survey: The minimum sample size of “30” is appropriate so the number of sample in the thesis is 30 farmer households according to each cultivation method 3) Method of expert consultation: interview managers at Phu Luong Cooperative’s managers and experts in energy, agriculture and transportation sectors 2.2.2 Method of processing data 1) Calculate sample statistical features and estimate for population: to exclude samples whose performance figures deviate significantly from the average 2) Use functions and tools in Excel to calculate, include: average function, minimum value, maximum value, variance and sum 10 3) IPCC’s GL 2006 was applied to calculate GHG emissions from key activities during rice life cycle 4) Process-based LCA approach of ISO was applied 5) Matrix analysis method: was used to rank the priority of mitigation options, based on the following criteria: mitigation potential, mitigation cost, technology availability and co-benefit 2.3 Conclusion of Chapter In order to implement the four research contents, the thesis applied the method of data collection and synthesis (through secondary data collection, field survey and expert consultation) and the methods of processing data, including calculating sample statistical features, applying Excel functions and tools, using the GL 2006 of IPCC, the LCA method of ISO and matrix analysis CHAPTER RESULTS AND DISCUSSION 3.1 Methodology for calculating the carbon footprint of rice products in the Red River Delta The study applied the process-based LCA approach in cooperation with the GL 2006 of IPCC [68], FAO [47] and COPERT of EURO [86] The calculation of GHG emissions from key activities is based on equations in GL 2006 of IPCC, FAO (for fertilizer, lime and pesticide production) and COPERT of EURO (transporting rice from fields to houses by motobikes) The calculation process consists of steps: (i) Selection of GHGs; (ii) Determination of the scope for calculation; (iii) Data collection and 13 ta: the time required to activity a on one hectare (hour/ha); MFCa,b: Mean Fuel Consumption, the characteristic fuel consumption for activity a with tractor b (liters/hour); ddiesel : the density of diesel (kg per liter) Fuel consumption=Diesel-use ×Calorific value diesel (Equa 6.2) where: Fuel consumption: The amount of fuel combustion (MJ/ha); Diesel-use a,b : The amount of diesel used for machinery operation (kg/ha); Calorific value diesel : Calorific value of diesel (MJ/kg); ❖ Lime application Emissions𝐶𝑂2−𝐶 = (M𝑙𝑖𝑚𝑒 *EFlime )+(Mdolomite *EFdolomite ) (Equa 7) where: EmissionsCO2–C: The amount of C emissions from lime application (tonnes of C); M: The amount of lime or dolomite applied (ton); EF: Emision factor (tC/ton of lime or dolomite) ❖ CO2 emissions from urea application CO2 -C emissions = M ×EF (Equa 8) where: CO2 – C emissions: Emissions of carbon from urea application (tonnes of C/ha); M: The amount of urea applied (tonnes of urea); EF: Emission factor (tonnes of C/tonnes of urea) ❖ N2O emissions from agriculture soils - Direct N2O emissions 14 N2ODirect-N = [(FSN+FAW +FBN + FCR)*EF1] + (FOS *EF2) (Equa 9) where : N2ODirect-N: Emission of N2O in unit of Nitrogen (kg N/yr) FSN: Annual amount of synthetic fertilizer nitrogen applied to soils adjusted to account for the amount that volatilizes as NH3 and NOx FAW: Annual amount of animal manure nitrogen intentionally applied to soils adjusted to account for the amount that volatilizes as NH3 and NOx FBN: Amount of nitrogen fixed by N-fixing crops cultivated annually FCR: Amount of nitrogen in crop residues returned to soils annually FOS: Area of organic soils cultivated annually EF1: EF for emissions from N inputs (kg N2O-N/kg N input) EF2: EF for emissions from organic soil cultivation (kg N2O-N/ha-yr) The conversion of N2O-N to N2O: N2O = N2O-N * 44/28 - Indirect N2O emissions: N2Oindirect-N = N2O(G)+N2O(L)+N2O(S) (Equa.10) where: KNK N2Oindirect-N: Emissions of N2O in units of nitrogen N2O(G): N2O emited from volatilization of applied synthetic fertilizer and animal manure N, and its subsequent atmospheric deposition of NOx and NH3 (kg N/yr); N2O(L): N2O emited from leaching and runoff of applied fertilizer and animal manure N (kg N/yr); N2O(S): N2O emited from discharge of human sewage N into rivers or estuaries (kg N/yr) 15 ❖ Transporting rice from fields to houses by motorbikes CO2 emissions = Distance traveled ×EFmotorbike (Equa.11) where: CO2 emissions: the amount of CO2 emissions from travelling by motorbike (kgCO2tđ); Distance traveled: The distance that motorbike travelled (km); EFmotorbike: Emission factor of motorbike (kgCO2tđ/km) ❖ Burning rice straw after harves Lfire =A ×MB ×Cf ×Gef ×10-3 (Equa 12) where: Lburning : amount of GHG emissions from fire (tons of each GHG) A: area burnt (ha); MB : mass of fuel available for combustion (tonnes/ha); Cf : combustion factor; Gef : emission factor (g/kg d.m.) The mass of fuel available for combustion (MB) or the output of straw burning on the field (Qst) is estimated by the equation according to Gadde et al (2009): Qst =Qp ×R×k (Equa 12.1) where: Qst : The amount of straw burned on the field (tonnes) Qp : The amount of rice (tonnes); k : The ratio of straw burned on the field to total straw b) Calcultion of carbon footprint 16 According to the IPCC's 5th Assessment Report (AR5) (2013), the GWP of CH4 is 28 and the GWP of N2O is 265 CFs = ∑3i=1[GWP(tieri )] CFy = CFs Grain yield where: CFs: the spatial carbon footprint (kg CO2e/ha); CFy: the yield-scaled carbon footprint (kg CO2e/kg) c) Uncertainly analysis Uncertainty analysis was conducted based on Equations 3.1 and 3.2 in Volume of GL 2006 of IPCC [68] 3.2 Greenhouse gas emissions from activities during rice life cycle 3.2.1 Electricity generation for operation of agricultural machinery and equipment Data on capacity (MWh), operation time (h/ha) and times of operation (times/crop) of water pumps, electric fans and rice milling machines were collected based on field survey data The emission factor of the Vietnamese electricity grid in 2017 was 0.864 tonnes of CO2/MWh (Decision No 330 /BDKH-GSPT dated 29 March 2019) Table 3.6 Greenhouse gas emissions from electricity generation for operation of agricultural machinery for rice cultivation Unit: kgCO2e/ha Source Spring season Summer season CM SRI WNR CM SRI WNR Pumps 4120.9 2846.2 2846.2 3434.1 2371.8 2371.8 Electric fans 0.004 0.003 0.002 0.004 0.003 0.002 17 Rice milling machines Total 114.93 114.93 114.93 114.93 114.93 114.93 4235.9 2961.1 2961.1 3434.1 2371.8 2371.8 3.2.2 Fertilizer production Emission factors for N, P2O5, K2O and NPK production are 3.63 kgCO2e/kg N, 0.13 kgCO2e/kg P2O5, 0.56 kgCO2e/ kg K2O and 4.59 kgCO2td /kg NPK, with respectively [84] Table 3.8 Greenhouse gas emissions from fertilizer production Unit: kgCO2e/ha Spring season Summer season Source CM SRI WNR CM SRI WNR N 526.35 457.68 655.14 513.77 450.21 640.20 P2O5 8.08 13.27 14.10 7.94 13.27 13.52 K2O 57.66 63.57 63.50 54.14 61.84 63.13 NPK 1250.6 1183.7 1002.4 1201.6 1183.7 957.30 Total 1842.7 1718.23 1735.17 1777.48 1709.03 1674.15 3.2.3 Lime production According to the survey data, farmers only use lime for basal fertilization The emission factor of lime production is 0.75 kgCO2/kg lime according to GL 2006 [68] Table 3.9 Greenhouse gas emissions from lime production Unit: kgCO2e/ha Source Spring season CM Summer season SRI WNR CM SRI WNR Lime production 23.15 0.00 12.76 23.15 0.00 12.76 18 3.2.4 Pesticide production The amount of pesticides sprayed for the Brown Planthowver was 0.2 kg/ha [65] The thesis assumed that according to the conventional method, farmers sprayed for the Brown Planthowver one time more than SRI and wide-narrow row methods The emission factor of pesticide production was 25.5kgCO2e/kg kg a.i [26] The proportion of active ingredients was assumed to be 25% Table 3.11 Greenhouse gas emissions from pesticide production Unit: kgCO2e/ha Source Pesticide production Spring season Summer season CM SRI WNR CM SRI WNR 2.55 1.28 1.28 2.55 1.28 1.28 3.2.5 Methane emissions from rice cultivation Data on cultivation areas and methods, rice varieties, and rice growth duration were collected from questionnaire results The methane emission factor (kgCH4/ha/day) was calculated based on IEA [57] and had a value of 2.50 (CM), 1.69 (SRI) and 1.61 (WNR in the spring season and 3.36 (CM), 3.09 (SRI) and 2.69 (WNR) in the summer season, with respectively Table 3.15 Methame emissions from rice cultivation Unit: kgCO2e/ha Crop Cultivation method CM SRI WNR Spring season 7870.93 5765.76 5556.19 Summer season 10646.16 10110.03 8990.94 19 3.2.6 CO2 emissions from urea application Data on the amount of urea and NPK fertilizer and type of NPK was collected from the survey results According to GL 2006, the emission factor of urea application is 0.2 kgC/kg N Table 3.16 CO2 emissions from urea application Unit: kgCO2e/ha Spring season CM SRI Summer season WNR CM SRI WNR Basal application 63.45 38.12 55.85 62.49 38.12 55.09 First application 15.81 12.12 18.35 15.27 12.12 17.88 2.29 9.47 6.78 2.29 9.05 6.50 81.55 59.71 80.99 80.05 59.30 79.47 Second application Total 3.2.7 N2O emissions from agricultural soils The emission factor of N2O emissions (kgN2O-N/kg N) from agricultural soils was calculated based on IEA [57] and had a value of 0.00572 (CM), 0.00545 (SRI and WNR) in the spring season and 0.00648 (CM), 0.00534 (SRI and WNR) in the summer season The emission factor of direct N2O emissions from agricultural soils is 0.003 kgN2O-N/kg N according to the GL 2006 Table 3.20 N2O emissions from agricultural soils Unit: kgCO2e/ha Sources Direct emissions Spring season Summer season CM SRI WNR CM SRI WNR 221.13 199.79 250.20 216.14 197.22 244.09 20 Indirect emissions 200.20 163.41 204.63 251.04 153.96 190.55 Total 421.33 363.20 454.83 467.17 351.19 434.65 3.2.8 Lime application EFdolomite is 0.13 (GL 2006) Table 3.21 Greenhouse emissions from lime application Unit: kgCO2e/ha Source Lime application Spring season Summer season CM SRI WNR CM SRI WNR 14.71 8.11 14.71 8.11 3.2.9 Diesel combustion for on-farm operation of agricultural machinery Farmers used plowing machine 2-3 times/crop, combine harvesters time/crop and two rice milling machines 300 hours/crop Table 3.23 The parameters used for the calculation Parameter MFC (l/h) Value Combine harvestors 30.5 l/h Plowing machines 14.80 l/h Density of diesel (kg/l) 0.84 kg/l Calorific value of diesel (TJ/Gg) 43.00 CO2 74100 N2O 178.80 EFdiesel (kgCO2/TJ) 21 Table 3.24 Greenhouse gas emissions from diesel combustion for on-farm operation of agricultural machinery Unit: kgCO2e/ha Source GHG Plowing Spring season Summer season CM SRI WNR CM SRI WNR CO2 1940 2058 2898.7 1986 2058 2858 machines N2O 4.68 4.97 6.99 4.79 4.97 6.90 Combine CO2 694.9 740.4 750.46 694 740.4 750.4 harvestors N2O 1.68 1.79 1.81 1.68 1.79 1.81 Milling CO2 3.82 3.82 3.82 3.82 3.82 3.82 machines N2O 0.01 0.01 0.01 0.01 0.01 0.01 2646 2809 3661.8 2691 2809 3621.5 Tổng 3.2.10 Transporting rice from fields to houses by motorbikes The average distance from fields to houses is 0.95 km The emission factor of motorcycles is 77.59 (g/km) according to COPERT of EURO [86] Table 3.26 Greenhouse gas emissions from transporting rice from fields to houses by motorbikes Unit: kgCO2e/ha Spring season Summer season Sources CM SRI WNR CM SRI WNR Rice transport 3.46 5.37 3.72 3.46 5.85 3.67 3.1.11 On-field burinng of rice stubble and straw after harvest Most households incorporated the straw into soils in the spring season and burned more in the summer season The percentage of 22 rice stubble compared to the total rice residue is 0.32 and that of rice straw is 0.68 [65] The emission factor of N2O is 0.0185 kgCO2e/kg of straw [68] and that of CH4 is 0.22397 [12] FCO is 0.8 [26] According to the survey, 15% of rice husk was incorporated into soils, 15% was used for barn renovation and the remaining was purchased and hence no emissions from rice husk burning Table 3.30 Greenhouse gas emissions from on-field burning or rice stubble and straw after harvest Unit: kgCO2e/ha Sources Rice stubble Rice straw Total GHG Spring season Summer season CM SRI WNR CM SRI WNR N2O 4.98 0.0 5.10 36.67 26.37 29.95 CH4 72.1 0.0 73.85 530.8 381.7 433.5 N2O 0.00 0.0 0.92 17.29 9.28 13.51 CH4 0.00 0.0 13.37 250.3 134.3 195.6 77.1 0.0 93.24 835.1 551.7 672.6 3.3 Results of rice carbon footprint in Phu Luong commune 3.3.1 Rice carbon footprint in Phu Luong commune The rice carbon footprint in the spring season was 2.88kgCO2e/kg (CM), 2.32kgCO2e/kg (SRI) and 2.42kgCO2e/kg (WNR) In the summer season, the results were 3.92 kgCO2e/kg (CM), 3.53 kgCO2e/kg (SRI) and 3.46 kgCO2e/kg (WNR) When comparing with other international studies on rice carbon footprint which also combined the LCA of ISO and IPCC’s GLs, the results of the thesis are not much different with the standard deviation of 0.85 23 3.3.2 Uncertainty analysis The uncertainty of rice carbon footprint in the spring season was 10.9% (CM), 10.5% (SRI) and 10.4% (WNR) and in the summer season was 12.3% (CM), 13% (SRI) and 12.1% (WNR) 3.4 Proposing measures to reduce greenhouse gas emissions The thesis proposed four mitigation options during the rice life cycle in the study area in 2020-2025, including: M1 Expansion of the application of the WNR cultivation method; M2 Reusage of rice straw in the summer season to produce organic fertilizers; M3 Production of biochar from rice stubble and straw in the spring season and M4 Mixing biodiesel with conventional diesel oil at a rate of 20% for the operation of agricultural machinery Option M1 should be prioritized owing to its highest mitigation potential, particularly 555.4 tCO2e (spring season) and 427.4tCO2e (summer season) in 2025 compared to the Business-As-Usual scenario This option also brings an economic benefit of $49.4/tCO2e in the spring season and $64.2/tCO2e in the summer season 3.5 Conclusion of Chapter Key GHG sources were: methane emissions from rice cultivation; diesel combustion for on-farm operation of agricultural machinery; electricity generation for irrigation and fertilizer production Four mitigation options were proposed: M1 Expansion of the WNR method; M2 Reusage of rice straw in the summer season to produce organic fertilizers; M3 Production of biochar from rice stubble and straw in the spring season and M4 Mixing biodiesel with conventional diesel oil at a rate of 20% for the operation of agricultural machinery 24 CONCLUSIONS AND RECOMMENDATIONS A Conclusions i) Metheodology The thesis developed a methodology for calculating rice carbon footprint, where the process-based LCA approach of ISO was mainly combined with the GL 2006 of IPCC, FAO and COPERT of EURO The calculation of GHG emissions from key activities was based on the GL 2006 The equations for calculating GHG emissions from the production of fertilizer, lime, and pesticide were derived from FAO and that from transporting rice by motorbikes were based on instructions in COPERT of EURO 2, with respectively ii) Rice carbon footprint Data were collected from interviews with 90 farmer households in Phu Luong commune, of which 30 households for each cultivation method: CM, SRI and WNR The emission factor of methane emissions from rice cultivation and N2O from agricultural soils in the study area were calculated based on IEA’s empirical measurement results For activities that had no site-specific emission factor, the GL 2006 default values or those from relevant studies were applied Key GHG sources in the rice carbon footprint include: methame emissions from rice cultivation; electricity generation for irrigation; diesel combustion for on-farm operation of agricultural machinery and fertilizer production The rice carbon footprint in the spring season were 17.2 tCO2e/ha (CM), 13.6tCO2e/ha (SRI) and 14.5tCO2e/ha (WNR) and those in the summer season were 20.09tCO2e/ha (CM), 18.08 tCO2e/ha (SRI) and 17.9 tCO2e/ha 25 (WNR) By yield unit, the rice carbon footprint in the spring crop was 2.88kgCO2e/kg (CM), 2.32kgCO2e/kg (SRI) and 2.42kgCO2e/kg (WNR) In the summer season, the results were 3.92 kgCO2e/kg (CM), 3.53 kgCO2e/kg (SRI) and 3.46 kgCO2e/kg (WNR) The uncertainty of the result in spring season was 10.9% (CM), 10.5% (SRI) and 10.4% (WNR) and in the summer season was 12.3% (CM), 13% (SRI) and 12.1% (WNR) The uncertainty of GHG emissions from non-mechanical sources was often higher than that from mechanical sources Successful pilot calculation in Phu Luong commune has demonstrated the feasibility of the methodology and hence it can be applied for other areas iii) Measures to mitigate rice carbon footprint Based on the calculation results, the thesis proposed four mitigation options, including: M1 Expansion of the application of the WNR cultivation method; M2 Reusage of rice straw in the summer season to produce organic fertilizers; M3 Production of biochar from rice stubble and straw in the spring season and M4 Mixing biodiesel with conventional diesel oil at a rate of 20% for the operation of agricultural machinery Option M1 should be a priority because of its highest mitigation potential and economic co-benefits Based on this study, rice carbon footprint in other areas can be calculated in order to identify appropriate mitigation options Therefore, the thesis had both both scientific and practical significance, contributing to the removal of possible trade barriers to rice exports in the post-2020 period and supporting Viet Nam in the achievement of mitigation targets as declared in the NDC 26 B Recommendations 1) Within the scope of a doctoral thesis, with limitation in time and data, the thesis only considered major activities during rice life cycle GHG emissions from seed production, the production, amortisation and maintenance of agricultural machinery and equipment and the transport of raw materials to the field need being further studied in future In addition, the study subject of the thesis was "paddy rice" so GHG emissions/removals due to land use change such as "slash and burn" was not considered in the study 2) The thesis calculated GHG emissions from the production of powdered pesticide so that GHG emissions from the production of liquid pesticide should be further studied 3) The thesis considered the N2O emissions from agricultural soils due to urea and NPK application Other sources such as the amount of N from agricultural residues and manure were excluded 4) When applying this methodology to other areas, apart from the site-specific emission factor of CH4 from rice cultivation and N2O from agricultural soils in Phu Luong commune, other emission factors can be referenced and used from the thesis For areas without site-specific emission factors, default values may be referred from the GL 2006 or Vietnam’s National Communications to UNFCCC 5) GHG emissions from diesel combustion for on-farm operation of agricultural machinery also account for a large proportion of rice carbon footprint in Phu Luong commune, so additional research on mitigation options for that source is needed LIST OF PUBLISHED SCIENTIFIC PAPERS OF THE AUTHOR Dao Minh Trang, Huynh Thi Lan Huong (2017), “Development of a methodological framework for calculation of carbon footprint of rice production in Viet Nam”, Viet Nam Journal of Science, Technology and Engineering, 59, 91 – 96 Dao Minh Trang, Huynh Thi Lan Huong, Mai Van Trinh and Chu Sy Huan (2019), “Carbon footprint of rice in Viet Nam: Case study of Phu Luong commune, Dong Hung district, in Thai Binh province in the spring and summer seasons”, Viet Nam Journal of Agricultural and Rural Development, 10, 3-11 Dao Minh Trang, Huynh Thi Lan Huong and Mai Van Trinh (2019), “Calculating carbon footprint of rice in Vietnam and proposing mitigation options”, Viet Nam Journal of Science, Technology and Engineering, 61, 84-89 Dao Minh Trang, Huynh Thi Lan Huong and Mai Van Trinh (2019), “Research on activities emitting greenhouse gases in life cycle of rice in Phu Luong commune, Dong Hung, Thai Binh province”, Viet Nam Journal of Agricultural Science and Technology, 4, 94-100 Ministry of Natural Resources and Environment (2015) Technical report on Viet Nam’s Intended Nationally Determined Contribution [Ed by Nguyen Khac Hieu, Tran Thuc, Pham Van Tan, Huynh Thi Lan Huong, Nguyen Van Thang, Dao Minh Trang, Nguyen Van Minh and Chu Thi Thanh Huong] Ha Noi, Viet Nam Nguyen Van Thiet, Luc Thi Thanh Them, Dao Thu Hang, Bui Thi Phuong Loan, Chu Sy Huan, Dao Minh Trang and Mai Van Trinh (2019), “Research on mitigation measures to reduce greenhouse gas emissions from paddy-rice cultivation in Thai Binh province”, Vietnam Journal of Agricultural Science and Technology, 9, 106-111 (certified) ... RICE CARBON FOOTPRINT AND RESEARCH AREA 1.1 Overview of product carbon footprint 1.1.1 Definition of “carbon footprint” “The quantity of GHGs expressed in terms of CO2-equivalent (CO2e), emitted... used the LCA to assess the impact of rice cultivation techniques such as Le Thanh Phong and Pham Thanh Loi [15] and Le Thanh Phong and Ha Minh Tam [14] Some other studies used empirical methods to... Nguyen Viet Anh and Nguyen Van Tinh (23), Nguyen Huu Thanh et al [17] and the Institute for Agricultural Environment (IEA) [65] 1.2.4 Existing gaps in current research Studies on rice carbon footprint