Assessment Environmental and Social Impacts for the Rice Straw Utilization Technical Models to Promote Circular Economy for Rice Production in Chau Thanh District - An Giang Province ☆

The study objective is to provide an initial scientific basis for calculating CO2 equivalent (CO2e) emission reduction from the three technical models such as rice-straw composting, rice-straw fermented for cattle feed, and straw mushroom production, which are rice-straw utilization alternatives instead of open-burning them in Chau Thanh district. The study calculation is based on the surveyed practical database, the theoretical emission factors (EF), and the implementation of EasyPol-Ex software version 5 (Ex-Act) to estimate the amount of CO2e emissions when switching. The results show that in 2022, Chau Thanh could avoid 330,236 tons of CO2 emissions by burning 171,637 tons of rice straw. The estimated amount of CO2 emitted from harvesting and rolling rice straw by machine was 4.375 g CO2e per kilogram of rice straw. The EF for transportation of rice straw to model implementation places was 740 gCO2e/kg. The additional EFs for mushroom, composting, and animal feed production models were 222g, 172g and 60g CO2e/kg, respectively. Results indicate that although the EF of rice straw collection and transportation was still high, the total CO2e from three models (including transportation) was still lower than the EF from straw burning. In addition, farmers who own the paddy field earned an extra 500,000 VND/ha per crop, and farmers earned an extra about 1.7 to 2.3 million VND per crop, depending on the model applied. The successful implementation of technical models promoted the concept of circular economy applied to rice production industries.