摘要：Thailand has a strategic national policy to increase organic rice farming. This study firstly applied Life Cycle Assessment for evaluating the quantitative environmental impacts at the regional and national levels to facilitate the national policy decision on the expansion of organic rice cultivation areas. The impact categories of interest included global warming, terrestrial acidification, freshwater eutrophication, terrestrial ecotoxicity, and freshwater ecotoxicity, and the life cycle impact assessment method applied was ReCiPe. The results showed that the life cycle environmental impacts from organic rice cultivation in the nine provinces in the North were lower than those from the 12 provinces in the Northeast, due mainly to the higher yields and lower use of fertilizers in the former. The methane emissions in the North (11,147 kg COsub2/sube/ha) were similar to those in the Northeast (11,378 kg COsub2/sube/ha). However, nitrous oxide emissions in the Northeast were higher than in the North due to the higher amounts of fertilizer used. If Thailand expands the rice farming by 50% in the North and by 50% in the Northeast, the greenhouse gas emissions could be reduced from 11,400 to 11,100 kg COsub2/sube/ha, but the impacts of terrestrial acidification, freshwater eutrophication, terrestrial ecotoxicity, and freshwater ecotoxicity could be increased by 0.0257 kg POsub4/sube (95%), 0.508 kg 1,4-DBe (53%), and 33.1 kg 1,4-DBe (17%), respectively. To reduce the global warming as well as other environmental impacts, Thailand should expand rice farming areas to the North. This information could be useful for supporting the policy decisions on which areas the organic rice farming should be expanded in to minimize the potential life cycle environmental impacts.
