Comparative Study of Conventional and Organic Rice Cultivation System in Northeast China Based on LCA

摘要

With the method of life cycle assessment, the paper takes Bayan County, Heilongjiang Province as the case to analyze the resources' consumption and pollutant releasing of conventional and organic rice cultivation system in northeast China. On the basis of that, the comparative environmental assessment was accomplished. The results showed that the significant environmental impact factors are global warming potential, acidification potential, eutrophication potential and fresh water eco-toxicity potential. The environmental impact index of conventional rice is 5.24 in comparison with 4.15 for organic rice. If conventional rice were widely replaced by organic rice, acidification, eutrophication, human toxicity and fresh water eco-toxicity potential would be reduced by 47%, 32%, 85% and 67%. However, global warming and fossil energy consumption potential would increase 65% and 14%. In terms of environmental impact, organic rice is not totally superior to conventional rice. In the system of conventional rice cultivation, the agricultural materials period contributes most to environmental impact, occupying more than 60% in eutrophication, fresh water eco-toxicity, terra firma eco-toxicity, human toxicity, acidification and fossil energy consumption potential. In the system of organic rice cultivation, growing period contributes most to environmental impact, taking the place of the agricultural materials period. Thus, actualizing energy-saving and cleaner production in the fertilizer industry, promoting fair irrigation projects and optimizing fertilizer application are the key points to control the potential environmental impacts.