基于生命周期的循环农业系统评价

针对"循环经济系统是低碳经济的实现途径之一"的观点,在国内外研究的基础上,改进LCA模型,以湖南某典型的循环鸭业产业进行实证研究.整个鸭产业生命周期中耗用的不可再生资源、土地、水资源分别为48.629MJ、2.36m2和1321.41kg,潜在的温室气体、环境酸化、富营养化、人体毒性、水体毒性、土壤毒性分别为11543.26g(CO2eq)、52.36g(SO2eq)、25.83g(PO4eq)、1.26、60.74、24.65g(1,4-DCBeq),加权评估后,富营养化、水体毒性、土壤毒性潜在威胁均高于温室气体.结果表明,建立在传统生产模式上的循环农业适宜"适度循环";循环农业不能盲目追求低碳发展,在降低碳排放的同时还须考虑土壤和生物固碳,才能全面评价碳排放问题;循环经济和循环农业在评估碳排放的同时,还需对环境酸化、富营养化、生态毒性等其他生态指标进行评估,建立系统评价体系;LCA能够较好地对循环农业进行整体评价,值得进一步研究.

Integrated Evaluation of Circular Agriculture System: a Life Cycle Perspective

For the point of view that recycling economy system is one of ways to achieve the low-carbon economy, we have made an evaluation on a typical circular agriculture duck industry in Hunan Province, China, through improving the framework of life cycle assessment (LCA). The analysis indicated that the consumption of non-renewable resources, land and water were 48.629 MJ, 2.36 m2 and 1 321.41 kg, while the potential greenhouse gas (GHGs), acidification, eutrophication, human toxicity, freshwater ecotoxicity and terrestrial ecotoxicity were 11 543.26 g (CO2 eq), 52.36g (SO2eq), 25.83g (PO4eq), 1.26, 60.74 and 24.65 g (1,4-DCBeq), respectively. The potential damage of aquatic eutrophication, freshwater ecotoxicity and terrestrial ecotoxicity was more serious than that of GHGs. Main results were following: i. the circular agricultural chain promoted the principle of "moderate circulation", which based on the traditional production methods; ii. circular agriculture could not blindly pursue low carbon development. Instead, soil and biological carbon sequestration should be considered, in addition to reducing carbon emissions; iii. circular economy and circular agriculture should take other potential environmental impacts into account such as acidification, eutrophication and ecotoxicity,with the exception to carbon emissions,to developed integrated system assessment; iv. LCA could provide a comprehensive assessment of circular agriculture, and it was worth of further study.