有机和常规苹果生产环境影响的生命周期评价

Environmental impact assessment via life cycle analysis for organic and conventional apple productions

  • 摘要: 本文以我国园艺产业中的重要果品——苹果的生产为研究对象,通过实地调研,采用生命周期评价方法,对山西浮山、陕西白水和甘肃天水等3个代表性地区的有机及常规苹果生产的环境影响进行了研究,以期为我国农业可持续发展和生态文明建设提供科学依据。结果表明,山西浮山的有机苹果生产养分利用效率高于常规苹果,陕西白水和甘肃天水相反。3个地区单位苹果有机生产方式的能源消耗均占常规方式的26%以下,有机生产的能量利用效率高于常规生产。在能源消耗、全球变暖、环境酸化以及富营养化等4类环境影响中,富营养化对环境影响的贡献最大,均占80%以上。有机和常规苹果生产的环境影响按照大小均表现为陕西白水>甘肃天水>山西浮山。由于山西浮山有机苹果的肥料等投入远低于常规苹果生产,产量相差不大,因而表现为有机苹果的综合环境影响仅为常规苹果的22%;陕西白水和甘肃天水呈现相反的情形,其有机苹果的综合环境影响分别是常规苹果的356%和138%。在高量有机养分投入的前提下,有机农业可以达到和常规农业相当的作物产量,但其代价是较高的负面环境影响和较低的养分和能源利用效率。

     

    Abstract: To set the scientific basis for sustainable agricultural development and ecological civilization construction in China, this study analyzed the impacts of organic and conventional apple productions on environment in Fushan of Shanxi Province, Baishui of Shaanxi Province and Tianshui of Gansu Province through life cycle analysis method. Data were collected via field visits and farmer interviews. The study used unit apple production as the basis for comparative analysis. The system boundary of apple production defined in the study included materials production and cropping stages. The impacts of apple production on environments were assessed at four aspects-energy consumption, global warming, environmental acidification and eutrophication. It was found that nutrient use efficiency in organic apple production in Fushan of Shanxi Province was higher than that in conventional apple production, which was the reverse of the results for Baishui of Shaanxi Province and Tianshui of Gansu Province. The yield of organic apple was similar to that of conventional apple in Baishui of Shaanxi Province and Tianshui of Gansu Province, while the yield of organic apple in Fushan of Shanxi Province was only 69% that of conventional apple. Nitrogen, phosphorous and potassium inputs in organic apple production in Fushan of Shanxi Province were 6.8%-18.8% those of conventional apple production. For the other two regions, however, nutrient input in organic production was about 72.7%-228.8% that of conventional production. Energy consumption per unit organic apple product in the three regions accounted for less than 26% of the conventional product; i.e., energy utilization efficiency of organic apple was higher than that of conventional apple. Among the four environmental impacts (energy consumption, global warming, environmental acidification and eutrophication), eutrophication contributed the most (over 80%) to total environmental impact. The impact of global warming for unit organic apple product in Fushan of Shanxi Province was smaller than that of conventional product (organic product was only 23% that of conventional product). However, organic apple production in Baishui of Shaanxi Province and Tianshui of Gansu Province was much higher than that of conventional production (organic apple was respectively 356% and 138% conventional apple for the two areas). Environmental acidification and eutrophication under organic apple production in Fushan of Shanxi Province was lower than that under conventional production, but the results for Tianshui of Gansu Province and Baishui of Shaanxi Province were the reverse. Total environmental impact of apple production was the highest in Baisui of Shaanxi Province, followed by Tianshui of Gansu Province and then Fushan of Shanxi Province. Total environmental impact of organic apple production was 22% that of conventional apple production in Fushan of Shanxi Province. Then in Baishui of Shaanxi Province and Tianshui of Gansu Province, total environmental impacts of organic apple production were respectively 356% and 138% those of conventional apple production. This discrepancy was mainly due to differences in the amount and types of fertilizer used. The results showed that organic production had crop yields comparable to those of conventional agriculture in terms of nutrient input. However, it also led to higher negative environmental impacts and lower nutrient and energy use efficiency in organic production.

     

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