吉林省玉米农田保护性耕作的环境影响评价

Assessment of Environmental Impacts by Conservation Tillage in Maize Fields in Jilin Province

以吉林省玉米农田4种保护性耕作为例,应用生命周期评价方法(Life Cycle Assessment,LCA)系统综合地评价吉林省玉米农田不同保护性耕作模式对环境的潜在影响。结果表明,四种保护性耕作模式的能源消耗、温室气体排放、环境酸化和富营养化的潜在环境影响分别平均比传统耕作模式减少14.62%、82.82%、15.37%和15.28%,主要由氮肥的生产及施用引起;水体毒性、土壤毒性及人体毒性则分别比传统耕作高7.40%、6.42%和7.38%,主要由农药的施用引起。综合各种环境影响类型,尽管4种保护性耕作模式较传统耕作模式能显著减缓全球变暖,但对其他环境类型的改变不明显,其中水体毒性为该种植系统中最主要的环境影响类型,富营养化次之。

Focused on 4 conservation tillage patterns applied in maize fields in Jilin Province,life cycle assessment LCA was used to synthetically assess the potential effect of different conservation tillage patterns on environment.Results showed that,compared to conventional tillage pattern,potential environmental effect of engery consumption,GHGs emission,acidification and eutrophication were lower,which accounted for 14.62%,82.82%,15.37% and 15.28% respectively.They all resulted from overused nitrogen fertilizer.However,freshwater ecotoxicity,terrestrial ecotoxicity and human toxicity were higher,with 7.40%,6.42% and 7.38% respetively.Use of pesticide caused serious environment risk on freshwater ecotoxicity,terrestrial ecotoxicity and human toxicity.Considering all kinds of environmental factors,although 4 conservation tillage patterns have great positive effect on decelerating global warming,they didn't affect other environmental categories strikingly.Furthermore,among which freshwater ecotoxicity and eutrophication were the primary categories of environment effects.