华北平原冬小麦-夏玉米种植系统生命周期环境影响评价

Life Cycle Environmental Impact Assessment in Winter Wheat-Summer Maize System in North China Plain

以华北平原集约高产粮区河北省栾城县为例,应用生命周期评价方法进行小麦-玉米轮作体系生命周期资源消耗与污染物排放清单分析,在此基础上进行生命周期环境影响评价。结果表明,在传统生产方式下,小麦生命周期环境影响较大的潜在因素是富营养化、水体毒素、环境酸化和土壤毒素;玉米生命周期环境影响较大的潜在因素是富营养化、环境酸化和水体毒素。小麦-玉米轮作体系下,氮肥、农药、电力的生产和使用过程是可能引起能源耗竭和气候变暖的主要因素,分别占整个体系的86.5%和66%;农民超量使用氮肥造成NH3挥发和NO3-N淋失,是导致潜在环境酸化和富营养化的关键;而农药的使用是造成潜在水体毒素、土壤毒素的主要原因。因此,工业领域要实施清洁生产机制,降低农资生产能耗;农业领域要减少氮肥、农药的使用量,推广节水灌溉技术。

Life cycle assessment（LCA） methodology was used to establish inventory of resource usage and emission and to assess life cycle environmental impacts of winter wheat-summer maize system in Luancheng County of Hebei Province, a high-yielding grain production region in North China Plain. The result showed that the significant potential environmental impacts of wheat production were aquatic eutrophication, fresh water ecotoxicity, acidification and terrestrial ecotoxicity in the convential production, and those of maize production were aquatic eutrophication, acidification and fresh water ecotoxicity. In the wheat-maize system, the energy depletion and global warming potentials were mainly from the energy- intensive production of fertilizers, pesticide and electricity, occupying 86.5% and 66% of the whole system, respectively. The acidification and aquatic eutrophication potential mainly resulted from NH3 volatilization and NO3-N losses, and the use of pesticide was the key factor associated with water and terrestrial ecotoxicity. Therefore, developing energy-saving ＆ clean production in industry, reducing consumption of nitrogenous fertilizer and pesticide, promoting water-saving irrigation technology in agriculture were the key points to control the life cycle environmental impacts of wheat -maize production in North China Plain.