河北省曲周县不同时期夏玉米生产的环境代价分析

Environmental impact assessment in summer maize system in different periods of Quzhou County in Hebei

将河北省曲周县1973—2013年夏玉米生产3体系根据当时的农业政策及发展特征分为4个时期,1973—1983年为改土治碱时期、1984—1993年为农业初步发展时期,1994—2003年为农业快速发展时期、2004—2013年为现代农业时期。用生命周期评价方法分析这一生产体系在4个时期的环境代价,结果表明:4个时期的环境影响因子中对能源消耗、全球变暖、环境酸化和富营养化的影响指数是递增的,对人体毒性、水体毒性和土壤毒性的影响指数是递减的;改土治碱时期影响最大的环境因子是富营养化(影响指数均值为0.121 40),其余3个时期的7项影响因子中对水体毒性的影响最大(其影响指数均值分别为0.856 65、0.812 16、0.542 08)。能源消耗主要存在于肥料生产过程,全球变暖主要存在于农资子系统中CO_2的排放以及农作系统中N_2O的排放,环境酸化主要存在于农作子系统中氮肥使用过程的NH_3挥发,富营养化主要存在于农作子系统中的NH_3挥发及NO_3-N淋洗,毒性主要存在于农药使用过程。推广高产高效技术是实现曲周县农业可持续发展、减少环境污染的重要举措。

Based on agricultural policy and development characteristics,the summer maize system from year 1973 to 2013 was divided into four periods：1973-1983 was the period of soil improvement and control salinity hazard;1984-1993 is the period of the initial development of agriculture;1994-2003 was the period of the rapid development of agriculture;And 2004-2013 was modern agriculture period.The impact of the four stages on environment was analyzed by using LCA （Life cycle assessment） and the result showed：that the increasing impacts of energy depletion,global warming,acidification and aquatic eutrophication were increasing while the impacts of human ecotoxicity,fresh water ecotoxicity and terrestrial ecotoxicity were decreasing at all periods;In the period of 1973-1983 was aquatic eutrophication （the impact index was 0.121 40） and the significant environmental impact of the next three periods was fresh water ecotoxicity （the impact indexes were 0.856 65、0.812 16、0.542 08,respectively）;Energy depletion was significant from fertilizer production process,global warming was significant from carbon emissions and nitrous oxide emissions,acidification was mainly resulted from NH3 volatilization,aquatic eutrophication was mainly caused by NH3 volatilization and NO3-N losses,and ecotoxicity was resulted from the use of pesticide.To promote high productivity and high efficiency is the important measure to achieve sustainable development of agriculture and reduce environmental pollution.