干旱区绿洲制种玉米生命周期环境影响评价——以张掖市为例

为定量分析干旱区绿洲农业的生态环境影响,在张掖市统计局投入产出调查基础上增补专项调查,以黑河流域中游张掖市主要三县区的制种玉米为例,采用生命周期评价(LCA)方法,将灌溉用水量纳入LCA清单,定量评估作物生命周期内投入产出的环境影响。结果显示,张掖市甘州区、高台县和临泽县制种玉米环境综合影响指数分别为0.608 0、0.538 1和1.259 5,其中:化肥的生产和施用对环境影响十分显著;淡水消耗量高于华北地区,低于陕西关中地区;与实行轮作的地区比较,环境污染指数较高。建议加大技术指导,测土配方施肥,并在气候及生产条件允许的区域改变耕作制度,调整种植结构。

Assessment of the environmental impact of seed maize production in oasis agriculture of arid regions based on the life cycle assessment method:A case study of Zhangye City

Based on the input-output survey of the Zhangye Municipal Bureau of Statistics, a survey was conducted to determine the environmental impact of seed maize production using the life cycle assessment method. The first step was to identify the evaluation objectives and scope, consider the two stages of agricultural production, and determine the production boundaries. The second step was an inventory analysis of irrigation water in the life cycle assessment list and a consideration of resource consumption and environmental emissions. The third step assessed the impact of evaluation and analysis, listed all material characteristics, performed standardization, and calculated the environmental impact index. The fourth step explained the results of the life cycle assessment. The comprehensive impact indices of the seed maize environment in the three counties of Zhangye were 0.608 0, 0.538 1, and 1.259 5. Significant effects of the production and application of chemical fertilizers were observed on the environment. Fresh water consumption was higher than in North China and the Guanzhong Region of Shaanxi Province, and a higher environmental pollution index was obtained when crop rotation was implemented. In view of these findings, it is proposed that agricultural technical guidance be increased, soil testing and fertilization be promoted, the farming system be altered, and the planting structure be adjusted in areas where climate and production conditions permit.