基于能值分析方法的高产粮区农田生态系统持续性分析

区域粮食高产农田生态系统是否可持续成为关系中国粮食安全的热点问题，该文运用能值分析和农户问卷调查相结合的方法，以山东省桓台县为例，分析了1996年和2006年华北高产粮区农田生态系统能值的投入产出总量、结构和可持续发展综合指标的变化。结果表明，1996年至2006年10年间，每公顷总能值投入增长了26.50%，而每公顷能值产出仅增长了5.71%；从能值结构看，桓台县农田生态系统有机能的利用大幅减少，对自然资源和不可更新工业辅助能的依赖性加强；从可持续发展综合指标看，系统环境所承受的压力增大，净能值产出率下降，系统可持续发展能力减弱。

Analysis on sustainability of farmland ecosystem with high yield based on emergy analysis methods

Whether the regional farmland ecosystem with high yield is sustainable or not is a key issue concerned food security. Based on the methods of emergy analysis and household questionnaire investigation, this paper studied the changes of the total amount of emergy input and output, the structure of emergy input and output and the comprehensive indexes of sustainable development from 1996 to 2006 in Huantai County with high yield in North China. The research results show that during the last 10 years, the total amount of emergy input rised by 26.50% while total amount of emergy output only rised by 5.71% per hectare; from the structure of emergy, the farmland ecosystem used less organic energy and more natural resources and industrial energy; from the comprehensive indexes of sustainable development, the environmental load ratio was increased that showed the environment carried more pressure; the emergy yield ratio was decreased; the emergy sustainable index was decreased which showed that the sustainability of farmland ecosystem in Huantai area was reduced.