Abstract: Emergy analysis was used to compare two agricultural systems in aspects of resource use,environmental impact,and eco-economic benefits.The systems analyzed were traditional cropping system(mode Ⅰ) and cropping-breeding coupled system(mode Ⅱ) practiced in Daliangwa Village,Huanxian County of Gansu Province.The results show that mode Ⅱ had lower production cost in comparison to mode Ⅰ,the fertilizer inputted decreased 50%,the proportion of nonrenewable industrial energy of modeⅡdecreased 32%,the proportion of the organic energy input increased 31%,but the relative economic input reduced 30%. The net energy yield ratio of mode Ⅱ was 2.65 times higher than mode Ⅰ,the environmental loading ratio of mode Ⅱ decreased 92%,so the resource use efficiency of mode Ⅱ was enhanced,environmental impact was dramatically decreased,and energy sustainable index was 31.25 times higher than that of mode Ⅰ.This case study clarified the mechanism of operating secondary production of grassland agriculture,i.e.introduction of grass into arable lands,which could significantly enhance the eco-economic benefits in comparison to the traditional agriculture,i.e.domination of grain harvest.

Key words: Emergy evaluation, Ecotone between farming and pasturing areas, Cropping mode, Cropping-breeding coupled mode

摘要： 应用能值分析方法对传统种植模式(模式Ⅰ)和种养耦合模式(模式Ⅱ)的资源利用、环境压力及生态经济效益进行比较研究。结果表明:与模式Ⅰ相比,模式Ⅱ的化肥投入减少一半,工业辅助能投入比例降低32%,有机能投入比例提高31%,但经济投入却降低30%;净能值产出率提高2.65倍,环境负载率降低92%,资源利用效率提高,环境压力显著减小,可持续性指数提高31.25倍;阐明了引草入田、加入次级生产,实行草地农业的生态经济效益高于以籽实生产为主的传统农业的原理。

关键词: 能值评价, 农牧交错带, 种植模式, 种养模式