草地农业的循环经济特征分析

Analysis of characteristics of the circular economy of grassland farming

通过对四墩子乡农业系统能值分析发现:1)四墩子乡全系统能值总流量121.007 6×1017 sej,草地亚系统能值总流量为89.27×1017 sej,占全系统能值总流量的73.77%,较农田与林地亚系统比重大。2)在各亚系统中,草地亚系统的能值投资率、环境负载率很低,而且系统太阳能值转换率最高,能值可持续发展指数相对也较大。3)草地农业系统与其它系统进行系统耦合,可使农业生态系统生产潜力得到大幅度提高。从而论证草地农业在整个大农业系统中处于物质、能量循环的中心,是实现农业循环经济的原发点。实施草地农业,进行广泛的系统耦合是促进农业循环经济发展的技术保障,也是中国农业结构调整的必然之路。

Circular economy characteristics of grassland agro-ecosystems in Sidunzi county were studied using emergy analysis.1） The agro-ecosystem＇s emergy flux of Sidunzi county was 121.007 6×10^17 sej（solar enjoules）,while the emergy flux of the grassland sub-system was 89.27×10^17 sej giving a ratio of 73.77%,which was greater than those of cropping and woodland sub-systems.2） Among these sub-systems,grassland agro-ecosystems had a proportionally lower emergy investment ratio and environment loading ratio,but had the highest solar emergy transformation rate and a relatively higher emergy-based sustainable index.3） The potential production of agro-ecosystems could be greatly improved by system coupling between grassland agro-ecosystems and other sub-systems.These results demonstrate that grassland farming occupies a central position in material and emergy cycles within mega-agriculture systems and this is the primary point to realize in the agricultural circular economies.The implementation of grassland farming and extensive systematic coupling are the technical support for promoting development of agricultural circular economies and the inevitable way for adjusting Chinese agricultural structure.