以牧草为纽带的循环农业能值分析

Emergy Analysis on a Recycling System at Agricultural Demonstration Region,a Small Hilly Watershed,in South China

以南方山地小流域为研究对象,在福州北峰开展以优质牧草为纽带的循环农业模式研究。为了评价该模式的可持续发展程度和经济效益,本文采用能值分析方法进行分析,结果表明,该循环农业模式对自然资源的利用程度高,能值自给率达11.23%;系统自产资源投入占总能值投入的34.25%,能值反馈率高达62.83%,表明该系统对外界购买能值的依赖程度低,自组织能力强;净能值产出率为1.69,环境负载率仅0.49,可持续发展指数为3.47,该循环农业模式是一种资源节约型、环境友好型、具有较高生产效率的农业生产模式,可在我国南方丘陵山地推广。

Using a small hilly watershed in south China as a model ,an agricultural recycling system was studied . Emergy analysis was applied to evaluate the system ＇s sustainability and economic impacts on the region . The planting and utilization of forage were conducted in Beifeng area near Fuzhou . The recycling system exhibited a potential in maximizing the utilization of the natural resources . Its self-providing rate of emergy was 11.23% ;the system produced 34.25% of the total invested emergy ; and , the emergy feedback rate was 62.83% . In other words ,the system was highly self-sufficient . The net producing rate of emergy was 1.49 and the sustainable development index as high as 3.06 ,while the environment loading rate merely 0.49. The emergy analysis suggested that this recycling system could be used as a demonstration model to promote the highly efficient ,resource-saving and environment-friendly application on similar hilly lands in south China .