稻鸭共作有机农业模式的能值评估

应用能值分析方法对稻鸭共作有机农业模式（模式Ⅰ）和对应的稻麦常规生产模式（模式Ⅱ）进行比较研究，并比较了两种模式的生态经济效益.结果表明，模式Ⅰ的能值效益高，自组织能力、可持续发展能力强，产品安全性高，净能值产出率（EYR）、系统产出能值反馈率（FYE）、能值可持续指标（ESI）分别是模式Ⅱ的1.57、14.1和8.71倍；基于能值的产品安全性指标（EIPS）模式Ⅰ为0，模式Ⅱ为-0.66；模式Ⅰ对环境的压力小于模式Ⅱ，能值投资率（EIR）,环境负载率（ELR）分别是模式Ⅱ的40.1%和18.3%；但模式Ⅰ的经济效益低于模式Ⅱ，其产出、毛收入和净效益分别低于模式Ⅱ15.7%、9.6%和29.6%；以能值 货币价值计算，模式Ⅰ的产投比、毛收入和净收入分别高于模式Ⅱ50%、102.6%和136.4%.随着生产系统的优化和市场对有机食品认知程度的提高，模式Ⅰ的经济效益具有提高的潜力.

Emergy value evaluation on rice-duck organic farming mode

Employing emergy value evaluation method, this paper compared the ecological and economic benefits of rice-duck organic farming system (mode I) and conventional rice-wheat rotation system (mode II) in Shanghai suburb. The results showed that mode I had better emergy benefits, higher self-organizing ability and sustainability, and higher product safety. The net emergy yield ratio (EYR), feedback ratio of yield emergy (FYE), and emergy sustainable index (ESI) of mode I were respectively 1.57, 14.1, and 8.71 times as much as those of mode II, and the emergy index of product safety (EIPS) was 0 in mode I but -0.66 in mode II. The emergy investment ratio (EIR) and environmental loading ratio (ELR) of mode I were 40.1% and 18.3% of mode II, respectively, suggesting that mode I had less environmental pressure than mode II. Mode I had lower economic benefits than mode II. The economic output, gross income, and net income of mode I were 15.7%, 9.6%, and 29.6% less than those of mode II , respectively. As for Em dollars, the output, gross income, and net income of mode I were respectively 50%, 102.6%, and 136.4% higher than those of mode II. With the system optimization and the development of organic food market, mode I had the potential to improve its economic benefits.