Emergy-Based Sustainability Assessment for a Five-in-One Integrated Production System of Apple, Grass, Pig, Biogas, and Rainwater on the Loess Plateau, Northwest China

Abstract

A five-in-one integrated production system (FIOIPS) was applied in the Weibei region of Shaanxi province, one of China’s major apple producing areas on the Loess Plateau. The FIOIPS comprises five linked organic subsystems, including apple, grass, pig, biogas, and rainwater. Despite being proposed as a cost-effective agroecosystem, the FIOIPS’s environmental sustainability and economic benefits remain unclear. In this study, we compared the FIOIPS with conventional (clean) tillage-based and grass-cultivation-in-orchard apple production systems commonly used in Weibei. Emergy flow and economic characteristics of the systems were analyzed by emergy and economic analysis using the emergy indices of transformity, renewability, emergy yield ratio, environmental loading ratio, emergy sustainability index, emergy exchange ratio, and feedback ratio of yield emergy. Although the FIOIPS has relatively low potential energy conversion efficiency and strong dependence on the inputs purchased from the market economy, it is superior to the other two systems regarding self-organizing capacity, renewable resource utilization efficiency, ecological environmental loading, economic benefits, and sustainability. From the perspectives of market economy and sustainability, the FIOIPS has promising applicability, feasibility and development potential for agricultural production on the Loess Plateau. Finally, disadvantages of the FIOIPS are discussed and possible solutions are provided for optimizing the integrated production system.

KEYWORDS:

• apple production
• resource utilization
• sustainability
• emergy analysis
• ecoagriculture