Integrated emergy and economic evaluation of three typical rocky desertification control modes in karst areas of Guizhou Province, China

Guizhou Province of China is a key karst area and is facing serious rocky desertification. Controlling the rocky desertification in karst areas in Guizhou has been formally established as a national goal. After decades of experience, some control modes are now recognized for their ability to reduce desertification and to provide income for the local community. However, a unified, integrated ecological and economic evaluation of these modes is lacking. The current study evaluated three modes (planting systems) and compared these modes with the planting of corn (CP), a traditional crop in this region. The three typical modes were pepper planting (PP), pitaya cultivation (PC), and honeysuckle-plum inter-planting (HPIP). Furthermore, the ecological and economic effects of adding livestock and biogas subsystems to the PP mode were quantified. The results showed that the PP mode provided the highest ecological-economic benefits, while the HPIP mode provided the highest ecological benefits. The addition of the livestock subsystem to the PP mode could improve the economic benefit density of the system with a tradeoff of environmental loading, while the addition of the biogas subsystem could partially correct for this. We suggest that local governments to strength the technology support for these modes in order to expand the production chains; this will include the development of processing facilities for livestock, biogas, and crops. Local governments should also help farmers maintain markets, create new markets (by branding the products, for example), and establish a short-term labor supply for crop harvesting.