Co-benefits assessment of integrated livestock and cropland system based on emergy, carbon footprint and economic return.

Abstract

The rapid specialization of livestock production contributes to spatially decoupled crop and livestock production. Relinking croplands and livestock to promote wastes and by-products exchange has been suggested to provide opportunities for sustainable intensification of agriculture systems. However, the environmental and economic performances of such crop-livestock systems remain highly context specific and unclear. This study proposed an emergy-LCA-based framework to study the GHG mitigation and ecological and economic benefits of the integrated crop planting and livestock feeding systems, by taking wheat maize rotation-swine systems (WMRS), tea-swine systems (TS) and citrus alfalfa intercropping-swine systems (CAIS) as the empirical cases. The results showed the three case modes can generally promote GHG mitigation and ecological and economic benefits. CAIS had the lowest carbon footprint per kcal product (0.12 g CO2-eq kcal-1), followed by TS (0.61 g CO2-eq kcal-1) and MWRS (0.66 g CO2-eq kcal-1). The significant difference in this indicator can be attributed to their different upstream input and manure management. Due to the lower dependence on purchased resources, CAIS also had the best performance on emergy-based sustainability and economic benefits. Based on our results, the policy implications, including promoting wastes and by-products exchange, choosing reasonable manure treatment mode and conducting systematic planning have been suggested to provide opportunities for GHG mitigation and sustainable intensification of agro-systems.