Expanding supporting land to reduce greenhouse gas emissions from livestock farms: Case studies in northern China

Abstract

Livestock farms in China are equipped with supporting land, which is a key factor in promoting the optimal combination of crop and livestock systems to reduce greenhouse gas (GHG) emissions from agricultural production. However, there is still a research gap on the process of carbon flow at the farm scale in China and the mechanisms by which supporting land affects GHG emissions. In this study, we used an agri-environmental impact assessment framework created through an extensive farm survey based on a localized database. GHG emissions from livestock production were accounted for on a farm-by-farm basis. The impact pathways of GHGs were also analyzed using structural equation modeling. The results showed that the completed coupling farms (consuming agricultural waste and supplying fodder) were 2840 kg CO2e/$1000 USD, which was approximately 13.1% lower than those from incomplete coupling farms (consuming agricultural waste or supplying fodder) and 20.2% lower than those from non-coupling farms. GHG emissions are positively correlated with the pig–land ratio (R2 = 0.62, p < 0.001). Assuming that China's farms could be fully integrated by 2030, it could reduce GHG emissions by 12–22% of current levels, or about 45.5–84.5 million tons CO2e. Our findings provide new insights about expanding land to improve manure and feed management, which can help stakeholders develop strategies to reduce GHG emissions from livestock production, contributing to the achievement of sustainable agricultural development across China and globally.