Nitrogen flow in food production and consumption system of Inner Mongolia from 2000 to 2020

Decoupled crop and livestock production caused serious disconnection of nitrogen utilization in agro-pastoral ecotone of northern China. In this study, we employed a material flow analysis approach to investigate reactive nitrogen (N_r) flow in the food production and consumption system in Inner Mongolia from 2000 to 2020. Results indicated that agricultural production system is the primary source of Nr input for the food consumption system. The environmental nitrogen load in Inner Mongolia has been increasing progressively, from 266 Gg in 2000 to 882 Gg in 2020, primarily due to the rapid increase in livestock farming and significant losses of nitrogen in feces and urine. Our results raise the attention to promote the close integration of farmland production and livestock system in the decoupled crop and livestock production system.