[Agricultural eco-economic system coupling in Zhifanggou watershed in hilly-gully region of Loess Plateau].

Agricultural eco-economic system coupling is an organic unit formed by the inherent interaction between agricultural ecosystem and economic system, and regulated and controlled by mankind moderate interference. Its status can be expressed by the circular chain-net structure of agricultural resources and agricultural industry. The agricultural eco-economic system in Zhifanggou watershed has gone through the process of system coupling, system conflict, system coupling, and partial conflict in high leverage, which is caused by the farmers' requirement and the state's macro-policy, economic means, and administrative means. To cope with the problems of agricultural eco-economics system coupling in Zhifanggou watershed, the optimal coupling model should be established, with tree-grass resources and related industries as the core.