Study on the agroecosystem health assessment in Western China

Agroecosystem with many comprehensive characteristics can be assessed through the measurement of its vigor, structure and resilience. Agroecosystem is very important to realize the healthy development of eco-agriculture. In this paper, based on the meaning of ecosystem health and the characteristics of agroecosystem, an assessment index system for agroecosystem in Western China was formed from the aspects of vigor, structure and resilience. The indexes included the NPP utilization rate, the land carrying capacity (ratio), the agricultural net output value of per km , the farmer net income per capita, the predominance of system produce, the population density, the diathesis of rural labourer, the vegetation coverage (ratio), the soil and water erosion rate, the land desertification rate, the water resources supply and demand ratio, the index of system stability, the greenness coverage (ratio), the resist capacity, the effective irrigation rate, the fertilizer, pesticide and plastic film dispensation of per arable land km, and the agricultural expenditure proportion. Then the paper used multiple methods and means such as comprehensive evaluation method, the analytic hierarchy process (AHP) and the geographic information system (GIS) to assess the healthy status of the six agricultural eco-zones in Western China. At last we got the following results: Agroecosystem in Sichuan basin district and Guangxi basin district were "sub-healthy", Qingzang plateau district, Yungui plateau district and Huangtu plateau were "not healthy", Mengxin district was "worst". The order from the best to the worst, among the six agricultural eco-zones in Western China, was Guangxi basin district, Sichuan basin district, Qingzang plateau district, Yungui plateau district, Huangtu plateau, and Mengxin district.