The application of system coupling in grassland agro-system in China Grassland Farming Is an Important Approach for the Sustainable Development of Agriculture in Gansu Province Coupling state of agricultural eco-economic system under emission mitigation and sink enhancement of non-point source pollution--A case study of Zhong County in the Three Gorges Reservoir Region Impacts of grazing on the system coupling between vegetation and soil in the alpine and subalpine meadows of Wutai Mountain Research progress and trend on grassland agroecology Principles of Grassland Resources Management Relationship of Interdependence and Contradictory between Ecological Restoration and Economic Development in theEcotone between Agriculture and Animal Husbandry in North China A Study on the Coupling Relationship of Soil and Vegetation of Leymus Chinensis Grassland in the Songnen Plain Research progress and trends in system coupling and discordance for grassland agroecosystems Landscape ecological mechanism on system coupling of the meta-ecosystem consisted of mountain,desert and oasis in Hexi corridor,Gansu,China Mechanisms and effects of agro-pastoral system coupling in the Inner Mongolian ecotone Analysis of characteristics of the circular economy of grassland farming