The S&T Project for Bumper Harvest of MOST studies on the diagnostic indicators for ecological health of farmlands in major grain production regions and has developed related key control technologies. The project has put forward preliminary diagnostic indicators for ecological health of farmlands and rice fields in northeast China’s black soils, the North China Plain and the Middle-Lower Yangtze Plain. Three bases have been established in northeast, north and south China for location-specific study on key technologies for eliminating soil restrictive factors and nutrient balance.