Abstract:

In order to get a better understanding of ecological and environmental situations of Yanchi County, Ningxia before and after its ecological restoration, it is necessary to analyze the changes in agricultural material inputs during the same period. GIS software was used to calculate the distribution centers of cropland and agricultural materials inputs during 2000-2008. It was found that: with declining of cropland area in waves, inputs of fertilizer and plastic sheeting increased in volatility, but input of pesticide showed a fluctuating downward trend; however, cropland area and agricultural inputs fluctuated in an opposite direction; cropland distribution center moved roughly in the opposite direction that distribution centers of agricultural materials inputs changed. A largest amount of cropland was returned to forest or grassland in 2003, resulting in that the ecological problems cased by low quality cropland had been alleviated, while non-point source pollution intensified because of increasing agricultural material inputs in cropland. After 2003, southeast-northwest transition zone not only had an increasing cropland, but also had higher agricultural material inputs. Thus, the study area still faced the ecological degradation caused by cropland expansion and the non-point source pollution caused by relatively higher agricultural inputs.