中文摘要：

为了深入探讨生态退耕前后宁夏盐池县的生态与环境状况,定量分析其农资投入的时空变化特点是现阶段的必要手段,主要利用GIS软件,计算研究区退耕前后的2000—2008年耕地面积和农资投入量的分布重心及其变化。结果表明：随着耕地数量的波动下降,化肥和农膜投入的总量呈波动上升趋势,而农药投入呈波动下降趋势,但耕地面积与农资投入量波动的方向相反;耕地分布重心的偏移方向大致与农资投入量分布重心的移动方向相反。生态退耕幅度最大的2003年,劣质耕地被大量退耕,但优质耕地面临农资投入增高所带来的面源污染问题。2003年后,西北—东南过渡区不仅耕地面积增加,且单位面积农资投入量维持较高。可见,现阶段研究区仍然面临耕地增加所带来的生态退化问题和农资投入较高所潜伏的面源污染问题。

英文摘要：

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.