土地综合生产力评价与土地质量变化研究

AGRICULTURAL LAND EVALUATION BASED ON DIFFERENT CROP PLANTING AT COUNTY LEVEL AND HOUSEHOLD BEHAVIOR

该研究是根据曲周县的农业生产情况 ,以地理信息系统为平台 ,初步选取与农业生产关系密切的地貌和土壤物理性质 ,地下水因子影响盐碱程度 ,土壤有机质、和养分含量及其他生产条件等四类 1 4个指标 ,进行分析。并通过相关性分析和逐步回归 ,针对小麦、玉米、棉花、蔬菜 ,筛选和确定影响其生产、产量的评价指标体系 ,并对筛选的指标进行量化分级和指标权重的量化 ,对影响与制约土地生产力的自然因素和社会经济因素进行综合评价。通过土地评价及其分析得出 : ①同一因素对不同作物有不同的影响 ; ②同一地块对不同作物生产力综合评价等级不尽相同 ; ③不同等级土地的土壤有机质的变化量、土壤养分含量的变化情况有一定差异 ,其主要影响因素是农户的生产投入差异 ,这种差异主要来自于农户种植结构的不同和不同区域、乡村农户间投入的不同 ; ④地下水的过度开发 ,农户氮肥的过量投入以及钾肥投入的不足是该地区土地和水资源退化的主要因素。

Land evaluation to different crop was done at county level, based on the aggregation of Bio-physical data (including water resource, soil type, the content of nutrient of soil and SOM, etc.) and Socio-economic information (including input and output of farm household and some statistic data at village level) with Geographic Information System (GIS). With the correlation analysis and stepwise model, the indicators of land production evaluation for winter wheat, maize, cotton, or vegetable were separately screened out from biophysical factors and socio-economical factors and their coefficients were attained for the land evaluation to different crop production. According to the analysis on soil quality change and input-output coefficient of farm household, the results indicates: 1) Same factor had different effect on agricultural production of different crop; 2) Same land had different class with regard to different crop; 3) Difference in the land use system among farm households and the difference in input and output among different villages were the key factors affecting the change of land quality; 4) Overexploitation of groundwater, farms' over fertilization of Nitrogen and shortage of K are the key factors which result in the degradation of water and land resources in Quzhou County.