中等尺度上土壤肥力质量的空间分布研究及定量评价

用修改后的内梅罗公式作为土壤质量的评价模型,将传统的统计方法与地统计学方法及GIS技术相结合,研究了金坛市土壤质量的空间分异规律,对金坛市土壤质量进行了定量化的评价。结果表明,金坛市土壤全氮以差级水平为主,pH、速效磷、速效钾、CEC和有机质均以中等级以上水平为主,综合肥力质量以中等水平为主;相对来说,全氮含量总体较低是金坛市土壤肥力的主要限制因子,pH值较低和速效磷水平较低是部分地区土壤生产力的主要限制性因子;金坛市土壤分质量及综合肥力质量的空间分布总体上具有以下特征:在东西方向上,中部纵贯全市南北的丹金溧漕河两侧的低洼圩区土壤质量指数相对较高,东部的高亢平原区次之,西部的丘陵区土壤质量指数最低;南北方向上,土壤质量指数西北低,向东南逐渐升高。土壤质量指数最高的区域主要分布于洮湖周围的河口区。金坛市土壤质量指数的这种分布特点明显与地形地势、径流方向和土地利用等有关,而地形地势是决定金坛市土壤质量空间分布的最根本的原因。

Study on Spatial Distribution of Soil Quality and Quantitative Evaluation of Soil Fertility Quality under Middle Spatial Scale

Spatial distribution and quantitative evaluation of soil fertility quality in Jintan county, Jiangsu province, have been studied through combinating the methods of statistics, geostatistics and GIS with the changed Nemoro formula as evaluation model.The results showed a low level of soil total nitrogen and a high level of soil pH, available phosphorus, available potassium, CEC and organic matter. The low pH and available phosphorus content may be comparative limiting factors of soil fertility in some area of Jintan county. As for the spatial distribution of soil qualities in Jintan county, it showed that soil quality index are the highest at the catchment of DanJinLi river area, followed by the plain in east Jintan county and then by the highland in west; it also showed that soil quality index became higher from northwest to southeast in Jintan county and the highest soil quality index was found in the influx area around the Lake Tao. The distributions of soil quality index in Jintan county are strongly related to topography, river flow and landuse patterns in Jintan county, but the topography in the county is the determinant of the distribution of soil quality index in Jintan county.