基于地统计学和GIS的通州区于家务乡 土壤肥力综合评价.

[Objective] The research has a guiding significance in quantitative management of agricultural soil fertility, land planning management and ecological construction of soil. The comprehensive evaluation method for the soil fertility which has been figured out will provide data support for land grading and quantitative research. [Method]8 fertility indexes (including total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, available potassium, organic matter and pH value) of the surface soil located at Yujiawu Township, Tongzhou District, Beijing were selected as the indexes for evaluating the soil fertility. Depending on index correlation coefficient method and membership function evaluation method, this paper figured out IFI value (IFI represents the soil fertility), by which soil fertility could be evaluated comprehensively. Then this paper analyzed the trend and space by geostatistical method and GIS technology. [Result]It was found that the variation coefficient of available phosphorus was the biggest, which was 107.04% while the variation coefficient of pH was the lowest, which was 2.80%. The sequence of variation coefficient is: available phosphorus > available potassium > available nitrogen > organic matter > total nitrogen > total phosphorus > total potassium > pH. Under a comprehensive comparison of the index interpolation error with different trends, linear should be selected for rapidly available potassium and IFI while constant should be selected for total nitrogen, available nitrogen and pH value, quadratic should be selected for other indexes. The semi-variance structure was good, which was consistent with the exponential model and Gaussian-type. Therefore, it had spatial correlation. The variation caused by structural factors played a leading role. [Conclusion] According to IFI value, the soil at the research area is divided into 5 levels---excellent soil, good soil, medium quality soil, bad soil and inferior quality soil. The area of good soil, medium quality soil and inferior quality soil accounts for 94.86%. From the special layout, we can know that the fertility of the soil at the research area is evenly distributed; from die north to the south, high fertility area and low fertility area are ribbonlike distributed, whose areas are almost the same. [ABSTRACT FROM AUTHOR]