洪泽湖农场土壤速效钾含量的地统计学和GIS分析

为了探索江苏省洪泽湖农场土壤速效钾的空间分布规律，精确衡量其土壤速效钾的供应能力，通过网格取样方法、利用GPS定位取得该农场的180个耕层（0~20 cm）土壤样品，应用地统计学分析方法进行实验变差函数的计算和最适合模型的拟合，得出土壤速效钾最好的理论模型为球状模型，随后用普通克立格估值方法绘制了土壤速效钾的空间分布图。通过对不同阶数趋势的土壤速效钾克立格（Kriging）插值误差的综合比较，表明其趋势效应参数应选取二阶。克立格估值标准差（KSD）作为内插象素值的标准差，为提高速效钾的制图精度提供了有用的信息。应用地统计方法和GIS技术研究土壤养分的空间分布规律、衡量土壤养分的供应能力，其方法和结果对于在农业生产中合理施肥、探索发展精确农业、农业可持续发展等方面都有重要的参考价值。

Geostatistical and GIS Analysis on Soil Available Potassium in the Hongze Lake Farm

In order to explore the spatial distribution of soil available potassium of Hongze Lake farm in Jiangsu Province,and then accurately measure the supply capability of soil available potassium,approximate grid approaches were employed for the sampling scenario with 180 global position system（GPS） established spots sampled in the farm topsoil（0-20 cm）.Geostatistics analysis was carried out,including calculation of experimental variograms and model fitting.The best theoretical model for semivariogram of soil A-K was spherical model.The ordinary Kriging estimates of soil A-K were mapped.Comprehensive comparisons of semivariogram parameters with different trend orders of the Kriging prediction errors of soil A-K indicated that the 2-order trend was preferable.Kriging standard deviations（KSD） were regarded as the standard deviations of the interpolated pixel values and provided valuable information for which would increase the accuracy of the A-K mapping.Geostatistics method and geographic information system（GIS） techniques were applied to investigate the spatial distribution of soil nutrient,and then to accurately measure the supply capacity of soil nutrient.The methods and results would be helpful for rational application of fertilizer,developing precision agriculture and sustainable agriculture.