Abstract:

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). Geostatistical 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 will be helpful for rational application of fertilizer, developing precision agriculture and sustainable agriculture.