Spatial variability of soil texture in a polder area. 1. Kriging
geostatistics. The variability was found to be the largest for the sand and silt contents, but occurred at shorter distances for the clay content. In order to apply puntual-kriging optimally, observations are required at least every 14,5 m for the depth data
spacing of 2 km in a square grid was found to result in an acceptable maximum kriging estimation error of 5,76 %. The proposed sampling strategy would require 408 observations in total. This is 71 % less than the sampling during the National Soil Survey.