A sample spacing up to 22 cm over a distance of several metres is just sufficient to collect information about preferential flow paths in a water-repellent sandy soil. When larger sample spacings were used, the water content distributions became more horizontally stratified. Increasing the sample size by pooling pairs of adjacently taken 100 cm3 soil samples over a distance of several metres still allowed preferential flow paths to be detected. Preferential flow paths were no longer observed for larger sample sizes. Enlarging the sample size reduces the calculated standard deviation and coefficient of variation. Sampling strategies must be flexible in design.
- soil analysis