A modified water drop method for addressing the spatial variability of hydrophobicity within individual pedons

Abstract

The development of hydrophobic layers during wildfire is well‐documented. Tests are often performed on a few points at the mineral soil surface. However, this may not accurately capture the spatial extent of these layers laterally or vertically. Here, we describe a method for performing the water drop test on an intact vertical soil face collected from the field at a resolution of 1 cm ² . Using spatial interpolation, a continuous cross‐sectional image of soil hydrophobicity can be obtained. The ability to assess the vertical distribution of water repellency in soil profiles using this approach enables greater understanding of the formation of these layers and their potential impact on the hydrological dynamics of fire‐affected soils.