Water potential and aggregate size effects on contact angle and surface energy

Soil wettability affects hydrological processes like infiltration, percolation, preferential flow, and surface runoff. Wettability is related to the soil-water contact angle, which in turn depends on the solid surface free energy. Little is known, however, about contact angles and their dependence on soil water potential. The main objective of this study was therefore to investigate the dynamics of contact angle due to variation of the water potential. Aggregate fractions of 2- to 4-, 1- to 2-, and