Influence of Soil Conditioners on Infiltration and Water Movement in Soils

Abstract

AbstractThe infiltration of water at 2mbar suction into horizontal columns of two soil materials of different textures was studied. The columns had been treated with two soil conditioners, Krilium and poly(vinyl alcohol). The soil‐water diffusivities were calculated from the water content distribution data. Treatment of a clay loam with the soil conditioners caused 1.5‐fold to 3‐fold increases in soil‐water diffusivity over the whole range of volumetric water contents. When expressed as a function of soil water potential, soil‐water diffusivity increased by this treatment more than 10‐fold at the lower soil‐water potentials. The same treatment had far less effect on the soil‐water diffusivity of a loamy sand. For both soils the rate of movement of the wetting front increased as a result of treatment with the soil conditioners.The calculated mean diffusivity and rate of movement of the wetting front in these soils was greater for n‐heptane than for water. The intrinsic diffusivity and penetrability differed for the two permeants. Changes in viscosity, surface tension, and apparent contact angle did not account fully for this dependence of diffusivity and penetrability on the permeating liquid.