Capillary Conductivity and Soil Water Diffusivity as Influenced by Moisture Content and Texture

Water transmission coefficients viz., unsaturated conductivity (K) and water diffusivity for 3 soils were determined. The values of K did not exhibit distinct variation in their magnitude as a function of soil texture. However, it decreased very rapidly with decrease in soil moisture potential having relationship of K = a/ψ/−n. The moisture diffusivity was higher in sand followed by Raipur red soil and Kharagpur sandy clay loam soil. As the initial moisture content increased the diffusivity values of each soil also increased. The maximum moisture diffusivity occurs at certain moisture content less than saturation mostly falling in the range of 0.25 to 0.30 cm3 cm−3 moisture content.