Methods of determining the coefficient of water conductivity in soils

The paper is aimed to consider the theory and methods of determining the coefficients of water conductivity and filtration. Soil columns and lysimeters were used for this purpose. It is shown that even a slightly expressed decrease in the moisture content can lead to decreasing the water conductivity in soil. In the range of high values of the moisture potential the coefficient of water conductivity is significantly higher for light-textured soils, on the contrary, within the range of middle and low values it seems higher for loamy soils. The maximum of water conductivity in any soil is close to filtration coefficients, but its minimum tends to zero. The coefficients of water conductivity and filtration become usually close under conditions of descending flow when the moisture is equal to the maximum water capacity or close to it.