Dielectric characteristics of soils and categories of soil water

摘要

The complex permittivity of the Ap horizons of a leached chernozem, gray forest soil, and soddy-podzolic soil, as well as those of kaolin and its mixtures with sand, was studied by the capacitance method. The relationships between the characteristics of losses (the imaginary component E > aEuro(3) and the loss tangent tan delta) and the water content (W) are more indicative of changes in the water categories than the analogous relationships of the real component (E > aEuro(2)), which characterizes the relaxation capacity of water molecules. The breakpoints on the curves tan E > aEuro(2) = f(W) and E > aEuro(3) = f(W) are more pronounced compared to the curve E > aEuro(2) = f(W) and better agree with the soil-geological constants: tan delta = f(W) at the W value close to the wilting point (WP) for all soils and at the maximum water adsorption capacity (MWAC) and maximum capillary sorption capacity (MCSC) for kaolin and its mixtures; E > aEuro(3) = f(W) at the MWAC, WP, and maximum molecular water capacity (MMWC) for the leached chernozem and soddy-podzolic soil. On the curve E > aEuro(2) = f(W), breakpoints were observed only for the gray forest soil and sand-clay mixtures.