Thermal diffusivity and temperature regime of soils in large lysimeters of the experimental soil station of Moscow State University

The thermal diffusivity of the upper horizons of model soddy-podzolic soils in the lysimeters depends on their water contents and varies within 2.1?4.32 × 10^?7 m²/s in the Ap horizon, 1.59?3.99 × 10^?7 m²/s in the B1 horizon, 1.28?3.74 × 10^?7 m²/s in the plowed B2 horizon, and 1.12?4.10 × 10^?7 m²/s in the B2 horizon. The dependence of the thermal diffusivity on the soil water content is described by an inverted parabolic curve for the Ap horizon, an S-shaped curve for the B1 and B2 horizons, and by a curve of transitional type for the plowed B2 horizon. The temperature regimes of model soils with different morphologies of the profile do not differ much and are close to the soil temperature regime under natural conditions on the plots of the weather station of Moscow State University.