Estimating Thermal Diffusivity of Soil Packed in a Cylinder Using an Analytical Solution

Abstract

Soil thermal properties are critical to many processes. For example, germination, crop growth, and nitrification depend on soil temperature, which is determined by thermal properties. Thermal properties are usually measured in situ using specially designed probes that enclose a heat source. Here we propose and validate an alternative method for estimating soil thermal diffusivity, based on changes in temperature at the center of a soil core subjected to changing thermal boundary conditions. This method formerly required numerical analysis because no analytical solution was known ; here we present an analytical solution. Estimates of thermal diffusivity of an Andisol at various moisture levels, obtained using the new method, compared favorably to results derived with the conventional probe method, showing that the new method constitutes a viable alternative.