Linear Equations for the Simultaneous Flow of Matter and Energy in a Continuous Soil System

Abstract

Some transfer processes in soil are considered with respect to recent developments in the theory of thermodynamics of irreversible processes. The theory provides a general and systematic guide for setting up interrelated equations describing the transport of one or more components through soil. Darcy's law and the “diffusion equation” are shown to be components of this general development. Particular attention is given to the non‐isothermal flow of moisture and energy through soil. A general relation between the fluxes induced by the combined gradients of moisture content, temperature, and solutes is also suggested.