The influence of soil structure and air content on gas diffusion in soils.

Abstract

A method is described of determining the diffusion coefficient of O2 in undisturbed soil samples. Calculations were made of errors involved when neglecting the storage term, temperature and pressure variations, O2 consumption and resistance of ambient air. The diffusion coefficient (Ds) is a function of air porosity (eg) and soil structure. At values of eg below 0.2, the effect of a puddled soil surface becomes evident. In puddled soils values of Ds at equal eg are far below those in non-puddled soils and the differences increase with decreasing eg. A wet soil crust can severely limit gas exchange by diffusion. (Abstract retrieved from CAB Abstracts by CABI’s permission)