Fig. 2. Air permeability (closed symbols; data from this study) and gas diffusivity (open symbols; data from Moldrup et al. (2003) as functions of volumetric soil-water content for Miura 3 Andisol. D_P and D₀ are the gas diffusivities in soil and free air, respectively. Measurements on three closely spaced 100-cm³ undisturbed soil cores are shown.