used the above understanding of oxidation kinetics to develop of soil oxygenation. the model allows for the diffusion of O2 into the soil, the diffusion of Fe towards the oxidizing surface, the rate of formation and concentration profile of the Fe(OH)3 formed, and the diffusion by acid-base transfer of the acidity formed: H3O+ diffusing away from the zone of acidification and HCO3 towards it. The principal equations are as fillows, expressed in planar geometry so as to be able to test the predictions against experimentally measured reactant profiles.