Nitrogen Transformations in Soil During Leaching; I. Theoretical Considerations

Transport equations describing the movement and simultaneous oxidation of NH 4 + to NO 3 ‐ and reduction of NO 3 ‐ to N 2 by microbial and/or chemical means were set up and solved both for leaching of a pulse and for a continuous application of NH 4 + and/or NO 3 ‐ salt at the soil surface. Both ionic adsorption owing to cation exchange and microbiological transformations have been considered and distinguished as reversible and irreversible processes, respectively. The possibilities of the model extended to a sequential transformation during transport of more than two nitrogen species have been examined.