Computer Modeling of Nitrogen Transformations in Soils

A nitrogen‐transformation model was formulated for simultaneous computation of various N transformations: nitrification, denitrification, mineralization, immobilization, ion exchange, and plant uptake. These processes were assumed to obey first‐order kinetics. Differential equations that describe the above processes are solved simultaneously by using the 4th‐order Runge‐Kutta method and the Adams‐Bashforth‐Moulton predictor‐corrector equations. The computer model was tested against data reported from several incubation studies. This model could be linked to a transport model to predict the temporal and spatial distribution of various N species in soil profiles.