In order to increase the efficiency of nitrogen (N) use, and to reduce the potential for environmemtal contamination, certain Environmentally Friendly Fertilization Practices (EFFPs) have been proposed and used in agriculture. Based on existing knowledge, a comprehensive N-dynamics model has been developed to describe N-behavior in the soil under EFFPs conditions. While including most of the relevant transport and transformation processes that are related to the N-cycle, the model emphasizes the description of some special phenomena that occur due to the application of EFFPs. Such phenomena include multi-dimensional N transport, N-release from controlled release nitrogen (CRN) granules, and nitrification inhibition caused by locally high ammonium concentrations. The model considers two-phase flow by water and air, multicomponent solute transport of ammoniacal nitrogen, carbon, oxygen, urea, nitrate, heat transfer, and pH changes in the soil. Chemical equilibria of ammoniacal N-species and carbonate species an also included.