Nitrification inhibitors differ in their chemical structure. This means that it is not easy to predict their environmental fate including their tendency to leach towards the groundwater. GEUS has a long history of research on the fate of organic chemicals in soil including the tendency of the chemicals to adsorb to soil particles and to degrade either fully or into various degradation products. In the amoA project, different methods for studying sorption and degradation will be applied to the model nitrification inhibitors. The methods will include a) high-resolution mass spectrometry for the identification of degradation products; b) small scale flask experiments for determining basic sorption coefficients and degradation rates of nitrification inhibitors and their degradation products; c) larger-scale column experiments to determine the tendency of nitrification inhibitors and their degradation products to leach towards groundwater and to determine differences in leaching between typical Danish soil types.