Jean Riotte (IRD-GET) and Laurent Ruiz (INRA/IRD-GET), together with M. Tripti (Post doc IISc) and Nils Dubois (M2 ISTOM), performed a field experiment within the frame of the ANR ATCHA project, aiming at assessing the fate of nitrates from irrigation by groundwater. The experiment was performed in the Berambadi catchment (M-TROPICS/BVET) on two soil types with 4 different groundwater compositions. Monitoring consisted in GHG (N2O, CO2, CH4), soil moisture and soil pore water composition.