To i) compile a dataset of N₂O emission obtained in Mediterranean conditions and evaluate the ability of a simulation soil-crop model (STICS) to predict the observed fluxes, ii) evaluate its ability to capture the effect of a gradient in mean precipitation and year to year irregularity on N₂O emissions in a Mediterranean transect and iii) to test the efficiency of several agricultural management strategies for mitigating N₂O emissions along such a climatic gradient.

 This work demonstrates the usefulness of modelling approaches combined with experimental data, to take into account climatic variability and explore how the efficiency of mitigation practices is affected by the agro-pedo-climatic conditions.

 To investigate and quantify the impact of different low-input cropping systems based on grain legumes without and with cover crops during fallow period, in order to produce a nitrate catch crop effect for mitigating N leaching.

 This study highlights the importance of a proper design of entire cropping systems, i.e. simultaneously modifying cash crop succession and cover crop, by adapting the crop rotation and the different management practices (i.e. N fertilization, irrigation, etc.) to mitigate the environmental impact of N leaching and reduce as much as possible pre-emptive competition phenomena due to cover crops.