Study area

Nutrients budgets at watershed scale, inventory of sources, N and P dynamics in aquifers (water residence time, storage zones, paths) and nutrient upwelling timing and quantity will be studied for the first time in two key sub-basins of the Po river, namely the Adda and the Ticino basins, in their sub-lacual sector. Results will be compared with the findings from the Oglio river basin. All these basins are characterized by groundwater upwelling at the transition between the higher and lower plain (in the springs belt area) and by a strong river hydrological alteration due to multiple water use. On the other hand, the basins strongly differ for crops, fertilizers applications and livestock population, likely resulting in a gradient of nutrient surplus and a consequent different impact on surface and groundwater quality. Nutrient cycling will be investigated also in relation to the type of irrigation and the amount of water used, with the aim of understanding how these agronomical practices affect groundwater upwelling, denitrification in soils, river water quality and ecosystem functioning.