Aim of the project

The issue of a continuous and increasing nitrogen (N) input represents one of the main threats affecting ecosystems, having significant and non-skippable impacts on surface (SW) and groundwater (GW) quality, greenhouse gas  (GHG) emissions, and finally human health. 

In this view, the Nitrogen Origin, EXport and Cycling in coastal irrigatEd SettingS project (NO3EXCESS) represents a multidisciplinary plan aimed at quantifying N loads in lowland agricultural settings by considering their origin, pathways, transformations, and impacts, with the final objective to identify and adopt the most effective countermeasures to reduce them.

Expected results

NO3 EXCESS outcomes will shed light on: 

i) the identification and quantification of all biogeochemical processes governing N processing and fate both in surface water (SW) and groundwater (GW), 

ii) the quantification of N species export to the terminal receptors, i.e. the coastal lagoons, 

iii) the identification of the most suitable remediation strategies (RS) to control eutrophication, by reducing N input to the coastal area (i.e. conservative management practices of aquatic vegetation), and to mitigate climate change by reducing greenhouse gas (GHG) emissions.

Understanding how agricultural practices affect GW-SW interactions and impair the quality of water conveyed to coastal zones is challenging. Therefore, quantifying the contribution of GW to the generation of N loads and the subsequent transfer of contamination to SW in coastal irrigated settings is crucial, particularly in European river basins where water quality requirements are defined by two specific directives, i.e. the Water Framework Directive and the Groundwater Directive.

Specifically, it is expected to obtain the following:

-          understand the role of seasonality in biogeochemical N processes acting in lowlands agricultural irrigated settings;

-          identify hot spots and hot moments of GHG emissions;

-          demonstrate the importance of including anthropogenic stressors, such as irrigation, drainage, fertilization and land cover, in the calculation of water and nitrogen budgets;

-          promote the use of a deterministic approach (like numerical simulations) to address water and N budgets calculations in a physically-based manner;

-          make “visible” the contribution of the GW in the generation of N loads and the consequent transfer of contamination to SW in coastal irrigated settings;

-          promote policy to foster effective RS to decrease N loads towards the coastal zones;

-          rise awareness about SW and GW pollution prevention.

The adoption of a holistic approach to N mass balance at the catchment scale is possible by the involvement of a multidisciplinary consortium with distinct and complementary expertise in aquatic ecology, biogeochemistry, hydrogeology, hydrogeochemistry, soil science, stratigraphy, and numerical modelling.