Ensuring global food security is one of the challenges of our society. Nitrogen availability is key for food production, while contributing to different environmental impacts. This paper aims firstly to assess nitrogen flows and to highlight hotspots of inefficient use of nitrogen along the European food chain, excluding primary production. Secondly, it aims to analyse the potential for reducing the identified inefficiencies and increase nitrogen circularity. A baseline and three scenarios-reflecting waste targets reported in EU legislation and technological improvements- are analysed. Results highlighted a potential to reduce reactive nitrogen emissions up to more than 45%. However, this would imply the conversion of reactive nitrogen in molecular nitrogen, such as urea, before re-entering in the food chain. Techniques to harvest reactive nitrogen directly from urine and wastewater are considered promising to increase nitrogen use efficiency along the food chain.
Nitrogen flows from post-farm gate to consumption in food system were investigated.
Only 45% of the nitrogen flows in the post-farm gate food system ends up as ingested N.
Emissions of reactive nitrogen can be reduced up to 70% in tested scenarios.
Tertiary wastewater treatment plants reduce reactive nitrogen emissions but not contribute to N circularity.
Nitrogen circularity can be increased with innovative techniques capturing reactive nitrogen.