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.

确保全球粮食安全是我们社会的挑战之一。氮的供应是粮食生产的关键，同时也会对环境产生不同的影响。本文首先旨在评估氮流量，并着重指出整个食物链（不包括初级生产）中氮利用效率低下的热点。其次，其目的是分析降低发现的效率低下和增加氮圆度的潜力。分析了基准和三种方案，它们反映了欧盟立法中报告的废物目标和技术改进。结果突出显示了将活性氮排放降低多达45％的潜力。但是，这意味着在重新进入食物链之前，反应性氮会在分子氮（例如尿素）中转化。