Nitrogen pollution policy beyond the farm

Nitrogen is a crucial input to food production and yet its oversupply in many parts of the world contributes to a number of environmental problems. Most policies dedicated to reducing agricultural nitrogen pollution focus on changing farmer behaviour. However, farm-level policies are challenging to implement and farmers are just one of several actors in the agri-food chain. The activities of other actors - from fertilizer manufacturers to wastewater treatment companies - can also impact nitrogen losses at the farm level and beyond. Consequently, policymakers have a broader range of policy options than traditionally thought to address nitrogen pollution from field to fork. Inspired by the concept of full-chain nitrogen use efficiency, this Perspective introduces the major actors common in agri-food chains from a nitrogen standpoint, identifies nitrogen policies that could be targeted towards them and proposes several new criteria to guide ex-ante analysis of the feasibility and design of different policy interventions. Sustainably feeding ten billion people by 2050 will require fundamental changes in the global food system - a broad portfolio of policy options and a framework for how to select them is essential. This Perspective builds on the concept of full-chain nitrogen use efficiency to propose policy interventions and criteria that target major actors in the agri-food chain.