Beyond circularity! Integration of circularity, efficiency, and sufficiency for nutrient management in agri-food systems

Abstract

Circularity is a new paradigm of nutrient management that is seeking to mitigate environmental impacts of agriculture by reducing nutrient losses through their recuperation and reuse. However, circular nutrient management is not an end goal in itself, but rather a means to a transition to sustainable food systems. We argue for a conceptually stronger and more explicit combination of circularity strategies with efficiency and sufficiency. A conceptual framework to combine these three transition strategies is presented and the relationship between the three strategies is demonstrated. An example of regional N flows is used to quantify the systemic effects of each strategy. Results show that circularity does not alter overall system’s efficiency but reduces primary inputs. Circularity can also lead to rebound effects if reused products have a lower efficiency than the products they replace. Targeting efficiency as a strategy has systemic, non-linear negative effects, as it reduces opportunities for implementation of circular solutions and reuse of nutrients. Sufficiency as a strategy can affect circularity, as a shift towards a more plant based diet will likely increase nutrient use efficiency, and will therefore reduce the available recoverable nutrients and limit circularity. Moreover, circularity, efficiency and sufficiency as strategies may have different time frames. Consequently, policy makers and practitioners need to consider the short-, medium- and long-term consequences of the three strategies and their relationships. Finally, regional nutrient management should aim to combine the three strategies in models, planning and decision making.