The circular nutrient economy: needs and potentials of nutrient recycling

Food production around the globe rests significantly on industrial fertilizers that make use of virgin phosphorus sources and energy-intensive fixation of nitrogen. At the same the nutrients ending up in the residues of the food system are inefficiently used as fertilizers. When produced in large quantities, organic biomasses such as animal manure may transform into a source of harmful nutrient pollution. This chapter argues for a transition from the utilization of virgin nutrients to nutrient recycling. It specifies criteria for a sustainable transition and provides an overview of the technological, practical and institutional dimensions critical for the change. The transition to the circular nutrient economy calls for policy measures that restrict inefficient nutrient use; generate demand for recycled fertilizers; and provide support for biomass processing before the markets for recovered resources are up and running. Public and private investments, technological developments and institutional shifts can create conditions for profitable and safe production and consumption of recycled nutrients.