Closing phosphorus (P) cycles at a local level faces many challenges. In our transdisciplinary research project, we developed and assessed scenarios of sustainable P use, focusing on stakeholders’ preferences in terms of desirability and probability. For a future sustainability assessment, we collaboratively developed six sustainability indicators.

Global food supply depends on the availability of phosphorus (P). To produce P fertilizer for agricultural use, phosphate rock is needed. Phosphate rock is, however, a finite and increasingly scarce resource and is mined only in a few countries. By using recycled phosphates as fertilizers, it might be possible to meet the agricultural demand of P in a more sustainable manner. Based on a Formative Scenario Analysis of the administrative district of Lüneburg in Northern Germany, this transdisciplinary study develops several scenarios aiming at closing the local P cycle. The most desirable scenario from the stakeholders’ perspective is characterized by two aspects: First, stakeholders from industry and agriculture are committed to the use of recycled phosphates, and second, policies support P recycling efforts. This scenario is, at the same time, regarded as the least probable one because it is unlikely that statutory rules will change soon and that recycled phosphates will be accepted in agriculture or by the industry. For a future sustainability assessment of the developed scenarios, a set of six sustainability indicators was developed.