Global food supply depends on the availability of macronutrients in soil especially phosphorus (P). To produce P fertilizer for agricultural use, phosphate rock is needed. Phosphate rock is, however, a finite and increasingly scarce resource. Problems caused by an excessive use and inappropriate application of P fertilizers also need to be addressed because they pose a major threat to agriculture, global food security and the environment. To guarantee a stable P supply into the future, it is not only necessary to reduce P consumption and to apply it more efficiently, but also to recycle P. Closed local P cycles could contribute to the transition towards a truly sustainable agriculture, which honors the integrity of ecosystems and meets the increasing global demand for healthy food for generations to come. 

To address such global challenges and to transform the current systems to become more sustainable, a strong collaboration among involved stakeholders is essential. Transdisciplinary is a suitable guiding concept for such collaborations.

The seminar will present the case study from Germany using a transdisciplinary research approach involving researchers and stakeholders from outside-academia (wastewater management and sewage, agriculture, environmental organizations). Based on a Formative Scenario Analysis of the administrative district of Lüneburg in Northern Germany, they jointly developed several scenarios aiming at closing the local P cycle, and a set of six sustainability indicators for future sustainability assessment.