Preferred future phosphorus scenarios: a framework for meeting long-term phosphorus needs for global food demand

Abstract

This paper puts phosphorus recovery in a global sustainability context, with particular reference to future phosphate rock scarcity and global food security. While phosphorus fertilizers are essential for sustaining high crop yields, all modern agricultural systems currently rely on constant input of mined phosphate rock. However, phosphate rock, like oil, is a finite resource, and global production of high quality phosphate rock is estimated to peak by 2033, after which demand for phosphorus fertilizers will increasingly exceed supply. Phosphorus cannot be manufactured; though fortunately there are a number of technologies and practices that together could potentially meet long-term future phosphate fertilizer needs for global food demand. This paper develops probable, possible and preferred long-term scenarios for supply and demand-side measures. The preferred scenarios together demonstrate how substantial reduction in demand for phosphorus can be achieved, and how the remaining demand can be met through high recovery and reuse of organic sources like human and animal excreta (e.g. direct reuse, struvite crystals), crop residues, food waste and ¿new¿ sources like seaweed, ash, bonemeal and some phosphate rock.