Towards Improved Policies for Sustainable Phosphorus Management.

Phosphorus (P) controls metabolism in biological systems that underpins global food security, yet consumption of our natural capital of P is reaching unprecedented levels. The P cycle depends on its aqueous transfer (there is no significant atmospheric phase), resulting in small ambient pools in natural ecosystems that are highly sensitive to P inputs. Human-derived inputs of P to water from sewage, industry and agriculture have contributed to the extent that currently P transfer from land to coastal waters is double that of pre-human fluxes.  This elevated P flux influences the ecosystem services upon which we depend, through degradation of natural resources (soils, freshwater) and loss of biodiversity. Controlling the flux of P between pools (most critically between land and water) must be the foci of new policies for P management and that our (perhaps misguided) preoccupation with managing stores of P (i.e., the ‘peak P’ argument) means we have missed a trick in the sustainable use of this critical resource.  A new and reinvigorated focus is required on: (1) the global P cycle and where in the earth system the major fluxes are located; (2) accumulation of P (including organic forms) in soil and opportunities for some biotechnological ‘root’ solutions; (3) opportunities for improved animal manure and human biosolid P management and recycling, and (4) the need for holistic & integrated systems thinking, new ‘demonstration catchment’ and ‘observatory’ science that cross discipline boundaries.  Ultimately, both global and national policy perspectives will be important here, but delivery of solutions will in the main depend on local responsibilities (institutionally and legally defined) and local action (funded from local or higher sources).  It is important to acknowledge many contributors to this work, who will be named and acknowledged in the oral presentation.