Work on organic phosphorus (P) will determine the prevalence and persistence of organic P compounds in soils and waters from a range of grassland environments and across a range of scales. Phytate and inositol P compounds are the main forms of organic P, and this work aims to build on our knowledge of the biogeochemistry of these compounds in order to understand the processes giving rise to their distribution and potential for bioavailability. Plants are almost certainly the main source of phytate and other inositol P in the environment. We will produce baseline information on organic P in a relevant range of grassland soils and waters representing a range of inorganic P and C contents. We will compare the quantity and chemical form of organic P in soils with greatly differing C: inorganic P ratios and contents, collaborating with the Scottish MRPs, Dundee University, and the Smithsonian Tropical Research Institute, Panama. We will then study the quantity and chemical form of organic P in soils and waters, along gradients of C and inorganic P content that reflects the stream source to estuary continuum. In the longer term, we intend to put our findings from UK grassland environments in context with some strategically taken samples from more pristine grassland sites in the world.

Little is known about how small scale soil system processes influence larger scale hydrological and biogeochemical patterns and to do this we will test the hypothesis that agricultural land management influences the timing, quantity and quality of water flows from the rhizosphere to catchment scales. Using Uplift, the focus will be to improve our understanding of the dominant processes and thresholds on the timing, quantity and quality of water flows from the rhizosphere to catchment scale.