The organic P consortium (OPC) is funded by Biotechnology and Biological Sciences Research Council (UK) to explore cropping strategies to target the use of recalcitrant soil organic P. This consortium gathers 14 academics from Lancaster University (Lancaster, UK), James Hutton Institute (Aberdeen and Dundee, UK) and Rothamsted Research (Devon, UK).
The project hypothesis is that: cropping systems selected to express favourable root exudate properties will facilitate sustainable agricultural production through improved access to soil organic phosphorus (Po). Specifically, we will use exemplar plant mixtures to investigate the ability of low molecular weight organic acid anions (LMWOAA) and phosphatases to access soil Po. Additionally, the interaction of Po, LMWOAA, and phosphatases with the soil solid phase will be investigated, through batch incubations and equilibrium modelling. A range of experiments are being conducted to identify potentially suitable strains of barley (Hordeum vulgare L.) and clover (Trifolium subterraneum L.) and will be followed by growth experiments incorporating different combinations of these plant lines to determine which combinations can most efficiently access soil Po, while minimizing losses of P via leaching. Experiments and techniques employed will include the screening of plant populations for LMWOAA and phosphatase exudation, using anion exchange resins and diffusive gradients in thin films (DGT), HPLC for root exudate analysis, enzyme hydrolysis and P-NMR analysis for identification of Po compounds and classes in soil extracts and soil pore water.