SIS - Choices and opportunities for sustainable use of phosphorus in food production

The limited global reserves of plant available phosphorus (P) urges to develop strategies that focus on a more efficient use of P, both derived from P accumulated in soil, primary mineral sources and as derived from secondary waste stream sources. The former excessive P application and subsequent accumulation and immobilization of P in agricultural soil imply that soil P is a P source that may be exploited to some extent. More efficient use of P in soil requires more knowledge on both processes in soil-plant system and on methods for exploiting soil P. Availability of P in soil is a complex interaction between plant roots, soil biology and physical and chemical conditions in soil. This SIS will characterize Norwegian soil types’ ability to bind and release P for more precise recommendations for P application, and explore the possibilities to take advantage of root exudates and mycorrhiza to increase availability of P in soil and secondary products. The project will include research on the genes or gene family inducing root exudation by P starvation in Norwegian Brassica species and barley cultivars, and interaction between soil, plant roots and root exudates in vivo under P starvation will be revealed. Variations in P transport capacity for native mycorrhizal fungal genotypes, and conditions where mycorrhiza is most efficient will be explored.