ABSTRACT
Under the rules of organic certification, phosphorus (P) deficiency in crops can be an important limitation to production. Phosphorus is notoriously difficult to extract from the soil; however, many plants have evolved to form a symbiotic association with soil fungi to cope with this difficulty. This chapter considers the arbuscular mycorrhizal (AM) symbiosis as a tool to reduce the problem of P nutrition in organic production. Current knowledge of AM fungi, soil P pools, the impacts of organic production on the AM fungal resources of soils, and the contribution of AM fungi to organic crop production is reviewed. From this overview emerge avenues that may lead to improvement in the P nutrition of crops in organic production.
