Abstract

Phosphorus (P) is essential to all living organisms and a major nutrient for successful crop production in organic farming. Organic production guidelines ban the use of highly soluble, manufactured P fertilizers, thus P sources for organic farming must come from P rock, green or animal manures, compost, and biofertilizers. In this article, we first briefly describe the P dynamics in soils, covering organic and inorganic P operational pools. Next, practical P sources for organic farming are discussed. These include phosphate rock, bone meal, animal and green manures, and compost. Bio-enhancers of soil P availability is covered next, including mycorrhizal fungi, P solubilizing microbes and biofertilizers with mixed microbial species. Detailed organic P molecules, such as phytate (monoesters phosphate) and nucleic acids (diester phosphates) and their hydrolyzing enzymes are presented. Finally, the role of organic P in crop growth is considered.

Keywords:Biofertilizers; Compost; Manures; Organic P; P Rock; Phosphatases; Phytate