In acidic soils with high levels of metal ions like Al3+ and Fe3+, phosphate is bound-up in the form of the corresponding insoluble metal phosphates, e.g. AlPO4 and FePO4. Phosphorus solubilization in such soils generally occurs via microbial mediated reduction of the metal ion resulting in the release of phosphate. A number of soil microbes, including Pseudomonas, Shewanella, and Geobacter, are involved in this process.
Application of BiOWiSH® microorganisms to soil promotes a shift in the rhizosphere microbiome, resulting in increased populations of certain beneficial microbes, including those with metal ion reductase activity (like Pseudomonas). In addition, the endophytic activity of BiOWiSH® microorganisms promotes improved plant uptake of the released phosphate by shifting the equilibrium of bound-to-soluble phosphate towards more soluble phosphate.
Therefore, addition of BiOWiSH® to soils improves phosphorus solubilization by promoting the growth of soil microbes capable of reducing metal phosphates, improving the uptake of the released phosphate by plants and shifting the equilibrium between bound and soluble phosphate towards more soluble phosphate.