As described by Sims and Pierzynski ( 2005 ), the major processes of the soil P
cycle that affect soil solution P concentrations are biologically mediated conver-
sions of P between inorganic and organic forms, i.e., mineralization–immobiliza-
tion; interactions between P in solution, and soil solid surfaces, i.e., sorption–
desorption and dissolution–precipitation, i.e., mineral equilibria.
4.3.1 Different Microbial Mechanisms of P-Solubilization
Microorganisms are observed as proprietor of diverse mechanism to solubilize both
organic and inorganic phosphate.
4.3.1.1 Organic P-Solubilization
Mineralization of organic phosphorus constituting 4–90% of the total soil P is
referred as Organic P solubilization (Khan et al. 2009 ). Each organism can act in
one or multiple ways to bring about the solubilization of insoluble P in soil. One of
Fig. 4.1 Schematic representation of P solubilization/mineralization by various organic/inorganic
substances produced by PSM
68 A. Walia et al.