Review on Mechanisms of Phosphate Solubilization in Rock Phosphate Fertilizer
Thilini Amarasinghe, Chamalki Madhusha, Imalka Munaweera, Nilwala Kottegoda
Abstract
Phosphorous (P) is an indispensable element for all life forms. Even though P is applied to the soil mostly in fertilizer, it has been found to be inefficient, because only a small portion of the applied P which is supplied is actually utilized by the plant. Therefore, there is a critical need to increase the solubilization of P in order to make it readily available for plants. Various methods of solubilizing P from Rock Phosphate (RP) are discussed in detail in this review article, which includes physical treatments, chemical treatments, and application of microorganisms as well. One of the main methods of P solubilization is the application of organic acids. Since citric acid is a tricarboxylic acid, it can act as a very good chelating agent to chelate with metal cations. Therefore, usage of citric acid to solubilize P from RP and mechanism are briefly discussed in this article. Further, methods for P solubilization such as colorimetric, volumetric, and gravimetric methods have been discussed in brief.