What is Potassium Fixation

Potassium (K) is one of the essential nutrients required for plants. Although the total pool of K in the soil is generally large, the bioavailable portion is meager. There are several mechanisms through which the insoluble K can be made available through soil microbes called “potassium solubilizing bacteria” or KSB. They play an important role in increasing the solubility of K for proper crop establishment under potassium deficient soils through the production of organic and inorganic acids, acidolysis, polysaccharides, complexolysis, chelation, and exchange reactions. Moreover, they also produce specific exopolysaccharides and biofilm that enhances the weathering of the K-rich minerals and increase the K concentration in the soil solution. Hence, the production and management of biological fertilizers containing KSB can be an effective alternative to chemical fertilizers. This chapter presents the underlying mechanisms and their role in providing sufficient K to the crops.