Potassium-Solubilizing Microorganisms and Their Role in Enhancing Soil Fertility and Health

Potassium, the third major plant nutrient, occurs in potassium-bearing minerals such as feldspars and micas. The soil-available K is usually very low and mostly becomes unavailable to plants. Furthermore, intensive cropping, runoff, leaching and soil erosion lead to soil potassium deficiency, providing stunted growth and limited physiological activities of plant. There are microbes (bacteria, actinomycetes and fungi) which are able to release soluble K from K-bearing minerals. KSMs, the soil microorganisms, could provide an alternative approach to make K available or soluble for the cropping system. These microbes secrete organic acids, which act as chelating agents to dissolve rock and chelate silicon ions releasing the K ions available to crops. These microbial cultures can be used as biofertilizers to make available K from mineral and rocks, ultimately influencing crop growth and quality which is a prerequisite for eco-friendly and sustainable agriculture.