Potassium solubilization: Mechanism and functional impact on plant growth

Abstract

A major constituent as well as an essential nutrient of all living cells is potassium (K). This form of K in the soil, however, is not available for uptake by plants. Chemical fertilizers are added to agricultural fields to provide the required K but with negative impact on the environment. K-bearing minerals are solubilized by potassium solubilizing bacteria (KSB) and the insoluble K is converted to soluble K that is easily assimilated by plants. They solubilize K from insoluble forms like mica, fledspar, and others by mechanisms that involve formation of organic acids, siderophores, and also capsular polysaccharides. The diversity and abundance of KSB is dependent on numerous factors, including soil type, climatic conditions, etc. KSB are mostly found in the rhizosphere of plants. These PGPR can be utilized as biofertilizers for sustainable agriculture and can be an efficient substitute to chemical fertilizers.