The use of soil microbial potassium solubilizers in potassium nutrient availability in soil and its dynamics

Background: An increase in population has led to a higher demand for food. Meeting up this demand has necessitated the use of chemical fertilizers. However, utilization of these fertilizers has a considerable deleterious effect on the soil, plant, human, environmental sustainability, and only increase the cost and reduced profitability. With these identified problems, there is a need for efficient and sustainable methods regarding managing natural resources to enhance food production. Naturally, potassium (K) is an abundant element present in the soil but in an inaccessible form. There is therefore a need to seek an alternative method to improve the K availability to plants noting that K is an essential plant nutrient that plays a major role in plant physiological and metabolic processes. Subsequently, employing microbial potassium solubilizers is an efficient method to enhance the potassium availability in the soil, which in turn improves productivity. Therefore, this review discusses the various types of potassium solubilizing microorganisms in soil, their mechanism of action, and their importance in sustainable crop production. Main body: Potassium solubilizing microorganisms (KSM) such as bacteria and fungi can solubilize K from an insoluble form to a soluble form to enhance uptake by plants. These microorganisms solubilize K through the production of organic acids such as tartaric acid, citric acid, and oxalic acid to release K from its minerals. Apart from making potassium available, these microbes can improve soil health and crop yield and act as bio-control agents by producing antibiotics. Potassium solubilizing microbes also produce hormones that help plants withstand both biotic and abiotic stresses. Hence, the application of KSM to agricultural soils will reduce the use of chemical fertilizers and enhance the sustainability of food production. Conclusion: One of the most efficient ways of improving plant utilization of potassium in the soil is to use potassium solubilizing microbes, which can make potassium ions available from minerals of both igneous and sedimentary origins. The use of potassium solubilizing microbes as biofertilizers may be the awaited solution to increasing crop productivity, concerns linked to chemical fertilizer application, and earth resource diminution.