The role of rhizosphere microbes as phosphate solubilizing bio fertilizers in shallot: a review

Abstract

Crops need nutrients to grow, develop, and produce yields, both in macro and micronutrients form. One of the essential macronutrients is phosphorus (P). Phosphorus is required by plants to produce plant biomass. Andisols are often used as agricultural lands in the highlands of the tropics. This soil type has high P retention and low available P. Andisol contains clay minerals with up to 97.8% P-retention. Therefore, this condition led to low P availability, but high total P in the soils. There was a tendency to increase the dose of inorganic fertilizers, especially P fertilizer in this area. A survey reported that shallot Andisol farmers applied P fertilizer about five times of shallot recommendation rate, however, the production has not increased, yet. The high rate of chemical fertilizers causes land degradation and environmental pollution. One of the solutions to increase phosphorus availability is by improving P solubility which increases P uptake by plants. Increasing P solubility is environmentally friendly and can be done by utilizing phosphate-solubilizing microbes which are often found in the plant rhizosphere. The use of phosphate-solubilizing microbes for plants today can be found in bio-fertilizers. This method could maintain soil health and give a good impact to the plant growth and production. This review would determine the use of phosphate-solubilizing microbes to manage P deficiency in Andisol soils. Some study cases about the effect of phosphate-solubilizing microbes on plant performances would also be addressed. Currently, it is hoped that farmers will begin to implement environmentally friendly agriculture by giving phosphate-solubilizing bio fertilizers to escalate available P and production.