**4. Role of rock phosphates and phosphate-solubilizing microbes in food security**

Food security is heavily dependent on phosphorus availability—an essential component of the mined phosphate rock [45]. The fertilizer industry is aware of the fact that the quality of RP reserve is declining and the extraction, processing, and shipping of phosphate rock are highly expensive [46–48]. With the current global population boom, coupled with insecurity challenges in mines posed by armed banditry herdsmen, Boko haram, and the Islamic State in West Africa Province (ISWAP) in this part of the world, optimizing food security is essential in curbing poverty and hunger management.

Emphasis on this chapter is not limited to improving RP solubility alone but also how to ensure food security under diminishing P resources due to injudicious use of P fertilizers [47]. This is made possible by application of phosphatesolubilizing microbes/biofertilzers in addition to the RP. This could be a more promising approach for safer and sustainable agriculture. PSM include bacteria (*Pseudomonas* sp., *Agrobacterium* sp., *Bacillus* sp., *Actinobacteria* etc), fungi (*Achrothcium*, *Alternaria*, *Arthrobotrys*, *Aspergillus*, etc.), and Arbuscular mycorrhizae (*Funneliformis mosseae, Rhizophagus irregularis,* etc). [12, 17, 48].

Therefore, inoculation of soil with PSMs was reported to be a widely accepted environmentally friendly approach for increasing soil soluble P concentrations and agricultural productivity [48]. It was established that bioavailable P content in soil is an important element that improves plant P uptake, which in turn results in higher crop yields [14, 24]; most studies have considered PSM as a promising inoculant/ biofertilizer for raising the productivity of agronomic crops in agroecological niches [49–51]. Soil microorganisms improve plant nutrient acquisition. They are involved in an extensive range of biological processes as well as the conversion of insoluble soil nutrients [34]. A number of these soil microbes are capable of solubilizing and mineralizing insoluble soil phosphorus for the growth of plants. To this end, application of phosphate PSMs as biofertilizers will bring favorable effects on plant growth and reduce the cost of production, which may likely enhance the farmers' income in sub-Saharan Africa.
