Screening of soil microbial communities for siderophore production and its growth response on Cowpea (Vigna unguiculata L.)

Abstract

This study investigated the isolation and screening of soil microbial communities from the rhizosphere of cowpea (Vigna unguiculata L.) for their siderophore production capabilities and evaluated their growth-promoting effects on cowpea. These siderophore-producing isolates were tested for their effects on cowpea growth, showing significant improvements in plant height, biomass, and chlorophyll content under iron-deficient conditions. The combination of siderophore-producing microbes with essential nutrients such as zinc, potassium, and phosphate led to the most notable results, including a 20% increase in plant height (up to 24 cm), a 40% increase in dry biomass (5.0 g), and higher chlorophyll content (SPAD reading of 17.0). Additionally, four of the siderophore-producing isolates exhibited antimicrobial activity, forming inhibition zones of up to 15 mm, suggesting a dual role in promoting plant health by enhancing nutrient uptake and suppressing pathogens. These findings highlight the potential of siderophore-producing microbes as effective bioinoculants to boost cowpea growth and resilience in nutrient-deficient and stressed environments. Further research, including field trials, is recommended to confirm their agricultural applicability.