Plant growth promotion of barley (Hordeum vulgare L.) by potassium solubilizing bacteria with multifarious plant growth promoting attributes

Abstract

Potassium (K) is the foremost macronutrients for growth of plant, soil health and fertility. The huge application of NPK chemical fertilizers negatively impacts the economy and is a threat to environmental sustainability. The rapid depletion of K mineral in soil is due to the application of agrochemicals agricultural fields for the production of crops in India. In present investigation, K-solubilizing microbes (KSM) were isolated and enumerated from cereal crops growing in Sirmour Himachal Pradesh. A total 125 bacteria were isolated and screened for K- solubilization on Aleksandrov agar plates and found that 31 bacterial strains exhibited K-solubilization. These 31 K-solubilizing strains of bacteria were additionally screened for other plant growth promoting (PGP) potential including solubilization of minerals, production of siderophores, ammonia, hydrogen cyanide and indole acetic acids. The performance of an efficient K-solubilizer was evaluated for plant growth promoting ability in pot assay under in vitro conditions. The strain EU-LWNA-25 positively influenced shoot length, fresh weight, carotenoids and total sugar content than the full dose, half dose and control. The strain enhancing physiological and growth parameters was identified by BLASTn analysis as Pseudomonas gessardii EU-LWNA-25. K-solubilizing plant growth promoting bacteria could be suitable bioinoculants for Rabi seasonal crops and overcomes the challenges of sustainable agriculture in K-deficient soil.

Intercropping Pinto Peanut in Litchi Orchard Effectively Improved Soil Available Potassium Content, Optimized Soil Bacterial Community Structure, and Advanced Bacterial Community Diversity

“…Microorganisms play a central role in the natural K cycles (Diệp and Hieu, 2013 ) and the K solubilizing microorganisms (KSMs), namely, Bacillus mucilaginosus, Bacillus edaphicus, Bacillus circulans, Paenibacillus spp., and Acidithiobacillus ferrooxidans (Singh et al, 2010 ; Rajawat et al, 2011 ; Basak and Biswas, 2012 ) are a rhizospheric microorganism which solubilizes the insoluble K to soluble forms of K for plant growth and yield (Meena et al, 2014 ). Researchers found that some bacterial strains could exhibit K-solubilization, promoting the absorption of K by plants (Subhashini, 2015 ; Kaur et al, 2021 ). Moreover, it is generally accepted that the major mechanism of mineral K-solubilization is the action of organic acids synthesized by rhizospheric microorganism (Aleksandrov et al, 1967 ; Meena et al, 2014 ).…”

Assessment of nitrogen-fixing endophytic and mineral solubilizing rhizospheric bacteria as multifunctional microbial consortium for growth promotion of wheat and wild wheat relative Aegilops kotschyi

“…Potassium is found in the soil as an insoluble K mineral, which cannot easily utilized by plant. In soil there are certain microbes present that can be employed to boost K availability from soil to plant are known as potassium solubilizing microbes ( Kaur et al., 2021 ). The over use of chemical fertilizer has negative effect on ecosystem which can be decrease by using phosphorus, potassium solubilizing microorganism in agriculture which can contribute for making sustainable agriculture ( Suyal et al., 2021 ).…”

Drought adaptive microbes as bioinoculants for the horticultural crops

“…Potassium (K) is an essential nutrient in protein synthesis, glycolytic enzymes, and photosynthesis ( Kaur et al., 2021b , Kaur et al., 2021a ; Kour et al., 2020 ). It is an important osmoticum that mediates cell expansion and turgor-driven movements.…”