Abstract
Pastures account for about 54% of the world's total land area.Currently, half of the world's pastures are degraded and salinized due to climate change and overexploitation.Salinization is one of the most serious abiotic stresses for plants.One way to address the problem is to mitigate salt stress by using beneficial microorganisms that can stimulate growth and improve plant immunity.The aim of the study was to isolate and identify salt-tolerant free-living nitrogen-fixing bacteria and study their effect on pasture grasses under salt stress.Soils were collected from the rhizosphere of pasture grasses growing on saline pastures in the southeast of Kazakhstan (Almaty region) and free-living nitrogen-fixing bacteria were isolated.Primary screening of bacteria was conducted and strains of salt-tolerant nitrogen-fixing bacteria were selected.Identification of the strains showed that the bacteria belong to different genera.The high stimulating effect of bacteria on the growth and development of cereal grasses growing on saline pastures has been shown.Thus, the use of salt-tolerant nitrogen-fixing bacteria helps plants resist salt stress and has great potential for maintaining their growth and development on saline soils.