Redution of salinity of an agricultural soil and growth of tomato (Solanum lycopersicum) using Bacillus velezensis in a greenhouse

Abstract

Objective: To determine the effect of the bacterium Bacillus velezensis on the reduction of salinity of an agricultural soil and on the growth of tomato plants (Solanum lycopersicum 'Rio Grande') under greenhouse conditions.Methodology: The study began with the search for strains of halophilic bacteria in agricultural soils with salinity problems and then with the selection of sodium chloride-tolerant strains, identified as Bacillus velezensis. In the greenhouse, agricultural soil from the Lambayeque region, Peru, with three salinity levels (low: 1,36 dS·m⁻¹, moderate: 3,84 dS·m⁻¹ and saline soil: 6,26 dS·m⁻¹) was used as a substrate in pots of 2 kg capacity and tomato plants were planted in them. B. velezensis (1×10⁷ CFU·mL⁻¹) was applied to the soil and compared with an uninoculated control. For 60 days, the electrical conductivity of the soil, height, vigor and root development of the plants were evaluated. Data were analyzed using ANOVA and Duncan's test (p ≤ 0,05). Results: B. velezensis reduced the 4 1 electrical conductivity of the soil by up to 30,38 % and persisted at 2,1 × 10 CFU.g- in saline soil, showing its desalination and survival capacity as a halophilic bacterium. It significantly increased the height of the plants up to 23,75 %, the vigor and root development, with respect to the control, in saline soil. Conclusions: B. velezensis wasshown to be a halophilic bacterium capable of significantly reducing the salinity of an agricultural soil and surviving in it. In addition, it was shown to promote tomato plant growth.