Native halotolerant consortia modulate soil–plant interactions under moderate salinity

Abstract

Soil salinity is a major limitation for rice production in arid regions, reducing plant growth, yield, and grain quality. This study assessed the effect of halotolerant strains of Bacillus subtilis and Pseudomonas putida on the growth, productivity, and soil chemical properties of Oryza sativa L. INIA 515 'Capoteña' under initial soil salinity of 4.75 dS m⁻¹. Eight treatments were evaluated, including bacterial consortia, and non-inoculated control. The selected strains exhibited high salt tolerance, with B. subtilis BacF and P. putida P4 growing at up to 10% NaCl. Although most physiological and agronomic variables did not differ significantly among treatments, treatment T5 (BacF + P4) showed a moderate tendency towards better values, particularly in panicle number, aerial biomass, total biomass, grain yield, and SPAD across the growth cycle. At the edaphic level, T5 significantly increased soil pH and promoted a slightly synergistic mobilisation of K, Mg, and Na. Structural equation modelling indicated that magnesium strongly enhanced total plant biomass, while organic matter positively influenced grain yield. These findings indicate that native halotolerant consortia may influence soil–plant interactions under controlled conditions, but agronomic benefits remain limited and require field validation.