Use of Microbial inoculants to Alleviate Soil Salinity and Improve Summer Squash Growth in Greenhouse Cultivation

Greenhouse soil cultivation is often affected by salt accumulation due to limited water exchange and intensive fertigation, which deteriorates soil structure and restricts crop performance.This study aimed to evaluate whether microbial inoculants could alleviate salinity stress by improving soil properties, thereby enhancing the growth and productivity of summer squash under greenhouse conditions.The study was conducted from May to November 2023 in Baeksan-myeon, Buan-gun, Republic of Korea.Among ten greenhouses at the site, four were selected and assigned to either an untreated control or a microbial inoculant (MI) treatment composed of Azotobacter vinelandii, Burkholderia vietnamiensis, Paenibacillus polymyxa, and Pseudomonas putida (>10 6 CFU mL -1 each).The MIs were applied by soil drenching at 14-day intervals from mid-May to late November 2023.Soil physical properties, soil chemical properties, plant growth traits, and fruit yield were measured.MI application improved soil physical conditions by reducing soil hardness and bulk density.Soil electrical conductivity and ammonium nitrogen concentrations were lower in the treatment group than in the control.Most other chemical properties, including phosphorus and calcium concentrations, showed no significant differences between the treatment and control groups.Early-stage vegetative growth was enhanced by MI application; however, late-stage plant height and stem diameter did not differ markedly between the two groups.Nevertheless, fruit yield was higher in the treatment group than in the control.MIs improved soil physical conditions and were associated with reduced salinity stress indicators, supporting enhanced summer squash performance and increased yield under greenhouse cultivation.These findings suggest that MIs can be used as a sustainable soil management option in intensive greenhouse systems.