Evaluating the Efficacy of Selected Plant Growth-Promoting Microorganisms in Optimizing Plant Growth and Soil Health in Diverse Soil Types

This study explores the efficacy of bio-efficient solutions, specifically plant growth-promoting microorganisms (PGPMs), in sustainable soil management. This research was conducted in 2020. It evaluates the impact of various single microbial inoculants, including <i>Enterobacter ludwigii</i>, <i>Bacillus subtilis</i>, <i>Pseudomonas fluorescens</i>, <i>Kosakonia cowanii</i>, and <i>Trichoderma harzianum</i>, on plant growth soil enzyme activity and organism abundance. Perennial ryegrass and mustard were used as test plants, in controlled environmental conditions. The results show generally positive effects of microbial inoculants on plant biomass (<i>E. ludwigii</i> increased ryegrass biomass by 9.75%, and <i>P. fluorescens</i> increased mustard biomass by up to 38.81% compared to the control) and on soil microbial activities. Our study further investigated the combined application of all these strains in five different soil types and textures. The results highlight the significance of soil physicochemical properties in determining inoculant efficacy; we found that clayey soils with higher colloid content support more robust microbial activity. Additionally, using natural clay minerals like alginite for enhancing soil conditions showed promising interactions with microbial inoculants, although application requires further optimization. These findings suggest that integrating microbial inoculants in sustainable agricultural practices could enhance plant growth, improve soil health, and reduce the need of chemical fertilizers. Future research should aim to refine the combinations and application methods of these bio-efficient solutions for broader agricultural applicability.