Amelioration Effects of Pseudomonas fluorescens on Acidified Soil and Subsequent Promotion of Maize Growth.

Soil acidification severely restricts agricultural productivity in red soil regions, and microbial remediation represents an eco-friendly restoration strategy. A pot experiment was conducted to investigate the dose-dependent effects of Pseudomonas fluorescens on acidified latosol, maize seedling growth, and rhizosphere bacterial communities. Five inoculation rates were applied (5.5 × 109-3.3 × 1010 CFU pot-1), together with a non-inoculated control. Pseudomonas fluorescens inoculation significantly increased soil pH and base cation contents, reduced exchangeable and hydrolytic acidity, and enhanced soil acid-base buffering capacity. Low to moderate inoculation rates promoted maize photosynthesis, root development, and nitrogen, phosphorus, and potassium accumulation, whereas the highest rate (3.3 × 1010 CFU pot-1) significantly inhibited seedling growth. Bacterial sequencing showed that inoculation reshaped rhizosphere community structure and enriched taxa, including Proteobacteria, Bacillota, Bacillus, and Pseudomonas. Overall, inoculation rates of 1.1 × 1010 and 2.2 × 1010 CFU pot-1 showed the most favorable responses across soil amelioration and maize growth-related traits, suggesting a suitable application range for acidified soil remediation. These results provide preliminary evidence that appropriate application of Pseudomonas fluorescens may contribute to the biological amelioration of acidified soils, although its field-scale effectiveness requires further validation.