# Microbial Inoculants Alleviate Continuous Cropping Obstacles in Eggplant Through Soil Properties and Rhizosphere Microbiota

## TL;DR

Microbial inoculants improve eggplant growth and soil health by altering the rhizosphere microbiota and soil properties.

## Contribution

The study identifies strain-specific effects of three bacterial inoculants on crop performance and soil properties in continuous eggplant cropping.

## Key findings

- BF1 increased plant height, stem diameter, and yield by 32.1%, 28.7%, and 142.4%, respectively.
- BF3 improved fruit quality and soil nutrients, raising amino acids, protein, and sugar contents by up to 68.9%.
- All inoculants increased beneficial bacteria and altered the rhizosphere microbial community structure.

## Abstract

Eggplant cultivation faces major challenges from continuous cropping obstacles, which degrade soil health and limit sustainable production. Microbial inoculants offer a promising strategy for addressing such issues by modifying the soil environment and rhizosphere ecology. In this study, a field experiment was conducted to evaluate the effects of three bacterial inoculants, including Bacillus zhangzhouensis (BF1), Bacillus mobilis (BF2), and Zhihengliuella halotolerans (BF3), on soil properties, microbial community structure, and crop performance in a continuously cropped eggplant system. The results showed that three inoculants exerted strain-specific effects: BF1 significantly promoted eggplant vegetative growth and yield, increasing plant height by 32.1%, stem diameter by 28.7%, and total yield by 142.4% relative to the control; BF3 selectively improved fruit quality and soil nutrient status, elevating eggplant fruit total amino acid, soluble protein, and soluble sugar contents by 68.9%, 52.3%, and 41.2%, respectively, and increasing soil organic carbon (SOC), total nitrogen (TN), and available nitrogen (AN) by 13.73%, 18.03%, and 84.92% compared with the control. BF2 showed limited efficacy relative to the control. All inoculants enhanced the abundance of beneficial bacteria and reshaped the rhizosphere microbial community structure. The findings demonstrate the potential of strain-specific microbial inoculants to alleviate continuous cropping obstacles and promote sustainable eggplant production.