Divergence in the tomato rhizosphere microbial community structure driven by three soil types

Area of Science:

• Agricultural Science
• Soil Science
• Microbiology

Background:

• Tomato cultivation in southern China is significantly influenced by diverse soil types, including loess, calcareous, and laterite soils.
• Understanding the interplay between soil properties, rhizosphere microbiome, and crop performance is crucial for optimizing agricultural practices.
• Previous research has not comparatively assessed the impact of these specific soil types on tomato-associated microbial communities in Guangxi.

Purpose of the Study:

• To investigate how loess, calcareous, and laterite soils affect tomato growth, soil fertility, and rhizosphere microbial communities in Guangxi.
• To provide the first comparative analysis of tomato-associated microbiomes across these major soil types.
• To identify soil-specific microbial and nutrient dynamics that influence tomato productivity.

Main Methods:

• Analysis of soil fertility parameters, including enzyme activities (β-glucosidase, acid phosphatase) and microbial biomass (carbon, phosphorus).
• Characterization of rhizosphere microbial communities (bacteria and fungi) using high-throughput sequencing.
• Comparative assessment of tomato growth and associated microbial profiles across the three soil types.

Main Results:

• Calcareous soil showed higher β-glucosidase activity and microbial biomass carbon; laterite soil exhibited increased acid phosphatase activity and microbial biomass phosphorus.
• Dominant bacterial phyla included Actinobacteriota, Proteobacteria, and Acidobacteriota; dominant fungal phyla were Ascomycota and Basidiomycota.
• Distinct microbial communities were associated with each soil type: loess favored *Ramliber*, *Bradyrhizobium*, and *Alternaria*; calcareous soil favored *Rubrobacter* and *Fusarium*; laterite soil supported *Bacillus*, *Sphingobium*, and *Curvularia*.

Conclusions:

• Laterite soil, with its higher phosphorus availability and beneficial microbes like *Bacillus*, provides a more favorable environment for tomato cultivation.
• Soil type significantly shapes rhizosphere microbial communities and enzyme activities, impacting tomato growth and nutrient dynamics.
• These findings offer a scientific basis for soil selection and management to enhance tomato productivity and promote sustainable agriculture.