Do inoculated microbial consortia perform better than single strains in living soil? A meta-analysis

Abstract

Microbial consortium inoculation has been proposed as a natural-based strategy to safeguard multiple ecosystem services. Still, its empirical effects and comparisons to single-species inoculation have yet to be systematically quantified. In this global meta-analysis of 51 live-soil studies, we compared the impact (mean and variability) of single-species and consortium inoculations on biofertilization and bioremediation. Our results showed that both single-species and consortium inoculations increased plant growth by 29% and 48%, respectively, and pollution remediation by 48% and 80%, respectively, compared with non-inoculated treatments. We revealed the potential mechanisms contributing to the effectiveness of consortium inoculation, which are associated with the diversity of inoculants and the synergistic effect between frequently used inoculums (e.g., Bacillus and Pseudomonas). Despite a reduction in efficacy in field settings compared to greenhouse results, consortium inoculation had a more significant overall advantage under various conditions. We recommend increasing original soil organic matter, N, and P content and regulating soil pH to 6-7 to achieve a better inoculation effect. Overall, these findings support the use of microbial consortia for improved biofertilization and bioremediation in living soil and suggest perspectives for constructing and inoculating beneficial microbial consortia.