Native and commercial microbial inoculants show equal effects on plant growth in dryland ecosystems

There are a wide variety of microbial inoculant types available to restoration practitioners, but little information as to which performs best under field conditions in dryland ecosystems. We used a meta-analysis of 62 dryland studies to provide the first quantitative comparison of native vs commercial, diverse vs single species, and fungal vs bacterial microbial inoculants. We found that while microbial inoculation increases plant growth compared to uninoculated counterparts, contrary to our expectations, the magnitude of effect was statistically similar for all the inoculant pairs. Our results suggest that land managers should use inoculant types that are readily available and easy to handle rather than complicated and expensive inoculants that combine multiple taxa of local origin microbes.