Phosphorus Solubilizing Bacteria Regulate Soil Phosphorus Activation Mechanisms and Impact on Available Nutrients: A Meta-Analysis

Background and aims The available phosphorus, nitrogen, and potassium concentrations in soil collectively serve as key indicators of soil fertility levels. Comprehending the effects of phosphorus solubilizing bacteria (PSB) on expeditious content levels is crucial for enhancing soil fertility and advancing sustainable agricultural development. Methods Using a meta-analysis method, this study systematically evaluated the effects of different factors, including soil pH, soil organic matter (SOM), PSB and crop types, on the changes in soil available nutrients (i.e., available phosphorus, nitrogen, and potassium) induced by PSB inoculation. Results PSB inoculation significantly increased soil available phosphorus (86.8%), nitrogen (64.9%), and potassium (41.9%) compared to non-inoculated controls. Subgroup analyses revealed that soil pH, SOM, PSB and crop types significantly modulated PSB-mediated augmentation in soil available phosphorus. SOM, PSB and crop types considerably affected PSB augmentation of soil available nitrogen. Meanwhile, PSB types notably impacted the increase of soil available potassium by PSB. Further analysis showed a significant negative correlation between soil pH and the ability of PSB to enhance soil available phosphorus, whereas SOM was significantly positively correlated with PSB to enhance soil available phosphorus and nitrogen. Conclusions These findings highlight the need for comprehensive consideration of soil pH, SOM, PSB and crop types when applying PSB to improve soil nutrient availability, This study offers empirical evidence for the systematic and efficient utilization of PSB to improve soil nutrient availability.