Regionally Divergent Relationships Between Microbial Communities and Environmental Gradients in Potato Production Systems.

Using soil microbiome data as indicators of soil health remains a challenging task in agriculture research. Microbiome data are complex and exhibit strong spatiotemporal variation and diverse responses to environmental factors. As a result, measurements of microbiota often are difficult to interpret and do not provide credible inferences about soil health status. In this study, we evaluated the distributions of soil microbial communities in three distinct potato growing regions of the Upper Midwest of the USA and compared their relationships with soil chemistry and management factors across regions. A total of 1270 soil samples were collected and analysed for microbial properties, including bacterial and fungal abundance, taxonomic and functional diversity and composition. We found substantial variation in the microbial community properties across spatial scales. Environmental factors were more strongly associated with community diversity at the class level than at finer taxonomic levels. Soil pH, soil organic matter (SOM), crop rotation schemes and fumigation correlated with different aspects of microbial properties, while most of the relationships were region-specific. Our results suggest that the microbiological component of soil health includes multiple aspects of the community properties, and region-specific recommendations are needed for developing soil health promoting practices.