Pea and canola enrich distinct rhizosphere bacterial communities even under intercropping

Abstract Microorganisms have implications for plant health and agricultural production, yet we are just beginning to understand the complexity of plant–microbe interactions in multispecies environments. Studies conducted to date have shown that plants are able to control the makeup of their microbial communities, yet their ability to control these communities is limited when grown near other plant species. Increased knowledge about these observations and their role in intercropping success is needed to allow us to utilize plant–microbe interactions to improve agricultural sustainability. Therefore, the goal of our study was to elucidate how the bacterial community may be contributing to the high yields observed in the pea–canola intercropping system (peaola). We aimed to determine if intercropping (1) alters bacterial abundance in bulk and rhizosphere soils; (2) affects plant recruitment of rhizosphere bacteria from bulk soil; (3) changes the predicted functions of bacterial communities related to nitrogen cycling; and (4) increases nitrogen availability in bulk soil and leaf tissue of peaola. In the bulk soil bacterial community, genera were not found to be differentially abundant despite previous findings that shifts were observed in the structure of the core microbiome. In the rhizosphere, we found that the composition of the bacterial community of pea and canola remained distinct when intercropped. Functional predictions suggested the enrichment of genes involved in nitrogen cycling processes, yet no significant differences were observed in nitrogen availability and plant tissue content.