Humalite Restructures Microbial Community Composition, Functions and Interaction Networks in the Canola Rhizosphere
Humic substances (HSs) are increasingly recognized for their role in enhancing soil biological functions and promoting more sustainable crop production. Humalite, an organic soil amendment derived from deposits in southern Alberta, is a particularly valuable source of HSs due to its high humic content and low levels of heavy metal contaminants. While Humalite has demonstrated agronomic potential, its effects on crop-associated microbiomes remain understudied. In this study, we investigated the effects of varying application rates of Humalite, under recommended NPK fertilization, on bacterial and fungal communities in the canola (Brassica napus) rhizosphere. Rhizosphere soils collected from canola plants at the flowering stage were used for high-throughput sequencing of the 16S rRNA gene and the ITS2 region to monitor shifts in bacterial and fungal assemblages. Overall, this research provides a new understanding of how Humalite influences the structure, functional potential, and interaction networks of rhizosphere microbes associated with canola, with implications for soil health management.