Distinct sources of silicon shape differently the rhizospheric microbial community in sugarcane

The rhizospheric microbial communities play a crucial role in promoting plant growth, productivity, and nutrient uptake, but these communities can be significantly affected by fertilizers. Particularly, the application of silicon (Si) has been shown to have a positive impact on the yield and quality of sugarcane, but its impact on the rhizospheric community is unknown. Thus, we aim to investigate how the application of two sources of silicon (K- and Na-silicate) influences the structure and composition of microbial communities in the rhizosphere of sugarcane. Our results showed that fertilization with Si promoted a shift in the microbial community in the rhizosphere compared to the control without Si application. Interestingly, the application of Na-silicate had a more significant effect on the microbial community than K-silicate, resulting in a shift in the community structure. Moreover, the application of Na-silicate resulted in a higher relative abundance of Proteobacteria (∼25 %) and Bacteroidetes (∼10 %), while K-silicate promoted an enrichment of Chloroflexi (∼15 %) and Acidobacteriota (∼10 %). Si application affects the niche occupancy, increasing the proportion of generalist microbes, which varied from ∼67 % to ∼90 % with the use of Na- and K-silicate, respectively. Together, these results indicated that different Si sources could promote distinct effects on the microbial community in the rhizosphere of sugarcane, which could be attributed to the composition of the fertilizer. The findings of this study underscore the significance of comprehending the impact of agricultural practices on the rhizosphere microbial communities to enhance plant growth, productivity, and sustainability. •Distinct Si sources shifted the microbial community in the rhizosphere of sugarcane.•Na-silicate had a more effect on the prokaryotic community than K-silicate.•Si affected the niche occupancy and increased the proportion of generalist microbes.