Graphene Changes Soil Chemical Properties and Bacterial Community of Haplic Cambisols in the Larix olgensis Rhizosphere

In recent years, graphene has been applied in all kinds of industries because of its unique advantages. Simultaneously, the influence of graphene on soil is becoming increasingly prominent, but little information is available regarding the effect of graphene on the soil microbial community, especially the situation related to plant growth. Our aim was to investigate the impact of grapheme upon bacterial community diversity and chemical properties in Haplic Cambisols of Larix olgensis rhizosphere. By adding graphene (0, 7.58, 15.15, 30.30, 75.76 and 151.52 mg kg−1, respectively expressed as CK, T1, T2, T3, T4 and T5) to Haplic Cambisols planted Larix olgensis seedlings, we identified bacterial community diversity, structure and metabolic function, and measured the pH, organic matter, hydrolytic nitrogen and available P and K contents of rhizospheric soil. Graphene could increase bacterial richness, and a certain concentration of graphene allowed for greater community diversity. Bacterial community structure did not change significantly with increasing graphene concentration in a certain range due to the resistance of bacteria to graphene. Proteobacteria and Acidobacteria were the dominant bacteria, accounting for an average of 40.4% and 20.2% of soil bacteria, respectively. Graphene significantly affected bacterial community composition and metabolic function and varied with its concentration. Several key soil properties, namely, pH, organic matter and hydrolytic nitrogen contents, characterized the graphene effect on soil bacteria, and the determination of rhizospheric soil biochemical processes and the expression analysis of nutrient uptake-related genes can be considered for further research in the future.