Biochar influences microbial assemblage complexity

We assessed changes in bacterial community composition and microbial assemblage patterns with biochar amendment in two soils with contrasting fertility under two cropping systems, napiergrass and sweet corn. Soil DNA was extracted at approximately 1 month and 1 year after biochar amendment and used as templates for sequencing of the 16s gene amplicons on the MiSeq Illumina platform. Biochar amendment in the low fertility soil resulted in decreased replicate dispersion and increased the microbial assemblage complexity. In the high fertility soil, biochar amendment resulted in modest changes in microbial community composition and assemblage patterns. Network analysis suggested that biochar addition, especially in the highly weathered, low fertility soil, confers higher-level organization, competition, and complexity to the soil microbiome that may result in higher resistance to change due to environmental perturbation and thereby increase system sustainability. Overall, biochar amendment had a greater influence on microbial community in the low fertility soil than in a high fertility soil.