Soil microbial communities play a significant role in nutrient cycling and soil conditioning that promotes plant growth and health. Four different soil amendments, which include untreated control, biochar at 11.2 Mg ha-1, poultry manure at 0.8 11.2 Mg ha-1 dry weight, and a combination of biochar and poultry manure, were applied annually for three consecutive years (2016, 2017, and 2018) in soybean plots in Red River Research Station, Bossier City, Louisiana. DNA were directly extracted from the soil samples in each treatment and were analyzed using QIIME2. Results showed that the composition and structure of bacterial communities varies from phylum to genus. In the phylum level, the top five dominant phyla were Proteobacteria, Acidobacteria, Bacteroidetes, Verrucomicrobia, and Gemmatimonadetes. The ten most abundant culturable genera throughout all the treatments were Blastocatella, Sphingomonas, Nitrospira, Desulfurellales, Nitrososphaera, Gemmatomonas, Bryobacter, Ramlibacter, Bacillus, and Paenibacillus. Interestingly, nitrifying bacteria of the phylum Nitrospirae known to promote plant growth and antimicrobial peptide-producing bacteria of the phylum Firmicutes were among the dominant phyla in the biochar and the poultry treated soils, respectively. Noteworthy, the microbial distribution in soil tends to become more even by repeated treatments of biochar for three consecutive years. This research provides the information about the significant changes of microbial community from the treatment of biochar, which could have an impact on soil-borne diseases of soybean.