Mixed cropping with legume and maize (Zea mays) may diversify soil microbial communities due to the different crops’ root-root interaction. Thus, mixed cropping system can be a tool more than just providing the fixed-N to maize. To investigate this, we performed a pot study using maize (Zea mays) and maize with one of three legumes (Vigna unguiculata, Mucuna pruriens, Phseolous vulgaris). They were cultivated for 50 days with chemical fertilizer (P and K), carbonized chicken manure or without fertilizer. After the pot experiment, we conducted 16S rRNA analyses. The bacterial communities of the maize-only soils were significantly different from those of the maize+legume soils. There was an interaction between the effect of legume species and the types of fertilizer. Chicken manure application strengthened the differences between the maize-only and the maize+legume, regarding soil bacterial communities. When averaged across the fertilizer treatments, Nitrospirae and Acidobacteria’s relative abundances decreased in the maize+legume pots. This might be related to the accumulation of NO₃⁻ in soils, observed in the maize+legume soils. Regarding the diversity of the soil bacterial communities, maize+phaseolous soils showed higher diversity when compared to maize-only soils, however, this was only true with the presence of chicken manure.