Functional diversity of bacterial communities in the rhizosphere of maize grown on a soil under organic and inorganic fertilization

Accurate knowledge of bacterial metabolic processes is essential for comprehending and manipulating the agroecosystem for proper nutrients management and crop production. In this study, we focused on evaluating the functional diversity of bacterial communities associated with the rhizosphere of maize treated with organic and inorganic fertilizers. Soil samples were collected from the maize rhizosphere and sequenced using Illumina NovaSeq technology. The samples were analyzed for functional potential using the MG-RAST online tool. Our result showed that the metabolic functions differed between the clusters of group 1 - compost 8 t ha−1, 60 kg ha−1, and control (Cp8, N1, and Cn0) and group 2–120 kg ha−1 and 4 t ha−1 (N2 and Cp4) based on the similarities of fertilizers effects on the metabolic functions of the soil bacterial communities. At the genus level, Capnocytophaga and Porphyromonas were dominant in the Cp4 (4 t ha−1 compost manure) samples, Actinoplanes, Saccharomonospora, and Thermobifida were predominant in Cp8 (8 t ha−1 compost manure) treated soil. Bacillus and Granulicatella were most abundant in soil treated with high levels inorganic fertilizers (N2–120 kg ha−1). And N1 (60 kg ha−1 inorganic fertilizer) treated soil supported bacteria belonging to Norcardiodes and Mycobacterium, while Arthrobacter, Micromonospora, and Xanthomonas were predominant in the control sample (Cn0). To maintain a viable and metabolically functional bacterial community in the soil, application of a high quantity of compost (8 t ha−1) or a small quantity of inorganic fertilizer (60 kg ha−1) is suitable.