Characteristics of bacterial community structure in tobacco-planting soils under different fertilization practices
To evaluate the fertilization practices on soil fertility and the microbial ecosystem, a tobacco pot experiment with different fertilization treatments was conducted in a completely randomized design. The five treatments were: no fertilizer (CK); N fertilizer (T1); NPK fertilizer (T2); NPK fertilizer plus decomposed straw (T3); biochar (T4). Compared to the T2 treatment, application of manure significantly increased the concentrations of soil organic carbon, mineral N and the dry matter accumulation of tobacco plants. The tobacco rhizosphere bacterial community was investigated using 16S rDNA high-throughput sequencing. The results indicated that the predominant bacterial phyla were Proteobacteria, Bacteroidetes and Firmicutes. At the genus level, the bacterial community was significantly altered by the presence of tobacco plants and the fertilizer treatments. The relative abundance of Aeromonas were significantly decreased in the fertilized soil. Compared with the T1 treatments, the relative abundance of Bacillus and Paenibacillus in the T2 treatment and Georgfuchsia and Pseudorhodoferax in the T4 treatment were significantly decreased and increased, respectively. The results indicate that application of chemical fertilizer and manure in the tobacco-planting soil could improve soil nutrients and influence the bacterial community structure and thus plant growth.