Since 2002, a long-term field experiment has been conducted to determine the effects of different organic fertilization treatments on the bacterial community characteristics and maize productivity in dryland red soil using high-throughput sequencing technology. The experiment consisted of four treatments:no manure, M0; low manure, M1; high manure, M2; and high manure with lime addition, M3. Our results showed that the different organic fertilization treatments(M1, M2, and M3) significantly promoted maize productivity with the highest values of pH, soil organic matter(SOM), total nitrogen(TN), and total phosphorus(TP) compared to that under the M0 treatment, and the high manure with lime addition(M3) treatment had the highest level of maize production. The different organic fertilization treatments significantly increased the Shannon index, Evenness index, Chao1 index, and ACE index and significantly shaped the composition of the bacterial community. TP and pH were the main variables determining soil bacterial diversity index based on random forest modeling analysis, whereas pH, SOM, TP, and TN were the main variables determining the structure of the soil bacterial community. Correlation analysis and structural equation modeling determined that TP and SOM indirectly affected maize productivity by varying the bacterial diversity and community structure. The results of this study provide the scientific basis for ensuring food security and sustainable agricultural development by improving the fertility and bacterial diversity in dryland red soil.
Keywords: bacterial community structure; bacterial diversity; dryland red soil; maize productivity; pig manure.