LAUSR

Abstract Chemical fertilizer is a commonly used practice in farms to increase crop quality and yield. Biochar improves nutritional status and quality of the soil. Whereas, there are few relative reports on the effectiveness of soil bacterial community structure and functional diversity by biochar and chemical fertilizer in the red soil. We utilized 16S rRNA sequencing to explore specific changes in structure and functions of bacterial community. The results indicated that amendment of biochar and fertilizer to red soil exhibited a significant effect on Proteobacteria. The combination of biochar and chemical fertilizer (FC) was the most beneficial to the bacterial community changes in red soil. The change of bacterial composition during FC treatment promoted the circulation of soil nutrients, improved the poor nutrient environment, and disease resistance and stress resistance of plants. Through the functional prediction of 16S, we confirmed that FC treatment significantly improved the functional abundance of red soil bacteria. In addition, biochar led to a slight change in the bacterial structure of red soil due to the low abundance of new species. The impact of chemical fertilizer on bacterial community structure was more significant under red soil conditions, but it significantly reduced the functional abundance. It could be suggested that the impact of biochar and chemical fertilizer on the bacteria community and bacterial functional diversity in red soil was different. The most effective treatment in red soil could be the combined application of biochar and fertilizer.