Effects of Biochar-based Fertilizer on Soil Physicochemical Properties and Rhizosphere Bacterial Community Structure

Abstract

The application of biochar in agriculture and environmental fields has received widespread attention. In order to explore the response mechanism of flue-cured tobacco rhizosphere bacterial community and functional fungal taxa to biochar fertilizer, mass field experiment and two treatment methods were set up in this study, one is CK: conventional fertilization, and the other is T: 50 kg/mu biochar base fertilizer + conventional fertilization (nitrogen reduction by 20%). The experimental results showed that the pH value, organic matter content, alkaline hydrolyzable nitrogen, available phosphorus and available potassium content of the soil applied to biochar-based fertilizer increased significantly, and the neutral phosphatase activity of the soil decreased significantly. The bacterial Shannon index, ACE index and CHAO index were significantly increased, and the amplitudes of which were 10.16%, 37.39% and 38.76%, respectively. The bacterial Simpson index was significantly reduced; Actinobacteriota had the highest abundance, 25.88%-39.91%, followed by Proteobacteria, with abundances of 20.88%-27.75%, respectively. Firmicutes were positively correlated with soil organic matter, alkaline hydrolyzable nitrogen and soil catalase, and positively correlated with available phosphorus and available potassium. The results show that biochar-based fertilizer can effectively improve soil physicochemical properties, increase soil enzyme activity, change soil microbial community structure, and drive the dynamic change of soil bacterial community composition, which is conducive to improving soil quality.