Biochar addition improves soil quality of tea plants via shift in bacterial community

Biochar is a safe soil amendment. To explore the effects of biochar prepared from specific raw materials at different pyrolysis temperatures on the soil properties and bacterial community structure, and to achieve the recycling of livestock and poultry manure and crop straw, different carbonization temperatures of swine manure biochar (350, 500, 650 ℃) and straw biochar (500 ℃) were set up through pot experiments. Compared with normal fertilization, the addition of swine-manure biochar obtained at 500 ℃ could increase the soil pH, total carbon, total phosphorus, total potassium, organic carbon, microbial biomass carbon, water-soluble organic carbon, and readily oxidized organic carbon contents but did not have a significant effect on the soil total nitrogen content. The biochar application could also increase the activities of polyphenol oxidase and beta-glucosidase but decrease protease, and amylase activities. The application of biochar increased the alpha diversity index of the bacterial community. Redundancy analysis showed that the soil organic carbon and protease were key environmental parameters that affect the main gradient of soil bacterial community composition. Biochar can significantly improve soil properties and affect soil bacterial community composition. Soil organic carbon and protease were the key drivers of the soil bacterial community composition changes. The application of biochar to soil may modestly improve its physicochemical properties, enzyme activity, and microbial community composition. The application of biochar is feasible for the improvement of low-nutrient tea orchard soil.

The online version contains supplementary material available at 10.1007/s13205-026-04731-0.