Abstract:In order to investigate the impact of biochar on the tea garden soil organic carbon, tea residue was made into biochar at 500 ℃. In this study, a 112-day incubation experiment was conducted to study the impact of biochar input on soil organic carbon contents and stability in three typical tea garden soils (purple soil, paddy soil, and yellow soil) of Ya’an. The study included five kinds of carbon soil ratio (CK, 0.5%, 1%, 2% and 4%), fifteen treatments in total, and samples were taken at 1, 2, 7, 30, 60, and 112 days of culture. Research showed that: tea residue biochar input can significantly increase the content and stability of total organic carbon (TOC) in purple soil, paddy soil, and yellow soil, and increases with the addition ratio, at the end of the cultivation period, the increasing ranges of total soil organic carbon in the three soils were 15.97%~96.64%, 13.01%~72.36%, and 15.29%~321.43%, respectively. Among them, the effect of increasing the TOC content of yellow soil was the best. After the addition of biochar, the contents of microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), and readily oxidized organic carbon (ROC) in the three tea garden soils had also been significantly increased. By the end of the cultivation period, the largest change in MBC content in the three soils was purple soil, with an increase range of 12.97%~40.35%, and the largest changes in WSOC and ROC contents were in yellow soil, with increases ranging from 12.50% to 50.00% and 5.66% to 54.72%, respectively. Tea residue biochar significantly improved the oxidation stability of three types of soil organic carbon, and increased with the addition ratio. The improvement range of oxidation stability coefficient was 28.07%~146.66%, 44.79%~225.66% and 447.18%~1 941.19%, respectively.