Abstract: Sample plots were established in 20-year Carya cathayensis stand in Lin’an, Zhejiang province. They were intensively managed for 10 years, including applying chemical fertilizer and herbicide. In October 2021, experiments were conducted by randomized blocks design on C. cathayensis stand treated by hickory hull biochar (BC), hickory hull mulching (HM), hickory hull organic fertilizer (OF) and CK. In October 2022,0-20 cm soil were sampled. The result demonstrated that soil pH elevated by 0.33-1.71 in the treatment of HM and BC treatments, compared to that in the CK. Treatments could increase evidently soil organic carbon content, except the control. Soil microbial biomass in the three treatments increased 22.1%-54.8% than that in the control, with more microbial groups. HM treatment resulted in an improved fungal-to-bacterial ratio (F/B). The tested treatments showed positive effect on enzymatic activities of soil carbon and nitrogen convertion, including α-glucosidase, β-glucosidase, cellobiose hydrolase, β-xyloglucosidase, and leucine aminopeptidase.