This study focused on a 5-year-old artificial Pinus yunnanensis forest in Yanyuan County. Five gradients of humic acid fertilizers were set up. By measuring the growth indicators of the trees, biomass accumulation, and nutrient content, the regulatory effect of humic acid on the growth and development of Pinus yunnanensis was systematically analyzed. The results showed that an appropriate amount of humic acid significantly promoted the growth of Pinus yunnanensis. Among them, the 25 kg/667 m² treatment had the best effect, with a growth rate of 1.82 cm in diameter, an increase of 49.2% compared to the control group; a growth rate of 0.86 m in tree height, an increase of 53.6%; a growth rate of 42.35% in volume, an increase of 50.5%; and the biomass and nutrient content and reserves of roots, stems, and leaves, as well as nitrogen, phosphorus, and potassium nutrients, all significantly increased under this treatment, with the total biomass increasing by 51.6% compared to the control group.

humic acid  /  Pinus yunnanensis  /  growth  /  biomass