Abstract:The emission rates of N2O and N2and denitrification rates of purple soils under four land use types (tea garden, orchard, woodland, and cropland), as well as their relations with soil pH and organic matter content were examined by using the anaerobic culture-15N labeling method. The results showed that the emission rates of N2O and N2 and denitrification rates were tea garden > cropland > orchard > woodland. The emission rates of N2O and N2 and denitrification rate were reduced as soil pH increased (P<0.01) and had the significant positive correlation with soil organic matter content (P<0.05). With the addition of biochar, the emission rate of N2 and denitrification rate were both increased, while the changes in N2O emission rate was affected by land use type, which changed insignificantly in tea garden, significantly decreased in orchard and cropland (P<0.05), and significantly increased in woodland (P<0.05). In conclusion, the denitrification process of purple soil under different land use types is mainly influenced by soil pH and organic matter content, and can be regulated by the addition of biochar.