【Objective】Denitrification is the primary pathway for removing NO3?-N in agricultural soil profiles, converting NO3?-N into N2, and reducing the risk of NO3?-N accumulation. However, due to methodological limitations, previous studies have mainly focused on the accumulation patterns in soil profiles or the transformation of NO3?-N in the surface soil, with less attention to its removal throughout the entire soil profile. Thus, the rate of denitrification and absolute amount of nitrate removal capacity along the soil profile remain unclear. Furthermore, the existence of “hot moments” and “hot spots” for denitrification in soil profiles is still unknown. 【Method】To evaluate the NO3?-N removal capacity of typical farmland profiles in southern China and to explore the hot moments and hot spots of denitrification, paddy fields (rice-wheat rotation), vegetable fields, and vineyard in the Taihu Lake region were selected for this study. Near in-situ incubation of flooded and non-flooded layers of the soil profile (0-300 cm) of these fields was performed using the Membrane Inlet Mass Spectrometer (MIMS) and Robotized continuous flow incubation system (RoFlow) over a year.【Result】Our results showed that the soil denitrification rate exhibited distinct hot moments and hot spots across the three planting patterns. Denitrification hot moments in rice fields were primarily observed in October during the rice season, with a rate of 17.6±1.0 nmol N g?1 h?1. The denitrification hot moments of vegetable fields and orchards mainly occurred in March, with rates of 44.2±2.5 nmol N g?1 h?1 and 45.3±7.5 nmol N g?1 h?1, respectively. The hot spots of denitrification in the paddy field occurred in the topsoil (0-20 cm) with an average rate of 3.4±0.4 nmol N g?1 h?1. The denitrification hot spots of the vegetable field and orchard mainly occurred at 20-100 cm, with average rates of 11.7±1.3 nmol N g?1 h?1 and 9.4±2.3 nmol N g?1 h?1, respectively. Also, the removal rate of NO3?-N in these denitrification hot spots exceeded 90%, and almost all NO3?-N in the soil profile was removed under the three planting patterns. Correlation analysis results indicated that the soil NO3?-N content was the primary limiting factor for denitrification. 【Conclusion】Our study reveals that the farmland soil profiles under the three planting patterns in the Taihu Lake area exhibit high denitrification rates with distinct denitrification hot moments and hot spots, effectively removing NO3?-N from the soil profile. These findings deepen our understanding of the NO3?-N removal process in farmland soil profiles, holding significant implications for accurately assessing the cumulative risk and removal capacity of NO3?-N in high N input areas of southern China.