| Summary: | Agricultural practices such as water and N management can contribute to greenhouse gas (GHG) emissions. Fertigation frequency and level are the two most important factors of irrigation scheduling. Proper irrigation management can establish moderate moist conditions throughout the crop growth period in the root zone and reduce GHG emissions and NH<sub>3</sub> volatilization. The main objective was to evaluate the possibility of reducing soil N<sub>2</sub>O and CO<sub>2</sub> emissions and NH<sub>3</sub> volatilization without crop yield reduction by manipulating the subsurface-drip fertigation (SDF) frequency and level. An experiment was carried out adopting three SDF frequencies, High-Frequency (7-day, HF), Medium-Frequency (8-day, MF), and Low-Frequency (10-day fertigation intervals, LF), and two irrigation levels, 80% (I<sub>80</sub>) and 70% (I<sub>70</sub>) of amount in farmer’s common practice (1500 m<sup>3</sup> ha<sup>−1</sup>). Urea, N > 46.2% at the rate of 90% of traditional fertilization level (270 Kg N ha<sup>−1</sup>) was injected with irrigation water. Results indicated that soil N<sub>2</sub>O, CO<sub>2</sub>, NO<sub>3</sub><sup>−</sup>-N, NO<sub>2</sub><sup>−</sup>-N, and water-filled pore space increased with fertigation frequency and an opposite pattern for NH<sub>4</sub><sup>+</sup>-N and NH<sub>3</sub>. HF significantly (<i>p <</i> 0.05) increased crop yield by 45.1% and 49.2% compared to LF, under I<sub>80</sub> and I<sub>70</sub> levels, respectively. At the same irrigation level, HF was the optimum management practice. Person correlation analysis showed significant correlations between NO<sub>2</sub><sup>−</sup>-N and N<sub>2</sub>O, CO<sub>2</sub> and soil temperature, and NH<sub>4</sub><sup>+</sup>-N and NH<sub>3</sub>. The study suggests that HF of SDF with emitters buried at 0.15 m depth helps to keep high Chinese cabbage yield increases GHG emissions, but is not significant, and decreases NH<sub>3</sub> volatilization.
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