TY - JOUR AU - Du, Linjuan AU - Pan, Cunzhen AU - Wang, Caiyun AU - Chen, Zhijun AU - Xiong, Yunwu AU - Huang, Guanhua PY - 2026 TI - Effects of salt stress on nitrification and denitrification rates and N2O emissions in soil using a 15N isotope tracing approach JO - International Journal of Agricultural and Biological Engineering SN - 1934-6344 SP - 191 EP - 197 VL - 19 IS - 3 AB - Nitrous oxide (N2O), a long-lived greenhouse gas, is primarily produced in agricultural soils through biological nitrification and denitrification processes. However, the effects of soil salinity on nitrogen transformation processes remain insufficiently understood, hindering the development of effective nitrogen management in salt-affected farmlands. In this study, laboratory incubation experiments combined with a 15N stable isotope tracing technique were conducted to quantify the effects of salt stress on nitrification and denitrification rates and their contributions to N2O emissions. The results showed that during the first week of incubation, slight and moderate salinity (NaCl contents of 0.04% and 0.10%; EC1:5≤1.10 dS/m) enhanced both nitrification and denitrification rates, whereas strong salinity (0.20% NaCl; EC1:5≥1.42 dS/m) inhibited these processes. In the first week of incubation, nitrification and denitrification contributed approximately 65%-70% and 30%-35% to the total N2O emissions under 60% water-filled pore space, respectively. These results indicate that nitrification represents the predominant source of N2O production in saline soils during the first week following fertigation. The findings suggest that nitrogen management practices for inhibiting the nitrification process (e.g., the addition of nitrification inhibitors in companion with fertigation) may mitigate N2O emissions in saline fields. This provides a scientific basis for optimizing nitrogen management in saline soils and reducing greenhouse gas emissions. UR - https://doi.org/10.25165/j.ijabe.20261903.10307 DO - 10.25165/j.ijabe.20261903.10307