Soil health and the dynamics of carbon (C) and nitrogen (N) in salt-affected soils are increasingly challenged by climate warming and intensive nitrogen fertilization, yet the interactive effects of temperature, urea application, and nitrification inhibitors on soil biochemical processes and gaseous emissions remain insufficiently understood. This study evaluated the combined effects of temperature (10–40 °C), urea fertilization, and a nitrification inhibitor (DCD) on soil properties and gaseous emissions in salt-affected soil using an 80-day incubation experiment. Three treatments were applied: control (CK), urea (U), and urea + DCD (U + DCD). Urea application increased soil pH initially, followed by a decline due to nitrification, while DCD moderated this decrease. NH 4 + concentrations declined rapidly in U but remained higher in U + DCD, whereas NO 3 − accumulation was greatest in U, particularly at 40 °C. Urea significantly increased microbial biomass carbon and dissolved organic carbon, with higher values observed at elevated temperatures. Enzyme activities (urease, catalase, invertase, phosphatase, and phenol oxidase) were also enhanced under urea application, peaking at 30–40 °C. CO 2 emissions were highest in U treatment, reaching 194.7 mg kg −1 at 40 °C, while NH 3 volatilization was strongly temperature-dependent, with cumulative losses up to 75.2 mg kg −1 . The addition of DCD reduced nitrification rates and moderated N losses compared to urea alone. However, this mitigation was accompanied by increased NH 3 volatilization under certain conditions, indicating a trade-off in nitrogen transformation pathways. Overall, increasing temperature amplified C and N transformations and gaseous emissions, while DCD partially mitigated these effects, suggesting its potential role in improving N use efficiency and soil management in salt-affected soils.
Shaaban et al. (Thu,) studied this question.