Temperature dependence of nitrous oxide production of a luvisolic soil in batch experiments

• N2O emission has been experimentally determined in a large range of temperature (5–45 °C).
• The results have been fitted to a 3 parameters (Amax, Topt, dti) Gaussian relationship to temperature.
• The range of temperature (dti) responses of N2O was larger from denitrification than for nitrification.
• Optimum temperatures (Topt) were higher for N2O associated to denitrification than to nitrification.
• N2O emission ratio was much higher for denitrification than for nitrification.

This study aims to determine the effect of temperature on N2O produced from a surface soil both in nitrification and denitrification experimental conditions. In a context of changes of both temperature and rainfall, formalizing temperature relationships of N2O production is useful for model parameterization of process-based modeling approaches.Samples of luvisolic soils were incubated in destructive slurry batches in controlled specific conditions designed to promote nitrification and denitrification. The experiments were run at seven temperatures, from 5 to 45 °C. When fitted with a sigmoid function overall potential activities show that the potential production rate of nitrate (NO3−nit) is optimal at a temperature of 32.5 °C and the potential reduction rate of nitrate (NO3−denit) being optimal at around 45 °C. Regarding the production rate of N2O, optimal values occur at a temperature about 10 °C higher than the optimum temperature for the respective processes, namely 42 °C for nitrification and 54.5 °C for denitrification. N2O emissions and nitrite production due to denitrification are around 10 times higher than nitrification. These findings show that a sigmoid function of N2O emissions from both denitrification and nitrification is more relevant than an exponential one.