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