Abstract

Simulation of emissions of the greenhouse gas N2O from agricultural land is still a challenge. This is mainly due to its high temporal variability, with low background emissions and a few transient peaks. In this study, a first attempt was made to simulate observations of N2O fluxes with a daily time step from managed peat soils. We used a new N2O module added to the extensively tested hydrological–biogeochemical model combination SWAP-ANIMO, hypothesizing that accurate simulation of the controlling factors would imply accurate simulation of the dynamics of the N2O emissions as well. We used daily N2O emission data from three sites in the Netherlands, with complementary data on soil moisture, mineral N content, and soil N2O concentration. Simulation of soil moisture, mineral N, and N2O concentration was reasonable to good. Still, simulation of the daily N2O emissions was poor, with model efficiencies <0, mainly due to overestimation of N2O emission from denitrification in the topsoil. We expect that the model overestimated diffusion of N2O from the topsoil to the atmosphere, thereby underestimating further reductions of N2O to N2. This was probably linked to the complex peat pore geometry. We concluded that the description of the N2O processes in our model was insufficient to accurately simulate daily N2O emissions from peat soils, even when the main controlling factors are accurately simulated. Improvement is expected from incorporation of the effects of (peat) pore geometry on soil moisture and consequently on N2O production, reduction, storage, and transport.

You do not currently have access to this article.