NOx and N2O fluxes in a nitrogen-enriched European spruce forest soil under experimental long-term reduction of nitrogen depositions

► We investigated long-term reduction of N depositions in a spruce stand. ► Net nitrification and nitrate in soil solution were reduced to undetectable levels. ► The soil changed from a net source for NOx into a net sink. ► NOx uptake was controlled by the NOx concentrations of the forest air. ► N2O fluxes did not change due to limited denitrification in the well-aerated soil.