Elevated CO2 and O3 modify N turnover rates, but not N2O emissions in a soybean agroecosystem

► Elevated CO2 and O3 did not affect N2O fluxes from a soybean agroecosystem. ► There was no interaction between soil moisture and elevated CO2 or O3 on N2O. ► Natural abundance 15N of soil N suggested longer-term changes in N-cycling. ► Elevated CO2 accelerated N-cycling, and elevated O3 decelerated N-cycling.