Diurnal fluxes of CO2 and N2O from cattle-impacted soil and implications for emission estimates

Short-term diurnal changes in emissions of CO2 and N2O were determined in a cattle overwintering area during three specific periods of the year. Production of both N2O and CO2, as determined with gas chambers buried in soil and spatially distributed changed rapidly, and the general course of fluxes of the two gases was different. CO2 emissions were basically controlled by temperature, and most gas chambers showed the same trends in CO2 flux, indicating low spatial heterogeneity. In contrast, N2O emissions were much more spatially heterogeneous and each chamber had its own time course of emission; therefore, the relationship between flux and temperature was more complicated for N2O than CO2. For estimating gas emissions over long periods, we strongly recommend the use of frequent emission measurements during periods of high gas fluxes.