Eddy-covariance and chamber measured GHG emissions from commercial cornfield

Water and nitrogen (N) use efficiencies remain generally low in the corn production systems. As a result, much of the excess N applied to these ecosystems is leached to ground water, or/and emitted to the atmosphere in the form of reactive N gases like nitrous oxide (N2O) and NOx. Traditional dynamic chamber technique is the standard method of point measuring trace gas emissions (can be used in small plot experiments in meters and hours scales) but the spatial and temporal variability make this method time and labor intensive for field scale experiments. To date, only recently has a fast response sensor become available that makes it possible to use Eddy Covariance technique. In this study, we used eddy covariance (EC) technique to continuously measure N2O emissions in a commercial corn field that provided the field scale measurements necessary for accurate and dynamic (seconds, minutes, or hours) results. We also used the traditional chamber technology to measure the N2O emissions in the field and compared to the EC technique. The EC and chamber methods gave similar results during the chamber measurement periods.