Greenhouse Gas Emissions from Two Saturated Riparian Buffers Located in Central Iowa.

Saturated riparian buffers have shown early promise as a conservation practice, removing a high percentage of total nitrate from tile water rerouted to seep through a riparian buffer. High removal rates are suspected to be from denitrification. If denitrification is incomplete a resulting product is nitrous oxide (N₂O), a powerful greenhouse gas and contributor to global climate change. The objective of this study was to measure greenhouse gas emissions (CO_2, CH_4, and N₂O) from two saturated riparian buffers located in Central Iowa. Greenhouse gas fluxes were measured from the soil surface and dissolved gas concentrations were measured from seepage water moving through the buffer. During the first year of measurements, N₂O emissions were found to be a small fraction of the total greenhouse gas emissions. Dissolved N₂O concentrations were greatest closest to the distribution tile and negligible at the stream edge. These data do not suggest high rates of incomplete denitrification, but more measurements are needed to ensure saturated riparian buffers are not trading a water quality problem for an air quality problem.