Improvements in agricultural nitrogen management can be designed to reduce nitrous oxide emissions, thus providing greenhouse gas mitigation. If included within carbon markets (voluntary or regulatory) or incentivized as part of a government program, farmers could be compensated for providing this environmental service. For the environmental benefit to be guaranteed and of high quality, the processes need to be well-understood and quantification of the GHG flux change must be within specified parameters. We discuss the technical and scientific information needed to bring nitrogen management into GHG markets or programs. Some key research gaps are pointed out, as well as some of the significant uncertainties in baseline data.