Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Proceedings
Publication Acceptance Date: 9/12/2003
Publication Date: 1/24/2004
Citation: Schuman, G.E., Ingram, L.J., Parkin, T.B. 2004. Nitrous oxide emissions from a northern mixed-grass rangeland interseeded with yellow-flowering alfalfa (medicago sativa ssp. falcata). Society for Range Management Meeting Abstracts. p. 323. Interpretive Summary:
Technical Abstract: Interseeding yellow-flowering alfalfa (Medicago sativa ssp. falcata) into northern mixed-grass rangelands has been shown to greatly increase total forage production of the rangeland, increase forage quality, increase soil carbon sequestration and increase total soil nitrogen. To evaluate whether the increased soil nitrogen influenced nitrous oxide emissions we measured nitrous oxide flux from native rangelands and interseeded rangelands across three interseeding dates (1965, 1987, 1998). Chamber measurements were made in June, August, and November 2003, representing peak growth, maturity, and dormancy of the ecosystem. The June and August measurements were made at ambient soil moisture and also after being wetted with 3.8 cm of water. Nitrous oxide emissions during the peak growth period were not greatly different between the native rangeland and interseeded rangeland or the ambient and wetted soil conditions for the 1965 and 1998 interseeding dates. This general lack of difference in nitrous oxide emissions indicates that the active growing plant community was effectively taking up the increased nitrogen available in the interseeded treatment and did not increase the potential for nitrous oxide emission. Therefore, preliminary evaluation of this management system indicates that interseeding a legume into a northern mixed-grass rangeland can significantly enhance forage production, forage quality and carbon sequestration without influencing nitrous oxide emissions.