|Peterson-munks, Brekke - Orise Fellow|
|Arango Argoti, Miguel Andres - Corpoica|
Submitted to: ASA-CSSA-SSSA Annual Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2015
Publication Date: 11/15/2015
Citation: Peterson-Munks, B., Steiner, J.L., Arango Argoti, M. 2015. Seasonal greenhouse gas and soil nutrient cycling in semi-arid native and non-native perennial grass pastures [abstract]. ASA-CSSA-SSSA Annual Meeting. Synergy in Science: Partnering for Solutions, November 15-18, 2015, Minneapolis, Minnesota. Abstract number 129-3. Available: https://scisoc.confex.com/crops/2015am/webprogram/authorp.html.
Interpretive Summary: Abstract only.
Technical Abstract: Photosynthetic metabolism in warm- and cool-season grass species affects greenhouse gas (GHG) emissions from soils. The major soil GHGs are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Monitoring seasonal variability of GHG and soil carbon (C) and nitrogen (N) from Central Oklahoma soils cropped with warm- or cool-season grasses has not been assessed. We hypothesized that the magnitude of labile soil C and N would increase with soil moisture followed by an increase in GHG emissions in cool-season pasture soils early in the growing season compared to warm-season pasture soils. Soils under warm-season grasses will experience a similar pattern but later in the growing season. This information could provide establish best management practices to mitigate GHGs and store soil C and N. A study was conducted at the USDA-ARS Grazinglands Research Laboratory, El Reno, OK using warm-season and cool-season grasses to: 1) determine seasonal soil C and N content and 2) obtain seasonal GHG emissions from associated soils. Bi-weekly sampling of GHGs and soils (0-15cm) occurred in warm- and cool-season pastures in replicates of five. Greenhouse gas samples were analyzed for CO2, CH4 and N2O using gas chromatography. Soil water content (SWC), physical properties and labile C and N were determined using standard methods. Initial results indicated that the magnitude of CO2 and N2O were proportional to SWC, and CH4 assimilation decreased in semi-arid soils under native perennial grasses compared to soils under non-native grasses. Soils under non-native grasses had increased magnitudes of CO2 and N2O, while CH4 assimilation was similar to soil under native grasses during warmer seasonal trends were moisture was limited. The implication of this research indicates that GHG fluxes from soils in semi-arid environments are altered by abiotic drivers and assimilate CH4.