Seasonal distribution of nitrous oxide emissions from soils in the Parkland region
- Agriculture and Agri-Food, Lethbridge, Alberta (Canada). Research Centre
- Battelle PNNL, Washington, DC (United States)
- Univ. of Alberta, Edmonton, Alberta (Canada). Dept. of Renewable Resources
The temporal variability of soil-derived N{sub 2}O emissions presents a major challenge to the accurate quantification of N{sub 2}O-N losses from agroecosystems. The authors characterized the seasonal distribution of N{sub 2}O emissions from two agricultural sites in the Parkland region of Alberta during 1993 and 1994. Treatments studied were fallow, and spring wheat (Triticum aestivum L.) with and without urea fertilizer, under conventional till management. Gas samples were collected from vented static soil chambers and were analyzed for N{sub 2}O with a gas chromatograph equipped with a {sup 63}Ni electron capture detector. Soil water content and concentrations of NO{sub 3}{sup {minus}}-N, NH{sub 4}{sup +}-N, and water-soluble organic C (WSOC) were measured several times during the season. A brief burst of N{sub 2}O emission was recorded at both sites during and immediately following spring snow melt. A second period of activity occurred between mid-June and mid-July. Between 16 and 60% of estimated annual N{sub 2}O-N loss occurred during spring thaw, while >80% of cumulative annual N{sub 2}O-N loss had occurred by mid-July. Mean soil NO{sub 3}{sup {minus}}-N concentration explained up to 65% of the temporal variability in geometric mean N{sub 2}O emissions. A multiple regression model that included fall soil concentrations of No{sub 3}{sup {minus}}-N, NH{sub 4}{sup +}-N, and WSOC explained 94% of the variability in estimated cumulative N{sub 2}O-N loss during the following spring thaw. Most N{sub 2}O-N losses in the Parkland region appear to occur during spring thaw and early summer; therefore, sampling schedules need to focus on these time periods. Management practices that minimize N availability during spring thaw may be an effective mitigation strategy for this region.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 290170
- Journal Information:
- Soil Science Society of America Journal, Vol. 62, Issue 5; Other Information: PBD: Sep-Oct 1998
- Country of Publication:
- United States
- Language:
- English
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