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Seasonal Distribution of Nitrous Oxide Emissions from Soils in the Parkland Region
Author(s) -
Lemke R. L.,
Izaurralde R. C.,
Nyborg M.
Publication year - 1998
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1998.03615995006200050025x
Subject(s) - nitrous oxide , soil water , environmental science , snow , spring (device) , fertilizer , hydrology (agriculture) , greenhouse gas , agroecosystem , snowmelt , zoology , atmospheric sciences , environmental chemistry , chemistry , soil science , agriculture , ecology , geography , meteorology , mechanical engineering , geotechnical engineering , organic chemistry , geology , engineering , biology
The temporal variability of soil‐derived N 2 O emissions presents a major challenge to the accurate quantification of N 2 O‐N losses from agroecosystems. We characterized the seasonal distribution of N 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 2 O with a gas chromatograph equipped with a 63 Ni electron capture detector. Soil water content and concentrations of NO ‐ 3 ‐N, NH + 4 ‐N, and water‐soluble organic C (WSOC) were measured several times during the season. A brief burst of N 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 2 O‐N loss occurred during spring thaw, while >80% of cumulative annual N 2 O‐N loss had occurred by mid‐July. Mean soil NO ‐ 3 ‐N concentration explained up to 65% of the temporal variability in geometric mean N 2 O emissions. A multiple regression model that included fall soil concentrations of NO ‐ 3 ‐N, NH + 4 ‐N, and WSOC explained 94% of the variability in estimated cumulative N 2 O‐N loss during the following spring thaw. Most N 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.