Nitrous oxide emission from an agricultural soil subjected to different freeze-thaw cycles

Three methods to estimate N2O fluxes as impacted by agricultural management

“…Numerous studies have shown that N 2 O production from denitrification is a episodic and spatially variable event Burton and Beauchamp 1982;Folorunso and Rolston 1984;Parkin 1987;Christenson and Tiedje 1990). While there are many elements which contribute to the variability in N 2 O production within soil, dramatic changes in environment associated with rapid thaw events (Goodroad and Keeney 1984ab;Christensen and Tiedje 1990;Christensen and Christensen 1991;Chen et al 1995) and following periods of rainfall (Goodroad and Kenney 1984a,b;Rudas et al 1991;Li et al 1992) have been shown to result in accumulation of N 2 O in the soil profile and intense flux events across a wide range of soils. The changes in N 2 O concentration in the soil profile have been attributed to biological production and/or consumption as well as changes in N 2 O solubility in water Kenney 1984b, 1985).…”

Spring thaw and growing season N2O emissions from a field planted with edible peas and a cover crop

“…Emissions of N 2 O fluctuate throughout the season, but, in general, large emissions have been found to occur during the late spring and early summer when N fertilizers are applied (Chen et al 1995;Mogge et al 1999;Webb et al 2000;Baggs et al 2003;Grant and Pattey 2003;Grant et al 2006). During this period, the emissions of N 2 O increase with soil moisture in response to rainfall.…”

“…Explanations for the enhanced emissions after snowmelt include a physical release of the N 2 O that was trapped beneath ice sheets or a frozen soil layer (Goodroad and Keeney 1984;Burton and Beauchamp 1994;Kaiser et al 1998;Ro¨ver et al 1998;Teepe et al 2000Teepe et al , 2001Koponen et al 2004;Pattey et al 2007), an increase in substrate availability for denitrification and microbial activity, and chemical N 2 O production (Koponen et al 2004;Christianson and Cho 1983;Ro¨ver et al 1998). Chen et al (1995) have discerned from soil core studies that soil N 2 O emissions increase significantly with the number of freeze-thaw cycles. Other studies have confirmed the impact that freeze-thaw cycles have on N 2 O emissions through the disruption of soil structure, which, in turn, releases substrates and stimulates denitrification Ro¨ver et al 1998;Prieme´and Christensen 2001;Teepe et al 2001;Mu¨ller et al 2002;Maljanen et al 2003;Koponen et al 2004;Merino et al 2004).…”

“…In Eastern Canada, emissions during snowmelt have been found to contribute anywhere from 30% (Grant and Pattey 1999) to 50% of the annual nitrous oxide emissions (WagnerRiddle and Thurtell 1998). A few studies have reported fluxes of two orders of magnitude greater during the spring thaw than during any other time of the year (Christensen and Tiedje 1990;Chen et al 1995). Explanations for the enhanced emissions after snowmelt include a physical release of the N 2 O that was trapped beneath ice sheets or a frozen soil layer (Goodroad and Keeney 1984;Burton and Beauchamp 1994;Kaiser et al 1998;Ro¨ver et al 1998;Teepe et al 2000Teepe et al , 2001Koponen et al 2004;Pattey et al 2007), an increase in substrate availability for denitrification and microbial activity, and chemical N 2 O production (Koponen et al 2004;Christianson and Cho 1983;Ro¨ver et al 1998).…”

“…During this period, the emissions of N 2 O increase with soil moisture in response to rainfall. The other period of large emissions is during the end of the snowmelt period when soils are thawing and microbial activity is increasing (Goodroad and Keeney 1984;Chen et al 1995;Grant and Pattey 1999;Maggiotto and Wagner-Riddle 2001;Pattey et al 2007). The sudden increase of moisture content in the soil profile induced by snowmelt and soil thawing promotes the emission of N 2 O.…”