Nitrous oxide and carbon dioxide fluxes from a bare soil using a micrometeorological approach
- Univ. of Guelph, Ontario (Canada)
Increasing atmospheric carbon dioxide (CO{sub 2}) and nitrous oxide (N{sub 2}O) levels have prompted research on management of the soil C and N pools. The impact of C and N fertilizer addition on N{sub 2}O and CO{sub 2} field emissions in not clear. We determined N{sub 2}O and CO{sub 2} fluxes from a 1-ha bare soil plot using micrometeorological methods with the objective of evaluating the effect of management practices (cultivation, irrigation, fertilizer, and sucrose applications) on the relative importance of both trace gases. Research was conducted at the Elora Research Station (Typic Hapludalf) in Ontario, Canada, over 7 mo. The N{sub 2}O concentration gradients were measured using a Tunable Diode Laser Trace Gas Analyzer and the CO{sub 2} gradients using an Infra-Red Gas Analyzer. The transport coefficients were calculated using a Bowen Ratio Energy Balance and two wind profile approaches. These three approaches resulted in similar hourly fluxes. Peak emissions of 250 ng N{sub 2}O m{sup {minus}1} s{sup {minus}1} were measured after wetting of dry soil (WFP < 0.4) through irrigation in 1991, and rain in 1992. Application of ammonium sulfate (100 kg N ha{sup {minus}1}) and irrigation increased N{sub 2}O emissions to 75 ng m{sup {minus}2} s{sup {minus}1}, with a smaller effect caused by two subsequent irrigations on wet soil (WFP >0.6). Carbon dioxide fluxes varied between 0.01 and 0.5 mg m{sup {minus}1} s{sup {minus}1} being the predominant gas contributing to an equivalent CO{sub 2} global-warming potential, but addition of sucrose increased the contribution of N{sub 2} O to twice the contribution of CO{sub 2}. The combined effect of C and N additions (e.g. manure and legume) on the N{sub 2}O emissions in irrigated or high rainfall areas should be considered in the efforts of atmospheric C sequestering. 40 refs., 7 figs., 1 tab.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 381013
- Journal Information:
- Journal of Environmental Quality, Journal Name: Journal of Environmental Quality Journal Issue: 4 Vol. 25; ISSN JEVQAA; ISSN 0047-2425
- Country of Publication:
- United States
- Language:
- English
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