The Influence of Nitrate, Nitrite, and Oxygen on the Composition of the Gaseous Products of Denitrification in Soil
1979
Firestone, M. K. | Smith, M. S. | Firestone, R. B. | Tiedje, J. M.
[¹⁸N]-N₂O produced by denitrification of ¹⁸NO⁻₃ in soil slurries readily exchanged with nonlabeled pools of added N₂O. This supports the role of N₂O as a free, obligate intermediate of denitrification in soils. The observation that N₂O diffuses freely from the site of active denitrification in soils means that any factor which produces a change in the relative rate of N₂O reduction compared to the rate of N₂O production can alter the proportion of N₂O and N₂ resulting. Increased concentration of NO₃⁻ and NO₂⁻ resulted in increased production of N₂O relative to N₂ as the product of denitrification. The influence of NO₂⁻ was much stronger than that of NO₃⁻, with low concentrations of NO₂⁻ causing N₂O to become a significant product of denitrification. This suggests that NO₂⁻, not NO₃⁻, may be the influential species. Additions of small quantities of O₂ (0.02 atm) caused a large decrease in denitrification activity and resulted in a significant increase in the N₂O/N₂ ratio.
显示更多 [+] 显示较少 [-]