Perspectives on measurement of denitrification in the field including recommended protocols for acetylene based methods

Soil Gas Diffusivity Controls N2O and N2 Emissions and their Ratio

“…Data sets from each experiment were tested for normality (Anderson and Darling, 1952) with residuals plotted versus fits to verify the assumption that the residuals had constant variance. Fluxes of N 2 O and N 2 were log transformed (In[value + 1]) according to Tiedje et al (1989). One-way ANOVA was used to determine differences among treatments on individual days with soil r b as a factor, and where differences occurred, Tukey's test was used to determine which means were significantly different from one another.…”

Evidence for the predominance of denitrification as a source of N2O in temperate agricultural soils based on isotopologue measurements

“…This is, in part, because some approaches for apportioning N 2 O production between nitrification and denitrification rely on chemical inhibitors or isotope labeling approaches. The former inherently alters soil conditions and microbial activity while the latter frequently requires the incubation of soil samples rather than in situ experimentation [Bateman and Baggs, 2005;Tiedje et al, 1989;Wrage et al, 2005]. Alternative approaches for evaluating the relative proportion of N 2 O emitted from nitrification and denitrification which solely rely on bulk d…”

“…This is, in part, because some approaches for apportioning N 2 O production between nitrification and denitrification rely on chemical inhibitors or isotope labeling approaches. The former inherently alters soil conditions and microbial activity while the latter frequently requires the incubation of soil samples rather than in situ experimentation [Bateman and Baggs, 2005;Tiedje et al, 1989;Wrage et al, 2005]. Alternative approaches for evaluating the relative proportion of N 2 O emitted from nitrification and denitrification which solely rely on bulk d 15 N and d 18 O analysis of N 2 O evolving from soils avoid biases imposed by inhibitors [Bol et al, 2003[Bol et al, , 2004Mandernack et al, 2000;Perez et al, 2000Perez et al, , 2001Tilsner et al, 2003;Webster and Hopkins, 1996;Wrage et al, 2004a;Yamulki et al, 2000Yamulki et al, , 2001.…”

Isotopologue fractionation during N2O production by fungal denitrification

“…The addition of the fungal inhibitor cycloheximide, for example, decreased the flux of N 2 O by 89% while the bacterial inhibitor streptomycin decreased the flux by only 23% 2. While inhibitor‐based studies demonstrate that fungi can be important in producing N 2 O in grassland soils, the use of inhibitors alters microbial activity 4–9. Thus, a less invasive approach for evaluating the importance of fungal denitrification to N 2 O flux is desirable.…”

“…2 While inhibitor-based studies demonstrate that fungi can be important in producing N 2 O in grassland soils, the use of inhibitors alters microbial activity. [4][5][6][7][8][9] Thus, a less invasive approach for evaluating the importance of fungal denitrification to N 2 O flux is desirable.…”