Experimental determinations of isotopic fractionation factors associated with N2O production and reduction during denitrification in soils

Multi-factorialin vivostable isotope fractionation: causes, correlations, consequences and applications

“…The main indicator for the assignment to its origin is its isotopomer analysis [69,253,254]. A recent extensive experimental study investigates the fundamentals of (net) IF factors associated with denitrification and N 2 O formation in soils [255].…”

Molecular techniques and stable isotope ratios at natural abundance give complementary inferences about N2O production pathways in an agricultural soil following a rainfall event

“…Atmospheric N 2 O concentrations were measured at two different heights above the soil surface in each field using a tunable diode laser trace gas analyzer (TGA100A, Campbell Scientific, Inc.). Fluxes were calculated from the measured concentration difference and the integrated eddy diffusivity of N 2 O (Wagner-Riddle et al, 1996) for periods when the wind direction allowed for a minimum fetch-to-height ratio of 50:1, which ensured >80% of the measured flux originated within the experimental field (Leclerc and Thurtell, 1990). Although this method is designed to measure the flux from 4 adjacent fields, this study is only concerned with data from 2 fields (Fig.…”

Nitrate denitrification with nitrite or nitrous oxide as intermediate products: Stoichiometry, kinetics and dynamics of stable isotope signatures

“…To explain it an inverse isotope effect was postulated by Maggi and Riley (2010). However, the isotope effects for d 15 N and d 18 O associated with N 2 O reduction may depend largely on the experimental setup, presumably due to varying impact of diffusive isotopic effects (Lewicka-Szczebak et al, 2014). Also, a high deviation of experimental isotope signatures occured during nitrous oxide reduction ( Fig.…”

“…However, the available organic material as the second rate-limiting substrate in denitrification was not taken into account and the initial lag in nitrous oxide concentration kinetics was not obtained. Aside from the relative reaction rates, isotope effects are influenced by substrate availability, kinetics of bond formation and destruction, chemical equilibrium and different physical isotope effects (e.g., diffusion or evaporation: Snider et al, 2009;Lewicka-Szczebak et al, 2014).…”