Mass spectrometric procedures for determination of dinitrogen (N2) and nitrous oxide (N2O) evolved during dentrification in soil treated with 15N-labeled fertilizer are based on the hypothesis that the nitrate (NO3$+-) undergoing denitrification can be assumed to exist in a single pool that is isotopically uniform. In the work reported, it is shown that 15Xn (the average mole fraction of 15N in the NO3- undergoing denitrification) will be overestimated when this assumption is invalid. Moreover, it is proved mathematically that the amount of N2 or N2O evolved is underestimated when 15Xn does not exceed 0.5. This proof does not hold for higher values of 15Xn, but it is concluded that underestimation also occurs in these cases, because no exceptions were found in over three million computer simulations involving evolution of N2 from multiple pools having 15N enrichments as high as 99.6 atom %.
|Original language||English (US)|
|Number of pages||6|
|Journal||Soil Science Society of America Journal|
|State||Published - 1988|
ASJC Scopus subject areas
- Soil Science