D.M. Kool
Wageningen University and Research Centre
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Publication
Featured researches published by D.M. Kool.
Rapid Communications in Mass Spectrometry | 2009
D.M. Kool; N. Wrage; O. Oenema; David Harris; J. W. van Groenigen
To effectively mitigate emissions of the greenhouse gas nitrous oxide (N(2)O) it is essential to understand the biochemical pathways by which it is produced. The (18)O signature of N(2)O is increasingly used to characterize these processes. However, assumptions on the origin of the O atom and resultant isotopic composition of N(2)O that are based on reaction stoichiometry may be questioned. In particular, our deficient knowledge on O exchange between H(2)O and nitrogen oxides during N(2)O production complicates the interpretation of the (18)O signature of N(2)O.Here we studied O exchange during N(2)O formation in soil, using a novel combination of (18)O and (15)N tracing. Twelve soils were studied, covering soil and land-use variability across Europe. All soils demonstrated the significant presence of O exchange, as incorporation of O from (18)O-enriched H(2)O into N(2)O exceeded their maxima achievable through reaction stoichiometry. Based on the retention of the enrichment ratio of (18)O and (15)N of NO(3)(-) into N(2)O, we quantified O exchange during denitrification. Up to 97% (median 85%) of the N(2)O-O originated from H(2)O instead of from the denitrification substrate NO(3)(-).We conclude that in soil, the main source of atmospheric N(2)O, the (18)O signature of N(2)O is mainly determined by H(2)O due to O exchange between nitrogen oxides and H(2)O. This also challenges the assumption that the O of N(2)O originates from O(2) and NO(3)(-), in ratios reflecting reaction stoichiometry.
Methods in Enzymology | 2011
D.M. Kool; J. W. van Groenigen; N. Wrage
Source determination of nitrous oxide (N(2)O) from soils has so far been complicated by methodological constraints: the frequently used (15)N tracer method could not differentiate between pathways related to nitrification, that is, nitrifier nitrification (NN), nitrifier denitrification (ND), and nitrification-coupled denitrification (NCD). To overcome this problem, a dual isotope method using both (15)N and (18)O was proposed. However, O exchange between nitrogen oxides and water has been found to disturb such a method. We here explain in detail a novel dual isotope method that allows to quantify O exchange in denitrification and to differentiate N(2)O production from NN, ND, NCD, and fertilizer denitrification (FD). The method has already been applied to a range of soils with good success. Potential of and scope for further improvement of the method are discussed.
Soil Biology & Biochemistry | 2011
D.M. Kool; Jan Dolfing; N. Wrage; Jan Willem van Groenigen
European Journal of Soil Science | 2010
D.M. Kool; N. Wrage; Sophie Zechmeister-Boltenstern; Michael Pfeffer; D. J. Brus; O. Oenema; J. W. van Groenigen
Rapid Communications in Mass Spectrometry | 2007
D.M. Kool; N. Wrage; O. Oenema; Jan Dolfing; J. W. van Groenigen
Soil Biology & Biochemistry | 2009
D.M. Kool; Christoph Müller; N. Wrage; O. Oenema; Jan Willem van Groenigen
Soil Biology & Biochemistry | 2006
D.M. Kool; Ellis Hoffland; E.W.J. Hummelink; Jan Willem van Groenigen
Soil Biology & Biochemistry | 2011
D.M. Kool; N. Wrage; O. Oenema; Chris van Kessel; Jan Willem van Groenigen
Soil Biology & Biochemistry | 2006
D.M. Kool; Ellis Hoffland; Sander Abrahamse; Jan Willem van Groenigen
Geoderma | 2006
D.M. Kool; Peter Buurman