HR: 1340h
AN: B13B-0226    [Abstracts]
TI: Biogenic emission of nitric oxide and nitrous oxide from arid and semi-arid soils: update of measurements, processes, controlling factors and the potential role of soil texture
AU: * Meixner, F X
EM: meixner@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department J.J.v.Becherweg 27, Mainz, 55128 Germany
AU: Ashuri, F
EM: ashuri@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department J.J.v.Becherweg 27, Mainz, 55128 Germany
AU: Trebs, I
EM: ivonne@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Biogeochemistry Department J.J.v.Becherweg 27, Mainz, 55128 Germany
AB: Recently it became evident, that arid and semi-arid soils may be a significant source of nitrogen oxide (NO) (and to a lesser extent also of nitrous oxide (N$_{2}$O)). Particularly, desert soils may provide rather high NO emissions just after seasonally limited and/or sporadical rain events due to the accumulation of nitrate and/or ammonium. N emissions from semi-arid and arid lands particularly contribute to the high error margins of global N emissions from soils, simply because of a very small number of corresponding measurements being available (both in the laboratory and in the field). We present (a) a summary of the underlying mechanisms of N emissions (chemodenitrifictaion, denitrification, nitrification), (b) a very recent update of available NO and N$_{2}$O measurements from semi-arid and arid soils worldwide, and (c) a review of those factors which control the N emissions (N availability and fertilization, soil moisture and temperature). We will particularly address the potential role of soil texture in the partitioning of NO vs. N$_{2}$O fluxes. The global importance of NO vs. N$_{2}$O from semi-arid and arid soils will be discussed.
DE: 1615 Biogeochemical processes (4805)
DE: 0315 Biosphere/atmosphere interactions
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting