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| Titel |
The annual ammonia budget of fertilised cut grassland – Part 1: Micrometeorological flux measurements and emissions after slurry application |
| VerfasserIn |
C. Spirig, C. R. Flechard, C. Ammann, A. Neftel |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 7, no. 2 ; Nr. 7, no. 2 (2010-02-08), S.521-536 |
| Datensatznummer |
250004487
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| Publikation (Nr.) |
 copernicus.org/bg-7-521-2010.pdf |
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| Zusammenfassung |
| Two commercial ammonia (NH3) analysers were customised to
allow continuous measurements of vertical concentration gradients. The
gradients were used to derive ammonia exchange fluxes above a managed
grassland site at Oensingen (Switzerland) by application of the
aerodynamic gradient method. The measurements from July 2006 to
October 2007 covered five complete growth-cut cycles and
included six applications of liquid cattle slurry. The average
accuracy of the flux measurements during unstable and near-neutral
conditions was 20% and the detection limit was
10 ng NH3 m−2 s−1. Hence the flux measurements
are considered sufficiently accurate for studying typical NH3
deposition rates over growing vegetation. Quantifying the overall
emissions after slurry applications required the application of
elaborate interpolations because of difficulties capturing
the initial emissions during broadspreading of liquid manure.
The emissions were also calculated with a mass balance
method yielding similar fluxes. NH3 losses after
slurry application expressed as percentage of emitted nitrogen versus
applied total ammoniacal nitrogen (TAN) varied between 4 and 19%,
which is roughly a factor of three lower than the values for broadspreading of liquid
manure in emission inventories. The comparatively low emission factors appear to be
a consequence of the low dry matter content of the applied slurry and soil
properties favouring ammonium adsorption. |
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