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Titel |
Investigating the stomatal, cuticular and soil ammonia fluxes over a growing tritical crop under high acidic loads |
VerfasserIn |
B. Loubet, C. Decuq, E. Personne, R. S. Massad, C. Flechard, O. Fanucci, N. Mascher, J.-C. Gueudet, S. Masson, B. Durand, S. Genermont, Y. Fauvel, P. Cellier |
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 ; 9, no. 4 ; Nr. 9, no. 4 (2012-04-26), S.1537-1552 |
Datensatznummer |
250006959
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Publikation (Nr.) |
copernicus.org/bg-9-1537-2012.pdf |
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Zusammenfassung |
Ammonia concentration and fluxes were measured above a
growing triticale field for two months during May and June 2010 at the
NitroEurope crop site in Grignon (Fr-Gri) near Paris, France. The
measurement campaign started 15 days following a 40 kg N ha−1
application of an ammonium nitrate solution. A new mini-wedd (Wet Effluent
Denuder) flow injection analyser with three channels (ROSAA, RObust and
Sensitive Ammonia Analyser) was used to measure NH3 fluxes using the
aerodynamic gradient method. The measured ammonia concentrations varied from
0.01 to 39 μg NH3 m−3 and were largely influenced by
advection from the nearby farm. The ammonia fluxes ranged from –560 to
220 ng NH3 m−2 s−1 and averaged
–29 ng NH3 m−2 s−1. During some periods the large
deposition fluxes could only be explained by a very small surface
resistance, which may be partly due to the high concentrations of certain
acid gases (HNO3 and SO2) observed in this suburban area. Ammonia
emissions were also observed. The canopy compensation point Cc was
around 1.5 μg NH3 m−3 on average. The canopy emission
potential Γc (Cc normalised for the temperature response of
the Henry equilibrium) decreased over the course of the measurement campaign
from Γc = 2200 to Γc = 450, the latter value being
close to the median stomatal emission potential (Γs) and lower
than the median ground emission potential (Γg) for managed
ecosystems reported in the literature. The temporal dynamics of the measured
NH3 flux compared well with the Surfatm-NH3 model using fitted
parameters. The subjectivity of the model fitting is discussed based on a
sensitivity analysis. |
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