 |
| Titel |
The relationship between NH3 emissions from a poultry farm and soil NO and N2O fluxes from a downwind forest |
| VerfasserIn |
U. Skiba, J. Dick, R. Storeton-West, S. Lopez-Fernandez, C. Woods, S. Tang, N. vanDijk |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 3, no. 3 ; Nr. 3, no. 3 (2006-08-04), S.375-382 |
| Datensatznummer |
250001065
|
| Publikation (Nr.) |
 copernicus.org/bg-3-375-2006.pdf |
|
|
|
|
|
| Zusammenfassung |
| Intensive livestock farms emit large concentrations of NH3, most of
which is deposited very close to the source. The presence of trees enhances
the deposition. Rates to downwind forests can exceed 40 kg N ha−1
y−1. The steep gradient in large NH3 concentrations of 34.3±20.4,
47.6±24.9, 21.7±16.8 µg NH3 m3 at the
edge of a forest 15, 30 and 45 m downwind of the farm to near background
concentrations within 270 m downwind (1.15±0.7 µg NH3
m3) provides an ideal site to study the effect of different rates of
atmospheric NH3 concentrations and inferred deposition on biological
and chemical processes under similar environmental conditions. We have
investigated the effect of different NH3 concentrations and implied
deposition rates on the flux of NO and N2O from soil in a mixed
woodland downwind of a large poultry farm (160 000 birds) in Scotland, which
has been operating for about 40 years. Measurements were carried out for a 6
month period, with hourly NO flux measurements, daily N2O fluxes close
to the farm and monthly at all sites, and monthly cumulative wet and dry N
deposition. The increased NH3 and NH4+ deposition to the
woodland increased emissions of NO and N2O and soil available
NH4+ and NO3− concentrations. Average NO and
N2O fluxes measured 15, 25 and 45 m downwind of the farm were 111.2±41.1,
123.3±40.7, 38.3±28.8 µg NO-N m−2
h−1 and 9.9±7.5, 34.3±33.3 and 21.2±6.1 µg
N2O-N m−2 h−1, respectively. At the background site 270 m
downwind the N2O flux was reduced to 1.75±2.1 µg N2O-N
m−2 h−1. NO emissions were significantly influenced by
seasonal and daily changes in soil temperature and followed a diurnal
pattern with maximum emissions approximately 3 h after noon. For
N2O no consistent diurnal pattern was observed. Changes in soil
moisture content had a less clear effect on the NO and N2O flux. In
spite of the large NO and N2O emissions accounting for >3% of the
N deposited to the woodland downwind of the farm, extrapolation to the
entire British poultry flock suggests that these NH3 emissions
contribute to less than 0.5% and 0.02%, respectively of the total
annual UK NOx and N2O emissions. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|