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| Titel |
Spatial distribution of soils determines export of nitrogen and dissolved organic carbon from an intensively managed agricultural landscape |
| VerfasserIn |
T. Wohlfart, J.-F. Exbrayat, K. Schelde, B. Christen, T. Dalgaard, H.-G. Frede, L. Breuer |
| 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. 11 ; Nr. 9, no. 11 (2012-11-15), S.4513-4525 |
| Datensatznummer |
250007393
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| Publikation (Nr.) |
 copernicus.org/bg-9-4513-2012.pdf |
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| Zusammenfassung |
| The surrounding landscape of a stream has crucial impacts on the aquatic
environment. This study pictures the hydro-biogeochemical situation of the
Tyrebækken creek catchment in central Jutland, Denmark. The intensively
managed agricultural landscape is dominated by rotational croplands. The
small catchment mainly consist of sandy soil types besides organic soils
along the streams. The aim of the study was to characterise the relative
influence of soil type and land use on stream water quality. Nine snapshot
sampling campaigns were undertaken during the growing season of 2009. Total
dissolved nitrogen (TDN), nitrate (NO3−), ammonium nitrogen and dissolved
organic carbon (DOC) concentrations were measured, and dissolved organic
nitrogen (DON) was calculated for each grabbed sample. Electrical
conductivity, pH and flow velocity were measured during sampling.
Statistical analyses showed significant differences between the northern,
southern and converged stream parts, especially for NO3− concentrations with
average values between 1.4 mg N l−1 and 9.6 mg N l−1.
Furthermore, throughout the sampling period DON concentrations increased to
2.8 mg N l−1 in the northern stream contributing up to 81% to
TDN. Multiple-linear regression analyses performed between chemical data and
landscape characteristics showed a significant negative influence of organic
soils on instream N concentrations and corresponding losses in spite of their
overall minor share of the agricultural land (12.9%). On the other hand,
organic soil frequency was positively correlated to the corresponding DOC
concentrations. Croplands also had a significant influence but with weaker
correlations. For our case study we conclude that the fractions of coarse
textured and organic soils have a major influence on N and DOC export in this
intensively used landscape. Meanwhile, the contribution of DON to the total N
losses was substantial. |
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