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| Titel |
Soil nitrous oxide emissions from winter wheat cropland at landscape scale |
| VerfasserIn |
Jiangxin Gu, Agnes Grossel, Bernard Nicoullaud, Philippe Rochette, Daniel J. Pennock, Catherine Hénault, Pierre Cellier, Guy Richard |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250036006
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| Zusammenfassung |
| An improved understanding of how variables such as soil type, water content or temperature,
interact to control N2O emissions at the landform scale is needed for scaling up emissions to
regional/national scales. In this study, N2O emissions were measured along three
sloping sites (1.6 - 2.1%) cropped to winter wheat within a 10-km2 area in Central
France by non steady-state chamber technique. The objectives were to measure N2O
emissions at the shoulder and foot-slope landform positions and to identify the
factors controlling their variations. Fluxes of N2O ranged from 0 to 0.11 mg N
m-2 h-1, increased exponentially with soil mineral nitrogen (N) concentrations
(r2 = 0.57, p < 0.001) and correlated with soil denitrification potential rate. The
soil mineral N content explained 31% (p < 0.05) of the variations in N2O fluxes
when the Water-Filled Pore Space (WFPS) was 60%. Landform positions had a significant, but not consistent effect
upon N2O fluxes with greater emission in the foot-slope position at only one of the
three sites. The differences in WFPS between shoulder and foot-slope positions
correlated linearly with the differences in N2O fluxes (r2 = 0.47, p < 0.001). While soil
water content could not explain a large proportion of the variation in N2O fluxes, it
modulated the effect of soil mineral N content. Our results therefore suggest that in this
agricultural landscape, the spatial variations in N2O emission were regulated by the
influence of hydrological processes on soil aeration and denitrification intensity. |
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