Effect of topography on nitrous oxide emissions from winter wheat fields in Central France
2011
Gu, Jiangxin, J. | Nicoullaud, Bernard, B. | Rochette, Philippe, P. | Pennock, Daniel J., D. J. | Hénault, Catherine | Cellier, Pierre, P. | Richard, Guy | Unité de recherche Science du Sol (USS) ; Institut National de la Recherche Agronomique (INRA) | Department of Soil Science ; University of Saskatchewan [Saskatoon] (U of S) | Environnement et Grandes Cultures (EGC) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech
no sp Assessment of Nitrogen Fluxes to Air and Water from Site Scale to Continental Scale
显示更多 [+] 显示较少 [-]英语. We assessed nitrous oxide (N2O) emissions at shoulder and foot-slope positions along three sloping sites (1.6-2.1%) to identify the factors controlling the spatial variations in emissions. The three sites received same amounts of total nitrogen (N) input at 170 kg N ha−1. Results showed that landscape positions had a significant, but not consistent effect on N2O fluxes with larger emission in the foot-slope at only one of the three sites. The effect of soil inorganic N (NH4+ + NO3−) contents on N2O fluxes (r2 = 0.55, p < 0.001) was influenced by water-filled pore space (WFPS). Soil N2O fluxes were related to inorganic N at WFPS > 60% (r2 = 0.81, p < 0.001), and NH4+ contents at WFPS < 60% (r2 = 0.40, p < 0.01), respectively. Differences in WFPS between shoulder and foot-slope correlated linearly with differences in N2O fluxes (r2 = 0.45, p < 0.001). We conclude that spatial variations in N2O emission were regulated by the influence of hydrological processes on soil aeration intensity.
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