Effects of farm heterogeneity and methods for upscaling on modelled nitrogen losses in agricultural landscapes
2011
Dalgaard, T., T. | Hutchings, N., N. | Dragosits, U., U. | Olesen, J.E., J.E. | Kjeldsen, C., C. | Drouet, Jean-Louis | Cellier, Pierre, P. | Department of Agroecology ; Aarhus University [Aarhus] | 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. The aim of this study is to illustrate the importance of farm scale heterogeneity on nitrogen (N) losses in agricultural landscapes. Results are exemplified with a chain of N models calculating farm-N balances and distributing the N-surplus to N-losses (volatilisation, denitrification, leaching) and soil-N accumulation/release in a Danish landscape. Possible non-linearities in upscaling are assessed by comparing average model results based on (i) individual farm level calculations and (ii) averaged inputs at landscape level. Effects of the non-linearities that appear when scaling up from farm to landscape are demonstrated. Especially in relation to ammonia losses the non-linearity between livestock density and N-loss is significant (p > 0.999), with around 20-30% difference compared to a scaling procedure not taking this non-linearity into account. A significant effect of farm type on soil N accumulation (p > 0.95) was also identified and needs to be included when modelling landscape level N-fluxes and greenhouse gas emissions.
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