The STICS model to predict nitrate leaching following agricultural pratices.

Nathalie Schnebelen (1, 2) , Bernard Nicoullaud (3) , Hocine Bourennane (3) , Alain Couturier (3) , Bernard Verbeque (4) , Christian Revalier (4) , Ary Bruand (5) , Emmanuel Ledoux (6)

1 InfoSol - InfoSol
2 BRGM - Bureau de Recherches Géologiques et Minières (BRGM)
3 Unité de Science du Sol
4 Chambre d'Agriculture du Loiret
5 ISTO - Institut des Sciences de la Terre d'Orléans
6 CIG - Centre d'Informatique Géologique

The aim of this paper was to develop an upscaling approach for the soil-crop model STICS in order to predict the impact of agricultural practices on nitrate leaching on both plot and regional scales. A case study was carried out on a "Nitrate Vulnerable Zone" located in central France. The performance of the spatial approach was evaluated by accounting for all the spatial and temporal variability existing within the studied area. The results indicate that N leaching and nitrate concentration in drainage water were slightly underestimated; by 3 kg N·ha-1 (16%) and 8 mg NO3-·L-1 (11%), respectively. The STICS scaling approach was used to assess the effectiveness of "Good Agricultural Practice" established within the area over a seven-year period. The simulation results provided evidence that such a practice had reduced the nitrate concentration by about 30% (36 mg NO3-·L-1). However, the rate of nitrate leaching remains too large and further improvements to agricultural practices are required.

Mots clés: crop model; STICS; upscaling; agricultural practices; nitrate leaching; decision support

Domaines: Interfaces continentales, environnement

Nathalie Schnebelen, Bernard Nicoullaud, Hocine Bourennane, Alain Couturier, Bernard Verbeque, et al.. The STICS model to predict nitrate leaching following agricultural pratices.. Agronomie, 2004, 24, pp.6-7, 423-435. ⟨10.1051/agro:2004039⟩. ⟨hal-00023861⟩