The Châlons Oilseed Rape Database holds the results of a comprehensive experiment on the dynamic fluxes of water, carbon and nitrogen within a soil-crop system at the field-scale, conducted in the Champagne region in France. The Châlons experiment started with the sowing of a rapeseed crop (Brassica napus L.) in September 1994, and stopped at its harvest in July 1995. It involved three fertilizer N treatments and a bare control. The soil was a rendzina overlying a subsoil of mixed compact and cryoturbed chalk. The variables monitored were: crop biomass, C and N content, soil matric potential, water and mineral N contents, actual evapotranspiration, nitrous oxide emissions, and ammonia volatilization, along with the usual meteorological data. Mass-balance estimates of water drainage and NO 3 leaching below the root-zone, along with 15 N balances accounting for the short-term dynamics of fertilizer N are also available. The data are accessible on the Internet through a World Wide Web server by means of a specific frontend, and may be used to test or calibrate soil-crop models. (© Inra/Elsevier, Paris.) Internet database / nitrogen cycle / rendzina / oilseed rape Résumé-Une base de données sur les cycles des éléments eau, carbone et azote dans un sol de rendzine sous culture de colza. La base de données CORD (Châlons Oilseed Rape Database) archive les résultats d'une expérience intensive conduite en région Champagne sur la dynamique des flux d'eau, de carbone et d'azote dans un système sol-plante, à l'échelle de la parcelle agricole. L'expérience a débuté au semis d'une culture de colza (Brassica napus L.) en sep-Communicated by Jim Douglas (Penicuik, UK)