Current information on how arable crops in Europe and in Germany, respectively, might respond to future atmospheric CO₂ concentrations [eCO₂] is mainly based on studies performed with isolated plants under optimized growth conditions or studies carried out in chambers or enclosures, i.e. under conditions which may result in misinterpretations of the the CO₂ fertilization effect. A FACE experiment was therefore carried out between 1999 to 2005 in an arable crop rotation (winter barley è sugar beet è winter wheat) at Braunschweig, Germany. The objectives were to assess effects of e[CO₂] (550 ppm) and the interaction with nitrogen supply on crop performance and on related agro-ecosystem properties. The design of the Braunschweig FACE experiment and key findings related to crop growth and yield and to selected soil responses will be presented.