Temporary Biological N Cońservation by Winter Oilseed Turnip (Brassica RapaL.) and its Influence on Following Crops and N-Percolation

As shown in field plot trials with application of 15N on loamy sand (albic luvisol), winter oilseed turnip (Brassica rapa L.; ssp. oleifera (Dc.) METZG.) incorporated considerable N amounts during the winter period. By this a reduction of N percolation into deeper soil layers was achieved. After mulching, about 30% of the catch crop N was taken up by the following crop, maize (Zea mays L., cv. ‘BEKENOVA’). Maize covered 11% of its total N demand deriving from the catch crop.