Die Bodenkultur - Journal for Land Management, Food and Environment


Nitrogen accumulation and nitrogen residues of field beans (Vicia faba L.)

Part 3: Utilisation and conservation of mineralized nitrogen after field beans by interplanting


Field trials were conducted to test methods of interplanting in order to conserve and to use mineralized nitrogen during a 6-8 months period after harvesting field beans. During flowering or at brown ripe stage of field bean crops winter rape and winter barley were undersown, respectively. The goal was to establish reasonable crops by undersowing without soil preparation, at first to ensure a quick and early uptake of mineralized nitrogen and secondly to grow a subsequent crop for grain production. Additionally winter rape and winter barley were sown after the harvest of field beans at locally conventional dates and methods. During a 6-8 months period the Nmin-content of the soil (kg N03-N/ha, depth 0 to 90 cm) and the N-uptake (kg N/ha) by winter rape and winter barley were measured. At full ripe stage grain yields of winter rape and winter barley were measured. Crops undersown during flowering emerged satisfactorily but suffered from lack of light. Crops undersown on the soil surface at brown ripe stage did not emerge under dry conditions. On the other hand undersown and fairly well developed crops reduced Nmi,-levels to 20 kg N/ha quickly and remarkably earlier as compared to conventionally sown rape or barley crops. Attempts to improve the coordination of field bean crops and undersown crops are discusssed. Grain yields of undersown winter rape and winter barley crops did not reach yield levels of conventionally sown crops, but efforts to optimize the lateron growth and yielding of undersown crops are under investigation.

Key-words: field beans, N,i,-content/soil, interplanting.