TY - GEN UR - https://orgprints.org/id/eprint/603/ PB - Stiftung Ökologie & Landbau (SÖL), Bad Dürkheim Y1 - 2002/// SP - 9 AV - public ID - orgprints603 N2 - The article underlines the importance of humus maintenance in organic farming and describes some important agronomic tools to achieve it based on long-term field experiments. The particular role of farmyard manure is discussed compared to other fertilizers. Effects of different crop rotation systems and of biodynamic preparations are also described. A1 - Raupp, Dr Joachim EP - 11 TI - Wie die Humusentwicklung langfristig sichern? KW - soil organic matter; sustainability; farmyard manure; mineral fertilizer crop rotation; biodynamics ER -