Erhöhte Trockenstresstoleranz von Kleegras nach reduzierter BodenbearbeitungA.BernerauthorB.NietlispachauthorR.FreiauthorU.NiggliauthorP.MäderauthorGrass-clover leys are an integral part of organic rotations. We performed an experiment with reduced tillage (RT) and conventional tillage (CT) using mouldboard ploughing in a rotation in Frick (Switzerland) on a heavy soil and 1000 mm mean annual precipitation. The grass-clover mixture was sawn in autumn 2005 after uniform seed bed preparation with a rotary hoe in both tillage systems without ploughing. After emergence most of the clover seedlings collapsed in the CT plots due to draught, while they survived in the RT plots. This led to a much higher share of clover in the mixture under RT. Grass-clover yields were 29 and 23% higher in RT than in CT plots in the first and second year of cultivation in 2006 and 2007, respectively. Grass grown in RT plots was higher in nitrogen (N), phosphorous (P), potassium (K) and magnesium (Mg) content than in CT plots; clover contained solely more P in RT plots. Over all grass-clover had better growing conditions in RT compared to CT plots in our experiment, reflecting after-effects of the differentiated tillage schemes applied for the preceding arable crops. It is suggested that reduced tillage has a high potential to improve water stress tolerance of cropping systems. Soil2009Conference paper, poster, etc.