Since 1994 four tillage systems are tested at 9 sites in southern and eastern Germany. The tillage treatments (ploughed = mouldboard ploughing 30 cm deep applied to the 3 main crops in the rotation, loosened = non inverting loosening 30 cm deep applied to all main crops, mulched = only shallow tillage 10 cm deep, direct drilled = no tillage except for sugar beets with 1-2 passes of shallow tillage) are applied to all main crops in the rotation which includes sugar beet followed by winter wheat and one more cereal crop. The investigation focuses on yield and quality as well as on the appearance of pests and diseases especially in sugar beet as affected by soil tillage. On average from 1994 to 2001 white sugar yield did not differ between the ploughed, loosened and mulched tillage systems. Direct drilling reduced yield, mainly due to lower field emergence during the first years. The development of pests and diseases can be promoted by plant residues left on the soil surface in reduced tillage systems. For sugar beet, this hypothesis needs to be tested for the important fungus Cercospora beticola as well as for slugs, which both have the potential to damage beet crops severely. First results from beet fields inoculated with Cercospora beticola in 1997 and 1998 showed no influence of tillage system on the appearance of Cercospora beticola three years later. The rapid rotting of sugar beet leaves probably limits the survival of this fungus. The appearance of slugs was noticeably increased with direct drilling as well as in the loosened and mulched tallage systems.