Ploughless tillage systems in a crop rotation with sugar beet -: Results of a large scale trial series

Considerable damage caused by erosion has accelerated the development of reduced tillage systems in German sugar beet production. Apart from a reduction of erosion on the sugar beet crop, these systems of conservation tillage offer further ecological and economical benefits when applied to all crops in the rotation. For testing and optimising different systems of conservation tillage, including direct drilling, an on-farm trial on 10 different sites in Southern and Eastern Germany was established between 1990 to 1992. The treatments were mouldboard ploughing (30 cm deep), loosening without soil inversion (30 cm deep), shallow cultivation (10 cm deep) and direct drilling (without any cultivation). Analyses focused on the yield of sugar beet, grain yield of winter wheat as affected by soil tillage. Averaged from 1994 to 1999 similar white sugar yields were observed in the treatments ploughing, loosening and shallow cultivation. Direct drilling reduced yield due to decreased field emergence. Grain yield of winter wheat was not influenced by the treatments ploughing, loosening and shallow cultivation, while it was slightly decreased by direct drilling. The coefficient of variation, as an indicator of yield stability, was unessential affected by the tested tillage systems.