A three-year field experiment investigated the potential yield benefits and soil effects from over winter cover crops in Scotland, U.K. Brassica composition of cover crops significantly increased the grain yield and grain nitrogen (N) concentration of the following spring barley crop. The increased yield with cover crops was outweighed by increased costs and thus without subsidy (Ecological Focus Area) payments there was decreased profitability for the following spring barley crop. Cover crop effects were mostly neutral on soil properties, but surface shear strength was significantly lower than in the stubble control. This indicates that even direct drilling of cover crops will loosen the surface soil. Cover crops varied in their effect on slug populations but in all cases slug numbers were below treatment thresholds. No cover crop effects were detected for total nematode and earthworm abundance or the total soil organic carbon concentration. This study indicates that cover crops can improve cereal production in a region with a short growing season with no negative impact on soil health or the agronomic sustainability.