The trend in use of heavier and more powerful tractors and harvesting equipment has resulted in a general increase in the depth of ploughing, and also in the depth to which soil compaction may be expected to take place. The avoidance of compaction has therefore been a major research priority for many years, as has been the investigation of how to achieve optimum seedbed conditions. Conservation tillage may be interpreted as any system that promotes good crop yields while at the same time maintaining soil fertility and minimizing soil and nutrient losses. Research in Scandinavia has included work on several alternatives, but most emphasis has been placed on systems that allow the use of conventional seed drills, as this is deemed most acceptable from an economic viewpoint. Fertilizer placement in the seedbed has been found to be equally important in ploughless systems as with conventional tillage.