Propagation of Soil Failure Front Associated with various Agricultural Tillage Tools

Current North American soil tillage practices loosen soil to depths of 75 to 150 mm (3 to 6 inches). As the soil is tilled, the failure path precedes the motion of the tillage tool. Previous research has examined the forces within the soil to predict the soil failure. This paper experimentally quantifies the rate and the path of the failure front through the soil. From high speed digital film analysis, the failure front was analysed for three tillage tools operating at 4 km/h speed. The tillage tools included sweep, knife opener and an elliptical tool. The depth of operation was either 75 mm or 100mm. Soil conditions, namely its moisture content and the level of compactness were recorded. For the sweep tillage tool, temporal profiles of the failure or crack growth were quantified from the high speed videography. If the tool operational speed can be increased to overcome the speed of the failure front, the soil disturbances will be minimal to non existent.