Abstract: A disk tiller blade which cuts, rather than pushes laterally, soil, in keeping with minimum tillage practices so as to greatly reduce the energy exerted in driving a gang of disks. The blade is generally circular and divided into either semicircular or quarter concavo-convex sections. The concave surface of each section faces in a direction opposite the concave surface of adjacent sections. Interconnecting members interconnect adjacent sections. In the semicircular section embodiment, the mounting means has a longitudinal axis which lies in a plane define in the interconnecting member. In the quarter section embodiment, each section is turned so that the plane defined by the outer edge of each section forms an angle of less than 90.degree. with the longitudinal axis of the mounting means. The shape of the disk is adjusted so that the perpendicular distance between each point along the outer edge of the disk to the longitudinal axis of the mounting means is constant.