An apparatus, which may be a tillage apparatus, has a flexible frame. The frame may be made from open members. The frame may support ground engagers and may be supported on wheel assemblies. The ground engagers may be connected to a spring trip mechanism. The ground engagers may be mounted to open members of the frame with a clamping style mechanism. The clamp mechanism may include wedge devices. The frame may be lowered and raised relative to wheels of the wheel assemblies with a lift mechanism. One row of ground engagers may be raised or lowered relative to the frame independent of another row of ground engagers. An anti-skid or skew control system may be employed in association with the independent height adjustment of one row of ground engagers. A system may be provided to maintain and control the height of a tow hitch forming part of the apparatus.