a chassis;

a plurality of ground contacting members coupled with and rotatable relative to the chassis;

a suspension coupled with an earth working tool, the suspension including a first shaft coupled with the chassis, a second shaft coupled with the earth working tool and movable relative to the first shaft in response to an external force applied to the earth working tool, a compressible member comprising a spring, the spring being compressible in response to movement of the second shaft relative to the first shaft in response to the external force wherein compression of the spring accommodates movement of the earth working tool relative to the chassis in response to the external force applied;

a first adjustment mechanism coupled with the earth working tool and coupled with the chassis; and

a second adjustment mechanism coupled with the suspension and coupled with the chassis;

wherein the earth working tool is rotatable relative to the chassis about at least two distinct axes of rotation and the first adjustment mechanism and the second adjustment mechanism are adjustable to position the earth working tool at a first vertical distance relative to a plane of an underlying ground surface and at a first pitch relative to the plane, and to position the earth working tool at a second vertical distance relative to the plane and at the first pitch relative to the plane, the second vertical distance being greater than the first vertical distance, and the suspension is coupled with the earth working tool at a first pivotal coupling, the first adjustment mechanism is coupled with the earth working tool at a second pivotal coupling and is coupled with the chassis at a third pivotal coupling, the second adjustment mechanism is coupled with the suspension at a fourth pivotal coupling and coupled with the chassis, and the first pivotal coupling defines a first one of the at least two distinct axes of rotation.