A first rear member is spaced apart from the front member and positioned generally parallel to the front member. A first pair of first pivotable arms are generally parallel to each other. The first pair of first pivotable arms are rotatably connected to the front member at two front pivot points. The first pair of first pivotable arms are rotatably connected to the rear member at two rear pivot points. At least one first opener (e.g., nutrient knife or projecting, ground-engaging member) extends downward from or with respect to the first rear member.
