A seed planting unit of an agricultural implement may include a wheel support arm having an upper portion and a lower portion. A wheel may be rotatably supported by the lower portion of the wheel support arm, the wheel configured to contact the soil surface to define a penetration depth setting for the ground engaging tool relative to the soil surface. A depth stop member may be provided in operative association with one of the support structure or the wheel support arm. A depth adjustment member may be selectively movable relative to the other of the support structure or the wheel support arm to vary a relative distance between an abutment portion of the depth adjustment member configured to abut against the depth stop member and the other of the support structure or the wheel support arm to set the penetration depth setting for the ground engaging tool.
