In one aspect, the disclosure describes an apparatus that harvests crops as the apparatus moves in a direction of travel across a field. The apparatus includes a crop harvesting assembly configured as a line of implements, the line being transverse to the direction of travel. First and second devices for adjusting a vertical position of left and right sides of the apparatus, respectively, are independently operable. Adjustment of a vertical position of at least one of the left and right sides of the apparatus results in tilting the line of implements relative to a horizontal plane defined at a ground surface under left and right ground contacting elements. In other aspects, a method and system are disclosed for automatically positioning a line of implements of an apparatus to follow a ground surface proximate the line of implements.