Abstract: A self-propelled combine has a pair of forward drive wheels and carries a forward, transversely elongated, harvesting header having a plurality of generally fore and aft passages adapted to receive respective rows of crop material as the machine advances and a cutting apparatus for each passage for severing the crop relatively close to the ground as it moves along the passage to leave a short upright crop stubble in each row. Two of the passages are in general fore and aft alignment with the respective drive wheels so that the wheels run over the stubble, and a pair of stubble mashing devices are mounted on the header forwardly of the respective drive wheels, each device including a skidlike stubble engaging element that is biased downwardly into contact with the ground so that it mashes the crop stubble against the ground in advance of the wheel to reduce tire wear caused by the wheel rolling over the upright stubble.