A baler is comprised of a plurality of reversibly driven belts or chains supported on a plurality of transverse rollers and defining an expendable bale-forming chamber. A bale discharge gate is provided for opening the chamber and discharging a bale therein onto the ground. The gate includes at least a portion of the belts or chains and a motor for driving the belts or chains in a direction opposite to that used for bale formation and is further operable to bring a portion of the belts or chains into contact with a discharged bale and to displace the bale rearwardly from the baler along the ground.