In a crop roll forming machine having a reversibly rotatable bale forming means and a drive means there is provided a control means affixed to the frame movable between at least a first position and a second position for cooperative interaction with the drive means and the bale forming means to selectively cause the bale forming means to cease being driven in a first direction and cause it to be driven in an opposing second direction when the control means is moved from the first position to the second position so that a completed crop roll is ejected rearwardly from the machine onto the ground.