Residue discharge system for a combine harvester including a cover assembly

A crop residue spreader has a plurality of deflector elements arranged in a first group and a second group, a planar spreader frame element having a bottom surface to which the first and second group of deflector elements are displaceably mounted, the planar spreader frame element comprising a guide slot extending in a direction substantially perpendicular to the longitudinal axis, a first cover plate that is displaceably mounted to a top surface of the planar spreader frame element; a second cover plate that is displaceably mounted to the top surface of the planar spreader frame element and whereby a relative displacement of the first and second cover plates away from each other causes a part of the guide slot to be uncovered and a third cover plate is configured to cover, at least partly, the uncovered part of the guide slot.