A harvester (10) is provided with a blower (26) and an air distribution manifold (16), which discharges a flow of air generated by the blower (18) as a curtain of air through outlet ports (22 and 23). This curtain of air intercepts and disperses the chaff as the chaff is discharged from the harvester. The outlet ports are disposed so that they impart a component of force to the air flowing from the manifold (18) in a direction transverse to the direction of travel of the harvester and laterally away from the harvester. In a preferred embodiment of the present invention, the air flow from the manifold cooperates with straw spreaders (19) to achieve more even and uniform distribution of the chaff.
