To form round bales of fibrous agricultural material, windrowed material is fed into a baling zone formed within a frame. The frame is formed of a stationary front part and a rear part pivotally connected to the front part. Circumferential peripheral surface of the baling zone is lined with conveying elements, either belts, chains, drums, rollers or the like can be used. The material enters in the lower portion of the front part through an opening between two adjacent conveying elements. As it is carried along by the conveying elements, the material is turned over on itself gradually producing a round bale limited in size by the circumferential periphery of the baling zone. As the zone becomes filled, the conveying elements compress the material, wherein the inner layers foist together in a stellate manner. When the bale is completed the rear part pivots away from the front part to discharge the bale.