Agricultural baler of the rectangular type comprising: - a wheeled frame; - a baling chamber mounted to said frame and extending generally fore-and-aft with respect to the intended direction of movement of the baler and having an inlet opening in the lower wall thereof; - compression means mounted for reciprocation within the baling chamber and back-and-forth over the inlet opening therein for compressing successive charges of crop material fed through said inlet opening into said baling chamber to form a bale thereof; - a feeder duct communicating at one end with the inlet opening in the baling chamber and curving downwardly and forwardly there from and terminating in a lower, forwardly facing open crop receiving mouth; this feeder duct comprising upper and lower curved wall means (32, 36) of which the upper wall means comprises slots, extending generally from said crop receiving mouth to said inlet opening in the baling chamber for cooperation with feeder tines; - feeder means comprising a feeder fork with feeder tines, wherein the feeder means are configured to move the feeder tines along two distinct trajectories, a packing trajectory for accumulating a charge of said crop material in the feeder duct, and a stuffing trajectory for stuffing said charge of said crop material into the baling chamber, the movement of the feeder means is directly derived from and synchronized with the movement of the reciprocing compression means; characterized in that the feeder means comprise the feeding fork comprising at its rearmost end for cooperating with the feeder duct a series of laterally spaced-apart elongated feeder tines, and at its other rearmost end being rotably coupled with a pair of cranks through pivots, which cranks are rotably coupled to the plunger, and wherein the fulcrum of the feeder fork is rotably coupled to one rearmost end of a spacer rod, which spacer rod is rotably coupled in a pivot point at its other rearmost end to the baler frame. - a wheeled frame; - a baling chamber mounted to said frame and extending generally fore-and-aft with respect to the intended direction of movement of the baler and having an inlet opening in the lower wall thereof; - compression means mounted for reciprocation within the baling chamber and back-and-forth over the inlet opening therein for compressing successive charges of crop material fed through said inlet opening into said baling chamber to form a bale thereof; - a feeder duct communicating at one end with the inlet opening in the baling chamber and curving downwardly and forwardly there from and terminating in a lower, forwardly facing open crop receiving mouth; this feeder duct comprising upper and lower curved wall means (32, 36) of which the upper wall means comprises slots, extending generally from said crop receiving mouth to said inlet opening in the baling chamber for cooperation with feeder tines; - feeder means comprising a feeder fork with feeder tines, wherein the feeder means are configured to move the feeder tines along two distinct trajectories, a packing trajectory for accumulating a charge of said crop material in the feeder duct, and a stuffing trajectory for stuffing said charge of said crop material into the baling chamber, the movement of the feeder means is directly derived from and synchronized with the movement of the reciprocing compression means;