An agricultural baler (1), comprising: a bale chamber (609)； a plunger (7)； a feeder duct (623)； and a rotor feeder unit (631). The rotor feeder unit (631) comprises: a rotor feeder unit bottom (642) distant from a rotor feeder (633) forming a lower boundary of a conveying channel (645) through the rotor feeder unit (631)； and scrapers (657) placed in a conveying direction behind the rotor feeder (633), the scrapers (657) extending in between the tines (643) and having a leading face (659) cooperating with the tines (643). The agricultural baler (1) further includes a position adjuster (640) configured to: displace the leading face (659) of the scrapers (657) relative to the rotor feeder unit bottom (642), and displace a top wall and / or the bottom wall (635, 637) of the feeder duct (623), in order to adjust the volume of the feeder duct (623).
