A system for modifying a row unit of a harvesting head, the system including at least one cutting disk adapted for being rotatably mounted to the frame of the row unit between a gathering chain drive sprocket and idler sprocket. The cutting disk includes a sprocket attached thereto for being engaged and driven by the gathering chain in order to rotate the cutting disk. Two counter-rotating cutting disks may be provided, each being driven by a separate gathering chain. A method for modifying a row unit includes loosening the gathering chains, removing existing stalk rolls and housings, installing a cover plate over a gearbox to which the housings were mounted, removing existing trash knives, drilling holes in the row unit frame for mounting the cutting disks, installing the cutting disks, and tightening the gathering chains such that the gathering chains engage sprockets attached to the cutting disks.
