A control system for monitoring and managing operation of a rotary disc cutterbar used in an agricultural machine. A controller in the system receives inputs on cutterbar drive power, machine travel speed, and crop cut quality. An operator interface allows suitable operational tolerances to be established. The controller examines crop cut quality, a determination of cut uniformity across the transverse width of the cutting swath, and determines changes in cutterbar drive speed and/or vehicle travel speed, if needed, to maintain crop cut quality within specified tolerances. Controller output may be directed to a display for instructing a machine operator to make necessary adjustments or it may initiate changes in machine subsystems to effect the necessary adjustments automatically.