A system measures the roughness of the ground surface over which an agricultural implement (10) passes as measured in the direction of travel (22). The system includes at least one ground sensor (40, 42) attached to the agricultural implement (10) that provides measurement of the distance to the ground. A controller (80) is connected to the at least one ground sensor (40, 42), and controls at least one adjustment of the agricultural implement (10). The at least one ground sensor (40, 42) provides instantaneous output (OFGS, ORGS) based on the distance to the ground to the controller (80). The controller (80) then calculates at least one statistical parameter (AVRGS, AVFGS, AAV) from the instantaneous output (OFGS, ORGS). The at least one statistical parameter (AVRGS, AVFGS, AAV) is calculated from variations in the distance to the ground in the direction of travel (22) of the agricultural implement (10).