Abstract: A soil cultivating apparatus including a tractor towing a row cultivator by means of a three-point linkage. The row cultivator includes a fixed portion and a moveable portion having soil scarifying tools. The movable portion is laterally moveable relative to the fixed portion by means of linkages and is effected by a hydraulic actuator under control of tool bar control systems which is able to determine the position of the moveable portion relative to the fixed portion by means of a sensor. Mounted upon the moveable potion is a DGPS antenna GPS receiver that forms part of the control system. The control system has a microprocessor which operatively executes a stored program. The microprocessor receives data from an intra-rig sensor and from the GPS receiver specifying the absolute coordinate of the movable portion relative to the earth.