Abstract: A transmitter is mounted on a cultivator hitched to a tractor or the like for emitting a noninvasive sensor beam generally parallel to and in front of a soil-cultivating implement which tills the soil. Mechanism detects echoes from obstructions in the path of the implement and controls mechanism for retracting the implement so that the implement does not engage the obstructions. When an obstruction has passed, the implement is returned to its working position extending transversely to the direction of movement of the cultivator.

Abstract: In a planting device for attaching to an agricultural vehicle a planting slide is mounted on a frame for reciprocating sliding motion horizontally in the direction of travel of the vehicle under the influence of a hydraulically operable pressure cylinder. A support plate is mounted on the slide for sliding adjustment vertically, upwards and downwards, and a hollow, funnel-shaped planting spade is pivotally mounted on the support plate on an axis which extends transversely to the direction of travel of the vehicle.The tip of the spade is held in a forwardly directed pivoted rest position by means of a pre-stressed spring, but upon rearward pivotting of the spade, as occurs in operation when the support plate slides down so that the spade penetrates the ground, a control valve having a stem articulated to the spade activates the pressure cylinder to push the slide rearwards on the slide.