This is not a peer-reviewed paper. Paper No. 011022 An ASAE Meeting Presentation DEVELOPMENT OF AN INSTRUMENTED SUBSOILER TO MAP SOIL HARD-PANS AND REAL-TIME CONTROL OF SUBSOILER DEPTH By

Abstract: An instrumented subsoiler shank was designed and built to measure the soil resistance while moving through the soil and for automatic control of the depth of several standard subsoiler shanks mounted on the same frame. Three load cells measure the resultant magnitude and direction of the soil reactions on the shank. Two load cells measure forces perpendicular to the straight shank with a constant distance between them and another load cell measures the force along the shank. The two perpendicular load cells are cantilevers with one side mounted to the center of the shank’s width and the other side connected to wheels running inside a hollow beam. The wheels enable the shank to be moved up and down for different depths with the aid of a hydraulic cylinder. The hydraulic cylinder is connected to the upper edge of the shank by the lengthwise load cell. The resultant force on the shank is calculated by using the three measured forces, their directions and locations. The instrumented shank was calibrated and tested in the field. While preliminary in nature, the results indicate that when the shank tip is above a soil hardpan, the soil force on the tip acts upward, and becomes negative when the shank tip is below the hardpan. These results indicate that it may be possible to determine the depth of the hardpan by observing when the vertical force on the shank tip passes through zero as the shan