An apparatus removes soil samples at intervals over a field of interest. The apparatus comprises a sampling assembly (60) that rotates on a track (32) riding on a plurality of idler wheels (29, 31). A probe (66) extends and retracts under the action of a scissored frame assembly (70), mechanically manipulated by passage of the scissored frame assembly (70) along a guide assembly (108). The probe (66) is extended into the ground and retracted on each revolution. An ejector (68) pushes soil from the probe (66) as it passes over a hopper (88) to retain the cores. The cores are pneumatically transferred from the hopper (88) to a plurality of sample collection containers (126). An electronic control system uses GPS location information to deposit collected cores in the appropriate container (126) based upon the current location of the apparatus in the field of interest.