Abstract: Disclosed is a subsoil rotary cultivator. The cultivator can advantageously include a tool bar which is mounted to the tractor in the usual fashion. Group frames are advantageously mounted upon the tool bar and have spring-loaded pivoting arms upon which are mounted main tubular members. The main tubular members support a disc assembly using bearings which are positioned within the main tubular member, preferably at the extreme ends thereof. A central shaft extends through the bearings and main tubular member and has a disc attached transversely at the lower end. A shield tube is attached to the rotating disc assembly and extends upwardly from near the disc thereby providing an exterior surface which rotates with the disc in order to deflect weeds, straw, viney plants, and other debris, thereby preventing the cultivator from becoming plugged when it is drawn through a field.