The feasibility of fall subsoiling in a wide-bed controlled-traffic production system was evaluated for cotton production on Tunica clay. Seed cotton yields for the 4 year period 1988-1991 are presented for twice--over disk harrow (conventional tillage) and for parabolic subsoiler (deep tillage) land preparation. Deep tillage plots consistently produced more seed cotton than conventionally tilled plots with differences ranging from 630 kg/ha (562 lb/a) to 53 kg/ha (47 lb/a). The four year average seed cotton yield for deep tillage was 830 kg/ha (56 lb/a) which compares to a 419 kg/ha (158 lb/a) average yield from conventionally tilled plots.