This research, the fourth in a series of experiments, was conducted on plots in a completely randomized block design with three treatments (conventional tillage, reduced tillage and zero tillage) and four repetitions. The objective was to evaluate the effect of the treatments on the soil physical properties (bulk density, porosity, and percentage of penetration resistance), soil organic matter, corn production (growth and performance), and earthworm populations. Bulk density and percent porosity of the soils were not significantly affected by the treatments. Increasing the tillage intensity (conventional tillage) of soils reduced the penetration resistance. Furthermore, there was a statistical differences (p<0.05) in penetration resistance between the zero tillage treatment compared to the conventional and reduced tillage treatments. The corn crop yield was statistically higher with the conventional tillage treatment (p<0.01).