Dry bean and soybean root rot has become an increasing problem in central Minnesota due to soil conditions associated with shallow tillage that result in reduced soil mixing. Low soil temperature and prolonged periods of saturated soils associated with reduced tillage practices often favor soil-borne fungal pathogens which enhance the incidence and severity of root diseases. This study was conducted to determine if a deep tillage method intended to improve soil drainage and reduce soil penetration resistance lessened the severity of root rots of dry bean and soybean when compared to conventional shallow tillage. Field plot experiments were conducted in sites with a history of root rot problems using a deep sub-soiling tillage versus the conventional chisel tillage. The experiment was conducted in a split plot design with tillage as the main plots and crop either dry bean or soybean as subplots. Irrigation was used in the study by meeting crop water requirements for dry bean and soybean, respectively. Soil temperature and water content were measured at different depths from each field plot during the study. Because soil temperature and water content are state variables that are highly dynamic, an automated electronic sensing system was used for the measurement. Other soil and plant parameters measured included soil penetration resistance, soil bulk density, soil pH, leaf area index, plant height, leaf chlorophyll, canopy temperature, and yield. Root rot severity was evaluated using a visual disease severity scale. Significant differences in soil temperature and water content were found between the two tillage treatments during wetting/drying and heating/cooling processes. Other soil and plant parameters exhibited mixed differences between the treatments and no significant increase in yield was observed. Root rot severity was lower in plots that received deep tillage than those that received chisel tillage. The results indicate that deep tillage can minimize low soil temperature with prolonged periods of saturated soil conditions that would help reduce root rot problems in dry bean and soybean production in Minnesota.