Reaction is slightly acid to moderately alkaline. These are the Bevier , Lerdal , and Mexico soils. Bevier soils have more than 8 percent sand in the lower part of the series control section. Lerdal soils average more than 1 percent rock fragments in the middle and lower parts of the series control section. Mexico soils have at least one subhorizon in the argillic horizon that contains more than 52 percent clay .
Clarksdale soils are on summits and side slopes on loess-mantled ground moraines.
Slope gradients commonly are 0 to 2 percent but range to 7 percent. Clarksdale soils formed in loess. They are in areas on uplands between Typic Hapludalfs on crests and side slopes near drainageways and Argiudolls on ground moraines farther from the drainageways. Climate is midcontinental with hot summers and cold winters. These are the Downs , Ipava , Keomah , Rozetta , Rushville , and Sable soils.