Ultisols
Ultisols are similar to Alfisols in that they have an ochric and argillic diagnostic features, however they are highly weathered and thus low in nutrients( the root ult comes from the Latin ultimus for ultimate). They have lower pH and organic matter than Alfisols and often are redder in color. With soil amendments they are productive. The surface soil usually is coarser-textured, making it easy to till, while the clay-enriched subsoil stores water for plant roots.
Ultisols are soils common to the southeastern United States. This region receives high amounts of precipitation because of summer thunderstorms and the winter dominance of the mid-latitude cyclone. Warm temperatures and the abundant availability of moisture enhances the weathering process and increases the rate of leaching in these soils. Enhanced weathering causes mineral alteration and the dominance of iron and aluminum oxides. The presence of the iron oxides causes the A horizon of these soils to be stained red. Leaching causes these soils to have low quantities of base cations.