More weathered, leached, faster decomposition. Alfisols found on younger, glacial deposits. In Southeast, many upland soil profiles lack A an E horizon. Topsoil eroded off during period of cotton cultivation. Erosion and low nutrient status help explain presence of pines instead of broadleaf, deciduous trees in many settings.
Evergreen trees exhibit slow nutrient cycling.
C. Parent material and time - Oxisols restricted to very old, granitic soils. Fe, Al, silica a. silica is dissolved and leached from the soil profile. Fe and Al remain. Oxisols are actually mined for iron and aluminum ore. The deep red color of oxisols is an expression of the iron and aluminum oxides.