Laterization is a pedogenic process common to soils found in tropical and subtropical environments. High temperatures and heavy precipitation result in the rapid weathering of rocks and minerals. Movements of large amounts of water through the soil cause eluviation and leaching to occur. Almost all of the by products of weathering, very simple small compounds or nutrient ions , are translocated out of the soil profile by leaching if not taken up by plants for nutrition. The two exceptions to this process are iron and aluminum compounds.
Iron oxides give tropical soils their unique reddish coloring.
Heavy leaching also causes these soils to have an acidic pH because of the net loss of base cations . Podzolization is associated with humid cold mid-latitude climates and coniferous vegetation . Decomposition of coniferous litter and heavy summer precipitation create a soil solution that is strongly acidic. This acidic soil solution enhances the processes of eluviation and leaching causing the removal of soluble base cations and aluminum and iron compounds from the A horizon . This process creates a sub-layer in the A horizon that is white to gray in color and composed of silica sand.