Soils of the Colombian Llanos Orientales, composition and classification of selected soil profiles

The area studied is representative of the tropical, treeless, nonflooded, savannas of Columbia. The parent material for all soils were mixed alluvial acid sediments. The soils are very acid, have a low cation exchange capacity, very low base retention, low percent of base saturation, high amount of exchangeable aluminum, and relatively high contents of free iron oxides and organic carbon. Surface layers are very low in available phosphorus and low in micronutrient content.