Ultisols

Derived from the Latin word ‘ultimus’ literally meaning last. Found in parts of the world that have tropical climates with high humidity, stable landscapes, and no new soil building events. I.e. (recent glaciation, volcanic activity) Occupy 8.1 % of global ice free land and support 18% of the population Makes up 9.2% of land in the U.S. Typically has a strong yellow or red color Heavily leached of Ca, Mg, and K Poor soils for continuous agriculture unless fertilizers and lime are applied. Ultisols have an ochric epipedon and an argillic or kandic horizon

Suborders Aquults Ustults Humults Xerults Udults Ground water close to surface part of each year and gentle slopes. Typically found along the Atlantic Coast and the Gulf of Mexico. Ustults Low OM and freely drained. Has a Ustic moisture regime that means limited rainfall but not quite arid. Found in Western Texas and California. Supports forests of savannahs and is used for pastureland. Humults High OM and freely drained. They have a dry season and a wet season. Found in the Pacific Northwest and Puerto Rico. Supports forest and is used for pasture and cropland. Xerults Freely dained. Found in Mediterranean climates in California and Oregon. Typically only supports coniferous forests but is sometimes is used for pasture and cropland Udults Relatively poor OM levels and freely drained. Found all along the Southern and Eastern parts of the U.S. Supports mixed forests but has been largely converted to farmland with the use of fertilizers

Sources https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_051241.pdf http://online.sfsu.edu/jerry/geog317/resources/Ultisols_l.pdf https://www.uidaho.edu/cals/soil-orders