The scientific classification of soils of Kerala is made based on classification system developed by USDA, the Soil Management Support Services. This multicategoric system is known as soil taxonomy. Each category is an aggregate of taxa, defined at about the same level of abstraction with smallest number of classes in the highest category and largest number in the lowest category. These categories are Order, Suborder, Great group, Subgroup, Family and Series. There are 12 orders under the System viz., Gelisols, Histosols, Spodosols, Andisols, Oxisols, Vertisols, Aridisols, Ultisols, Mollisols, Alfisols, Inceptisols and Entisols. Of these, eight orders are encountered in Kerala. They are Histosols, Spodosols, Vertisols, Ultisols, Mollisols, Alfisols, Inceptisols and Entisols.