Soil Classification

Abstract

Soil classification is the orderly arrangement of soils according to some known or inferred characteristics. Soils are classified to organize information regarding their properties and behavior so that they can be used for different purposes with the maximum benefit under sustainable management. Systematic soil classifications began in the last part of the nineteenth century and were mainly based on ideas of soil genesis and soil forming factors as influenced by the philosophy of Dokuchaiev. Dokuchaiev himself proposed a soil classification system in 1879 before presentation of his Ph.D. thesis on the Russian Chernozems in 1883 (Gimenez JE, São Paulo, Unesp, Geociências 1:15–21, 2011). There are two types of soil classification: process oriented and property oriented. The process-oriented classification systems are known as genetic soil classification systems (Bokheim JG, Gennadiyev AN, Geoderma 95:53–72, 2000). Soil classification systems based on observed properties are known as natural classification systems, and those on inferred properties are technical systems. There are regional and international soil classification systems. Examples of regional classification systems include Australian soil classification system (Isbell RF, The Australian soil classification. CSIRO Publishing, Collingwood, 1996; Isbell RF, The Australian soil classification, Revised edn. CSIRO Publishing, Collingwood, 2002), the Canadian soil classification system (Agriculture Canada Expert Committee on Soil Survey, The Canadian system of soil classification, 2nd edn. Canadian Government Publishing Centre, Ottawa, 1987), soil classification of England and Wales (Avery BW, Soil classification for England and Wales (higher categories). Soil Survey technical monograph no. 14, Harpenden, 1980), French soil classification system (Baize D, Girard MC, Referentiel pedologique 1995. Institut National de la Recherche Agronomique, Paris, 1995), and so on. Among international systems, Soil Taxonomy (USDA, Soil classification, a comprehensive system. United States Department of Agriculture, Government Printing Office, Washington, DC, 1960; USDA, Soil taxonomy: a basic system of soil classification for making and interpreting soil survey. United States Department of Agriculture, Government Printing Office, Washington, DC, 1975) and World Reference Base for Soil Resources (FAO, World reference base for soil resources. ISSS–ISRIC–FAO. World Soil Resources report no. 84, Rome, 1998) are popularly used worldwide at present. These systems have their own terminology and diagnostic features for different taxa.