FAO soil classification
Encyclopedia
The Food and Agriculture Organization of the United Nations (FAO) developed a supra-national classification, also called World Soil Classification, which offers useful generalizations about soil
s pedogenesis
in relation to the interactions with the main soil-forming factors. It was first published in form of the UNESCO
Soil Map of the World (1974) (scale 1 : 5 M.). Many of the names offered in that classification are known in many countries and do have similar meanings.
Originally developed as a legend to the Soil Map of the World, the classification was applied by United Nations
sponsored projects. Many countries modified this system to fit their particular needs.
The Soil Units (106) were mapped as Soil Associations, designated by the dominant soil unit:
Soil Units form 26 World Classes. The FAO soil map was a very simple classification system with units very broad, but was the first truly international system, and most soils could be accommodated on the basis of their field descriptions. The FAO soil map was intended for mapping soils at a continental scale but not at local scale.
In 1998 this system was replaced by the World Reference Base for Soil Resources
.
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
s pedogenesis
Pedogenesis
Pedogenesis is the science and study of the processes that lead to the formation of soil ' and first explored by the Russian geologist Vasily Dokuchaev , the so called grandfather of soil science, who determined that soil formed over time as a consequence of...
in relation to the interactions with the main soil-forming factors. It was first published in form of the UNESCO
UNESCO
The United Nations Educational, Scientific and Cultural Organization is a specialized agency of the United Nations...
Soil Map of the World (1974) (scale 1 : 5 M.). Many of the names offered in that classification are known in many countries and do have similar meanings.
Originally developed as a legend to the Soil Map of the World, the classification was applied by United Nations
United Nations
The United Nations is an international organization whose stated aims are facilitating cooperation in international law, international security, economic development, social progress, human rights, and achievement of world peace...
sponsored projects. Many countries modified this system to fit their particular needs.
The Soil Units (106) were mapped as Soil Associations, designated by the dominant soil unit:
- with soil phases (soil properties, such as saline, lithic, stony),
- with three textural classesSoil textureSoil texture is a qualitative classification tool used in both the field and laboratory to determine classes for agricultural soils based on their physical texture. The classes are distinguished in the field by the 'textural feel' which can be further clarified by separating the relative...
(coarse, medium, and fine) - three slopes classes superimposed (level to gently undulating, rolling to hilly, and steeply dissected to mountainous)
Soil Units form 26 World Classes. The FAO soil map was a very simple classification system with units very broad, but was the first truly international system, and most soils could be accommodated on the basis of their field descriptions. The FAO soil map was intended for mapping soils at a continental scale but not at local scale.
In 1998 this system was replaced by the World Reference Base for Soil Resources
World Reference Base for Soil Resources
The World Reference Base for Soil Resources is the international standard taxonomic soil classification system endorsed by the International Union of Soil Sciences . It was developed by an international collaboration coordinated by the International Soil Reference and Information Centre and...
.
FAO Soil Units
- Acrisols
- AndosolsAndosolsAndosols are soils found in volcanic areas formed in volcanic tephra. In some cases can andosols also be found outside active volcanic areas. Andosols cover an estimate of 1-2% of earth's ice-free land surface...
- Arenosols
- CambisolsCambisolsA Cambisol in the FAO World Reference Base for Soil Resources is a soil with a beginning of soil formation. The horizon differentiation is weak...
- Chernozems
- Ferralsols
- FluvisolsFluvisolsA Fluvisol in the FAO World Reference Base for Soil Resources is a genetically young soil in alluvial deposits . Apart from river sediments, they also occur in lacustrine and marine deposits....
- GleysolsGleysolsA Gleysol in the FAO World Reference Base for Soil Resources is a wetland soil that, unless drained, is saturated with groundwater for long enough periods to develop a characteristic gleyic colour pattern...
- Greyzems
- GypsisolsGypsisolsGypsisols in the FAO World Reference Base for Soil Resources are soils with substantial secondary accumulation of gypsum . They are found in the driest parts of the arid climate zone.In the USDA soil taxonomy they are classified as Gypsids , in the Russian soil classification they are called...
- Histosols
- Kastanozems
- Lithosols
- Luvisols
- Nitosols
- Phaeozems
- Planosols
- Podzols
- Podzoluvisols
- RankersRankersRankers are soils developed over non-calcareous material, usually rock. They are regarded in some soil classifications as lithomorphic soils, a group which also includes rendzinas, similar soils over calcareous material. They are often called A/C soils, as the topsoil or A horizon is immediately...
- RegosolsRegosolsA Regosol in the FAO World Reference Base for Soil Resources is very weakly developed mineral soil in unconsolidated materials. Regosols are extensive in eroding lands, in particular in arid and semi-arid areas and in mountain regions...
- RendzinaRendzinaRendzina is a dark, grayish-brown, humus-rich, intrazonal soil. It is one of the soils most closely associated with the bedrock type and an example of initial stages of soil development...
s - Solonchaks
- SolonetzSolonetzSolonetz is a type of soil in FAO soil classification. They have, within the upper 100 cm of the soil profile, a so-called "natric horizon" . There is a subsurface horizon , higher in clay content than the upper horizon, that has more than 15% exchangeable sodium...
- Vertisols
- Yermosols
See also
- USDA soil taxonomyUSDA soil taxonomyUSDA Soil Taxonomy developed by United States Department of Agriculture and the National Cooperative Soil Survey provides an elaborate classification of soil types according to several parameters and in several levels: Order, Suborder, Great Group, Subgroup, Family, and Series.- Example of...
- International Committee on Anthropogenic SoilsInternational Committee on Anthropogenic SoilsThe International Committee on Anthropogenic Soils defines its mission as follows. "ICOMANTH is charged with defining appropriate classes in soil taxonomy for soils that have their major properties derived from human activities...
(ICOMANTH) - Soil types