Alfisol
As alfisol to the designated according to USDA Soil Taxonomy well developed soils with a through Lessivierung resulting Tonanreicherungshorizont in the subsoil. They are found particularly in the temperate latitudes in regions with a relatively humid climate, for example in the east and south-west of Australia , the East Indies , the south-east and west of Africa , on the east coast and in the south-west of Brazil , occasionally in Canada and the USA and in a wide strip of France and the Benelux countries through Central and Southeastern Europe to Russia .
Usually slightly to moderately acidic, alfisols are considered very fertile soils and are accordingly often used for agriculture. They are often found under deciduous forests , where the leaves that fall annually are quickly incorporated into the mineral soil and decomposed and the most favorable forms of humus , e.g. B. Mull , can arise.
Globally, about 12.6 million square kilometers of soil or 10 percent of the ice-free land area are covered by alfisoles.
classification
There are a total of five suborders:
- Aqualf: Alfisole with hydromorphic characteristics in the subsoil.
- Cryalf: Alfisole over permafrost .
- Udalf Alfi brine humid moderate climate areas in which the precipitation the evaporation exceeds.
- Ustalf: Alfisole (sub) tropical areas with monsoon climates or summer rains.
- Xeralf: Alfisol of the humid subtropics (e.g. Mediterranean regions ).
In the German soil system, they essentially correspond to the parabroun earths . In the international soil classification according to the World Reference Base , they correspond to the Luvisoles , Lixisoles and Retisoles . Alfisols with a high content of exchangeable sodium belong to the solo nets , Alfisols with a marked backwater influence belong to the stagnosols and planosols .
literature
- Soil Survey Staff: Soil Taxonomy: A Basic System of Soil Classification for Making and Interpreting Soil Surveys. 2nd edition. Natural Resources Conservation Service. US Department of Agriculture Handbook 436.Washington DC, USA, 1999.
- Soil Survey Staff: Keys to Soil Taxonomy. 12th edition. Natural Resources Conservation Service. US Department of Agriculture. Washington DC, USA, 2014.
