Kastanozem

The Kastanozem (from Latin : castanea = chestnut, or Russian : Каштан = chestnut and semlja = soil ) is a reference soil group of the international soil classification World Reference Base for Soil Resources (WRB), which belongs to the group of humus accumulation soils . It is the zonal soil of the semi-arid short grass steppe .

Occurrence

Kastanozemes are found mainly in the dry middle latitudes in the areas of the short-grass steppes

• Northern hemisphere: Eurasian steppe (southern Ukraine , southern Russia , Kazakhstan and Mongolia ), Great Plains ( Canada , central USA , northern Mexico )
• Southern hemisphere: grasslands of the pampas and dry forests of the Gran Chaco ( Paraguay , northern Argentina and southern Bolivia ).

Main features

Soil profile of a Calcic Kastanozem

It is named after the chestnut brown color , which results from the high humus content . The humus is worked in deeply by soil diggers ( bioturbation ). The dark, humus-rich mineral topsoil horizon is called mollic horizon in the WRB . In addition, Kastanozemes contain secondary calcium deposits, partly in the topsoil. A leaching of base cations is only insignificant due to the low precipitation. Kastanozemes have a rich soil life, favorable pH values and high nutrient contents .

use

Kastanozemes are basically very fertile locations. Because of the low and irregular rainfall, unwatered areas are constantly at risk of drought . In large areas, therefore, pasture farming dominates .

Used sites are prone to soil erosion and overgrazing . With irrigation there is a great risk of salinization . Fires are not uncommon in the steppes. They lead to the accumulation of pyrogenic carbon .

Similar soil types

The Chernozem , the zonal soil of the moister and cooler long-grass steppe , is closely related . Due to the better water supply, however, Chernozemes are more humus and darker (to deep black). Due to the harder winters, they are also more intensely ransacked than the Kastanozem and thus more profoundly humic. They therefore have a chernic horizon , which is to be understood as a more developed variant of the mollic horizon .

The WRB soil type Phaeozem , which occurs in the relatively moist transition area between forest and steppe, is also similar .

According to the German soil systematics , most of the Kastanozemes with thick Axh horizons belong to the types Kalktschernosem and Tschernosem in the class of black earths, with less thick A-horizons to various other types, e.g. B. to the Pararendzina .

See also

• Black earth

Web links

• Profile photos (with classification) WRB homepage
• Profile photos (with classification) IUSS World of Soils

swell

• https://www.uni-hohenheim.de/tebaldi/lehre/pics/steppen.pdf
• http://www.geo.unizh.ch/bodenkunde/download/Vorles2005Kap7.pdf

literature

• IUSS Working Group WRB: World Reference Base for Soil Resources 2014, Update 2015. World Soil Resources Reports 106, FAO, Rome 2015. ISBN 978-92-5-108369-7 ( PDF 2.3 MB).
• W. Zech, P. Schad, G. Hintermaier-Erhard: Soils of the world. 2nd Edition. Springer Spectrum, Heidelberg 2014. ISBN 978-3-642-36574-4 .
• W. Amelung, H.-P. Blume , H. Fleige, R. Horn, E. Kandeler , I. Kögel-Knabner , R. Kretschmar, K. Stahr , B.-M. Wilke: Scheffer / Schachtschabel textbook of soil science. 17th edition. Heidelberg 2018. ISBN 978-3-662-55870-6 .