Luvisol

Luvisol (LV) is a reference soil assembly of the World Reference Base for Soil Resources (WRB). Luvisols are soils that are rich in bases and characterized by clay shifting (lessivation). The clay fraction is dominated by three-layer clay minerals . Luvisols are found in all not very humid climates on young land surfaces, but are particularly common in the temperate zone. The diagnostic horizon is the argic horizon (Bt) characterized by tone enrichment .

The typical horizon sequence according to the FAO Guidelines for Soil Description is:

• A - topsoil with mostly medium humus contents
• E - clay depletion horizon ( eluvial )
• Bt - clay enrichment horizon ( illuvial ) in the subsoil
• C - parent rock

description

The still little advanced weathering is characterized by highly exchangeable three-layer clay minerals ( high-activity clays ) such as vermiculite , smectite and illite . The potential cation exchange capacity in the Bt horizon is ≥ 24 cmol _c / kg clay. The Bt horizons are often intensely colored, which is due to the formation and accumulation of iron oxides . Luvisols show no intensive leaching of base cations and are characterized in the subsoil by a high effective base saturation ≥ 50%, which is associated with relatively high pH values. The topsoils usually have a medium humus content.

Luvisols are excellent arable soils that have been cultivated in Germany since the Neolithic . The combination of moderately acidic topsoils and subsoils with higher pH values enables the availability of all important plant nutrients . Long-term use of the fields makes intensive fertilization necessary. The slightly water-retaining effect of the clay-rich subsoil is more advantageous in somewhat drier areas and only has disadvantages in regions with high rainfall. The main problem is the risk of erosion. Luvisols are often made from loess and then have a silt-rich , poorly aggregated topsoil. In the hill countries of central and southern Germany, eroded Luvisol areas are widespread, and in some cases the erosion extends to the Bt horizon. The Luvisole on the central Chinese loess plateau shows extreme erosion phenomena .

Related soil types

The WRB knows five reference soil groups with an obligatory argic horizon . Only the retisols have additional retic properties. The other four do not have any and are differentiated according to potential cation exchange capacity per kg clay (KAK / kg clay) in the argic horizon and effective base saturation (BSeff) in the subsoil. With the Luvisoles, both are high. In the case of the alisols , the KAK is high and the BS is low. The KAK is low and the BS high for the Lixisols , and both are low for the Acrisols .

Web links

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

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 .
• FAO: Guidelines for Soil Description. Prepared by R. Jahn, V. Asio, H.-P. Blume , O. Spaargaren and P. Schad. Rome 2006. ISBN 92-5-105521-1 .