Fluvisol

Soil profile of a Calcaric Fluvisol

Fluvisol (FL) (from Latin: fluvius = river) is one of the 32 reference soil groups of the World Reference Base for Soil Resources (WRB). The group comprises young soils made up of stratified, fluvial , marine or lacustrine deposits. According to the German soil systematics , floodplain soils fall into this group - provided they do not belong to the Gleysols , Phaeozemes or Umbrisoles .

Diagnostic features

Fluvisols are defined by the presence of fluvic material that begins at a depth of no more than 25 cm. Fluvic material is characterized by visible stratification over at least 25% of the soil volume in a specified depth range. Organic carbon contents, which decrease irregularly with depth, are sufficient as an indicator of stratification. The stratification results from floods that are so young that the stratification has not yet become invisible through soil-forming processes such as structure formation or bioturbation .

Horizons

Fluvisols usually have only a weak profile differentiation with predominantly A and C horizons, some of which can contain lime, salt and sulfide concentrations. Due to the influence of water on the soil, hydromorphic features (rust spots) are often present.

distribution

Fluvisols are azonal soils and occur on all continents and in all climates. They are tied to the floodplains of the coasts, rivers and lakes where sedimentation predominates. The Fluvisole reference soil group covers an area of ​​350 million hectares worldwide, more than half of which is in the tropics .

Properties and use

Most Fluvisols have a high natural fertility, as nutrients are regularly replenished; But depending on the location, the material supplied and the groundwater level, fluvisols have a wide variety of properties. This means that the usage potential varies greatly. Wherever unpredictable floods occur, the agricultural use potential is limited. Rice cultivation is a classic form of use on fluvisols in tropical and subtropical regions. Mangroves or other salt-tolerant plants can often be found in salt-rich locations (e.g. coastal areas) .

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 .