Gyttja
Gyttja (also called gray mud soil or mudde ) is a subhydric soil (underwater soil ) in well-aerated, nutrient-rich waters. The gray to gray-black organism- rich mud consists of fine mineral material that is heavily interspersed with organic substances that have arisen through extensive degradation of plant and animal substances. Gyttja soils consist of a well-mixed humus layer rich in organic components (Fh horizon), which is essentially made up of excrement particles from sediment-eating animals, above the water-saturated mineral soil (G horizon).
Drained soils of this type are rich in nutrients and have a high water retention capacity, but they swell and shrink considerably when the humidity changes .
If the sludge is oxygen-free and therefore hardly revitalized, it is digested sludge ( sapropel ) instead . In very acidic, nutrient-poor and oxygen-poor waters, a soil known as Dy or brown sludge soil forms, the thin organic layer of which is largely due to colloidally precipitated organic matter.
The term Gyttja goes back to the Swedish term for "mud" or "silt" and was introduced into scientific literature by Hampus von Post in 1862. The largely synonymous term Mudde was introduced as a technical term by CA Weber in 1907.
In the international soil classification World Reference Base for Soil Resources (WRB), the underwater character of these soils is expressed by the qualifier Subaquatic. Gyttjen can belong to the reference soil groups Gleysol , Arenosol and Fluvisol .
Individual evidence
- ↑ Hampus von Post : Studier öfver Nutidens koprogena Jordbildningar. Gyttja, Dy, Torf och Mylla (= Kongliga Svenska Vetenskaps-Akademiens Handlingar. NF Vol. 4, No. 1, ZDB -ID 214062-7 ). Norstedt, Stockholm 1862.
Web links
literature
- 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 .