An anthrosol (or anthropogenic soil) in the
World Reference Base for Soil Resources The World Reference Base for Soil Resources (WRB) is an international soil classification system for naming soils and creating legends for soil maps. The currently valid version is the fourth edition 2022. It is edited by a working group of the In ...
(WRB) is a type of
soil
Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
that has been formed or heavily modified due to long-term human activity, such as from
irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...
, addition of organic waste or wet-field cultivation used to create
paddy field
A paddy field is a flooded field (agriculture), field of arable land used for growing Aquatic plant, semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in sout ...
s.
[Major Soils of the World. ISRIC, Wageningen, The Netherlands. 2001](_blank)
![Terra Preta2](https://upload.wikimedia.org/wikipedia/commons/c/c7/Terra_Preta2.JPG)
Such soils can be formed from any parent soil, and are commonly found in areas where agriculture has been practiced for centuries. Anthrosols can be found worldwide, though they tend to have different
soil horizon
A soil horizon is a layer parallel to the soil surface whose physical, chemical and biological characteristics differ from the layers above and beneath. Horizons are defined in many cases by obvious physical features, mainly colour and texture. ...
s in different regions. For example, in northwestern Europe anthrosols commonly have
plaggic or terric (strongly affected by
manure
Manure is organic matter that is used as organic fertilizer in agriculture. Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the fertility of soil by adding organic matter and nutri ...
) horizons, and together they cover some 500,000 hectares.
Due to the broad range of anthrosol compositions and structures compared to other soils of the same order of classification, there is debate on whether anthrosol should be included as an independent soil group.
Composition
Anthrosols can have different characteristics based on their origins. A high
phosphate
In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid .
The phosphate or orthophosphate ion is derived from phospho ...
concentration is a common indicator of decaying organic matter, such as bones, tissue, or excrement. A dark color can also be the result of a high amount of organic matter, or of calcium carbonate, iron, and manganese. A high
pH or
carbonate
A carbonate is a salt of carbonic acid (H2CO3), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word ''carbonate'' may also refer to a carbonate ester, an organic compound containing the carbonate g ...
concentration, in anthropogenic terms, is likely the result of the addition of
wood ash
Wood ash is the powdery residue remaining after the combustion of wood, such as burning wood in a fireplace, bonfire, or an industrial power plant. It is largely composed of calcium compounds along with other non-combustible trace elements presen ...
to the soil. Presence of human artifacts such as tools and waste can also be present in anthrosols. Other indicators include nitrogen, calcium, potassium, magnesium, iron, copper, and zinc concentrations.
In archaeology
The presence of anthrosols can be used to detect long-term human habitation, and has been used by archaeologists to identify sites of interest. Anthrosols that can indicate such activity can be described as, for instance, plaggic (from the long-term use of manure to enrich soil), irragic (from the use of flood or
surface irrigation
Surface irrigation is where water is applied and distributed over the soil surface by gravity. It is by far the most common form of irrigation throughout the world and has been practiced in many areas virtually unchanged for thousands of years.
S ...
), hortic (from deep cultivation, manure use and presence of other anthropogenic organic matter such as kitchen waste), anthraquic (from ''anthros'' – man and ''aqua'' – water – meaning produced by man-made soil moisture management including irrigation or
terracing). Anthrosols can be detected by visual inspection of soils, or even from satellite imagery.
Other uses
Because of a high concentration of minerals, and in particular decayed organic matter, anthrosols are useful for agriculture. In an environmental context, anthrosols act as a
carbon sink
A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide () from the atmosphere.
Globally, the two most important carbon si ...
.
See also
*
Anthrepts In the USDA soil taxonomy, Anthrepts is a term for soil with evidence of human habitation and farming.
See also
* Anthrosols in the World Soil Classification.
*Inceptisols
Inceptisols are a soil order in USDA soil taxonomy. They form quickly ...
from a different soil classification system
*
Necrosol
*
Technosols A Technosol in the World Reference Base for Soil Resources is a Reference Soil Group that combines soils whose properties and pedogenesis are dominated by their technical origin. They contain either a significant amount of artefacts (something in t ...
*
Terra preta
''Terra preta'' (, locally , literally "black soil" in Portuguese) is a type of very dark, fertile anthropogenic soil ( anthrosol) found in the Amazon Basin. It is also known as "Amazonian dark earth" or "Indian black earth". In Portuguese its f ...
References
Further reading
* Howard, J. (2017
Anthropogenic Soils Springer International Publishing,
* W. Zech, P. Schad, G. Hintermaier-Erhard: Soils of the World. Springer, Berlin 2022, Chapter 12.3.2.
External links
profile photos (with classification)WRB homepage
profile photos (with classification)IUSS World of Soils
{{Soil type
Pedology
Types of soil