chernozem

File:Chernozem map.svg classification:

{{legend|#d95f0e|Dominant (more than 50% of soil cover)}}

{{legend|#fec44f|Codominant (25–50%)}}

{{legend|#fff7bc|Associated (5–25%)}}]]

The name comes from the Russian terms for black (чёрный čjornyj) and soil, earth or land (земля zemlja). The soil, rich in organic matter presenting a black color, was first identified by the Russian geologist Vasily Dokuchaev in 1883 in the tallgrass steppe or prairie of Eastern Ukraine and European Russia. It is distinct from the similar terra preta of the Amazon rainforest.

Chernozem covers about 230 million hectares of land. There are two "chernozem belts" in the world. One is the Eurasian Steppe that extends from eastern Croatia (Slavonia), along the Danube (northern Serbia, northern Bulgaria (Danubian Plain), southern and eastern Romania (Wallachian Plain and Moldavian Plain), and Moldova, to northeast Ukraine across the Central Black Earth Region of Central and Southern Russia into Siberia. The other stretches from the Canadian Prairies in Manitoba through the Great Plains of the United States as far south as Kansas.[https://books.google.com/books?id=GTHrCAAAQBAJ&dq=kansas+Chernozem+soil&pg=PA58 Ecology of Arable Land – Perspectives and Challenges] by M. Clarholm and L. Bergström {{ISBN|978-94-010-6950-2}}

Chernozem layer thickness may vary widely, from several centimetres up to 1.5 metres (60 inches) in Ukraine,[http://www.britannica.com/EBchecked/topic/612921/Ukraine/30095/Soils Ukraine: Soils] in Encyclopædia Britannica as well as the Red River Valley region in the northern United States and Canada (location of the prehistoric Lake Agassiz).

The terrain can also be found in small quantities elsewhere (for example, in 1% of Poland, Hungary, and Texas). It also exists in Northeast China, near Harbin. The only true chernozem in Australia is located around Nimmitabel, some of the richest soils on the continent.KG McQueen. "[http://regolith.org.au/docs/cars/carspub2.pdf The Tertiary Geology And Geomorphology Of The Monaro: The Perspective In 1994]" Centre For Australian Regolith Studies, Canberra 1994

Previously, there was a black market for the soil in Ukraine. The sale of agricultural land was illegal in Ukraine from 1992 to 2020,{{cite web |title=Ukraine lifts ban on sale of farmland in bid to receive international funds |url=https://www.euronews.com/2020/03/31/ukraine-lifts-ban-on-sale-of-farmland-in-bid-to-receive-international-funds |website=Euronews |date=31 March 2020 }} but the soil, transported by truck, could be traded legally. According to the Kharkiv-based Green Front NGO, the black market for illegally acquired chernozem in Ukraine was projected to reach approximately US$900 million per year in 2011.[https://www.kyivpost.com/article/opinion/op-ed/black-market-for-rich-black-earth-116610.html Black market for rich black earth], Kyiv Post (9 November 2011)

Chernozemic soils are a soil type in the Canadian system of soil classification and the World Reference Base for Soil Resources (WRB).

Chernozemic soil type "equivalents", in the Canadian system, WRB, and U.S. Department of Agriculture soil taxonomy:

• 1761: Johan Gottschalk Wallerius (plant decomposition)Wallerius J. G. Agriculturae fundamenta chemica, åkerbrukets chemiska grunder. Upsaliae, 1761. 8, 4, 322 p.; The natural and chemical elements of agriculture. London, York: Bell, Etherington, 1770. 198 p.
• 1763: Mikhail Lomonosov (plant and animal decomposition)'Lomonosov M. V. § 125. // On the strata of the Earth: a translation of "O sloiakh zemnykh" (1763) / translated by S. M. Rowland, S. Korolev. Boulder: Geological Soc. of America, 2012. 41 p. (Special paper; 485) "And so, there is no doubt that black soil is not primordial matter, but that it has been produced by the decomposition of animal and plant bodies over time"
• 1799: Peter Simon Pallas (reeds marsh){{cn|date=July 2023}}
• 1835: Charles Lyell (loess){{citation|title=Life of Sir Roderick I, Murchison|volume=1|first1=A. |last1=Geikie | year=1875 |asin=B0095632AU}}
• 1840: Sir Roderick Murchison (weathered from Jurassic marine shales)
• 1850: Karl Eichwald (peat){{cn|date=July 2023}}
• 1851: А. Petzgold (swamps)
• 1852: Nikifor Borisyak (peat){{cn|date=July 2023}}
• 1853: Vangengeim von Qualen (silt from northern swamps)
• 1862: Rudolf Ludwig (bog on place of forests){{cn|date=July 2023}}
• 1866: Franz Josef Ruprecht (decomposed steppe grasses) {{citation|title=The Origins of the Russian Chernozem Soil (Black Earth): Franz Joseph Ruprecht's 'Geo-Botanical Researches into the Chernozem' of 1866 |first1=Anastasia A. |last1=Fedotova |journal=Environment and History |volume=16|issue=3 |date=August 2010 |pages=271–293|jstor=20723789 |doi=10.3197/096734010x519762|url=http://www.environmentandsociety.org/node/7607 |url-access=subscription }}
• 1879: First chernozem papers translated from RussianDokoutchaief B. Tchernozème (terre noire) de la Russie d'Europe. St.-Ptb.: Soc. Imp. libre économ., 1879. 66 p. (Comptes-rendus Soc. Imp. libre économ. T. 4).
• 1883: Vasily Dokuchaev published his book Russian Chernozem with a complete study of this soil in European Russia.Dokuchaev V. V. Russian Chernozem (1883) // Israel Program for Scientific Translations Ltd. (for USDA-NSF), S. Monson, Jerusalem, 1967. (Translated from Russian into English by N. Kaner)
• 1929: Otto Schlüter (man-made){{citation |first1=Eileen |last1=Eckmeier |first2=Renate |last2=Gerlach |first3=Ernst |last3=Gehrt |first4=Michael W.I. |last4=Schmidt |title=Pedogenesis of Chernozems in Central Europe—A review |journal=Geoderma |volume=139 |issue=3–4 |year=2007 |pages=288–299 |doi=10.1016/j.geoderma.2007.01.009 |url=http://www.geo.unizh.ch/~mschmidt/downloads/Eckmeier_Geoderma_2007.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160308210844/http://www.geo.unizh.ch/~mschmidt/downloads/Eckmeier_Geoderma_2007.pdf |archive-date=8 March 2016 |bibcode=2007Geode.139..288E }}
• 1999: Michael W. I. Schmidt (neolithic biomass burning){{citation|last1=Schmidt |first1=M.W.I. |last2=Skjemstad |first2=J.O. |last3=Jäger |first3=C. |year=2002 |title=Carbon isotope geochemistry and nanomorphology of soil black carbon: Black chernozemic soils in central Europe originate from ancient biomass burning |journal=Global Biogeochemical Cycles |volume=16 |issue=4 |doi=10.1029/2002GB001939 |quote=These data challenge the common paradigm that chernozems are zonal soils with climate, parent material and bioturbation dominating soil formation, and introduce fire as a novel, important factor in the formation of these soils |bibcode=2002GBioC..16.1123S |pages=70–1–70–8|s2cid=56045817 |doi-access=free }}{{citation|last1=Eckmeier|first1=E.|title=Detecting prehistoric fire-based farming using biogeochemical markers|year=2007|publisher=University of Zurich, Faculty of Science.|doi=10.5167/uzh-3752|quote=It is now an open question as to whether Neolithic settlers did indeed prefer to grow crops where Chernozems occurred or if Neolithic burning formed the chernozemic soils. |url=http://www.zora.uzh.ch/3752|type=Dissertation}}

As seen in the list above, the 19th and 20th-century discussions on the pedogenesis of Chernozem originally stemmed from climatic conditions from the early Holocene to roughly 5500 BC. However, no single paleo-climate reconstruction could accurately explain geochemical variations found in Chernozems throughout central Europe. Evidence of anthropomorphic origins of stable pyrogenic carbon in Chernozem led to improved formation theories. Vegetation burning could explain Chernozem's high magnetic susceptibility,{{citation |first1=Eileen |last1=Eckmeier |first2=Renate |last2=Gerlach |first3=Ernst |last3=Gehrt |first4=Michael W.I. |last4=Schmidt |title=Pedogenesis of Chernozems in Central Europe—A review |journal=Geoderma |volume=139 |issue=3–4 |year=2007 |pages=288–299 |doi=10.1016/j.geoderma.2007.01.009 |url=http://www.geo.unizh.ch/~mschmidt/downloads/Eckmeier_Geoderma_2007.pdf |url-status=dead |archive-url=https://web.archive.org/web/20160308210844/http://www.geo.unizh.ch/~mschmidt/downloads/Eckmeier_Geoderma_2007.pdf |archive-date=8 March 2016 |bibcode=2007Geode.139..288E |quote=magnetic susceptibility of soil material may reflect past fires}} the highest of the major soil types.{{cite book|title=Soil Magnetism|editor-first=Neli|editor-last=Jordanova|year=2017|chapter=Chapter 8 - The discriminating power of soil magnetism for the characterization of different soil types

|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780128092392000085

|pages=349–365|doi=10.1016/B978-0-12-809239-2.00008-5|isbn=978-0-12-809239-2|publisher=Academic Press|quote=Chernozem soils exhibit similar features worldwide and are generally characterized by significant magnetic enhancement in the upper soil horizons.}} Soil magnetism increases when soil minerals goethite and ferrihydrite convert to maghemite on exposure to heat.{{Cite journal|url=https://pubs.geoscienceworld.org/claymin/article-abstract/39/1/85/56468/Mineralogy-of-a-burned-soil-compared-with-four?redirectedFrom=fulltext|doi = 10.1180/0009855043910122|title = Mineralogy of a burned soil compared with four anomalously red Quaternary deposits in Denmark|year = 2004|last1 = Nørnberg|first1 = P.|last2 = Schwertmann|first2 = U.|last3 = Stanjek|first3 = H.|last4 = Andersen|first4 = T.|last5 = Gunnlaugsson|first5 = H.P.|journal = Clay Minerals|volume = 39|issue = 1|pages = 85–98|bibcode = 2004ClMin..39...85N|s2cid = 129974901|url-access = subscription}} Temperatures sufficient to elevate maghemite on a landscape scale indicate the influence of fire. Given the rarity of such natural phenomena in the modern day, magnetic susceptibility in Chernozem likely relates to control of fire by early humans.

Humification can darken soils (melanization) absent a pyrogenic carbon component. Given the symphony of pedogenic processes that contribute to the formation of dark earth, Chernozem summarizes different types of black soils with the same appearance but different formation histories.

• Loam
• Dark earth
• Terra preta
• Vertisol
• Mollisol
• Soil organic matter

{{Notelist}}

• IUSS Working Group WRB: World Reference Base for Soil Resources, fourth edition. International Union of Soil Sciences, Vienna 2022. {{ISBN|979-8-9862451-1-9}} ([https://wrb.isric.org/files/WRB_fourth_edition_2022-12-18.pdf]).

{{Reflist}}

• W. Zech, P. Schad, G. Hintermaier-Erhard: Soils of the World. Springer, Berlin 2022, Chapter 5.3.2. {{ISBN|978-3-540-30460-9}}

{{Commons category|Chernozem}}

{{Wiktionary|chernozem}}

• [https://wrb.isric.org/picture-gallery/ profile photos (with classification)] WRB homepage
• [https://www.iuss.org/index.php?article_id=73 IUSS profile photos (with classification)] {{Webarchive|url=https://web.archive.org/web/20180909150525/https://www.iuss.org/index.php?article_id=73 |date=9 September 2018 }} IUSS World of Soils

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Category:Canadian Prairies

Category:Geology of Canada

Category:Geology of Russia

Category:Geology of the United States

Category:Geology of Ukraine

Category:Great Plains

Category:Pedology

Category:Types of soil