Chernozem (from rus, чернозём, p=tɕɪrnɐˈzʲɵm, r=chernozyom; "black ground"), also called black soil, is a black-colored

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 ...

containing a high percentage of

humus In classical soil science, humus is the dark organic matter in soil that is formed by the decomposition of plant and animal matter. It is a kind of soil organic matter. It is rich in nutrients and retains moisture in the soil. Humus is the Lati ...

(4% to 16%) and high percentages of

phosphorus Phosphorus is a chemical element with the symbol P and atomic number 15. Elemental phosphorus exists in two major forms, white phosphorus and red phosphorus, but because it is highly reactive, phosphorus is never found as a free element on Ea ...

and

ammonia Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogeno ...

compounds. Chernozem is very

fertile Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Ferti ...

soil and can produce high

agricultural yield In agriculture, the yield is a measurement of the amount of a crop grown, or product such as wool, meat or milk produced, per unit area of land. The seed ratio is another way of calculating yields. Innovations, such as the use of fertilizer, the c ...

s with its high moisture storage capacity. Chernozems are a Reference Soil Group of 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 Inte ...

(WRB).

Distribution

The name comes from the Russian terms for black and soil, earth or land (''chorny'' + ''zemlya''). The soil, rich in organic matter presenting a black color, was first identified by Russian geologist

Vasily Dokuchaev Vasily Vasilyevich Dokuchaev (russian: Васи́лий Васи́льевич Докуча́ев; 1 March 1846 – 8 November 1903) was a Russian geologist and geographer who is credited with laying the foundations of soil science. The ...

in 1883 in the tallgrass

steppe In physical geography, a steppe () is an ecoregion characterized by grassland plains without trees apart from those near rivers and lakes. Steppe biomes may include: * the montane grasslands and shrublands biome * the temperate grasslan ...

or prairie of

European Russia European Russia (russian: Европейская Россия, russian: европейская часть России, label=none) is the western and most populated part of Russia. It is geographically situated in Europe, as opposed to the cou ...

. Chernozem cover about 230 million

hectares The hectare (; SI symbol: ha) is a non-SI metric unit of area equal to a square with 100-metre sides (1 hm2), or 10,000 m2, and is primarily used in the measurement of land. There are 100 hectares in one square kilometre. An acre is a ...

of land. There are two "chernozem belts" in the world. One is the

Eurasian steppe The Eurasian Steppe, also simply called the Great Steppe or the steppes, is the vast steppe ecoregion of Eurasia in the temperate grasslands, savannas and shrublands biome. It stretches through Hungary, Bulgaria, Romania, Moldova and Tra ...

which extends from eastern

Croatia , image_flag = Flag of Croatia.svg , image_coat = Coat of arms of Croatia.svg , anthem = "Lijepa naša domovino"("Our Beautiful Homeland") , image_map = , map_caption = , capit ...

(

Slavonia Slavonia (; hr, Slavonija) is, with Dalmatia, Croatia proper, and Istria, one of the four historical regions of Croatia. Taking up the east of the country, it roughly corresponds with five Croatian counties: Brod-Posavina, Osijek-Baranja, ...

), along the

Danube The Danube ( ; ) is a river that was once a long-standing frontier of the Roman Empire and today connects 10 European countries, running through their territories or being a border. Originating in Germany, the Danube flows southeast for , ...

(northern

Serbia Serbia (, ; Serbian: , , ), officially the Republic of Serbia (Serbian: , , ), is a landlocked country in Southeastern and Central Europe, situated at the crossroads of the Pannonian Basin and the Balkans. It shares land borders with Hung ...

, northern

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Mac ...

( Danubian Plain), southern and eastern

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central, Eastern, and Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, Serbia to the southwest, Moldova to the east, a ...

(

Wallachian Plain The Romanian Plain ( ro, Câmpia Română) is located in southern Romania and the easternmost tip of Serbia, where it is known as the Wallachian Plain ( sr, Vlaška nizija/Влашка низија). Part of the historical region of Wallachia, it ...

and Moldavian Plain), and

Moldova Moldova ( , ; ), officially the Republic of Moldova ( ro, Republica Moldova), is a landlocked country in Eastern Europe. It is bordered by Romania to the west and Ukraine to the north, east, and south. The unrecognised state of Transnist ...

, to northeast

Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian invas ...

across the

Central Black Earth Region The Central Black Earth Region, Central Chernozem Region or ''Chernozemie'' (russian: Центрально-черноземная область, Центральная черноземная область, Центрально-черноз ...

of Central Russia, southern Russia into

Siberia Siberia ( ; rus, Сибирь, r=Sibir', p=sʲɪˈbʲirʲ, a=Ru-Сибирь.ogg) is an extensive geographical region, constituting all of North Asia, from the Ural Mountains in the west to the Pacific Ocean in the east. It has been a part o ...

. The other stretches from the

Canadian Prairies The Canadian Prairies (usually referred to as simply the Prairies in Canada) is a region in Western Canada. It includes the Canadian portion of the Great Plains and the Prairie Provinces, namely Alberta, Saskatchewan, and Manitoba. These pro ...

Manitoba , image_map = Manitoba in Canada 2.svg , map_alt = Map showing Manitoba's location in the centre of Southern Canada , Label_map = yes , coordinates = , capital = Win ...

through the Great Plains of the US as far south as Kansas. Similar soil types occur in Texas and Hungary. Chernozem layer thickness may vary widely, from several centimetres up to 1.5 metres (60 inches) in Ukraine, as well as the

Red River Valley The Red River Valley is a region in central North America that is drained by the Red River of the North; it is part of both Canada and the United States. Forming the border between Minnesota and North Dakota when these territories were admitted ...

region in the Northern US and Canada (location of the prehistoric

Lake Agassiz Lake Agassiz was a large glacial lake in central North America. Fed by glacial meltwater at the end of the last glacial period, its area was larger than all of the modern Great Lakes combined. First postulated in 1823 by William H. Keating, ...

). The terrain can also be found in small quantities elsewhere (for example, on 1% of Poland). It also exists in

Northeast China Northeast China or Northeastern China () is a geographical region of China, which is often referred to as "Manchuria" or "Inner Manchuria" by surrounding countries and the West. It usually corresponds specifically to the three provinces east of ...

, near Harbin. The only true chernozem in Australia is located around

Nimmitabel Nimmitabel is a small town in the Monaro region in southeast New South Wales, Australia, in the Snowy Monaro Regional Council local government area. At the , Nimmitabel had a population of 320. Etymology Nimmitabel means "the place where m ...

, with some of the richest soils in the nation. Previously, there was a

black market A black market, underground economy, or shadow economy is a clandestine market or series of transactions that has some aspect of illegality or is characterized by noncompliance with an institutional set of rules. If the rule defines the ...

for the soil in Ukraine. The sale of agricultural land has been illegal in Ukraine since 1992 until the ban was lifted in 2020, but the soil, transported by truck, was able to be sold and bought. According to

Kharkiv Kharkiv ( uk, wikt:Харків, Ха́рків, ), also known as Kharkov (russian: Харькoв, ), is the second-largest List of cities in Ukraine, city and List of hromadas of Ukraine, municipality in Ukraine.

Canadian and United States soil classification

Chernozemic soils are a

soil type A soil type is a taxonomic unit in soil science. All soils that share a certain set of well-defined properties form a distinctive soil type. Soil type is a technical term of soil classification, the science that deals with the systematic categori ...

in the Canadian system of soil classification and the

History

Theories of Chernozem origin: * 1761:

Johan Gottschalk Wallerius Johan Gottschalk Wallerius (11 July 1709 – 16 November 1785) was a Swedish chemist and mineralogist. Biography Wallerius was born at Stora Mellösa in Närke (now Örebro County), Sweden. He was a son of provost Erik Nilsson Wallerius and h ...

(plant decomposition) * 1763:

Mikhail Lomonosov Mikhail Vasilyevich Lomonosov (; russian: Михаил (Михайло) Васильевич Ломоносов, p=mʲɪxɐˈil vɐˈsʲilʲjɪvʲɪtɕ , a=Ru-Mikhail Vasilyevich Lomonosov.ogg; – ) was a Russian polymath, scientist and wri ...

(plant and animal decomposition) * 1799:

Peter Simon Pallas Peter Simon Pallas Fellow of the Royal Society, FRS FRSE (22 September 1741 – 8 September 1811) was a Prussian zoologist and botanist who worked in Russia between 1767 and 1810. Life and work Peter Simon Pallas was born in Berlin, the son ...

(reeds marsh) * 1835:

Charles Lyell Sir Charles Lyell, 1st Baronet, (14 November 1797 – 22 February 1875) was a Scottish geologist who demonstrated the power of known natural causes in explaining the earth's history. He is best known as the author of '' Principles of Geol ...

(loess) * 1840: Sir Roderick Murchison (weathered from Jurassic marine shales) * 1850:

Karl Eichwald ), present-day Latvia , death_date = , death_place = St. Petersburg, Russia , citizenship = Russian Empire , nationality = Baltic German , fields = GeologyMedicine , workplaces = Kazan University, ...

(peat) * 1851: А. Petzgold (swamps) * 1852: Nikifor Borisyak (peat) * 1853: Vangengeim von Qualen (silt from northern swamps) * 1862: Rudolf Ludwig (bog on place of forests) * 1866:

Franz Josef Ruprecht Franz Josef Ruprecht (1 November 1814 – 4 April 1870) was an Austrian-born physician and botanist active in the Russian Empire, where he was known as Frants Ivanovič Ruprekht (russian: link=no, Франц Ива́нович Ру́прехт). ...

(decomposed steppe grasses) * 1879: First chernozem papers translated from Russian * 1883:

published his book ''Russian Chernozem'' with a complete study of this soil in European Russia. * 1929: Otto Schlüter (man-made) * 1999: Michael W. I. Schmidt (neolithic biomass burning) As seen in the list above, the 19th and 20th-century discussions on the

pedogenesis Soil formation, also known as pedogenesis, is the process of soil genesis as regulated by the effects of place, environment, and history. Biogeochemical processes act to both create and destroy order (anisotropy) within soils. These alterations l ...

of Chernozem originally stemmed from climatic conditions from the early

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

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 In electromagnetism, the magnetic susceptibility (Latin: , "receptive"; denoted ) is a measure of how much a material will become magnetized in an applied magnetic field. It is the ratio of magnetization (magnetic moment per unit volume) to the ap ...

, the highest of the major soil types. Soil magnetism increases when soil minerals

goethite Goethite (, ) is a mineral of the diaspore group, consisting of iron(III) oxide-hydroxide, specifically the "α" polymorph. It is found in soil and other low-temperature environments such as sediment. Goethite has been well known since ancient ...

and

ferrihydrite Ferrihydrite (Fh) is a widespread hydrous ferric oxyhydroxide mineral at the Earth's surface, and a likely constituent in extraterrestrial materials. It forms in several types of environments, from freshwater to marine systems, aquifers to hyd ...

convert to

maghemite Maghemite (Fe2O3, γ-Fe2O3) is a member of the family of iron oxides. It has the same spinel ferrite structure as magnetite and is also ferrimagnetic. It is sometimes spelled as "maghaemite". ''Maghemite'' can be considered as an Fe(II)-defi ...

on exposure to heat. Temperatures sufficient to elevate maghemite on a landscape scale indicates the influence of fire. Given the rarity of such natural phenomenon in the modern-day, magnetic susceptibility in Chernozem likely relates to

control of fire by early humans The control of fire by early humans was a critical technology enabling the evolution of humans. Fire provided a source of warmth and lighting, protection from predators (especially at night), a way to create more advanced hunting tools, and ...

. Humification can darken soils (

melanization Melanin (; from el, μέλας, melas, black, dark) is a broad term for a group of natural pigments found in most organisms. Eumelanin is produced through a multistage chemical process known as melanogenesis, where the oxidation of the a ...

) absent a pyrogenic carbon component. Given the symphony of

pedogenic Soil formation, also known as pedogenesis, is the process of soil genesis as regulated by the effects of place, environment, and history. Biogeochemical processes act to both create and destroy order (anisotropy) within soils. These alterations l ...

processes that contribute to the formation of dark earth, the term Chernozem summarizes different types of black soils with the same appearance but different formation histories.

Notes

References

* IUSS Working Group WRB: World Reference Base for Soil Resources, fourth edition. International Union of Soil Sciences, Vienna 2022.

.

External links

profile photos (with classification)
WRB homepage
IUSS profile photos (with classification)
IUSS World of Soils {{Authority control Canadian Prairies Geology of Canada Geology of Russia Geology of the United States Geology of Ukraine Great Plains Pedology Types of soil

Distribution

History

See also

Notes

References

Further reading

External links