Chernozem

Chernozem (/ˈtʃɜːrnəzɛm/ CHUR-nə-zem), also called black soil, regur soil or black cotton soil, is a black-colored soil containing a high percentage of humus (4% to 16%) and high percentages of phosphorus and ammonia compounds. Chernozem is very fertile and can produce high agricultural yields with its high moisture-storage capacity. Chernozems are a Reference Soil Group of the World Reference Base for Soil Resources (WRB).

Studies of the steppe soils of the Poltava region in the Russian Empire in 1883, conducted by geologist Vasily Dokuchaev, showed that the peasants called all soils by color, so the scientist began to use such names. Chernozem was black in color due to the large amount of organic matter. Dokuchaev was the first to describe the chernozem of the European part of the Russian Empire, and discovered its fertility. 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.

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 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.

Previously, there was a black market for the soil in Ukraine. The sale of agricultural land was illegal in Ukraine from 1992 to 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.

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: