Wallachian Plain
Chernozems cover about 230 million hectares of land. There are two "chernozem belts" in the world. One is the Eurasian steppe which 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 Russia, southern Russia into Siberia. The other stretches from the Canadian Prairies in Manitoba 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 region in the Northern US and Canada (location of the prehistoric Lake Agassiz).