The Mixedgrass Soils
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The characteristic soils of the Mixedgrass Subregion are Dark Brown
Chernozems as contrasted with the Brown Chernozems of the Dry Grassland Subregion. A few Black Chernozems occur on moister sites along the northern and western boundaries of this Subregion.
Chernozems are a typical prairie soil. They were formed only 100,000 years ago under aerobic conditions where water flowed freely through the upper layers. They were created by the sudden and rapid addition of
organic matter coupled with high
levels of humidity.
If you were to look at a cross-section of a Chernozem, you might see things like earthworm tracks and animal burrows filled in with different types of soils. Animals like these aerated the soils and were crucial in the formation of Chernozems.
Although there are many different kinds of Chernozems, there is very little difference between them.
It is interesting to note that Black Chernozems are formed as a result
of high levels of precipitation in any particular area.
Chernozems are generally dry, and as such, can only support vegetation like tall grasses. Sometimes, though, patches of
deciduous woodlands can grow as well.