What Types of Soil are Found in the Midwestern States?

Loess

• Loess constitutes a unique soil formation found in the American Midwest, China and parts of Eastern Europe. This formation occurs when areas of topsoil have different compositional elements than the rock and mineral layers of earth found beneath the topsoil. Loess occurs in the Midwest due to glacial movement, which dragged debris for countless miles millions of years ago and created new types of soil throughout the region, and because of the powerful winds that sweep the area, moving soil and other organic material around the region.

Mollic Epipedon

• Mollic epipedon constitutes a soil classification of the U.S. Department of Agriculture that occurs in temperate, humid regions with large amounts of grass. The Midwest fits this description to a "T"; mollic epipedon occurs commonly throughout the region. This type of soil constitutes a dark top layer composed of a mixture of soil and decomposed grass. The organic matter added to the soil by the decomposing or decomposed grass makes this type of soil especially fertile. Any type of soil with this top layer of decomposing grass constitutes a mollic epipedon. Other types of epipedon, or top layers, occur in other regions throughout the country.

State Soils

• Each state in the U.S. has an official state soil. These soils occur commonly throughout the state and in some cases hold special significance for the state and its inhabitants. Drummer soils, the official state soil of Illinois, cover more than 1.5 million acres of the state. Drummer soils are loess soil types. Another loess type, Tama, the official state soil of Iowa, provides the perfect rooting material for the tall prairie grasses common in the state. The official Nebraska state soil, Holdredge, covers 1.8 million acres of the state and provides a growing medium for corn, soybeans and other grain crops, all instrumental in the state economy.

Soil Types In General

• The general soil types available throughout most of the U.S. occur in the Midwest. These soil types include sand, silt, loam and clay. Sandy soils have large soil particles, high water retention capacity and provide a well-aerated planting medium. Clay soils exhibit compaction, or densely packed particles with poor water retention, little aeration and, in extreme cases, soil so densely packed that roots express difficulty growing. Silt sits between these two in quality and often proves the best naturally occurring medium in which to grow plants.