The Brown Soils of the North Central States

The group of brown soils, so named because of a brown coloration, form a distinct soil region of the humid portion of the United States. In their regional distribution they include large areas of the NorthCentral States, Michigan, Wisconsin, Indiana, Ohio, New York, Pennsylvania, Kentucky, Tennessee, Missouri, and portions of the surrounding states. The regional limits are not well defined. To the north occur the gray forest or podsol soils; on the south are the yellow and gray soils of the more humid region; on the west there is a blending with the dark prairie soils of the Central Plains. The limits are irregular and may project great distances into any of the surrounding Soil regions. The southern limits are especially irregular because of more varied land forms. It is evident that the soils of eo large an area have considerable variation and include many series and types. However, there ifl a uniformity in the primary characteristics the color of the soil, the soil profile, and its general chemical characteristics so far as content of organic matter and lime carbonate are concerned. so that a distinct soil group is formed.