The East-Central Uplands

Eric Winters.

The East-Central Uplands includes parts of 14 States--Kentucky (which is approximately at the center of the region), Arkansas, Oklahoma, Kansas, Missouri, Illinois, Indiana, Ohio, West Virginia, Virginia, North Carolina, South Carolina, Georgia, and Tennessee.

On the south is the Southeastern Uplands, where cotton is a major crop. On the north and eastward to Ohio, the region adjoins the Midland feed area, where corn, soybeans, and small grains are of major importance. Agriculturally and climatically, the region represents a transition zone between these two major agricultural regions.

Nine subregions are delineated on the map, largely on the basis of differences in soil properties. The differences, however, frequently correlate with such features as relief and parent rock. The important subregions are:

The Piedmont in Virginia and North Carolina (PD);

The Blue Ridge in Georgia, North Carolina, Tennessee, and Virginia, including the Smoky Mountains (BR);

The Appalachian Valley in Tennessee and Virginia, which includes the Shenandoah Valley area (AV);

The Allegheny-Cumberland Highlands, which include the Cumberland Plateau area of Tennessee, the eastern mountainous area of Kentucky, most of West Virginia, and the southeastern part of Ohio (AC);

The "bluegrass" areas of Tennessee and Kentucky, which represents soil areas naturally high in phosphate (BG);

The Southern Illinois Gray Prairies (SGP);

The Ozarks in Missouri, Oklahoma, and Arkansas (OZ);

The Cherokee-Parsons soil area of Missouri, Kansas, and Oklahoma (CP) ; Parts of Kentucky, Tennessee, Ohio, Indiana, Illinois, and Missouri.

THE CLIMATE of the region is humid. Temperatures are medium warm on the southern borders and at lower elevations and medium cool at the high elevations and at the higher latitudes.

The total precipitation is 40 inches on the western and northern boundaries and 50 inches on the southern boundary. At some of the higher elevations, particularly in the Blue Ridge and parts of the Appalachian-Cumberland Highlands, the rainfall is 50 to 80 inches.

More than half of the total precipitation comes between April and October, but it is irregularly distributed, and droughts may be frequent. September through November generally is the driest period.

Much of the precipitation comes as snow at the higher latitudes and elevations. Relatively little snow falls in the southern part. The general range of snowfall is 5 inches at the southern boundary to 20 inches on the northern boundary, but it may be as high as 40 inches in parts of the Appalachian-Cumberland Highlands and the Blue Ridge. Most of the area has snow on the ground fewer than 20 days in a year.

The 60-degree isotherm of average annual temperature nearly coincides with the southern boundary of the region. The 55-degree isotherm follows rather closely along the northern boundary from Kansas to Ohio. The 50-degree isotherm touches the boundary of the region in eastern Ohio and dips down into West Virginia and Virginia at the higher elevations.

The average January temperature for the southern part is 40 F. For the northern part it is 30 . The average July temperatures are 80 on the southern boundary, 75 on the northern boundary, and 70 at the higher elevations.

The date of the last killing frost in the spring ranges from March 30 to April 30, from south to north, and is as late as May 10 in some localities in the Appalachians. The first killing frost in the fall ranges from October 30 in the south to October 10 in the north and at higher elevations.

The growing season is 180 to 200 days in most of the region at lower elevations, 160 days for eastern Ohio, and 120 to 130 days for some areas of high elevation in the Appalachians.

The depth of frost penetration ranges from an average of 3 inches on the southern boundary to more than 15 inches at high latitudes and elevations.

Soils of the region have a number of properties in common, mostly because of the similarity in climate. The natural vegetation was mainly deciduous forest.

In such an environment, the well-drained upland soils usually have a surface layer (A horizon) that is acid, relatively light colored, low in organic matter, and medium in texture, due in part to eluviation of clay.

The subsoil (B horizon) of these soils is acid, very low in organic matter, brownish red to yellowish brown or even yellow or mottled in places where drainage is less rapid; it is finer in texture than the surface soil, partly because of clay accumulated from above. The permeability of the subsoil layer is only moderate because of its relatively high clay content.

The slow permeability of the subsoil and the low amount of organic matter, the medium texture, and weakly developed structure of the surface layer make these soils on sloping land susceptible to losses from erosion when they are not protected by vegetative cover, particularly when rainfall is intensive. If heavy rain comes when the surface soil is nearly saturated, the erosion hazard is especially great. Evidences of erosion, such as exposed subsoils and gullies on the sloping cultivated lands, are common.

Most of the soils originally were moderate to low in fertility, but many of them respond to good management.

The region represents a zone of transition from the Gray-Brown Podzolic to the Red-Yellow Podzolic soils. Members of both of these zonal great soil groups are present. Gray-Brown Podzolic soils generally occur at higher latitudes and at higher elevations and usually are developed from till and loess parent materials in Indiana and Illinois. Red-Yellow Podzolic soils are more common in areas of warmer temperatures. Intrazonal soil groups are represented chiefly by the Planosols, which generally are less permeable in the subsoil than the associated zonal soils. Slow permeability of subsoils may be associated with claypan development, as in southern Illinois, or with a fragipan development, as in western Kentucky.

The most important representative of the azonal soils is the alluvial soil group, which includes bottom lands adjacent to the major and minor streams and narrow bands of slope wash or colluvium at footslopes. Because these alluvial soils generally are higher infertility and productivity than the associated soils of the area, they are important to the agriculture of the region, and the well-drained areas usually are farmed intensively. Large areas of other azonal soils, including Regosols and Lithosols, occur on steep slopes.

The transition in climate across the region from cool temperate to warm temperate is paralleled by a transition in agricultural practices. In the northern and cooler parts, for example, spring oats are grown, but winter oats are grown in the southern and warmer portions. Red clover and timothy are adapted in the cooler areas, but lespedeza and redtop are more widely used in the warmer portions. Winter annuals, such as crimson clover and ryegrass, are used widely in the southern part but not in the northern part. This wide range of adapted crops makes for great flexibility in rotations.

The total land area in the region is about 150 million acres, about 8 percent of the total area of the United States. About 102 million acres are in farms. The number of farms is approximately 1 million, which is 18 percent of the total number of farms in the United States. Many of the farms are classed as residential and part-time farms. Many are operated by their owners.