LOCATION SAMPSEL MOEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Argiaquolls
TYPICAL PEDON: Sampsel silty clay loam, on a convex, north-facing slope of 6 percent, in a pasture, at an elevation of about 918 feet. (Colors are for moist soil unless otherwise stated.)
Ap--0 to 5 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry, very dark brown (10YR 2/2) kneaded; strong very fine granular structure; slightly hard; friable; many fine roots; neutral; abrupt smooth boundary. (4 to 9 inches thick)
A--5 to 12 inches; black (10YR 2/1) silty clay loam, dark gray (10YR 4/1) dry, very dark brown (10YR 2/2) kneaded; strong fine granular structure; friable; common fine roots; moderately acid; clear smooth boundary. (3 to 12 inches thick)
Btg1--12 to 16 inches; very dark grayish brown (10YR 3/2) silty clay loam, grayish brown (2.5Y 5/2) dry, very dark grayish brown (2.5Y 3/2) kneaded; moderate very fine subangular blocky structure; friable; common fine roots; many faint clay films on faces of peds; common medium distinct olive brown (2.5Y 4/4) Fe masses in ped interiors; few worm casts; moderately acid; clear smooth boundary. (0 to 7 inches thick)
Btg2--16 to 35 inches; olive gray (5Y 4/2) silty clay, light olive brown (2.5Y 5/4) kneaded; moderate fine subangular blocky structure; firm; few fine roots; many distinct clay films on faces of peds; many fine prominent yellowish brown (10YR 5/6) and yellowish brown (10YR 5/8) Fe masses in ped interiors; neutral; clear smooth boundary.
Btg3--35 to 37 inches; olive gray (5Y 5/2) silty clay, olive brown (2.5Y 4/4) kneaded; weak fine subangular blocky structure; firm; few faint clay films on faces of peds; many fine prominent yellowish brown (10YR 5/6) Fe masses in ped interiors; few medium brown soft accumulations of iron-manganese oxides; slightly effervescent; slightly alkaline; abrupt smooth boundary. (Combined thickness of the Btg horizon is 16 to 48 inches.)
BCg--37 to 66 inches; gray (5Y 5/1), olive (5Y 5/3) and light olive brown (2.5Y 5/4) silty clay; weak medium subangular blocky structure; firm; common light olive brown (2.5Y 5/3) soft shale lenses; strongly effervescent; moderately alkaline; gradual smooth boundary. (0 to 30 inches thick)
Cr--66 to 76 inches; olive brown (2.5Y 4/4) soft shale; firm; common very dark brown concretions; strongly effervescent; moderately alkaline.
TYPE LOCATION: Caldwell County, Missouri; 3 miles north of Cowgill; located about 35 feet north and 255 feet east of the southwest corner of section 3, T. 55 N., R. 27 W.; USGS Cowgill topographic quadrangle; lat. 39 degrees 35 minutes 52 seconds N. and long. 93 degrees 55 minutes 31 seconds W., NAD 83.
RANGE IN CHARACTERISTICS: Depth to soft shale bedrock ranges from 40 to 80 inches. The thickness of the solum ranges from 36 to more than 70 inches. The mollic epipedon ranges from 10 to 24 inches in thickness. The mollic epipedon includes the A horizon and usually the upper part of the Btg horizon. Reaction ranges from moderately alkaline to moderately acid, and is most acid in the upper part.
The A horizon has hue of 10YR or 2.5Y, value of 2 or 3 and chroma of 1 or 2. It commonly is silty clay loam, but some is silt loam.
The Btg horizon has hue of 10YR to 5Y, value of 3 to 6 and chroma of 1 or 2, except for higher chroma Fe masses. It is silty clay loam, silty clay or clay. Gravel content of the lower Btg horizon ranges from 0 to 10 percent.
The BCg horizon is mottled with hue of 2.5Y or 5Y, value of 4 to 6 and chroma of 1 to 4. Texture is similar to the Btg horizon.
The Cr horizon has hue of 2.5Y or 5Y, value of 3 to 5 and chroma of 2 to 6. Reaction is neutral to moderately alkaline.
COMPETING SERIES: These are the Chancellor, Clarinda, Coatsburg, Edinburg, Haig, Mazaska, Minnetonka, Sacville, Terrabella, Sampsel, Virden, and Worthing series. None of these soils have a Cr (paralithic) horizon within 80 inches. In addition, Chancellor, Clarinda, Coatsburg, Haig, Mazaska, Minnetonka, Terrabella, and Worthing soils have mean annual air temperatures of less than 54 degrees F. Edinburg soils do not have coarse fragments in the series control section. Virden soils have carbonates in the lower part of the series control section.
GEOGRAPHIC SETTING: Sampsel soils are on gently to strongly sloping hillslopes. Slope ranges from 2 to 14 percent. These soils formed in residuum from alkaline or calcareous shales. In some places loess or pedisediment or glacial till or residuum from cherty limestone or colluvium and alluvium is present. Mean annual air temperature is 47 to 57 degrees F. Mean annual precipitation is 34 to 39 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Grundy, Lagonda, Polo and Snead soils in the series northern distribution and the Hartville and McGirk soils in its southern distribution. Grundy and Lagonda soils are somewhat poorly drained. Grundy soils are upslope from the Sampsel soils. Lagonda soils are on sideslopes higher or lower in the landscape than the Sampsel soils. Polo soils are well drained soils and are on ridgetops and on side slopes upslope from Sampsel soils. Snead soils are moderately deep and are on steeper slopes below the Sampsel soils. McGirk and Hartville soils have ochric epipedons. McGirk soils are on footslopes and Hartville soils are on stream terraces below the Sampsel soils.
DRAINAGE AND PERMEABILITY: Poorly drained. Runoff is medium. Permeability is slow. In undisturbed areas, a perched water table has an upper limit of 0 to 1.5 feet during November to May in most years.
USE AND VEGETATION: Most areas are cultivated to corn, wheat, and soybeans. Some is used for hay and pasture. Native vegetation was tall prairie grasses.
DISTRIBUTION AND EXTENT: Missouri. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Indianapolis, Indiana
SERIES ESTABLISHED: Daviess County, Missouri, 1940.
REMARKS: A similar soil, Sacville is to be established in south Missouri where on a lower slope position and more than 80 inches to soft shale bedrock. The concept of the Sampsel series will be to keep it on higher slope positions and have a paralithic horizon at a depth of 40 to 80 inches.
Diagnostic horizons and surface features recognized in this series are: mollic epipedon - the zone from the surface of the soil to a depth of 16 inches (Ap, A and Bt horizons); argillic horizon - the zone from approximately 12 to 37 inches (Btg1, Btg2 and Btg3 horizons).