LOCATION STURKIE AR+MOEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Cumulic Hapludolls
TYPICAL PEDON: Sturkie silt loam, 1 percent slope in pasture. Colors are for moist soil unless otherwise stated.)
Ap--0 to 7 inches; very dark grayish brown (10YR 3/2) silt loam; weak medium granular structure; friable; many fine and medium roots; moderately acid; abrupt smooth boundary. (4 to 10 inches thick)
A1--7 to 19 inches; very dark grayish brown (10YR 3/2) silt loam; weak medium granular structure; friable; many fine and medium roots and pores; moderately acid; clear smooth boundary. (10 to 14 inches thick)
A2--19 to 28 inches; very dark grayish brown (10YR 3/2) silt loam; weak medium subangular blocky structure; friable; many fine and medium roots and pores; moderately acid; clear smooth boundary. (6 to 12 inches thick)
Bw1--28 to 46 inches; brown (10YR 4/3) silt loam; weak medium and coarse subangular blocky structure; friable; few fine and medium roots; common medium and coarse pores; slightly acid; gradual smooth boundary. (12 to 20 inches thick)
Bw2--46 to 57 inches; dark brown (10YR 3/3) silt loam; weak medium and coarse subangular blocky structure; friable; few fine and medium roots; common medium and coarse pores; slightly acid; gradual smooth boundary. (8 to 60 inches thick)
C1--57 to 70 inches; dark brown (10YR 3/3) silt loam; common medium distinct brown (10YR 5/3) mottles; massive; friable; common medium and coarse pores; neutral; gradual smooth boundary. (0 to 15 inches thick)
C2--70 to 80 inches; brown (10YR 5/3) loam; common medium distinct yellowish brown (10YR 5/6) mottles; massive; friable; few fine and medium roots; common fine and medium pores; 5 percent rounded gravel; neutral.
TYPE LOCATION: Fulton County, Arkansas; about 4 miles southeast of Salem on Highway 62, then about 4.5 miles east on county road in NW1/4NE1/4SE1/4 sec. 35, T. 20 N., R. 7 W.
RANGE IN CHARACTERISTICS: The mollic epipedon ranges from 24 to more than 50 inches in thickness. Reaction ranges from moderately acid to mildly alkaline in the A and Bw horizons and slightly acid to moderately alkaline in the C horizon.
The A horizon has hue of 7.5YR or 10YR, value of 2 or 3, and chroma of 1 to 3. Texture of the Ap horizon is silt loam, fine sandy loam, or loam and textures of the lower A horizons are silt loam or silty clay loam. Coarse fragments range from 0 to 5 percent by volume.
The Bw horizon has hue of 7.5YR or 10YR, value of 1 to 5, and chroma of 2 to 4, or hue of 7.5YR, value of 3, and chroma of 2. The chroma is 2 only where the value is 3 or less. Texture is silt loam or silty clay loam. Rock fragments range from 0 to 5 percent by volume.
The C horizon has similar colors to the Bw horizon. Mottles are in shades of yellow or brown. Texture is silt loam, loam, clay loam, or silty clay loam. Rock fragments range from 0 to 10 percent. In some pedons, the texture of the lower C horizon ranges from sandy loam to loamy fine sand. There are calcium carbonates below a depth of 50 inches in some pedons.
COMPETING SERIES: These are the Allison, Anthon, Huntsville, Ivan, Judson, Kennebec, Kenridge, Napier, Rossville, and Worthen series. Allison soils have less sand in the upper part of the series control section. Anthon, Huntsville, Judson, Kennebec, and Napier soils have a mean annual soil temperature of 49 to 54 degrees F.. In addition, Judson soils average between 30 to 35 percent clay, and Kennebec soils lack chroma 3 above depths of 36 inches. Ivan and Rossville soils have free carbonates within 30 inches of the surface. Kenridge soils have a chroma of 1 or 2 immediately below the mollic epipedon. Worthen soils have more gray in the B horizons and contains less sand in the upper part of the profile.
GEOGRAPHIC SETTING: Sturkie soils are on flood plains and natural levees along streams. The flood plains are often dissected by intermittent streams. Sturkie soils formed in silty alluvium. Slopes range from 0 to 3 percent. Mean annual precipitation near the type location varies from 42 to 45 inches and the mean annual temperature varies from 53 degrees to 58 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Agnos, Arkana, Britwater, Gassville, Gepp, Healing, Moko, and Portia series. Agnos, Arkana, Gassville, and Gepp soils have more than 35 percent clay in the upper 20 inches of the argillic horizon and are on sideslopes of the uplands. Britwater and Portia soils have a fine-loamy control section and are on stream terraces, nearby footslopes and gently sloping upland positions. Healing soils are on slightly higher natural levees, lack mollic colors below 24 inches, and have an argillic horizon. Moko soils have sola 6 to 20 inches thick, have a loamy-skeletal control section, and are on steeper adjacent sideslopes of the uplands.
DRAINAGE AND PERMEABILITY: Sturkie soils are well drained. Runoff is negligable to low. Permeability is moderate. These soils flood occasionally or frequently when not protected.
USE AND VEGETATION: Most of these soils are used for pasture, hayland, or cropland. Tame grasses are mainly bermudagrass and tall fescue. Native trees are southern red oak, white oak, American sycamore and eastern cottonwood.
DISTRIBUTION AND EXTENT: Ozark Highlands (MLRA 116A) and the Ozark Border (MLRA 116B) area of Arkansas and Missouri. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Fulton County, Arkansas; 1979.
REMARKS: These soils were formerly included in the Healing series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the surface to a depth of 28 inches (Ap, A1, and A2 horizons).
Cambic horizon - the zone from 28 to 57 inches (Bw1 and Bw2 horizons)
Cumulic feature - mollic colors deeper than 20 inches from the surface.
Udic moisture regime.
Particle-size control section - the zone from 10 to 40 inches.