LOCATION TALMO SD+NEEstablished Series
TAXONOMIC CLASS: Sandy-skeletal, mixed, mesic Udorthentic Haplustolls
TYPICAL PEDON: Talmo loam - on a 9 percent, south-facing, convex slope in a bluegrass pasture. When described the soil was dry throughout. (Colors are for dry soil unless otherwise stated.)
A--0 to 7 inches; dark gray (10YR 4/1) loam, black (10YR 2/1) moist; weak fine granular structure; slightly hard, friable; neutral; gradual smooth boundary. (7 to 10 inches thick)
2Bk--7 to 60 inches; brown (10YR 5/3) very gravelly sand, dark brown (10YR 4/3) moist; single grain; loose; coatings of carbonates on the undersides of pebbles; 45 percent gravel; strongly effervescent; moderately alkaline.
TYPE LOCATION: Lake County, South Dakota; about 2 1/2 miles west of Chester; 72 feet south and 2,230 feet east of the northwest corner, sec. 21, T. 105 N., R. 51 W.
RANGE IN CHARACTERISTICS: The depth to sand and gravel is 14 inches or less. Thickness of the mollic epipedon ranges from 7 to 14 inches. The soil contains carbonates at the surface in some pedons when plowed. The particle size control section contains over 35 percent rock fragments 2mm or larger in size by volume. Some pedons have up to 25 percent stones and boulders on the surface.
The A horizon has value of 3 to 5 and 2 or 3 moist, and chroma of 1 or 2. It is loam, gravelly loam, gravelly sandy loam, or sandy loam and is neutral or slightly alkaline. Gravel content ranges from 5 to 35 percent. Some pedons have thin AC horizons of gravelly loam texture.
The 2C or 2Bk horizon has hue of 7.5YR, 10YR, or 2.5Y, value of 5 to 7 dry and 4 to 6 moist, and chroma of 2 to 4. It typically is very gravelly sand, very gravelly loamy sand, extremely gravelly loamy sand, or extremely gravelly sand with 35 to 75 percent by volume of gravel. Some pedons have fine sand below depths of 60 inches. It is slightly alkaline or moderately alkaline. Calcium carbonate coatings on pebbles in the 2C horizon range greatly in thickness and amount.
COMPETING SERIES: There are no other series in the family.
GEOGRAPHIC SETTING: Talmo soils are nearly level to steep on outwash plains and terraces and along steep slopes of terrace escarpments. They also are on knolls and ridgetops in undulating to hilly glacial morainic deposits. Surfaces are plane or convex with slope gradients ranging from 0 to 40 percent. These soils formed in gravelly outwash sediments of glacial outwash plains or moraines. The mean annual air temperature ranges from 45 to 52 degrees F, and mean annual precipitation ranges from 17 to 26 inches. Growing season is about 130 to 155 days; average growing season precipitation ranges from 14 to 20 inches; and growing degree days are 2700 to 3500.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Delmont, Dempster, Enet, and Oahe soils. These soils are on similar landscapes. Delmont soils are sandy-skeletal between 14 and 20 inches. Dempster soils have a silty sola and have gravelly sediments at depths of 20 to 40 inches. Enet and Oahe soils are sandy-skeletal between depths of 20 and 40 inches.
DRAINAGE AND PERMEABILITY: Excessively drained. Surface runoff is slow and most is rapidly absorbed. Permeability is rapid.
USE AND VEGETATION: Mainly as range. Native species include needleandthread, sideoats grama, blue grama, sedges, plains muhly, and forbs.
DISTRIBUTION AND EXTENT: East-central and southeastern South Dakota. The Talmo series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Lake County, South Dakota, May, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of about 7 inches (A horizon). The Bk is presumed to have less than a 5 percent increase in CaC03 over the underlying horizon.