LOCATION LETCHER SD+NDEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, frigid Calcic Natrudolls
TYPICAL PEDON: Letcher fine sandy loam - on plane slope of less than 1 percent under native vegetation. When described the soil was moist throughout. (Colors are for dry soil unless otherwise stated.)
A1--0 to 8 inches; dark gray (10YR 4/1) fine sandy loam, black (10YR 2/1) moist; weak fine and medium subangular blocky structure parting to weak fine and medium granular; slightly hard, very friable; strongly acid; clear smooth boundary.
A2--8 to 12 inches; dark gray (10YR 4/1) sandy loam, black (10YR 2/1) moist; weak medium and coarse subangular blocky structure parting to very weak fine and medium granular; slightly hard, very friable; moderately acid; abrupt smooth boundary. (Combined A horizons is 5 to 15 inches thick.)
E--12 to 15 inches; light brownish gray (10YR 6/2) sandy loam, very dark grayish brown (10YR 3/2) moist; few fine faint mottles of yellowish brown (10YR 5/6); weak fine and medium subangular blocky structure parting to very thin platy; slightly hard, very friable; neutral; clear wavy boundary. (0 to 10 inches thick)
Btn--15 to 19 inches; dark grayish brown (10YR 4/2) sandy loam, very dark grayish brown (10YR 3/2) moist; strong very coarse columnar structure; extremely hard, firm; light brownish gray (10YR 6/2) coatings on tops of columns; neutral; clear smooth boundary. (3 to 11 inches thick)
Btnk--19 to 25 inches; dark grayish brown (10YR 4/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak very coarse prismatic structure; hard, very friable; common fine and medium accumulations of salt and carbonate; slight effervescence; strongly alkaline; clear smooth boundary. (0 to 12 inches thick)
BC--25 to 32 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; hard, very friable; few fine striations and accumulations of carbonate; slight effervescence; strongly alkaline; abrupt smooth boundary. (0 to 12 inches thick)
Ab--32 to 40 inches; gray (10YR 5/1) loam, very dark gray (10YR 3/1) moist; weak medium subangular blocky structure; very hard, firm; few fine striations and accumulations of carbonate; slight effervescence; strongly alkaline; abrupt smooth boundary.
Bkb--40 to 48 inches; dark gray (10YR 4/1) sandy loam, black (10YR 2/1) moist; weak fine and medium subangular blocky structure; very hard, friable; many fine striations and accumulations of carbonate; strong effervescence; strongly alkaline; abrupt smooth boundary. (Combined Ab and Bkb horizons are 0 to 20 inches thick.)
C--48 to 60 inches; light brownish gray (2.5Y 6/2) and light gray (2.5Y 7/2) sandy loam, dark grayish brown (10YR 4/2) moist; common fine faint mottles of reddish yellow (7.5YR 6/8) moist; massive; hard, friable; strong effervescence; strongly alkaline.
TYPE LOCATION: Edmunds County, South Dakota; about 10 miles east and 9 miles north of Ipswich; 285 feet west and 120 feet north of the southeast corner of sec. 6, T. 124 N., R. 66 W.
RANGE IN CHARACTERISTICS: The depth to free carbonates ranges from 10 to 25 inches. Buried horizons of loam or sandy loam are in most pedons and are typically below 30 inches.
The A horizon has value of 3 to 5 and 2 or 3 moist, and chroma of 1.5 or 1. Typically it is loam, fine sandy loam, or sandy loam but is loamy sand and loamy fine sand in some pedons. It is strongly acid to slightly alkaline.
The E horizon has hue of 10YR or 2.5Y, value of 4 to 7 and 2 to 5 moist, and chroma of 1 or 2. It is loamy fine sand, fine sandy loam, or sandy loam. It is lacking in some pedons when plowed. It ranges from strongly acid to slightly alkaline.
The Btn horizon has hue of 10YR or 2.5Y, value of 4 or 5 and 3 or 4 moist, and chroma of 2 or 3. It is sandy loam, fine sandy loam, or loam averaging less than 18 percent clay and more than 15 percent fine or coarser sand. It has strong or moderate, coarse or very coarse, columnar structure in the upper part, but is prismatic when the upper part is disturbed by plowing. It typically has accumulations of carbonates and salts in the lower part. It ranges from neutral to strongly alkaline.
The BC horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 3 or 4 moist, and chroma of 2 or 3. It is sandy loam, fine sandy loam, loam, or loamy sand. Some pedons do not have accumulations of carbonates and some pedons have accumulations of salt. It ranges from slightly to strongly alkaline. Some pedons do not have a BC horizon.
Some pedons have a Bk horizon.
The C horizon has hue of 10YR, 2.5Y, or 5Y; value of 5 to 7 and 3 to 6 moist; and chroma of 1 to 4. Typically it is sandy loam or fine sandy loam but is loam or loamy fine sand in some pedons. It ranges from slightly to strongly alkaline. The C horizon typically has common or many mottles. Clay loam glacial till or loamy and clayey lacustrine sediments are at depths between 40 and 60 inches in some pedons.
COMPETING SERIES: There are no other series in this family. Other similar soils are Cathay, Desart, Ekalaka, Larson, Lemert, Miranda, Noonan, Sorum, Stirum, and Whitelake soils. Cathay soils do not have columnar structure and have a fine-loamy control section. Desart, Ekalaka, and Noonan soils have A horizons with chroma greater than 1.5. In addition, the Desart soils have combined A and E horizons thicker than 20 inches and are well drained. Larson, Miranda, Noonan, and Sorum soils have a fine-loamy control section. Lemert soils have a combined thickness of A and E horizons less than 5 inches and have visible salt or gypsum crystals within a depth of 16 inches. Stirum soils have an aquic soil moisture regime. Whitelake soils have a warmer soil temperature regime.
GEOGRAPHIC SETTING: Letcher soils are on nearly level to undulating, outwash, delta, and till plains. Surfaces are plain or slightly hummocky, and slope gradients range from 0 to 6 percent. The soil formed in sandy and loamy glacial outwash materials and in loamy glacial till. Mean annual temperature ranges from 34 to 45 degrees F, and mean annual precipitation ranges from 14 to 21 inches. Growing season is about 120 to 130 days; average growing season precipitation from 13 to 18 inches; and growing degree days are about 2600 to 3000.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Larson, Lemert, Miranda, and Noonan soils and Parshall soils. Larson and Noonan soils are on similar landscapes. Lemert soils are in slight depressions and swales. Miranda soils are on similar landscapes and are in the lows of the microrelief. Parshall soils do not have a natric horizon and are on convex positions above the Letcher soils.
DRAINAGE AND PERMEABILITY: Somewhat poorly or moderately well drained. Surface runoff is low to high. Permeability is slow in the Btn horizon and moderate or moderately rapid in the underlying material. A temporary water table is at a depth of 3.5 to 6 feet in the spring of most years.
USE AND VEGETATION: Used for pasture, hay, and small grain. Native vegetation includes little bluestem, needleandthread, prairie sandreed, western wheatgrass, blue grama, big bluestem, prairie junegrass, and sedges.
DISTRIBUTION AND EXTENT: North-central and northeastern South Dakota and central and eastern North Dakota. It is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Spink County, South Dakota, 1955.
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 12 inches and from 15 to 32 inches (A1, A2, Btn, Btnk, BC horizons); albic horizon- the zone from 12 to 15 inches (E horizon); argillic (natric) horizon - the zone from about 15 to 25 inches (Btn, Btnk horizons).