LOCATION LARSON ND+SDEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Calcic Natrudolls
TYPICAL PEDON: Larson loam--cultivated. (Colors are for dry soils unless otherwise stated)
Ap--0 to 6 inches; very dark gray (10YR 3/1) loam, black (10YR 2/1) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many roots; neutral; abrupt smooth boundary. (Combined A horizons 5 to 12 inches thick)
E--6 to 7 inches; gray (10YR 5/1) silt loam, black (10YR 2/1) moist; moderate medium subangular blocky structure parting to moderate thin platy; slightly hard, friable, slightly sticky and slightly plastic; many roots; neutral; abrupt wavy boundary. (0 to 4 inches thick)
Btn1--7 to 13 inches; dark gray (5Y 4/1) clay loam, black (5Y 2/1) moist; strong medium columnar structure parting to moderate, medium and fine angular blocky; hard, very firm, sticky and plastic; thin gray (5Y 5/1) coatings on tops of columns; slightly alkaline; gradual wavy boundary.
Btn2--13 to 16 inches; dark gray (5Y 4/1) clay loam, very dark gray (5Y 3/1) moist; strong medium prismatic structure parting to moderate medium angular blocky; hard, very firm, sticky and plastic; slight effervescence; slightly alkaline; gradual wavy boundary. (Combined Btn horizons 5 to 16 inches thick)
Bkyz--16 to 22 inches; olive gray (5Y 5/2) clay loam, dark olive gray (5Y 3/2) moist; moderate medium prismatic structure parting to moderate fine angular blocky; slightly hard, firm, sticky and plastic; common gypsum crystals and fine segregations of salts; strong effervescence; moderately alkaline; gradual wavy boundary.
Bk--22 to 36 inches; light olive gray (5Y 6/2) clay loam, olive (5Y 4/3) moist; moderate medium prismatic structure parting to moderate medium angular blocky; slightly hard, firm, sticky and plastic; violent effervescence; moderately alkaline; gradual wavy boundary. (Combined Bk horizons 6 to 40 inches thick)
C--36 to 60 inches; pale olive (5Y 6/3) clay loam, olive (5Y 4/3) moist; common medium distinct yellowish brown (10YR 5/4) moist redoximorphic concentrations; massive; hard, firm, sticky and plastic; strong effervescence; moderately alkaline.
TYPE LOCATION: Eddy County, North Dakota; about 15 miles east and 4 1/2 miles north of New Rockford; 2140 feet south and 100 feet east of the northwest corner, sec. 1, T. 149 N., R. 64 W.
RANGE IN CHARACTERISTICS: The soil contains 0 to 10 percent by volume pebbles or stones and a few boulders.
The A horizon has 10YR or 2.5Y hue, value of 3 to 5 and 2 or 3 moist, and chroma of 1. It typically is loam, but included are fine sandy loam, silt loam or clay loam. It is slightly acid or neutral.
The E horizon has hue of 10YR or 2.5Y, value of 5 to 7 and 2 to 5 moist, and chroma of 1 to 3. It is fine sandy loam, very fine sandy loam, loamy fine sand, loam or silt loam. It is slightly acid to slightly alkaline.
The Btn horizon has hue of 10YR, 2.5Y or 5Y, value of 4 to 6 and 2 to 4 moist, and chroma of 1 to 3. It has a chroma of 4 in the lower part of some pedons. It typically is clay loam, but included are loam and silty clay loam. It typically contains 25 to 30 percent clay but ranges from 18 to 35 percent. It is neutral to strongly alkaline. It has moderate or strong columnar or prismatic structure which parts to angular or subangular blocky structure in many pedons. Some pedons have a Btk horizon. Bty horizons are allowed below a depth of 16 inches.
The By, Bz and Bk horizons have hue of 2.5Y or 5Y, value of 5 to 8 and 4 to 6 moist, and chroma of 1 to 4. They are loam or clay loam. They are moderately alkaline or strongly alkaline. The Bk horizon contains 10 to 25 percent calcium carbonate disseminated or in masses, but has 15 percent in some part. The By and Bz horizons contain few to many gypsum or salt crystals. Some pedons have a BC horizon.
The C horizon has hue of 10YR, 2.5Y or 5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It typically is loam, but it is silt loam or clay loam in some pedons. It is moderately alkaline or strongly alkaline. It is stratified and has layers of coarser or finer textures below 40 inches in some pedons.
COMPETING SERIES: There are no competing series in the same family.
GEOGRAPHIC SETTING: Larson soils are on level to undulating till plains. Slope commonly is less than 3 percent, but ranges to 15 percent. The soils formed in calcareous, glacial till containing pockets of silt, fine sand and other sorted materials. Mean annual air temperature ranges from 37 to 45 degrees F, and mean annual precipitation from 15 to 20 inches. Most of the moisture falls in the spring and summer.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cathay Emrick, Fram, Heimdal, Miranda, Parnell, Swenoda and Tonka soils. Cathay and Miranda soils are on similar landscapes with Larson soils. Cathay soils have tonguing or interfingering of albic materials into the Btn horizon. Miranda soils have visible salt crystals within 16 inches of the surface. Emrick, Fram, Heimdal and Swenoda soils are on nearby till plains. They are in complex with Larson soils in some areas. They do not have natric horizons. In addition, Fram soils have calcic horizons within depth of 16 inches. Parnell and Tonka soils are in depressions. They are very poorly and poorly drained, respectively. In addition, they do not have natric horizons and are fine.
DRAINAGE AND PERMEABILITY: Moderately well and somewhat poorly drained. Runoff ranges from negligible to medium depending on slope. Permeability is slow in the Btn horizons and moderately slow or moderate in the C horizon. A seasonal high water table is at a depth of 2 to 4 feet at some time during the period of April through June in the somewhat poorly drained phase and at a depth of 3 to 5 feet at some time for the same period in the moderately well drained phase.
USE AND VEGETATION: Soils are cropped to small grains and used for hay and pasture. Native vegetation was western wheatgrass, green needlegrass, needleandthread, blue grama, sandberg bluegrass, inland salt grass, fringed sage, and a variety of forbs.
DISTRIBUTION AND EXTENT: Central and eastern North Dakota, and northeastern South Dakota. The soil is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Wells County, North Dakota, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 16 inches (Ap, E, Btn1, and Btn2 horizons); the Bkyz horizon has the color but not the organic matter content to be part of the mollic epipedon; natric horizon - the zone from 7 to 16 inches (Btn1 and Btn2 horizons); calcic horizon - the zone from 22 to 36 inches (Bk horizon).
ADDITIONAL DATA: Laboratory data for S49ND-38-1, S49ND-38-13, and 49ND- 48-14.