LOCATION ALKABO NDEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, frigid Glossic Natrustolls
TYPICAL PEDON: Alkabo silt loam on a plane northeast facing slope of 2 percent in a small grain field. (Colors are for dry soil unless otherwise stated)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; slightly acid; abrupt smooth boundary. (Combined A horizons 5 to 10 inches thick)
B/E--6 to 9 inches; dark brown (10YR 4/3) (B) and brown (10YR 5/3) (E) silt loam, very dark grayish brown (10YR 3/2) (B) and dark grayish brown (10YR 4/2) (E) moist; moderate medium prismatic structure parting to strong medium angular blocky; hard, firm, slightly sticky and slightly plastic; common faint clay films on faces of peds; slightly acid; clear smooth boundary. (0 to 8 inches thick)
Btn1--9 to 13 inches; yellowish brown (10YR 5/4) silt loam, brown (10YR 4/3) moist; strong medium prismatic structure parting to moderate medium angular blocky; hard, firm, sticky and plastic; many prominent clay films on faces of peds; few clean sand grains on faces of peds; neutral; clear wavy boundary.
Btn2--13 to 17 inches; light olive brown (2.5Y 5/4) silt loam, olive brown (2.5Y 4/4) moist; moderate medium prismatic structure parting to moderate medium angular blocky; hard, firm, sticky and plastic; many prominent clay films on faces of peds; neutral; clear wavy boundary. (Combined Btn horizons 6 to 18 inches thick)
Bk1--17 to 27 inches; light olive brown (2.5Y 5/4) silt loam, olive brown (2.5Y 4/4) moist; moderate medium prismatic structure parting to moderate medium angular blocky; slightly hard, friable, sticky and plastic; common fine and medium irregularly shaped masses of carbonates; strong effervescence; moderately alkaline; gradual wavy boundary.
Bk2--27 to 45 inches; light gray (2.5Y 7/2) silt loam, grayish brown (2.5Y 5/2) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, sticky and plastic; common medium and few coarse irregularly shaped masses of carbonates; violent effervescence; moderately alkaline; gradual wavy boundary. (Combined Bk horizons 10 to 30 inches thick)
2C--45 to 60 inches; olive (5Y 5/3) clay loam, olive (5Y 4/3) moist; massive; hard, firm, very sticky and very plastic; about 10 percent gravel; strong effervescence; moderately alkaline.
TYPE LOCATION: Burke County, North Dakota; about 5 miles north and 3 miles east of Columbus; 2,100 feet east and 3OO feet north of the southwest corner of sec. 6, T. 163 N., R. 93 W.
RANGE IN CHARACTERISTICS: Thickness of the mollic epipedon typically is 7 to 18 inches but ranges to 30 inches in some pedons. Depth to glacial till ranges from 40 to more than 60 inches. Depth to carbonates typically ranges from 15 to 30 inches but ranges to 50 inches in some pedons. The upper lacustrine sediments have 0 to 2 percent coarse fragments and the glacial till 2C horizon has 2 to 10 percent coarse fragments of mixed lithology. A thin lag line ranging up to 6 inches thick and containing up to 30 percent coarse fragments is at the contact between the two sediments in some pedons.
The A horizon has hue of 10YR, value of 3 or 4 and 2 or 3 moist, and chroma of 2. It is loam, silt loam, fine sandy loam or very fine sandy loam. It is slightly acid or neutral.
The B/E 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 loam or silt loam. It is slightly acid or neutral.
The Btn horizon has hue of 10YR or 2.5Y, value of 4 to 6 and 3 to 5 moist, and chroma of 2 to 4. It is silt loam or silty clay loam. It is neutral or slightly alkaline. Some pedons have a Btkn horizon.
The Bk horizon has hue of 2.5Y or 5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It is silt loam or silty clay loam. It is moderately alkaline or strongly alkaline. Some pedons have a By, Byz or 2Bk horizon.
The 2C horizon has hue of 2.5Y or 5Y, value of 5 to 7 and 4 to 6 moist, and chroma of 2 to 4. It is loam or clay loam. It is moderately alkaline or strongly alkaline. Some pedons have a C horizon. Where present, it is silt loam or silty clay loam.
COMPETING SERIES: This is the Sherryl series. The Sherryl series has carbonates at depths of 10 inches or less. In addition, it is in mountain valleys at elevations of 4500 to 5000 feet.
GEOGRAPHICAL SETTING: The Alkabo soils are on level and nearly level lake plains. Slope ranges from 0 to 3 percent slopes. Alkabo soils formed in glaciolacustrine sediments. Mean annual temperature ranges from 40 to 45 degrees F, and mean annual precipitation ranges from 14 to 17 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Farnuf, Niobell and Noonan soils. Farnuf soils do not have natric horizons. Niobell and Noonan soils are fine-loamy and formed entirely in glacial till.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Surface runoff is slow.
USE AND VEGETATION: Most areas are cropped with small grains. Native vegetation is short grass prairie of blue grama, western wheatgrass and little bluestem.
DISTRIBUTION AND EXTENT: Northwestern North Dakota and possibly north eastern Montana. The soil is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Burke County, North Dakota, 1991.
REMARKS: Revised 11/91.
Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 9 inches (Ap and B/E horizons); Natric horizon - the zone from 9 to 17 inches (Btn1 and Btn2 horizons); glossic criteria - presence of B/E horizon and clean sand grains on faces of peds in Btn1 horizon.
ADDITIONAL DATA: Sample numbers S90ND013-247.