LOCATION NIOBELL ND+SDEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Glossic Natrustolls
TYPICAL PEDON: Niobell loam - on a nearly level convex slope of 1 percent under cropland. (Colors are for dry soil unless otherwise stated. Where described the soil was moist throughout.)
Ap--0 to 6 inches; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; common fine roots; many fine pores; about 2 percent gravel; slightly acid; abrupt smooth boundary. (5 to 10 inches thick)
B/E--6 to 9 inches; light brownish gray (10YR 6/2) (E) and brown (10YR 4/3) (B) loam, dark grayish brown (10YR 4/2) (E) and dark brown (10YR 3/3) (B) moist; weak coarse prismatic (B) and moderate medium and fine platy (E) structure; hard, very friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine pores; gray (10YR 6/1) patches of silt and sand grains on faces of peds; about 2 percent gravel; slightly acid; clear wavy boundary. (0 to 7 inches thick)
Btn1--9 to 13 inches; brown (10YR 4/3) clay loam, dark brown (10YR 3/3) moist; moderate medium prismatic structure parting to moderate medium and fine angular blocky; hard, firm, sticky and plastic; few very fine roots; common fine pores; many distinct very dark grayish brown (10YR 3/2) moist clay films on faces of peds and lining pores; tops and sides of upper 2 inches of prisms coated with patches of cleaned sand grains; about 2 percent gravel; neutral; gradual wavy boundary.
Btn2--13 to 19 inches; brown (10YR 5/3) clay loam, dark grayish brown (10YR 4/2) moist; moderate medium prismatic structure parting to strong medium and fine angular blocky; very hard, firm, sticky and plastic; few very fine roots; common fine pores; many distinct dark brown (10YR 3/3) moist clay films on faces of peds and lining pores; about 2 percent gravel; moderately alkaline; clear wavy boundary. (Combined Btn horizons 5 to 20 inches thick)
Bky1--19 to 22 inches; light olive brown (2.5Y 5/4) loam, olive brown (2.5Y 4/4) moist; weak coarse prismatic structure parting to weak coarse and medium subangular blocky; hard, friable, sticky and slightly plastic; common medium and fine crystals of gypsum; many large masses of carbonates; about 2 percent gravel; slight effervescence; moderately alkaline; gradual wavy boundary.
Bky2--22 to 29 inches; light yellowish brown (2.5Y 6/3) loam, olive brown (2.5Y 4/3) moist; weak medium and fine subangular blocky structure; hard, friable, sticky and slightly plastic; many fine crystals of gypsum; about 2 percent gravel; common medium and fine masses of carbonates; violent effervescence; strongly alkaline; gradual wavy boundary. (Combined Bk horizons 4 to 24 inches thick)
BCky--29 to 44 inches; light yellowish brown (2.5Y 6/3) loam, olive brown (2.5Y 4/4) moist; massive; very hard, firm, sticky and slightly plastic; common fine crystals of gypsum; about 2 percent gravel; few fine masses of carbonates; strong effervescence; strongly alkaline; gradual wavy boundary.
C--44 to 60 inches; light yellowish brown (2.5Y 6/4) loam, olive brown (2.5Y 4/4) moist; few fine distinct brown (10YR 5/3) and few fine prominent gray (5Y 5/1) moist relict mottles; massive; very hard, firm, sticky and slightly plastic; about 2 percent gravel; few small fragments of lignite; few gypsum crystals; few masses of carbonates; slight effervescence; strongly alkaline.
TYPE LOCATION: Divide County, North Dakota; about 3 miles east of Crosby; 2215 feet north and 100 feet east of the southwest corner, sec. 25, T. 163 N., R. 97 W.
RANGE IN CHARACTERISTICS: Rock fragments comprise 1 to 8 percent by volume of the soil.
The A horizon has hue of 10YR, value of 3 to 5 and 2 or 3 moist, and chroma of 2 or 3. It is loam, silt loam or clay loam. It is moderately acid to neutral. It has weak or moderate subangular blocky or granular structure.
The B/E horizon has hue of 2.5Y or 10YR, value of 4 to 7 and 3 to 5 moist, and chroma of 1 to 3. It is loam, silt loam or very fine sandy loam. It is moderately acid to neutral. It has weak or moderate prismatic or blocky structure or weak or moderate coarse to fine platy structure. Some pedons have E, BE or E/B horizons.
The Btn horizon has hue of 10YR or 2.5Y, value of 3 to 6 and 2 or 4 moist, and chroma of 2 to 4. It is clay loam, clay or silty clay having more than 15 percent fine sand and coarser sand. It is slightly acid to moderately alkaline. It has moderate or strong columnar or prismatic structure which parts to moderate or strong angular or subangular blocky.
The Bky horizon has hue of 10YR or 2.5Y, 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 Bk horizons with properties of the Bky horizon. Some pedons have BCk horizons.
The C 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. It may contain masses of carbonates in the upper part. In addition, it may contain gypsum and other salts and a few stones. Mottling inherent to the till is in some pedons at depths below 30 inches.
COMPETING SERIES: These are the Belfield and Lennep series. Belfield soils no not have coarse fragments and formed in residum or alluvium. Lennep soils have 50 to 60 percent clay in the natric horizon.
GEOGRAPHIC SETTING: Niobell soils are on level to gently rolling till plains. Slope gradients commonly are less than 3 percent, but range from 0 to 9 percent. The Niobell soils formed in firm loam or clay loam till. Mean annual air temperature ranges from 34 to 45 degrees F, and mean annual precipitation from 12 to 18 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bowbells, Max, Miranda, Noonan, Tonka and Williams soils. Bowbells, Max and Williams soils are on higher lying or more rolling areas. They do not have natric horizons. Miranda and Noonan soils are on nearby areas. They do not have tonguing or interfingering of the E horizon of more than 1 inch into the Btn horizon. In addition, Miranda soils have visible gypsum or other salts within depths of 16 inches. Tonka soils are in closed basins and depressions. They are poorly drained.
DRAINAGE AND PERMEABILITY: Well drained or moderately well drained. Runoff ranges from negligible to medium depending on slope. Permeability is moderate on the surface and slow in the Btn horizon. A seasonal high water table is at a depth of 3.5 to 5.0 feet at some time during the period of April through June in the moderately well drained phase. It is at a depth of 4 to more than 6 feet for the same period in the well drained phase.
USE AND VEGETATION: Used for spring seeded small grains and pasture. Native vegetation includes green needlegrass, western wheatgrass, needleandthread, blue grama, Sandberg bluegrass, some upland sedges and a variety of forbs.
DISTRIBUTION AND EXTENT: Northwestern and west-central North Dakota, and north-central South Dakota. The soil is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: St. Paul, Minnesota
SERIES ESTABLISHED: Edmunds County, South Dakota, 1973.
REMARKS: Diagnostic horizons and features recognized in this pedon are: mollic epipedon - the zone from the surface of the soil to a depth of 7 inches after mixing (Ap horizon); natric horizon - the zone from 9 to 19 inches (Btn1 and Btn2 horizons).
ADDITIONAL DATA: S58NDak-51-3 and S58NDak-51-4 in Soil Survey Investigations No. 2, pages 56 to 59.