LOCATION LABU NE+SD
Established Series
Rev. I-MD
12/2022
LABU SERIES
The Labu series consists of moderately deep, well drained, slowly permeable soils formed in residuum weathered from clay shales. These upland soils have slopes ranging from 2 to 30 percent. Mean annual temperature is about 49 degrees F, and mean annual precipitation is about 21 inches.
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Haplustepts
TYPICAL PEDON: Labu silty clay on a 16 percent convex southwest-facing slope in rangeland. When described the soil was moist in the upper 12 inches. (Colors are for dry soil unless otherwise stated.)
A--0 to 6 inches; dark grayish brown (10YR 4/2) silty clay, dark brown (10YR 3/3) moist; moderate fine granular structure; hard, firm, sticky, and very plastic; common fine roots; strong effervescence; moderately alkaline; clear smooth boundary. (4 to 6 inches thick)
Bw1--6 to 14 inches; grayish brown (2.5Y 5/2) silty clay, dark grayish brown (2.5Y 4/2) moist; weak coarse prismatic structure parting to moderate medium and fine blocky; hard, firm, sticky, and very plastic; common fine roots; upper 2 inches contain few shale fragments; strong effervescence; moderately alkaline; clear smooth boundary.
Bw2--14 to 25 inches; light brownish gray (2.5Y 6/2) silty clay, light olive brown (2.5Y 5/4) moist; weak medium and coarse blocky structure parting to moderate medium and fine subangular blocky; very hard, very firm, very sticky and very plastic; few fine and common very fine roots; common pressure faces; few fine segregations of lime; violent effervescence; moderately alkaline; clear wavy boundary. (Combined Bw horizon is 12 to 24 inches thick.)
C--25 to 34 inches; light gray (2.5Y 7/2) shaly clay, grayish brown (2.5Y 5/2) moist; massive; very hard, very firm, very sticky and very plastic; few fine roots in upper 3 inches; common pressure faces; few distinct lime concretions and oxidized iron stains; violent effervescence; moderately alkaline; clear smooth boundary. (4 to 10 inches thick)
Cr--34 to 60 inches; light gray (2.5Y 7/2) bedded shale, grayish brown (2.5Y 5/2) moist; massive breaking to moderate medium and coarse platy shale fragments; very hard, very firm; violent effervescence; moderately alkaline.
TYPE LOCATION: Boyd County, Nebraska; 6 miles west and 5 miles north of Butte; 1520 feet east and 300 feet south of the northwest corner, sec. 27, T. 35 N., R. 14 W.
RANGE IN CHARACTERISTICS: The thickness of solum is typically 25 inches and ranges from 16 to 28 inches. Depth to bedrock ranges from 20 to 40 inches. The solum averages between 45 to 60 percent clay. It is neutral through moderately alkaline. Cracks 1/2 inch to 1 1/2 inches wide and several feet long commonly extend through the solum when the soil is dry. Tongues of the A horizon material are common in the Bw horizon and some extend through the solum when the soil is dry. A horizon material is common in the Bw horizon and some extend into the C horizon.
The A horizon has hue of 10YR or 2.5Y, value of 4 through 6 and 3 through 5 moist, and chroma of 1 through 3. It commonly is silty clay, but includes clay. Reaction is neutral through moderately alkaline.
The Bw horizon has hue of 10YR through 5Y, value of 5 or 6 and 4 or 5 moist, and chroma of 2 through 4. It is silty clay or clay. Pressure faces are common to many. Reaction is mildly alkaline or moderately alkaline.
Some pedons have a BC horizon.
The C horizon has hue of 10YR through 5Y, value of 5 through 7 and 4 through 6 moist, and chroma of 2 through 4. It is clay or shaly clay. Some pedons contain fine gypsum crystals. Reaction is mildly alkaline or moderately alkaline.
The Cr horizon has hue of 10YR through 5Y, value of 6 or 7 and 3 through 6 moist, and chroma of 2 through 4. Platy shale fragments are medium or coarse.
COMPETING SERIES:
Boro is the only series in this family. Similar soils are
Boyd,
Bristow,
Lakoma,
Monowi,
Millboro,
Norrest,
Okaton,
Opal,
Promise, and
Sansarc. Boro soils lack bedded shale between depths of 20 and 40 inches. Boyd, Opal, and Promise soils have mollic epipedons and Opal, and Promise soils have more than 60 percent clay in the control section. Also, Promise soils are deeper than 40 inches to bedded shale. Bristow, Okaton, and Sansarc soils are less than 20 inches to bedded shale. Lakoma soils lack vertic characteristics. Monowi soils lack montmorillonitic mineralogy and have higher amounts of gypsum. Millboro soils have mollic epipedons and argillic horizons. Norrest soils have mixed mineralogy and argillic horizons.
GEOGRAPHIC SETTING: Labu soils are in the dissected shale plains which border the major streams and drainageways. Slopes are convex and range from 2 to 30 percent. Labu soils formed in clay residuum weathered from dark colored shales. The mean annual temperature ranges from 46 to 56 degrees F, and the mean annual precipitation ranges from 18 to 24 inches.
GEOGRAPHICALY ASSOCIATED SOILS: These are the competing Boyd, Bristow, Monowi, Promise, and Sansarc soils and Mariaville and Reliance soils. Boyd soils are generally on lower slopes. Bristow and Sansarc soils are on steeper slopes. Monowi soils are generally lower in the landscape. Promise soils are on lower foot slopes. Mariaville soils formed from siltstone and occur above Labu soils. Reliance soils are deep and formed in silty materials and occur generally above Labu.
DRAINAGE AND PERMEABILITY: Well drained. Runoff is medium or rapid. Permeability is slow.
USE AND VEGETATION: Used for rangeland, hayland, and cultivated cropland. Western wheatgrass, big bluestem, little bluestem, green needlegrass, sideoats grama, and blue grama are the major native grasses. Winter wheat, sorghum, and alfalfa are the main crops.
DISTRIBUTION AND EXTENT: North-central Nebraska. The series is of moderate extent.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Salina, Kansas.
SERIES ESTABLISHED: Keya Paha County, Nebraska, 1977.
National Cooperative Soil Survey
U.S.A.