LOCATION LAMBERT MTEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, calcareous, frigid Typic Ustorthents
TYPICAL PEDON: Lambert silt loam - grassland. (Colors are for dry soil unless otherwise noted)
A--0 to 5 inches; grayish brown (2.5Y 5/2) silt loam, dark grayish brown (2.5Y 4/2) moist; weak fine granular structure; soft, very friable, slightly sticky, slightly plastic; many very fine roots and interstitial pores; slightly effervescent; moderately alkaline; gradual boundary. (2 to 7 inches thick)
C1--5 to 22 inches; light brownish gray (2.5Y 6/2) silt loam, dark grayish brown (2.5Y 4/2) moist; weak medium prismatic structure in the upper part and grading to massive in the lower part; many very fine roots in the upper part grading to few very fine in the lower part; common very fine and fine tubular pores; strongly effervescent; moderately alkaline; gradual boundary. (15 to 20 inches thick)
C2--22 to 36 inches; light olive gray (5Y 6/2) silt loam, olive gray (5Y 4/2) moist; massive; hard, friable, slightly sticky, slightly plastic; few very fine roots; common very fine and fine tubular pores; strongly effervescent; moderately alkaline; gradual boundary. (10 to 30 inches thick)
C3--36 to 60 inches; light olive gray (5Y 6/2) very fine sandy loam, olive gray (5y 4/2) moist; massive; slightly hard, very friable, nonsticky, nonplastic; few very fine roots; strongly effervescent; moderately alkaline.
TYPE LOCATION: Yellowstone County, Montana, 550 feet west and 600 feet north of S1/4 corner of sec. 7, T.1S., R.27E.
RANGE IN CHARACTERISTICS: Lambert soils are usually moist but are dry in the upper part of the C horizons for cumulative period of three months after late June. Mean annual soil temperature ranges from 44 to 47 degrees F.
The A horizon has hue of 10YR or 2.5Y, value of 5 or 6 dry, and chroma of 2 or 3.
The C horizon has hue of 10YR, 2.5Y or 5Y, value of 6 or 7, and chroma of 2 or 3. It has 18 to 35 percent clay and has less than 15 percent fine and coarser sand in the 10 to 40 inch particle-size control section. It contains a few lime nodules in its upper part of the profile in some pedons. A few seams or nests of gypsum occur below 30 inches in some pedons. Stratification below 30 inches ranges from very fine sandy loam to light silty clay loam.
COMPETING SERIES: This is the Lantry series. Lantry soils have a paralithic contact at depths of 20 to 40 inches.
GEOGRAPHIC SETTING: The Lambert soils are on steep and very steep slopes of uplands and on level to sloping fans and terraces. The soils formed in very deep, calcareous silt loam sediments that may be deeply weathered, weakly consolidated bedrock or are deposited by wind as loess, by water as alluvium, or are glaciolacustrine deposits or silty glacial drift. The thickness of these deposits is usually more than five feet. Slopes range from 0 to 65 percent. The climate is semiarid. The average annual precipitation is 10 to 15 inches, the mean annual air temperature is 40 to 45 degrees F., mean annual January air temperature 20 to 25 degrees F. and mean July air temperature 65 to 70 degrees F.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cabba, Chama, Cherry, Farland and Shambo soils. Cabba soils have a paralithic contact at a depth of 10 to 20 inches. They are on steep shoulder slopes. Chama, Farland and Shambo soils occur on rolling to nearly level terrain and have mollic epipedons.
DRAINAGE AND PERMEABILITY: Well-drained; medium to very rapid runoff; moderately slow permeability.
USE AND VEGETATION: The moderately sloping areas are about equally divided between cropland and native pasture. The steep areas are all range. Uncultivated areas are chiefly in western wheatgrass, blue grama, threadleaf sedge and needle-and-thread grass.
DISTRIBUTION AND EXTENT: Eastern Montana and adjacent states. The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Dawson County, Montana, 1971.
REMARKS: Diagnostic horizons and features recognized in this pedon are: Ochric epipedon - the zone from the surface of the soil to a depth of 7 inches (A and C1 horizons).