LOCATION CRUMP OR
Established Series
Rev. JSC/AON/TDT
01/2023
CRUMP SERIES
The Crump series consists of very deep, very poorly drained soils formed in decomposed organic material over silty lacustrine sediments. They are in concave areas adjacent to open water areas in lake basins. Slopes are 0 to 1 percent. The mean annual temperature is about 47 degrees F. and the mean annual precipitation is about 9 inches.
TAXONOMIC CLASS: Fine-silty, mixed, superactive, nonacid, mesic Histic Humaquepts
TYPICAL PEDON: Crump muck, wet meadow (Colors are for moist soil unless otherwise noted.)
Oa--0 to 8 inches; black (10YR 2/1) muck, gray (N 5/0) dry; weak fine platy structure parting to moderate fine granular; very friable; many very fine roots; many very fine pores; neutral (pH 6.8); abrupt smooth boundary. (8 to 14 inches thick)
2C1--8 to 13 inches; black (N 2/0) silt, gray (N 6/0) dry; moderate fine platy structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine and fine tubular pores; neutral (pH 7.0); clear smooth boundary. (4 to 15 inches thick)
2C2--13 to 26 inches; very dark grayish brown (2.5Y 3/2) silt loam, light gray (2.5Y 7/1) dry; many medium faint very dark gray (2.5Y 2/2) mottles; moderate medium subangular blocky and moderate very fine granular structure; slightly hard, firm, sticky and plastic; common very fine and fine roots; many very fine and fine tubular pores; water table at depth of 20 inches; neutral (pH 7.2); gradual smooth boundary. (12 to 15 inches thick)
2C3--26 to 60 inches; very dark grayish brown (2.5Y 3/2) silt loam, light gray (2.5Y 7/1) dry; many medium faint very dark brown (2.5Y 2/2) mottles; moderate medium subangular blocky and moderate very fine granular structure; slightly hard, firm, sticky and plastic; few very fine roots; many very fine tubular pores; slightly alkaline (pH 7.4).
TYPE LOCATION: Lake County, Oregon; in Warner Valley; 200 feet west and 520 feet north of the E1/4 corner section 34, T. 38 S., R. 24 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 47 to 50 degrees F. Soils are wet or ponded under natural conditions. The histic epipedon is 8 to 14 inches thick. Rubbed fiber content is less than 10 percent. The soils are slightly acid to slightly alkaline. The particle-size control section averages 18 to 30 percent clay and less than 15 percent material coarser than very fine sand.
The Oa horizon has hue of 10YR or neutral, value of 2 moist and 4 or 5 dry, and chroma of 0 or 1 moist and dry.
The 2C horizon has hue of 10YR or neutral, value of 2 through 4 moist, 6 or 7 dry and chroma of 0 through 2 moist and dry. It is silt loam or silty clay loam with strata of silt. It has 10 to 30 percent clay.
Pumice and ash layers less than 2 inches thick may occur at depths of 20 inches or more.
COMPETING SERIES: This is the
Olentangy series. Olentangy have coprogenous earth at 24 to 50 inches.
GEOGRAPHIC SETTING: Crump soils are in concave areas adjacent to open water areas in lake basins. Elevation is 4,400 to 5,000 feet. Slopes are 0 to 1 percent. The soils formed in decomposed organic material over silty lacustrine sediment with a mixture of diatomaceous earth. The mean annual precipitation is 7 to 10 inches. The mean July temperature is 67 to 69 degrees F., the mean January temperature is 28 to 30 degrees F., and the mean annual temperature is 47 to 49 degrees F. The frost-free period is 70 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Boravall,
Ozamis,
Pit,
Reese and
Tulana soils. These soils lack a histic epipedon. Boravall and Reese soils are saline and sodic. Pit soils are clayey throughout and crack to the surface. Tulana soils have a mollic epipedon and andic soil characteristics at the surface. Ozamis soils have a mollic epipedon and are fine-loamy.
DRAINAGE AND PERMEABILITY: Very poorly drained; moderate permeability. A water table is at 1 foot above the surface to 3.5 feet below the surface throughout the year. Flooding is rare. A drained phase is recognized. Areas which have been drained may lack the histic epipedon and are considered taxadjuncts.
USE AND VEGETATION: Used for irrigated crops, pasture, recreation, and wildlife habitat. The potential native plant community consists of cattails, tules, bulrushes, and sedges.
DISTRIBUTION AND EXTENT: Pleistocene Lake basins of southeastern Oregon, MLRA 24 and 23. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Lake County, Oregon, Southern Part; 1991.
REMARKS: Diagnostic horizons and other features recognized in this pedon are:
Histic epipedon: the zone from 0 to 8 inches (Oa horizon)
The superactive cation exchange activity class was added in 03/2003 to the taxonomic classification by the National Soil Survey Center on request of the Reno MLRA office, without review of the soil series property data. The remainder of this document has not been updated.
National Cooperative Soil Survey
U.S.A.