LOCATION DOBENT             WY
Established Series
Rev. JEI/PSD/JAL
11/2002

DOBENT SERIES


The Dobent series consists of very deep, somewhat poorly drained soils formed in alluvium on flood plains of low stream terraces. Slope ranges from 0 to 3 percent. The mean annual temperature is about 46 degrees F., and the mean annual precipitation is about 8 inches.

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, calcareous, mesic Typic Fluvaquents

TYPICAL PEDON: Dobent loam with a slope of 1 percent, cultivated and leveled. (Colors are for dry soil unless otherwise noted.)

Ap1--0 to 7 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; weak coarse subangular blocky fragments; hard, friable, slightly sticky and slightly plastic; many fine and very fine roots; common fine and very fine pores; calcareous, lime disseminated; strongly alkaline; abrupt smooth boundary. (3 to 8 inches thick)

Ap2--7 to 14 inches; light brownish gray (10YR 6/2) clay loam, brown (10YR 5/3) moist; weak coarse subangular blocky fragments; hard, friable, moderately sticky and moderately plastic; few medium distinct reddish brown redox concentrations and few very fine faint light gray redox depletions; many fine and very fine roots; 2 fine and very fine pores; calcareous, lime disseminated; moderately alkaline; abrupt smooth boundary. (5 to 8 inches thick)

C1g--14 to 22 inches; light brownish gray (10YR 6/2) loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; common medium distinct reddish brown redox concentrations and few medium faint light gray (N 7/) redox depletions; few fine roots; few fine and very fine pores; calcareous, lime disseminated; moderately alkaline; clear wavy boundary. (4 to 15 inches thick)

C2g--22 to 60 inches; light brownish gray (10YR 6/2) loam, stratified with thin lenses of sandy loam, very fine sandy loam and silty clay loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; few large distinct reddish brown redox concentrations and common medium distinct light gray (N 7/) redox concentrations; few fine roots to 30 inches; calcareous, lime mostly disseminated, few soft masses; slightly alkaline; free water at 30 inches.

TYPE LOCATION: Washakie County, Wyoming; 997 feet south and 1296 feet west of the NE corner of sec. 36, T. 46 N., R. 92 W.

RANGE IN CHARACTERISTICS: The mean annual soil temperature is 48 to 51 degrees F., and the mean summer soil temperature is 62 to 68 degrees F. The particle-size control section averages loam but individual horizons are highly variable with strata of loam, clay loam, sandy loam, silty clay loam, silt loam, and very fine sandy loam. Clay averages 18 to 27 percent and sand less than 35 percent coarser than fine sand.

The Ap or A horizons have hue of 5Y through 10YR, value of 6 or 7 dry, 4 or 5 moist, chroma of 2 or less dry and moist. They are loam but strata of clay loam through silt loam occur in some pedons. Reaction ranges from slightly alkaline to strongly alkaline. EC is normally 4 to 8 mmhos/cm.

The C horizon has hue of 5Y through 10YR, value of 6 or 7 dry, 4 or 5 moist, and chroma of 2 or less dry and moist in the matrix. Neutral to light gray redox features are also present. Textures are quite variable but average loam. This horizon is slightly alkaline to strongly alkaline, and has 4 to 8 mmhos/cm EC.

COMPETING SERIES: This is the Pogo series. Pogo soils have 27 to 35 percent clay in the particle-size control section.

GEOGRAPHIC SETTING: Dobent soils formed in stratified alluvium on flood plains which receive occasional overflow from the major stream. Slopes are 0 to 3 percent. The mean annual precipitation is 7 to 9 inches. The mean annual temperature is 43 degrees to 46 degrees F., and the mean summer temperature is 64 degrees to 70 degrees F. Elevations range from 3740 to 5120 feet. The frost-free season is normally 110 to 140 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Las Animas, Lostwells, and Shoshone soils. All these soils occur on the same landscape but normally on second terrace positions. Las Animas and Shoshone soils have a coarse-loamy control section. Lostwells soils average more than 35 percent fine sand or coarser in the particle-size control section and lack low chroma mottles.

DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability.

USE AND VEGETATION: Primary use is irrigated cropland, hay, and pasture. Some areas have bee used for urbanization. Native vegetation is Indian saltgrass, alkali sacaton, sedges, and willows.

DISTRIBUTION AND EXTENT: North-central Wyoming. These soils are of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: Washakie County (Big Horn River Irrigated Area), Wyoming; 1972.


National Cooperative Soil Survey
U.S.A.