LOCATION DUMAS              TX+NM

DUMAS SERIES

TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Aridic Paleustolls

TYPICAL PEDON: Dumas loam, on a nearly level plain, 0.5 percent slope in cultivated field at an elevation of about 1,052 meters (3,450 ft). (Colors are for dry soil unless otherwise stated.)

A--0 to 18 cm (0 to 7 inches); brown (10YR 5/3) loam, dark brown (10YR 3/3) when moist; moderate fine granular structure; hard, friable; few very fine pores; neutral; abrupt smooth boundary. (6 to 12 inches thick)

Bt1--18 to 38 cm (7 to 15 inches); brown (10YR 4/3) clay loam, dark brown (10YR 3/3) moist; moderate coarse prismatic structure parting to moderate fine and very fine subangular blocky; hard, friable; common medium and fine pores; few wormcasts; few distinct clay films on ped faces; neutral; gradual smooth boundary. (0 to 10 inches thick)

Bt2--38 to 56 cm (15 to 22 inches); brown (7.5YR 4/4) clay loam, dark brown (7.5YR 3/4) moist; moderate coarse prismatic structure parting to moderate medium and fine subangular blocky; very hard, firm; few fine pores; few distinct clay films on ped faces; neutral; clear wavy boundary. (6 to 18 inches thick)

Bt3--56 to 86 cm (22 to 34 inches); yellowish red (5YR 5/6) clay loam, yellowish red (5YR 4/6) moist; moderate coarse prismatic structure parting to moderate medium and fine subangular blocky; hard, friable; few distinct clay films on ped faces; few films, threads, very fine masses and nodules of calcium carbonate; strongly effervescent; moderately alkaline; clear wavy boundary. (5 to 20 inches thick)

Btk1--86 to 114 cm (34 to 45 inches); reddish yellow (7.5YR 6/6) clay loam, strong brown (7.5YR 4/6) moist; moderate coarse prismatic structure parting to moderate fine subangular blocky; hard, friable; few distinct clay films on ped faces; common films, threads, fine nodules and masses of calcium carbonate comprising about 10 percent by volume; violently effervescent; moderately alkaline; gradual wavy boundary. (10 to 25 inches thick)

Btk2--114 to 170 cm (45 to 67 inches); light brown (7.5YR 6/4) clay loam, brown (7.5YR 4/4) moist; moderate fine subangular blocky structure; hard; friable; common fine pores; many masses and nodules of calcium carbonate comprising about 30 percent by volume; violently effervescent; moderately alkaline; gradual wavy boundary. (15 to 25 inches thick)

Btk3--170 to 203 cm (67 to 80 inches); reddish yellow (7.5YR 7/6) clay loam, strong brown (7.5YR 5/6) moist; weak medium subangular blocky structure; hard, friable; many medium and fine pores; common masses and nodules of calcium carbonate comprising about 15 percent by volume; violently effervescent; moderately alkaline.

TYPE LOCATION: Sherman County, Texas; about 1.6 kilometers (1 mile) east and 3.2 kilometers (2 miles) south of Texhoma on Farm Market Road 1290. In a pasture 1.1 kilometers (0.7 mile) south and 9 meters (30 feet) east of the northwest corner of sec. 75, Block 1C GH&H RR Co. Survey: Latitude: 36 degrees, 28 minutes, 50 seconds N; Longitude: 101 degrees, 44 minutes, 56 seconds W; Frisco Creek West, Texas USGS quad; NAD 83.

RANGE IN CHARACTERISTICS:
Soil moisture: An ustic moisture regime bordering on aridic. The soil moisture control section is dry in some or all parts for more than 180 but less than 220 days, cumulative, in normal years. July through August and December through February are the driest months. These soils are intermittently moist in September through November and March through June.
Mean annual soil temperature: 13 to 15 degrees C (54 to 59 degrees F).
Thickness of the mollic epipedon: 25 to 46 cm (10 to 18 in).
Depth to secondary carbonates: 50 to 86 cm (20 to 34 in).
Depth to calcic horizon: 86 to 127 cm (30 to 50 in).
Solum thickness: More than 203 cm (80 in).
Particle-size control section: 18 to 35 percent silicate clay.

A horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5, 3 or less moist
Chroma: 2 or 3
Texture: loam, clay loam, or sandy clay loam
Effervescence: none
Reaction: neutral or slightly alkaline

Bt horizons (upper part):
Hue: 7.5YR or 10YR
Value: 4 or 5, 3 to 4 moist
Chroma: 2 to 4
Texture: clay loam or sandy clay loam
Effervescence: none
Reaction: neutral to moderately alkaline

Bt horizons (lower part):
Hue: 5YR or 7.5YR
Value: 4 to 6, 3 to 5 moist
Chroma: 4 to 6
Texture: clay loam or sandy clay loam
Visible secondary calcium carbonate: less than 3 percent in the form of films, filaments, masses and nodules.
Effervescence: none to strong
Reaction: neutral to moderately alkaline

Btk horizons:
Hue: 5YR or 7.5YR
Value: 5 to 8, 4 to 7 moist
Chroma: 4 to 6
Texture: clay loam or sandy clay loam
Visible calcium carbonate: 3 to 49 percent by volume in the form of nodules, films, filaments, masses and nodules.
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline

Btkk horizons (where present):
Hue: 5YR or 7.5YR
Value: 6 to 8, 5 to 7 moist
Chroma: 1 to 4
Texture: clay loam or sandy clay loam
Visible calcium carbonate: 50 to 70 percent by volume in the form of masses, nodules, and finely disseminated carbonates.
Effervescence: violent
Reaction: strongly alkaline

COMPETING SERIES:
There are no competing series. Similar soils include the Darrouzett, Gruver, Oslo, Sherm, and Texline series.
Darrouzett, Gruver, and Sherm series: have more than 35 percent silicate clay in the particle-size control section.
Oslo series: have less than 15 percent by weight fine sand or coarser in the particle-size control section and effervescent horizons throughout.
Texline series: have a calcic horizon within 60 cm.

GEOGRAPHIC SETTING:
Parent material: loamy eolian sediments of Pleistocene age.
Landform: nearly level to gently sloping eolian plains.
Slopes: 0 to 5 percent.
Elevation: 916 to 1,448 meters (3,000 to 4,100 ft).
Mean annual air temperature: 12 to 14 degrees C (55 to 57 degrees F)
Mean annual precipitation: 432 to 559 mm (17 to 22 in)
Frost-free period: 170 to 200 days
Thornthwaite annual P-E Index Values: 25 to 36

GEOGRAPHICALLY ASSOCIATED SOILS:
These include the similar Gruver, Oslo, Perryton, Sherm, and Texline series and the Dalhart, Dallam, Perico, Rickmore, and Sunray series.
Gruver, Oslo, Perryton, Sherm, and Texline soils: are on similar landscape positions.
Dalhart and Dallam soils: are on slightly higher landscape positions and have an ochric epipedon.
Perico and Rickmore soils: are on similar landscape positions and have an ochric epipedon.
Sunray soils: are on similar landscape positions and have a calcic horizon within 60 cm.

DRAINAGE AND PERMEABILITY: Well drained and moderate permeability. Surface runoff is very low on 1 to 3 percent slopes and low on 3 to 5 percent slopes.

USE AND VEGETATION: Mainly used for crop production. Principal crops are corn, soybeans, grain sorghum, and winter wheat. A considerable amount of acreage is irrigated. Climax vegetation is dominantly short grasses with a few mid grasses and includes blue grama and buffalograss, with lesser amounts of vine-mesquite, western wheatgrass, sideoats grama, galleta, or tobosa, silver bluestem, wild alfalfa, and prairie clover. This soil has been correlated to the Deep Hardland (077AY001TX) ecological site in MLRA-77A.

DISTRIBUTION AND EXTENT: Southern High Plains, Northern Part (MLRA 77A in LRR H) north of Canadian River in the Texas panhandle and adjoining areas of New Mexico and Oklahoma. The series is moderately extensive.

MLRA OFFICE RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: Sherman County, Texas; 1970.

REMARKS: Series revised MLRA-77 Soil Survey; Hansford County, Texas; 2001. For classification purposes the silicate clay content of the argillic horizon is calculated on a carbonate free basis.
Diagnostic horizons and features recognized in this pedon are:

Mollic epipedon: 0 to 38 cm. (A and Bt1 horizons)
Argillic horizon: 18 to 203 cm. (Bt1, Bt2, Bt3, Btk1, Btk2, Btk3 horizons)
Calcic horizon: 86 to 203 cm. (Btk1, Btk2, Btk3 horizons)

ADDITIONAL DATA: NSSL data available: S89NM-021-001 (Harding County, New Mexico).

TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006.