LOCATION DARROUZETT TX+OKEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, thermic Pachic Paleustolls
TYPICAL PEDON: Darrouzett silty clay loam, on a 1.5 percent slope in a cultivated field at an elevation of 796 meters (2,426 ft). (Colors are for dry soil unless otherwise stated.)
Ap--0 to 15 (0 to 6 inches); grayish brown (10YR 5/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular and weak fine structure; hard, friable; sticky; neutral; abrupt smooth boundary. (10 to 30 cm thick)
Bt1--15 to 36 cm (6 to 14 inches); dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium angular blocky structure; very hard, very firm; sticky; few wormcasts; common fine and very fine tubular pores; few faint clay films on ped faces; neutral; clear smooth boundary. (13 to 30 cm thick)
Bt2--36 to 58 cm (14 to 23 inches); dark grayish brown (10YR 4/2) silty clay loam, dark brown (10YR 3/3) moist; moderate medium angular blocky structure; very hard, firm; sticky; few wormcasts; common very fine tubular pores; common distinct clay films on ped faces; moderately alkaline; gradual smooth boundary. (18 to 38 cm thick)
Bt3--58 to 89 cm (23 to 35 inches); brown (10YR 4/3) silty clay loam, dark brown (10YR 3/3) moist; weak medium and coarse angular blocky structure; very hard, firm; sticky; few wormcasts; few very fine tubular pores; common distinct clay films on ped faces; few very fine masses, films, and threads of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (0 to 50 cm thick)
Bt4--89 to 140 cm (35 to 55 inches); brown (10YR 5/3) silty clay loam, brown (10YR 4/3) moist; weak coarse prismatic structure parting to weak medium angular blocky; very hard, firm; sticky; few wormcasts; common medium to very fine tubular pores; common distinct clay films on ped faces; about 2 percent by volume of very fine masses, threads, and films of calcium carbonate; strongly effervescent; moderately alkaline; gradual smooth boundary. (0 to 60 cm thick)
Btk1--140 to 190 cm (55 to 75 inches); strong brown (7.5YR 5/6) clay loam, strong brown (7.5YR 4/6) moist; weak coarse prismatic structure parting to weak fine angular blocky; very hard, firm; sticky; common fine and very fine tubular pores; common distinct clay films on ped faces; about 2 percent by volume of very fine masses and nodules to 1 cm diameter of calcium carbonate; strongly effervescent; moderately alkaline; clear wavy boundary. (30 to 60 cm thick)
Btk2--190 to 229 cm (75 to 90 inches); pink (7.5YR 8/4) silty clay loam, pink (7.5YR 7/4) moist; weak medium subangular blocky structure; very hard, friable; many medium and very fine tubular pores; few faint clay films on ped faces; about 30 percent by volume calcium carbonate in the form of masses and nodules up to 2 cm in diameter; violently effervescent; moderately alkaline; gradual wavy boundary. (25 to 76 cm thick)
Btk3--229 to 254 cm (90 to 100 inches); pink (7.5YR 7/4) silty clay loam, light brown (7.5YR 6/4) moist; weak medium subangular blocky structure; very hard, friable; common fine and very fine tubular pores; few faint clay films on ped faces; about 15 percent by volume calcium carbonate in the form of masses and nodules up to 1 cm in diameter; violently effervescent; moderately alkaline.
TYPE LOCATION: Lipscomb County, Texas; from the intersection of State Highway 15 and Farm Road 2172 in Darrouzett, Texas; 0.80 kilometer (0.5 mile) west on State Highway 15 and 12 meters (40 feet) south of road. Latitude: 36 degrees, 26 minutes, 42.7 seconds N; Longitude: 100 degrees, 20 minutes, 01.6 seconds W; Darrouzett 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 205 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: 16 to 18 degrees C (61 to 64 degrees F)
Thickness of the mollic epipedon: 50 to 100 cm (20 to 40 in)
Depth to secondary calcium carbonate: 38 to 71 cm (15 to 28 in)
Depth to calcic horizon: 127 to 203 cm (50 to 80 in)
Solum thickness: more than 203 cm
Particle-size control section: 35 to 45 percent silicate clay
A horizon:
Hue: 7.5 YR or 10YR
Value: 4 or 5, 3 or 4 moist
Chroma: 2 or 3
Texture: loam, silt loam, clay loam, or silty clay loam
Effervescence: None
Reaction: neutral to moderately alkaline
Upper Bt horizons:
Hue: 7.5YR or 10YR
Value: 4 or 5, 3 or 4 moist.
Chroma: 2 or 3
Texture: clay loam, silty clay loam, or clay
Effervescence: none to slight
Reaction: neutral to moderately alkaline
Lower Bt horizons:
Hue: 5YR to 10YR
Value: 4 or 5, 3 or 4 moist
Chroma: 3 to 6
Texture: clay loam, silty clay loam, or clay
Effervescence: none to strong
Reaction: moderately alkaline
Btk horizon:
Hue: 5YR or 7.5YR
Value: 5 or 8, 4 or 7 moist
Chroma: 4 to 6
Texture: clay loam, silty clay loam, or clay
Secondary calcium carbonate: masses and nodules range from 10 to 60 percent by volume
Effervescence: strong or violent
Reaction: moderately alkaline or strongly alkaline
COMPETING SERIES: These are the
Bethany and
Rotan series. Similar soils also include the
Alibates,
Gruver,
Perryton,
Richfield,
Sherm, and
Zella series.
Alibates series: have between 18 and 35 percent silicate clay in the particle-size control section and do not have a mollic epipedon that ranges from 50 to 100 cm thick.
Bethany series: formed in Permian age sediments and do not have a calcic horizon.
Gruver and Sherm series: have mean annual soil temperatures less than 15 degrees C and do not have a mollic epipedon that ranges from 50 to 100 cm thick.
Perryton series: have mean annual soil temperatures less than 15 degrees C.
Rotan series: formed in loamy alluvium of Quaternary age and have a calcic horizon between 76 and 150 cm.
Richfield and Zella series: have mean annual soil temperatures less than 15 degrees C and do not have a calcic horizon.
GEOGRAPHIC SETTING:
Parent material: loamy and clayey eolian sediments of Pleistocene age
Landform: nearly level to gently sloping eolian plains
Slopes: 0 to 1 percent
Mean annual air temperature: 15 to 17 degrees C (59 to 63 degrees F).
Mean annual precipitation: 432 to 559 mm (17 to 22 in)
Frost free period: 180 to 220 days (0.5 to 0.6 yr)
Elevation ranges from 670 to 1,143 meters (2,050 to 3,500 ft)
Thornthwaite annual P-E Index Values: 25 to 36
GEOGRAPHICALLY ASSOCIATED SOILS:
These are the similar
Alibates series and the
Ady,
Berda,
Laverne,
Manson,
Mobeetie,
Plemons,
Potter, and
Veal series.
Alibates and Ady soils are on similar but slightly lower landscape positions and have 18 to 35 percent silicate clay in the control section.
Berda, Laverne, Manson, Mobeetie, Plemons, Potter, and Veal series are on lower landscape positions and have less than 35 percent silicate clay in the control section.
DRAINAGE AND PERMEABILITY: Well drained and moderately slow permeability. Surface runoff is low on 0 to 1 percent slopes and medium on 1 to 5 percent slopes.
USE AND VEGETATION: Mainly cultivated to corn, grain sorghum, and winter wheat. Climax native vegetation includes buffalograss and blue grama, with lesser amounts of sideoats grama, vine-mesquite, western wheatgrass, galleta, and silver bluestem. This soil has been correlated to the Clay Loam (077EY051TX) ecological site in MLRA-77E.
DISTRIBUTION AND EXTENT: Southern High Plains, Breaks of northwestern Texas and Oklahoma (MLRA-77E in LRR H). The series is moderate in extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Lipscomb County, Texas; 1971.
REMARKS: Series revised during the MLRA-77 Update Soil Survey; 2007. These soils were formerly included in the Pullman, Sherm, and Richfield series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: 0 to 58 cm (Ap, Bt1, and Bt2 horizons)
Argillic horizon: 15 to 254 cm (Bt and Btk horizons)
Calcic horizon: 190 to 254 cm (Btk2 and Btk3 horizon)
ADDITIONAL DATA: none
TAXONOMIC VERSION: Keys to Soil Taxonomy, Tenth Edition, 2006.