LOCATION NUKRUM TX
Established Series
Rev. JDK-BJW-ACT
01/2017
NUKRUM SERIES
The Nukrum series consists of very deep, well drained, slowly permeable soils formed in calcareous clayey slope alluvium derived from claystone. These nearly level to gently sloping soils occur on footslopes and toeslopes of hillslopes on dissected plains. Slope ranges from 0 to 5 percent. Mean annual precipitation is about 686 mm (27 in) and mean annual air temperature is about 18.3 degrees C (65 degrees F).
TAXONOMIC CLASS: Fine, smectitic, thermic Pachic Vertic Haplustolls
TYPICAL PEDON: Nukrum silty clay - cropland.
(Colors are for dry soil unless otherwise stated.)
Ap--0 to 15 cm (0 to 6 in); dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure; hard, firm, slightly sticky; common fine and medium roots; slightly effervescent; moderately alkaline; abrupt smooth boundary. Thickness is 13 to 23 cm (5 to 9 in)
A--15 to 61 cm (6 to 24 in); dark grayish brown (10YR 4/2) silty clay, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; hard, firm, sticky; common fine and medium roots; few fine pores; cracks extend to depths greater than 20 inches; strongly effervescent; moderately alkaline; gradual wavy boundary. Combined thickness of the A horizons is 38 to 147 cm (10 to 58 in)
Bk--61 to 142 cm (24 to 56 in); grayish brown (10YR 5/2) silty clay, dark grayish brown (10YR 4/2) moist; moderate medium subangular blocky structure; hard, firm, sticky; few fine roots; few fine pores; few films and threads and masses of calcium carbonate; strongly effervescent; moderately alkaline; gradual wavy boundary. Thickness is 0 to 94 cm (0 to 37 in)
BCk--142 to 203 cm (56 to 80 in); brown (10YR 5/3) silty clay loam; brown (10YR 4/3) moist; massive; hard, firm, slightly sticky; 5 percent concretions and masses of calcium carbonate; violently effervescent; moderately alkaline.
TYPE LOCATION: Brown County, Texas; from the Brown County Courthouse, 2.5 miles south on U.S. Highway 377, then 0.7 mile southwest on Chapel Hill Road and 600 feet south of the road in a cultivated field.
USGS topographic quadrangle: Bangs East, TX.
Latitude: 31 degrees, 41 minutes and 01 seconds N;
Longitude: 99 degrees, 00 minutes, and 18 seconds W;
Datum: NAD 83
UTM Easting 499536.79 m, UTM Northing 3505368.76 m, UTM Zone 14.
RANGE IN CHARACTERISTICS:
Soil Moisture: Typic ustic soil moisture regime. The soil moisture control section is dry in some or all parts for more than four-tenths but less than six-tenths of the cumulative days in normal years.
Solum thickness is greater than 203 cm (80 in).
Thickness of the mollic epipedon: 51 to 147 cm (20 to 58 in)
Cracks: 1 to 3 cm wide extend from the surface to depths of more than 51 cm (20 in) and are open for more than 135 days in most years
Depth to identifiable secondary carbonate: 25 to 114 cm (10 to 45 in)
Depth to calcic horizon: more than 102 cm (40 in)
Particle-size control section (weighted average)
Clay content: 38 to 60 percent
A Horizon
Hue: 5YR, 7.5YR, 10YR
Value: 3 to 5
Chroma: 2 to 3
Texture: silty clay, clay, clay loam
Clay content: 38 to 60 percent
Structure: subangular blocky or angular blocky
Pressure faces: visible when the soil is moist
Rock fragments: 0 to 5 percent; limestone and calcium carbonate
Reaction (pH): slightly alkaline to moderately alkaline (7.4 - 8.4)
Bk or Bw Horizon (where present)
Hue: 5YR, 7.5YR, 10YR
Value: 4 to 6
Chroma: 2 to 4; or is brownish yellow (10YR 6/6)
Texture: clay loam, silty clay, or clay
Clay content: 38 to 60 percent
Structure: subangular blocky or angular blocky
Pressure faces: visible when the soil is moist
Rock fragments: 0 to 7 percent; limestone and calcium carbonate
Identifiable secondary carbonate: less than 1 to 10 percent by volume; concretions and soft masses
Calcium carbonate equivalent: 2 to 10 percent
Reaction (pH): slightly alkaline to moderately alkaline (7.4 - 8.4)
BCk Horizon
Hue: 5YR, 7.5YR, 10YR
Value: 4 to 7
Chroma: 2 to 6; or is pale red (2.5YR 6/2) or light brownish gray (2.5Y 6/2)
Texture: silty clay loam, clay loam, silty clay, or clay
Clay content: 30 to 55 percent
Rock fragments: 0 to 15 percent; limestone and calcium carbonate
Identifiable secondary carbonate: 5 to 20 percent by volume; concretions, nodules, or soft masses
Calcium carbonate equivalent: 15 to 30 percent
Reaction (pH): slightly alkaline to moderately alkaline (7.4 - 8.4)
COMPETING SERIES: There are no other soil series in the same family. Similar soils are the
Garvin,
Knippa,
Krum,
Matoy, and
Rowena series.
Garvin soils: are moist in the soil moisture control section for longer periods, contain exchangeable sodium within the control section, and have an irregular decrease in organic matter with depth.
Knippa and
Rowena soils: have calcic horizons at depths of less than 102 cm (40 in) and have mixed mineralogy.
Krum soils: are moist in the soil moisture control section for longer periods.
Matoy soils: have a lithic contact with limestone between 20 and 40 inches.
GEOGRAPHIC SETTING:
Parent material: calcareous, clayey slope alluvium derived from claystone of Pennsylvanian or Permian age
Landscape: dissected plains
Landform: footslopes and toeslopes of hillslopes and to a lesser extent on terraces
Slope: 0 to 5 percent
Mean annual precipitation: 635 to 737 mm (25 to 29 in)
Thornthwaite P-E Index: 38 to 44
Mean annual air temperature: 17.2 to 18.9 degrees C (63 to 66 degrees F)
Frost-free period: 220 to 240 days
Elevation: 350.5 to 640.1 m (1150 to 2100 ft)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Rowena series, and the
Frio,
Leeray,
Nuvalde, and
Throck series.
Frio soils: occur on lower flood plains and do not have vertic properties.
Leeray soils: occur on similar to slightly lower positions and have intersecting slickensides and gilgai microrelief.
Nuvalde soils: occur on similar to slightly lower alluvial terraces, have a fine-silty particle-size control section, and do not have vertic properties.
Rowena soils: occur on similar to slightly lower alluvial terraces.
Throck soils: occur on higher positions, are less than 152 cm (60 in) to densic bedrock, and do not have a mollic epipedon.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is slow. Runoff is medium on slopes less than 1 percent and high on 1 to 5 percent slopes.
USE AND VEGETATION: Used for cropland, pastureland, and range. Small grains, forage sorghums, and grain sorghums are the main crops. Coastal bermudagrass and Kleingrass are the main pasture grasses. Native vegetation is mostly sideoats grama, Texas wintergrass, buffalograss, pricklypear, mesquite, and liveoak.
DISTRIBUTION AND EXTENT: North-central Texas; LRR H - Central Great Plains Winter Wheat and Range Region; MLRA 78A - Rolling Limestone Prairie and MLRA 80B - Texas north-central prairies. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Brown County, Texas; 1975.
REMARKS: The Nukrum series was formerly included in the Krum or Rowena series.
11/1991 - Classification change from mixed mineralogy to smectitic mineralogy based on Texas A&M University laboratory samples from the series type location in Brown County and from type locations in Callahan and Mason Counties, Texas.
Edited 01/2017 (RFG & ROG): Classification change from Vertic Haplustolls to Pachic Vertic Haplustolls based on historical range in characteristics and new class in Keys to Soil Taxonomy, Ninth Edition, 2003.
Changed to tabular format and included metric values. Updated competing series, geographic setting, and associated soils sections.
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: 25 to 100 cm (10 to 40 in) (A and Bw horizons)
Mollic epipedon: 0 to 61 cm (0 to 24 in)(Ap and A horizons)
Cambic horizon: 61 to 142 cm (24 to 56 in)(Bw horizon).
Calcic horizon: 142 to 203 cm (56 to 80 in) (BCk horizon)
Vertic feature: the occurrence of dry weather cracks from 1 to 3 cm (0.4 to 1.2 in) wide that extend from the surface to more than 51 cm (20 in) in depth. The particle-size control section has 38 to 60 percent clay.
Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014
National Cooperative Soil Survey
U.S.A.