LOCATION PLEMONS                 TX+OK

Established Series
TCB-RM
09/2015

PLEMONS SERIES


The Plemons series consists of very deep, well drained, moderately permeable soils that formed in calcareous, loamy sediments derived from the upper part of the Ogallala Formation of Miocene-Pliocene age. These soils are on gently to strongly sloping valley sides, draws, or broad erosion remnants. The slope ranges from 1 to 12 percent. The mean annual precipitation is 496 mm (18 in) and the mean annual temperature is 16 degrees C (58 degrees F).

TAXONOMIC CLASS: Fine-silty, mixed, superactive, thermic Calcidic Paleustalfs

TYPICAL PEDON: Plemons loam, on north-facing, convex, 4 percent slope in rangeland at an elevation of 1,085 m (3,560 ft). (Colors are for dry soil unless otherwise stated.)

A--0 to 15 cm (0 to 6 in); brown (7.5YR 4/3) loam, dark brown (7.5YR 3/3) moist; weak medium and coarse subangular blocky structure; slightly hard, friable; common very fine and fine roots; violently effervescent; moderately alkaline; clear smooth boundary. (10 to 18 cm [4 to 7 in] thick)

Btk1--15 to 33 cm (6 to 13 in); brown (7.5YR 4/4) clay loam, dark brown (7.5YR 3/4) moist; moderate coarse prismatic structure parting to weak medium subangular blocky; hard, firm; few very fine and fine roots; common fine tubular pores; few faint clay films on ped surfaces; estimated 30 percent by volume of calcium carbonate in the form of filaments and finely disseminated carbonates; 20 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; clear smooth boundary

Btk2--33 to 61 cm (13 to 24 in); strong brown (7.5YR 5/6) clay loam, strong brown (7.5YR 4/6) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; very hard, firm; few very fine and fine roots; common fine tubular pores; few faint clay films on ped surfaces; estimated 40 percent by volume of calcium carbonate in the form of masses, nodules, and finely disseminated carbonates; 26 percent calcium carbonate equivalent; violently effervescent; moderately alkaline; gradual smooth boundary.

Btk3--61 to 117 cm (24 to 46 in); strong brown (7.5YR 5/6) clay loam, strong brown (7.5YR 4/6) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; very hard, firm; few very fine roots; common fine tubular pores; common distinct clay films on ped surfaces; common fine black (10YR 2/1) masses of oxide accumulation on ped surfaces; estimated 30 percent by volume of calcium carbonate in the form of masses, nodules, and finely disseminated carbonates; 12 percent calcium carbonate equivalent; violently effervescent; strongly alkaline; gradual smooth boundary.

Btk4--117 to 147 cm (46 to 58 in); strong brown (7.5YR 5/6) silty clay loam, strong brown (7.5YR 4/6) moist; moderate coarse prismatic structure parting to moderate medium subangular blocky; very hard, firm; few distinct clay films on ped surfaces; common fine black (10YR 2/1) masses of oxide accumulation on ped surfaces; estimated 18 percent by volume of calcium carbonate in the form of masses, nodules, and finely disseminated carbonates; violently effervescent; moderately alkaline; gradual smooth boundary.

Btk5--147 to 193 cm (58 to 76 in); strong brown (7.5YR 5/6) clay loam, strong brown (7.5YR 4/6) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; very hard, firm; common distinct clay films on ped surfaces; common fine black (10YR 2/1) masses of oxide accumulation on ped surfaces; estimated 6 percent by volume of calcium carbonate in the form of filaments and masses; strongly effervescent; moderately alkaline; clear smooth boundary. (Combined thickness of the Btk horizons (140 to 178 cm [55 to 70 in])

2Btk6--193 to 203 cm (76 to 80 in); strong brown (7.5YR 5/6) clay, strong brown (7.5YR 4/6) moist; weak coarse prismatic structure parting to moderate medium subangular blocky; hard, firm; common distinct clay films on ped surfaces; many fine black (10YR 2/1) masses of oxide accumulation on ped surfaces; estimated 4 percent by volume of calcium carbonate in the form of filaments and masses; slightly effervescent; moderately alkaline.

TYPE LOCATION: Potter County, Texas; 800 m (0.5 miles) north of the intersection of State Highway 136 and Farm Road 293 on State Highway 136, 160 m (0.1 miles) west-northwest in rangeland; Latitude 35 degrees, 21 minutes, 40.2 seconds N; Longitude: 101 degrees, 38 minutes, 34 seconds W; Mayer, 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 205 days, cumulative, in normal years. July through August and December through February are the driest months. These soils are intermittently moist September through November and March through June.
Mean annual soil temperature: 16 to 18 degrees C.
Depth to visible secondary carbonates: 0 to 20 cm (0 to 8 in)
Depth to calcic horizon: 10 to 60 cm (4 to 24 in)
Solum thickness: more than 203 cm (203 in)
Particle-size control section: 18 to 35 percent silicate clay and less than 15 percent by weight fine sand or coarser in the particle-size control section

A horizon:
Hue: 5YR to 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 3 to 5
Texture: loam
Effervescence: strong or violent
Reaction: moderately alkaline
Surface fragments: 2 to 20 mm calcium carbonate nodules and fragments range from 0 to 10 percent

Btk horizons:
Hue: 5YR to 7.5YR
Value: 4 to 7, 3 to 6 moist
Chroma: 4 to 6
Texture: clay loam, silty clay loam, sandy clay loam
Visible secondary carbonates: 3 to 49 percent by volume as films, filaments, masses, nodules, and finely disseminated carbonates
Calcium carbonate equivalent: 2 to 40 percent (zone of maximum carbonate accumulation is between 10 and 75 cm [4 to 30 in])
Effervescence: violent
Reaction: moderately or strongly alkaline

Btkk horizon (where present):
Hue: 5YR to 7.5YR
Value: 6 to 8
Chroma: 1 to 4
Texture: clay loam or clay
Visible secondary carbonates: 49 to 70 percent by volume as masses, nodules, and finely disseminated carbonates
Calcium carbonate equivalent: 30 to 50 percent by weight
Effervescence: violent
Reaction: moderately alkaline or strongly alkaline

2Btk horizons: (where present)
Hue: 5YR or 7.5YR
Value: 4 to 6, 3 to 5 moist
Chroma: 4 to 6
Texture: loam, clay loam, silty clay, clay
Visible secondary carbonates: 3 to 8 percent as films, filaments, masses, and nodules
Calcium carbonate equivalent: 0 to 5 percent
Effervescence: slight or strong
Reaction: moderately alkaline

COMPETING SERIES: There are no competing series in the same family. Similar soils the Manson, Mansker, Posey, and Tulia series.
Manson series: have a mollic epipedon.
Mansker series: have a mollic epipedon and carbonatic mineralogy.
Posey and Tulia series: have more than 15 percent by weight fine sand or coarser in the particle-size control section; in addition Tulia soils have carbonatic mineralogy.
GEOGRAPHIC SETTING:
Parent material: calcareous, loamy sediments mainly derived from the upper part of the Ogallala Formation of Miocene-Pliocene age.
Landform: valley sides, draws, or broad erosion remnants.
Slopes: 1 to 8 percent but range to 12 percent.
Mean annual air temperature: 15 to 17 degrees C (55 to 61 degrees F).
Mean annual precipitation: 432 to 559 mm (17 to 21 in).
Frost-free period: 180 to 220 days.
Elevation: 670 to 1,158 m (2,300 to 3,800 ft).
Thornthwaite annual P-E Index Values: 25 to 36.

GEOGRAPHICALLY ASSOCIATED SOILS: These include the similar Manson soils and the Ady, Alibates, Berda, Bippus, Mobeetie, Paloduro, Potter, Sprone, Texroy, and Veal soils.
Manson soils: are on similar landscape positions.
Ady and Alibates soils: are on similar landscape positions and have more than 15 percent by weight fine sand or coarser in the particle-size control section and do not have a calcic horizon within 60 cm.
Berda and Paloduro soils: are on slightly lower landscape positions and do not have argillic horizons.
Bippus and Sprone soils: are on lower landscape positions and do not have an argillic horizon or have a calcic horizon within 61 cm (24 in).
Mobeetie and Veal soils: are on slightly lower landscape positions and have less than 18 percent silicate clay in the particle-size control section; in addition Veal soils have carbonatic mineralogy.
Potter soils: are on similar landscape positions and have a loamy-skeletal particle size control section and carbonatic mineralogy.
Texroy soils: are on lower landscape positions and do not have a calcic horizon within 61 cm (24 in).

DRAINAGE AND PERMEABILITY: Well drained and moderate permeability. Surface runoff is very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, and medium on 5 to 12 percent slopes.

USE AND VEGETATION: Primarily used for livestock grazing. Where cultivated, the principal crops are grain sorghum, small grains, and forage crops. Climax vegetation is mainly mid and short grasses and includes blue grama, sideoats grama, and buffalograss, with lesser amounts of vine-mesquite, western wheatgrass, galleta or tobosa, silver bluestem, wild alfalfa, and prairieclover with a light to moderate overstory of mesquite. This soil has been correlated to the Limey Upland (R077EY057TX) range site in MLRA-77E.

DISTRIBUTION AND EXTENT: Southern High Plains, Breaks (MLRA-77E in LRR H) of Texas and Oklahoma. The series is of moderate extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Temple, Texas

SERIES ESTABLISHED: MLRA-77 Soil Survey; Carson County, Texas; 1995.

REMARKS: These soils were formerly included in the Mansker and Posey series.

Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 15 cm (0 to 6 in). (A horizon)
Argillic horizon: 15 to 203 cm (6 to 80 in). (Btk horizons)
Calcic horizon: 15 to 61 cm (6 to 24 in). (Btk1 and Btk2 horizons)

ADDITIONAL DATA: NSSL data available - Sample number: S97TX-375-001 (Potter County, Texas).

Taxonomic Version: Keys to Soil Taxonomy, Twelfth Edition, 2014.


National Cooperative Soil Survey
U.S.A.