LOCATION MONTELL TX

Established Series
Rev. CLG-WJG-RM
11/2010

MONTELL SERIES

The Montell series consists of very deep, moderately well drained, very slowly permeable soils that formed in clayey alluvium. These nearly level to very gently sloping soils are on valley sides or valley floors. Slopes range from 0 to about 3 percent. Mean annual air temperature is about 21 degrees C (70 degrees F) and mean annual precipitation is about 610 mm (24 in).

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Sodic Haplusterts

TYPICAL PEDON: Montell clay, on a linear, 0.5 percent slope in native rangeland; elevation is 299 m (981 ft). (Colors are for dry soil unless otherwise stated.)

A--0 to 18 cm (0 to 7 in); gray (10YR 5/1) clay, dark gray (10YR 4/1) moist; moderate medium subangular blocky structure parting to moderate very fine granular, upper 1.0 cm has a weak thin platy crust; hard, firm, very sticky, very plastic; many very fine and fine, and few medium and coarse roots; common fine and medium tubular pores; few fine krotovinas; few fine snail shell fragments; SAR is 1; violently effervescent; moderately alkaline; clear smooth boundary. (10 to 31 cm [4 to 12 in] thick)

Bnss--18 to 58 cm (7 to 23 in); gray (10YR 5/1) clay, dark gray (10YR 4/1) moist; strong coarse angular blocky structure; very hard, very firm, very sticky, very plastic; many very fine and fine, and few medium and coarse roots; few fine and medium tubular pores; few wedge shaped peds with long axes tilted 10 to 30 degrees from horizontal; few prominent slickensides; few rounded limestone pebbles; few fine krotovinas; few fine snail shell fragments; SAR is 16; very slightly saline; violently effervescent; moderately alkaline; clear wavy boundary. (25 to 71 cm [10 to 28 in] thick)

Bnssz1--58 to 81 cm (23 to 32 in); grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; common fine gray (10YR 5/1) streaks; strong coarse angular blocky structure; very hard, very firm, very sticky, very plastic; common very fine and few fine and medium roots; few fine and medium tubular pores; few wedge shaped peds with long axes tilted 10 to 30 degrees from horizontal; few prominent slickensides; few rounded limestone pebbles; few fine snail shell fragments; few fine krotovinas; SAR is 29; moderately saline; violently effervescent; moderately alkaline; clear wavy boundary.

Bnssz2--81 to 132 cm (32 to 52 in); pale brown (10YR 6/3) clay, pale brown (10YR 6/3) moist; common fine gray (10YR 5/1) streaks; moderate coarse angular blocky structure; very hard, very firm, very sticky, very plastic; few very fine and fine roots, and few medium and coarse roots; few fine and medium tubular pores; common fine distinct yellowish brown (10YR 5/4) relic redox concentrations; few wedge shaped peds tilted 10 to 30 degrees from horizontal; few prominent slickensides; few fine and medium krotovinas of dark colored material; 2 percent of films, soft masses, and clusters of gypsum crystals; 2 percent of films and soft masses of calcium carbonate; SAR is 22; moderately saline; violently effervescent; moderately alkaline; gradual wavy boundary. (combined Bnssz subhorizons are 25 to 102 cm [10 to 40 in] thick)

Byz--132 to 203 cm (52 to 80 in); very pale brown (10YR 7/3) clay, pale brown (10YR 6/3) moist; moderate fine angular blocky structure; very hard, firm, very sticky, very plastic; few very fine and fine roots, and few medium roots; few fine tubular pores; common fine distinct reddish yellow (7.5YR 6/6) relic redox concentrations; few prominent black coats on faces of peds; few fine and medium krotovinas of dark colored material; 2 percent of films and soft masses of calcium carbonate; 30 percent of films, soft masses and clusters of gypsum crystals and other salts; SAR is 1; moderately saline; violently effervescent; moderately alkaline.

TYPE LOCATION: Kinney County, Texas; from the intersection of Texas Highway 131 and Farm Road 1572 in Spofford; 2 miles south on Texas Highway 131 to the intersection of Farm Road 1908; 375 feet northeast of gate in rangeland. Spofford, Texas USGS topographic quadrangle. Latitude: 29 degrees, 08 minutes, 48 seconds N; Longitude: 100 degrees, 26 minutes, 02 seconds W.; NAD 83.

RANGE IN CHARACTERISTICS:
Solum thickness is more than 80 inches.
Weighted average silicate clay content of the particle-size control section is 35 to 50 percent.
Texture is silty clay or clay throughout with total clay content of 40 to 60 percent.
Exchangeable sodium ranges from 15 to more than 40 percent in some horizon within 102 cm (40 in) of the soil surface.
Calcium carbonate equlivant ranges from 10 to 40 percent throughout.
Reaction is slightly or moderately alkaline throughout.
When dry, cracks 1 to more than 5 cm (0.4 to more than 2 in) wide at the surface extend to a depth of 31 cm (12 in) or more. Cracks open 150 to 210 cumulative days during most years. Gilgai relief, in undisturbed areas, have microknolls 1.5 to 3.7 m (5 to 12 ft) in diameter and 8 to 31 cm (3 to 12 in) higher than the microdepressions. Slickensides begin at a depth of 15 to 51 cm (6 to 20 in).

A horizon
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 1
Salinity: 0.4 to 4 dS/M

Bnss horizons
Hue: 10YR or 2.5Y
Value: 4 to 6
Chroma: 1
Salinity: 2 to 16 dS/M

Bnssz horizons
Hue: 10YR or 2.5Y
Value: 4 to 7
Chroma: 1 to 4
Salinity: 2 to 16 dS/M

Byz horizon
Hue: 10YR or 2.5Y
Value: 4 to 7
Chroma: 1 to 4
Crystalline salts, mainly gypsum, range from 5 to 35 percent. Relic redox features are in shades of red, brown, or gray in some pedons.

COMPETING SERIES: These are the Arroyada (TX), Catarina (TX), Coquat (TX), Cotulla (TX), Duvert (I-TX), Lasalle (TX), Mercedes (TX), Monwebb (TX), Victine (TX), and Victoria (TX) series.
Arroyada and Coquat soils: are somewhat poorly drained and formed in Holocene alluvium on flood plains
Catarina and Cotulla soils: have colors of chroma greater than 2 in the upper 30 cm (12 in)
Duvert soils: have a paralithic contact between 51 to 102 cm (20 and 40 in) of the surface, and are well drained.
Lasalle soils: have hue of 7.5YR or redder in the B horizons.
Mercedes soils: are slightly saline in the upper 102 cm (40 in).
Monwebb soils: have a mollic epipedon
Victoria and Victine soils: Victoria soils are well drained and depth to SAR of more than 13 ranges from 71 to 99 cm (28 to 39 in). Victine soils are somewhat poorly drained and have higher SAR in the upper 51 cm (20 in).

GEOGRAPHIC SETTING:
Parent material: clayey alluvium
Landform: valley sides or valley floors
Slope: 0 to 3 percent
Mean annual temperature: 21 to 23 degrees C (69 to 74 degrees F)
Mean annual precipitation: 508 to 711 mm (20 to 28 in)
Precipitation Pattern: June to August and December to February are the driest months,while September to November and March to May are the wettest months.
Frost-free period: 240 to 310 days.
Elevation: 122 to 366 m (400 to 1200 ft).
Thornthwaite annual P-E indices: 20 to 30.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Caid, Catarina, Knippa, and the Uvalde series.
Caid soils: are in a fine-loamy family, have an argillic horizon, and are on slightly higher positions.
Catarina soils: have higher SARs closer to the surface and on similar positions.
Knippa and Uvalde soils: have a calcic horizon and are on similar to slightly lower positions.

DRAINAGE AND PERMEABILITY: Moderately well drained. Permeability is very slow. Runoff is high on slopes less than 1 percent and very high on 1 to 3 percent slopes. Water enters the soil rapidly when it is cracked, but very slow when the soil is moist and cracks are closed.

USE AND VEGETATION: Largely used for native rangeland and wildlife habitat. Range vegetation consists mainly of fourflower trichloris, alkali sacaton, tobosa, vine mesquite, curlymesquite, white tridens, whiplash pappusgrass and other short and midgrasses. Nonsaline areas produce pink pappusgrass, sideoats grama, and buffalograss also. Invading plants include scrubby mesquite, whitebush, and pricklypear. The ecological site is Clay Flat 18-25 PZ (R083BY415TX).

DISTRIBUTION AND EXTENT: Western and Central Rio Grande Plain, Texas; LRR I, MLRA 83B and 83C. The series is of large extent (about 571,000 acres correlated).

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

SERIES ESTABLISHED: Uvalde County, Texas; 1940.

REMARKS: Classification changed 3/94 from Entic Pellusterts to Sodic Haplusterts based on Issue 16 of Soil Taxonomy.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 18 cm (0 to 7 in) (A horizon).
Cambic horizon: 18 to 203 cm (7 to 80 in) (Bnss, Bnssz, Byz horizons).
Gypsic horizon: 132 to 203 cm (52 to 80 in) (Byz horizon).
Vertisol features - Cracks when dry; slickensides at 18 to 132 cm (7 to 52 in).

ADDITIONAL DATA: National Soil Survey Laboratory data on type location S85TX271-1 (86P1227-1231).
Soil Interpretation Record Number: TX0213 (nonsaline), TX0873 (saline), TX0990 (saline, flooded).

TAXONOMIC VERSION: Keys to Soil Taxonomy, Eleventh Edition, 2010.

National Cooperative Soil Survey
U.S.A.