LOCATION MIDFIELD                TX

Established Series
KBH-RM-AKS
07/2019

MIDFIELD SERIES

The Midfield series consists of very deep, moderately well drained soils that formed in loamy fluviomarine deposits derived from the Beaumont Formation. These nearly level to gently sloping soils are on coastal prairies. Slope ranges from 0 to 2 percent. Mean annual temperature is about 20 degrees C (68 degrees F) and mean annual precipitation is about 1145 mm (49 in).

TAXONOMIC CLASS: Fine, smectitic, hyperthermic Chromic Vertic Hapludalfs

TYPICAL PEDON: Midfield loam--cropland (Colors are for moist soil unless otherwise stated.)

Ap--0 to 13 cm (0 to 5 in); brown (10YR 4/3) loam, brown (10YR 5/3) dry; weak fine subangular blocky; soft, friable; many very fine roots; common very fine and fine interstitial and tubular pores; moderately acid; gradual smooth boundary. (10 to 61cm [4 to 24 in] thick)

Bt1--13 to 32 cm (5 to 13 in); 50 percent dark brown (10YR 3/3), 40 percent brown (10YR 4/3) clay loam, 50 percent brown (10YR 4/3), brown (10YR 5/3) dry; moderate medium angular blocky; moderately hard, firm; many very fine tubular pores; 3 percent distinct very dark gray (10YR 3/1) clay films on faces of peds; 3 percent fine distinct brownish yellow (10YR 6/6) masses of oxidized iron with sharp boundaries lining pores and 7 percent fine prominent strong brown (7.5YR 5/6) masses of oxidized iron with sharp boundaries lining pores;; moderately acid; clear wavy boundary. (Combined thickness of the Bt horizons is 38 to 159 cm [15 to 63 in])

Bt2--32 to 81 cm (13 to 32 in); dark yellowish brown (10YR 4/4) silty clay, yellowish brown(10YR 5/4) dry; strong medium angular blocky structure; moderately hard, firm; common very fine roots; common very fine tubular pores; 6 percent distinct dark grayish brown (10YR 4/2) clay films on surfaces of peds; 3 percent fine distinct strong brown (7.5YR 4/6) masses of oxidized iron with sharp boundaries on surfaces of peds and 2 percent fine prominent yellowish red (5YR 4/6) masses of oxidized iron with sharp boundaries on surfaces of peds; neutral; clear smooth boundary

Bt3--81 to 101 cm (32 to 40 in); strong brown (7.5YR 5/6) silty clay, brownish yellow (10YR 6/6) dry; moderate medium angular blocky structure; very hard, firm; common very fine roots; common very fine tubular pores; 7 percent prominent very dark gray (10YR 3/1) clay films on surfaces of peds; 3 percent fine distinct spherical black (10YR 2/1) iron-manganese nodules; 7 percent distinct yellowish red (5YR 5/8) masses of oxidized iron with sharp boundaries on surfaces of peds; moderately alkaline; gradual wavy boundary.

2Btk1--101 to 131 cm (40 to 52 in); yellowish red (5YR 5/6) silty clay loam, reddish yellow (5YR 6/6) dry; weak coarse prismatic structure parting to moderate medium subangular blocky structure; very hard, firm; common very fine roots between peds; few very fine tubular pores; 4 percent prominent dark gray (5YR 4/1) clay films on surfaces of peds; very few very fine mica flakes; 2 percent white (10YR 8/1) fine calcium carbonate masses and 6 percent white (10YR 8/1) fine calcium carbonate nodules; slight effervescence; moderately alkaline; gradual wavy boundary. (Combined thickness of the 2Btk horizons is 23 to 102 cm [9 to 40 in])

2Btk2--131 to 203 cm (52 to 80 in); yellowish red (5YR 5/6) silt loam, reddish yellow (5YR 6/6) dry; weak coarse prismatic structure parting to moderate medium subangular blocky structure; very hard, firm; common very fine roots between peds; few very fine tubular pores; 2 percent prominent dark reddish gray (5YR 4/2) clay films on surfaces of peds; very few very fine mica flakes; 2 percent white (10YR 8/1) fine calcium carbonate masses and 4 percent white (10YR 8/1) fine calcium carbonate nodules; slight effervescence; neutral; gradual wavy boundary.

TYPE LOCATION:
Matagorda County, Texas; from the intersection of Texas Highway 60 and Farm Road 521 in Wadsworth Farm Road; 3.2 miles east on Farm Road 521 to county road; 0.4 mile south on county road to field road; 0.5 mile east on field road; 190 yards northwest in cropland.

USGS topographic quadrangle: Wadsworth, TX
Latitude: 29 degrees, 41 minutes, 42.71 seconds N
Longitude: 95 degrees, 50 minutes, 43.14 seconds W

Decimal Degrees
Latitude: 28.8304917
Longitude: -958809306
Datum: WGS 84

UTM Easting: 218877.16
UTM Northing: 3192615.87
UTM Zone: 15

RANGE IN CHARACTERISTICS:
Soil Moisture: A udic soil moisture regime. The soil moisture control section is from 10 to 61 cm (4 to 24 in) in depth. These soils remain moist in some part of the soil moisture control section for more than 275 days in normal years, with rainfall being fairly uniform throughout the year. The winter months have slightly less rainfall, but soil moisture is highest due to decreased evapotranspiration. Soil moisture is lowest during the summer months when evapotranspiration is highest.

Mean annual soil temperature: 22 to 23 degrees C (71.5 to 72.5 degrees F)

Particle-size control section (weighted average)
Clay content: 39 to 52 percent

A horizon
Hue: 10YR
Value: 2 to 4
Chroma: 1 to 3 (pedons with value less than 4 are less than 25 cm [10 in] thick)
Texture: loam, silt loam, fine sandy loam or very fine sandy loam
Clay content: 6 to 25 percent
Iron accumulations: amount- 0 to 3 percent, color-shades of brown (Iron accumulations are typically associated with pedons in rice culture.)
Reaction (pH): strongly acid to slightly acid (pH 5.1 to 6.5)

E horizon (where present)
Hue: 10YR
Value: 4 to 6
Chroma: 3 or 4
Texture: loam, silt loam, fine sandy loam or very fine sandy loam
Clay content: 5 to 16 percent
Iron accumulations: amount- 0 to 3 percent, color-shades of brown (Iron accumulations are typically associated with pedons in rice culture.)
Reaction (pH): strongly acid to slightly acid (pH 5.1 to 6.5)

Bt horizon (upper part)
Hue: 10YR
Value: 4 to 6
Chroma: 2 to 4 (chroma of 2 is considered due to abnormally wet periods)
Texture: clay loam, sandy clay, clay, or silty clay
Clay content: 30 to 55 percent
Iron accumulations: amount- 1 to 10 percent,
Redox depletions: amount-0 to 5 percent, color- shades of gray (depletions are considered to have formed in abnormally wet periods)
Reaction (pH): strongly acid to neutral (pH 5.1 to 7.3)

Bt horizons (lower part)
Hue: 7.5YR or 10YR
Value: 4 to 6
Chroma: 2 to 8 (chroma of 2 is considered due to abnormally wet periods)
Texture: sandy clay loam, clay loam, clay, or silty clay
Clay content: 30 to 50 percent
Iron accumulations: amount- 2 to 25 percent, color- shades of brown, red or yellow (red iron accumulations are less than 20 percent)
Redox depletions: amount-0 to 5 percent, color- shades of gray (depletions are considered to have formed in abnormally wet periods)
Reaction (pH): slightly acid to slightly alkaline acid (pH 6.1 to 7.8)

2Btk horizons
Hue: 2.5YR or 5YR
Value: 4 to 6
Chroma: 4 to 8
Texture: sandy clay loam, silt loam, clay loam, silty clay loam, or clay
Clay content: 20 to 46 percent
Iron accumulations: amount- 2 to 25 percent, color- shades of brown, red or yellow (red iron accumulations are less than 20 percent)
Redox depletions: amount-0 to 15 percent, color- shades of gray (depletions are considered to have formed in abnormally wet periods)
Secondary carbonates: amount-1 to 10 percent, kind-nodules or masses
Reaction (pH): neutral to moderately alkaline (pH 6.6 to 8.4)

COMPETING SERIES:
There are no series in the same family. Similar soils are the Levac, Telf, Telferner, and Yeaton series.
Levac, Telferner, and Yeaton soils: remain saturated for more than 30 cumulative days in normal years.
Telf soils: mixed mineralogy

GEOGRAPHIC SETTING:
Parent material: Loamy fluviomarine deposits derived from the Beaumont Formation of Pleistocene age
Landscape: Coastal plains
Landform: relict meander belt ridges
Slope: 0 to 2 percent
Precipitation Pattern: Rainfall is fairly uniform throughout the year, with slight peaks in the spring and fall months.
Mean annual precipitation range: 1092 to 1245 mm (43 to 49 in)
Thornthwaite annual P-E indices: 62 to 70
Mean annual air temperature range: 19.5 to 20.6 degrees C (67 to 69 degrees F)
Frost-free period: 270 to 285 days
Elevation: 3.7 to 46 m (12 to 150 ft)
GEOGRAPHICALLY ASSOCIATED SOILS:
These are the Texana and Tidehaven (T-TX) series.
Texana soils: mollic epipedon on a similar landform.
Tidehaven soils: are saturated above the argillic horizon for 30 cumulative days in normal years; on a slightly lower landform

DRAINAGE AND PERMEABILITY:
Drainage class: Moderately well drained
Permeability class: slow
Runoff: medium on slope less than 1 percent and high on slope greater than 1 percent.

USE AND VEGETATION:
Used mainly for cropland and pastureland. A few areas are in rangeland. Native vegetation includes bluestems and paspalums.
Ecological sites assigned to phases and components of this series are listed below. Current ecological site assignments are in Web Soil Survey. Components of this series include the following ecological sites: Loamy Prairie

DISTRIBUTION AND EXTENT:
General area: Texas coastal plain, mainly from the Colorado River to the Brazos River.
Land Resource Region: T- (Atlantic and Gulf Coast Lowland Forest and Crop Region)
Major Land Resource Area: 150A- Gulf Coast Prairies
Extent: small

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

SERIES ESTABLISHED: Matagorda County, Texas, 2016.

REMARKS: These soils were previously mapped as the Katy series. Diagnostic horizons and features recognized in this pedon are:

Particle size control section: 13 to 63 cm (5 to 25 in). (Bt1 and Bt2 horizon)
Ochric epipedon: 0 to 13 cm (0 to 5 in). (Ap horizon)
Argillic horizon: 13 to 203 cm (5 to 80 in). (Bt horizons)
Secondary carbonates: 101 to 203 cm (40 to 80 in) (2Btk1 and 2Btk2 horizons)
Lithologic Discontinuity: 101 to 203 cm (40 to 80 in) (2Btk1 and 2Btk2 horizons.

Additional Comments: The lithologic discontinuity was determined by the ratio of very fine sand to fine sand which is markedly different than the overlying horizons and coincides where the horizon color is 5YR or redder and the presence of mica flakes. The reddish subsoil and mica flakes are considered to be a marker of Colorado River sediments.

ADDITIONAL DATA: Soil survey office lab data available on the typical pedon (NASIS user site id of S2015TX3212500).

Taxonomic version: Keys to Soil Taxonomy, Twelfth Edition, 2014

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National Cooperative Soil Survey
U.S.A.