LOCATION NORWOOD TX+AR LA OKEstablished Series
TAXONOMIC CLASS: Fine-silty, mixed, superactive, hyperthermic Fluventic Eutrudepts
TYPICAL PEDON: Norwood silt loam--cultivated.
(Colors are for dry soil unless otherwise stated.)
Ap1--0 to 4 inches; light brown (7.5YR 6/4) loam, pink (7.5YR 7/4) dry; weak fine subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common fine and few coarse roots; common fine and few coarse pores; few fine fragments of snail shells; common worm casts; strongly effervescent; slightly alkaline; clear wavy boundary.
Ap2--4 to 10 inches; brown (7.5YR 4/2) loam, brown (7.5YR 5/4) dry; weak coarse subangular blocky structure; soft, very friable, slightly sticky and nonplastic; common fine and few coarse roots; common fine and few coarse pores; few fine fragments of snail shells; few worm casts; strongly effervescent; moderately alkaline; clear smooth boundary. (combined thickness of A horizons is 4 to 20 inches)
Bw--10 to 18 inches; yellowish brown (10YR 5/4) silt loam, yellowish brown (10YR 5/4) dry; weak medium prismatic structure parting to moderate fine subangular blocky; soft, very friable, slightly sticky and slightly plastic; common fine roots; common fine to coarse pores; few fine fragments of snail shells; few films and threads of calcium carbonate; few fine mica flakes; few worm casts; strongly effervescent; moderately alkaline; clear smooth boundary. (thickness ranges from 0 to 26 inches)
Bk--18 to 28 inches; reddish yellow (7.5YR 6/6) silt loam, pink (7.5YR 7/4) dry; weak coarse prismatic structure parting to weak medium subangular blocky; soft, friable, slightly sticky and slightly plastic; common fine roots; many fine and medium pores; few fine faint reddish brown and common fine and medium faint strong brown (7.5YR 4/6) masses of iron accumulation; 10 percent discontinuous horizontal light brownish gray (10YR 6/2) iron depleted bedding planes, 1 to 3 millimeters thick; few thin iron-manganese coatings; common films and threads of calcium carbonate; few worm casts; strongly effervescent; moderately alkaline; clear smooth boundary. (thickness ranges from 0 to 20 inches)
BC1--28 to 34 inches; reddish yellow (7.5YR 6/6) silt loam, pink (7.5YR 7/4) dry; weak coarse prismatic structure parting to weak medium subangular blocky; soft, friable, slightly sticky and slightly plastic; common fine roots; common fine and medium pores; common fine and medium distinct strong brown (7.5YR 4/6) masses of iron accumulation with diffuse boundaries; few fine faint strong brown (7.5YR 4/6) masses of iron accumulation along pore linings and root channels; 25 percent continuous horizontal grayish brown (10YR 5/2) iron depleted bedding planes 4 millimeters thick; few thin iron-manganese coatings in some pores; few worm casts; violently effervescent; moderately alkaline; clear smooth boundary.
BC2--34 to 44 inches; light brown (7.5YR 6/4) silt loam, pink (7.5YR 7/4) dry; weak coarse prismatic structure parting to weak medium subangular blocky; soft, friable, slightly sticky and slightly plastic; common fine roots; many fine to coarse pores; few fine distinct yellowish red (5YR 4/6) masses of iron accumulation with clear boundaries; 35 percent discontinuous horizontal strong brown (7.5YR 4/6) silty clay loam bedding planes 4 to 6 millimeters thick; few thin iron-manganese coatings in some pores; few worm casts; violently effervescent; moderately alkaline; abrupt smooth boundary.
BC3--44 to 49 inches; brown (7.5YR 5/4) silty clay loam, pink (7.5YR 7/4) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and plastic; common fine roots; common fine to coarse pores; common fine and medium faint strong brown (7.5YR 4/6) masses of iron accumulation with clear boundaries; few strong brown (7.5YR 4/6) masses of iron accumulation with diffuse boundaries along pore linings; few gray (10YR 5/1) iron depletions along some pores; 35 percent discontinuous horizontal bedding planes 1 to 3 millimeters thick; few worm casts; violently effervescent; moderately alkaline; abrupt smooth boundary. (combined thickness of BC horizons is 15 to 40 inches)
Ab--49 to 53 inches; brown (7.5YR 4/2) clay, brown (10YR 4/3) dry; weak medium angular blocky structure; very hard, very firm, very sticky and very plastic; common fine roots; common fine and medium pores; few red (2.5YR 4/6) masses of iron accumulation with diffuse boundaries along pore linings; few thin iron-manganese coatings in some pore linings; few fragments of snail shells; few fine mica flakes; few worm casts; violently effervescent; moderately alkaline; abrupt smooth boundary. (0 to 3 to 10 inches thick)
Bwb1--53 to 63 inches; light yellowish brown (10YR 6/4) very fine sandy loam, light brown (7.5YR 6/4) dry; weak coarse prismatic structure parting to weak fine and medium subangular blocky; soft, very friable, nonsticky and nonplastic; few medium distinct yellowish brown (10YR 5/8) masses of iron accumulation with clear boundaries; few medium distinct very pale brown (10YR 7/3) iron depletions with diffuse boundaries; violently effervescent; moderately alkaline; clear smooth boundary.
Bwb2--63 to 80 inches; yellowish brown (10YR 5/4) very fine sandy loam, brown (7.5YR 5/4) dry; weak coarse prismatic structure parting to weak medium subangular blocky; soft, very friable, nonsticky and nonplastic; many fine and medium pores; few medium faint yellowish brown (10YR 5/6) masses of iron accumulation with diffuse boundaries along pore linings; few fine distinct gray (10YR 6/1) iron depletions with diffuse boundaries along pore linings; few fine mica flakes; few worm casts; violently effervescent; moderately alkaline.
TYPE LOCATION: Colorado County, Texas; in Garwood, from the intersection of Texas Highway 71 and Farm Road 950; 6.5 miles east on Farm Road 950; 1.0 mile north of Farm Road 102; 2.6 miles west on County Road 79A, and 100 feet west in cropland; USGS Eagle Lake topographic quadrangle; lat. 29 degrees, 30 minutes, 29 seconds N and long. 96 degrees, 21 minutes, 0 seconds W.
RANGE IN CHARACTERISTICS: Solum thickness is variable, but typically ranges from 60 to more than 80 inches. Bedding planes and/or buried profiles occur in the majority of pedons. Bedding planes, where present, occur between 15 and 40 inches. Buried horizons, where present, are between a depth of 30 and 60 inches.
The A horizon has hue of 5YR to 10YR, value of 4 to 6, and chroma of 2 to 6. Where the A horizon has moist value of less than 3.5, it is less than 6 inches thick. Texture is mainly silt loam or silty clay loam, but ranges to clay loam, loam, or very fine sandy loam. Reaction is slightly alkaline or moderately alkaline.
The Bw horizon has hue of 5YR to 10YR, value of 4 to 7, and chroma of 2 to 6. Texture is silt loam, silty clay loam, or loam, with clay content ranging from 20 to 35 percent. Structure of the Bw horizon ranges from weak medium to coarse prismatic parting to weak to moderate, fine to medium subangular blocky or moderate or strong, very fine and medium granular.
The Bk horizon, where present, has color similar to the Bw horizon. Calcium carbonate in the form of films and threads range from few to common.
The BC and C horizons, where present, have colors similar to the Bw and Bk horizons. Calcium carbonate in the form of films and threads range from none to few. Bedding planes are present within the BC and C horizons. Masses of iron accumulation in shades of brown, yellow, and red range from few to many in the BC horizon and are absent in C horizons.
The Ab horizon has hue of 7.5YR or 10YR, value of 3 to 5, and chroma of 2 to 5. Texture is silt loam, loam, or silty clay loam. Reaction is moderately alkaline.
The Bwb horizon has hue of 7.5YR or 10YR, value of 4 to 6, and chroma of 3 to 7. Texture is silt loam, loam, clay loam or silty clay loam. Reaction is moderately alkaline.
The C horizon, where present, has hue of 5YR or 7.5YR, value of 4 to 7, and chroma of 3 to 6. Texture is loam, silt loam, silty clay loam, or very fine sandy loam with thin strata of coarser and finer textures. Bedding planes are evident throughout the C horizon.
COMPETING SERIES: These include the Clemville series. Similar soils are the Weswood and Yahola series. Clemville soils have clayey layers in the lower part of the 10- to 40- inch particle-size control section. Weswood and Yahola soils have a Ustic moisture regime. In addition, Yahola soils have a coarse-loamy particle-size control section.
GEOGRAPHIC SETTING: Norwood soils are on nearly level flood plains. Slopes are mainly less than 1 percent, but range up to 8 percent along beveled edges bordering natural drains. The soils formed in stratified, calcareous, loamy alluvium of mixed origin. Mean annual temperature ranges from 62 to 70 degrees F. and mean annual precipitation ranges from 35 to 50 inches. Frost free days range from 230 to 270. Elevation ranges from 15 to 300 feet. Thornthwaite annual P-E index exceeds 58.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Asa, Brazoria, Clemville, and Pledger series. Asa soils have a mollic epipedon and occur in slightly higher positions. Brazoria and Pledger soils have a very-fine particle-size control section, a nd occur in slightly lower positions further from stream channels. In addition, Pledger soils have a mollic epipedon. Clemville soils occur in similar positions.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderate. Runoff is negligible on slopes less than 1 percent, very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, and medium on 3 to 8 percent slopes. Flooding ranges from rare to frequent except where protected by levees.
USE AND VEGETATION: Used mainly for cropland. Crops are cotton, soybeans, alfalfa, sorghum, and oats. Some areas are in improved bermudagrass pasture. Native vegetation includes pecan, cottonwood, elm, oak, and hackberry trees and mid and tall grasses.
DISTRIBUTION AND EXTENT: Mainly along the lower Brazos and Colorado River systems and their tributaries. The series is extensive.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: McLennan County, Texas, 1947.
REMARKS: Classification change from Typic Udifluvents to Fluventic Eutrudepts (1998) based on recognition that the majority of pedons have a weak cambic horizon as evidenced by removal of carbonates, slight color change in the Bw horizon, and landscape position conducive to the development of a cambic horizon.
Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 10 inches. (Ap horizons)
Cambic horizon - 10 to 18 inches. (Bw horizon)
Calcic horizon - 18 to 28 inches. (Bk horizon)
Fluventic feature--bedding planes and irregular organic carbon distribution
ADDITIONAL DATA: NSSL data from the type location in Colorado County, TX (S93TX-089-001). Data for THD from Brazoria County, Texas (S76TX039-008).
TAXONOMIC VERSION: Soil Taxonomy, Second Edition, 1999.