LOCATION CHINA TXEstablished Series
TAXONOMIC CLASS: Fine, smectitic, hyperthermic Oxyaquic Dystruderts
TYPICAL PEDON: China clay--cropland.
(Colors are for moist soil unless otherwise stated.)
Ap--0 to 4 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; moderate fine angular blocky structure; extremely hard, extremely firm; many fine and medium roots; few fine pores; about 5 percent dark gray crayfish krotovina; very strongly acid; clear smooth boundary.
A1--4 to 9 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; moderate coarse platy structure parting to moderate medium angular blocky; extremely hard, extremely firm; common fine and medium roots; few fine pores; common fine prominent yellowish red (5YR 4/6) iron accumulations; about 5 percent dark gray crayfish krotovina; very strongly acid; clear smooth boundary.
A2--9 to 20 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; medium fine angular blocky structure; extremely hard, extremely firm; few fine and medium roots; few fine pores; common fine prominent yellowish red (5YR 4/6) iron accumulations; few distinct pressure faces; about 5 percent dark gray crayfish krotovina; very strongly acid; gradual wavy boundary. (combined thickness of the A subhorizons is 10 to 30 inches)
Bss1--20 to 28 inches; very dark gray (10YR 3/1) clay, dark gray (10YR 4/1) dry; medium fine angular blocky structure; extremely hard, extremely firm; few fine roots; few fine pores; few fine prominent yellowish brown (10YR 5/8) iron accumulations; common prominent pressure faces; few distinct slickensides; about 5 percent dark gray crayfish krotovina; very strongly acid; gradual wavy boundary.
Bss2--28 to 37 inches; dark gray (10YR 4/1) clay, gray (10YR 5/1) dry; moderate fine angular blocky structure; extremely hard, extremely firm; few fine roots; few fine pores; common fine prominent yellowish brown (10YR 5/8) iron accumulations along root channels and pores; many prominent pressure faces; common prominent slickensides; about 5 percent dark gray crayfish krotovina; very strongly acid; clear wavy boundary.
Bss3--37 to 42 inches; dark gray (10YR 4/1) clay, gray (10YR 5/1) dry; moderate fine angular blocky structure; extremely hard, extremely firm; few fine roots; few fine pores; common fine prominent yellowish brown (10YR 5/8) and few fine prominent yellowish red (5YR 4/6) iron accumulations; many prominent pressure faces; common prominent slickensides; about 5 percent dark gray crayfish krotovina; very strongly acid; clear wavy boundary. (combined thickness of the Bss subhorizons is 15 to 30 inches)
Bssy--42 to 55 inches; dark gray (10YR 4/1) clay; moderate coarse prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots; few fine pores; common fine prominent yellowish brown (10YR 5/8) and few fine prominent yellowish red (5YR 4/6) iron accumulations; many prominent pressure faces; common prominent slickensides; 5 percent fine and 20 percent medium gypsum crystals in clusters; about 5 percent dark gray crayfish krotovina; very strongly acid; clear wavy boundary. (0 to 20 inches thick)
Bssyg--55 to 60 inches; gray (10YR 5/1) clay; moderate coarse prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots; few fine pores; common fine and medium prominent yellowish brown (10YR 5/8) and common fine prominent dark red (2.5YR 3/6) iron accumulations; many prominent pressure faces; common prominent slickensides; 20 percent fine crystals of gypsum dispersed in horizon and 10 percent medium gypsum crystals in clusters and seams; about 5 percent dark gray crayfish krotovina; strongly acid; clear wavy boundary. (0 to 15 inches thick)
Bssg--60 to 80 inches; gray (10YR 6/1) clay; moderate coarse prismatic structure parting to strong fine angular blocky; extremely hard, extremely firm; few fine roots; few fine pores; common fine and medium prominent dark red (2.5YR 3/6) and common fine and medium prominent yellow (2.5Y 7/6) iron accumulations; many prominent pressure faces; common prominent slickensides; about 5 percent dark gray crayfish krotovina; strongly acid. (10 to 30 inches thick)
TYPE LOCATION: Jefferson County, Texas; from the intersection of Interstate Highway 10 and U.S. Highway 90 in Beaumont; 12.2 miles west on U.S. Highway 90; 3.8 miles south on South China Road; 400 feet east on field road that crosses a canal; 75 feet south in cropland. (Latitude 29N, 59, 34; Longitude 94W, 20, 07)
RANGE IN CHARACTERISTICS: The range in characteristics includes 50 percent or more of the pedon. Solum thickness is more than 80 inches. Thickness of mollic colors range from 12 to 40 inches. The texture is clay throughout. Weighted average clay content of the control section ranges from 45 to 60 percent. When dry, cracks 0.5 to about 1 inch wide extend from the surface to a depth of 12 inches or more. Cracks remain open for less than 60 cumulative days during most years. Slickensides and wedge shaped peds begin at a depth ranging from 10 to 24 inches. Undisturbed areas have gilgai microrelief with microknolls 6 to 15 inches higher than microdepressions. Distance from center of the microknoll to center of microdepression ranges from 3 to 12 feet. Gypsum crystals make up 5 to 25 percent of the gypsic horizon. Depth to a gypsic horizon is about 40 inches, but ranges from 25 to 50 inches. The gypsic horizon is best expressed and thickest in the microknoll and is thinner and deeper in the microdepression.
Microknolls make up 5 to 25 percent of the pedon. Typically, colors in the microknoll have value of 4 or more. Calcium carbonate concretions, mainly in clusters, range from 1 to 5 percent in the lower part of the microknoll in some pedons.
The A horizon has hue of 10YR to 5Y, value of 3, and chroma of 1. In rice culture Ap horizons, 4 to 6 inches thick, include value that ranges to 4. Redoximorphic features range from none to few in shades of brown or gray and are developed by rice culture. Gypsum crystals range from none to few. Reaction ranges from extremely acid to very strongly acid.
The Bss horizon has hue of 10YR to 5Y, value of 3 to 4, and chroma of 1 or less. Redoximorphic features range from few to common in shades of brown, yellow, or gray. Redoximorphic features in the upper part are developed or enhanced by rice culture. Gypsum crystals range from none to few. Reaction ranges from extremely acid to moderately acid.
The Bssy and Bssyg horizons have hue of 10YR to 5Y, value of 4 to 7, and chroma of 1 or less. Iron accumulations range from few to common in shades of yellow or brown. Gypsum crystals are fine, medium, or coarse. The fine crystals are mainly in clusters and seams. The medium and coarse crystals are up to 1/2 inch across and are disseminated throughout the matrix. In some pedons they are concentrated in clusters. Reaction ranges from very strongly acid to slightly acid.
The Bssg horizon has hue of 10YR to 5Y, value of 6 or 7, and chroma of 1 or less. Iron accumulations range from few to many in shades of brown or yellow and from few to common in shades of red. Reaction ranges from moderately acid to slightly alkaline.
COMPETING SERIES: This is the League series. Similar soils are the Bacliff, Beaumont, and Vamont series. Bacliff, Beaumont, and League soils do not have a gypsic horizon. In addition, Bacliff and Vamont soils are Hapluderts. Beaumont soils are Aquerts and have color value of 4 or more throughout.
GEOGRAPHIC SETTING: China soils are on the broad, nearly level Coastal Prairie east of the Trinity River. Slopes are plane and gradients are less than 1 percent. These soils formed in clayey flood basin deposits on alluvial plains or deltas of the Pleistocene age Beaumont Formation. Mean annual precipitation ranges from 50 to 60 inches, and mean annual temperature ranges from 70 to 72 degrees F. Frost free days range from 250 to 270 days. Elevation ranges from 10 to 40 feet above sea level. The Thornthwaite P-E index is 68 to 80.
GEOGRAPHICALLY ASSOCIATED SOILS: These include the competing Beaumont and League soils and the Labelle, Morey, and Viterbo soils. Beaumont soils are slightly lower in the landscape. League soils are on similar positions. Viterbo soils are on slightly lower positions, are more alkaline, and have a argillic horizon. Labelle and Morey soils are slightly higher in the landscape and have an argillic horizon.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained. Runoff is low. Permeability is very slow.
USE AND VEGETATION: Mainly used for growing rice and pasture. Rice is usually grown on a 1 in 4 year rotation. Improved pasture is used for bahia grass production. Some areas are used for native pasture. Native grasses are mainly little bluestem, indiangrass, eastern gamagrass, switchgrass, Florida paspalum, big bluestem, brownseed paspalum, knotroot bristlegrass, sedges and rushes.
DISTRIBUTION AND EXTENT: The Gulf Coast Prairies of Texas, and possibly Louisana, (MLRA 150A) east of the Trinity River. The series is of moderate extent.
MLRA OFFICE RESPONSIBLE: Temple, Texas
SERIES ESTABLISHED: Jefferson County, Texas; 1996. The name comes from the nearby town of China.
REMARKS: These soils were formerly included with the Beaumont and Lake Charles series.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - from the surface to a depth of 28 inches. (Ap, A1, A2 and Bss1 horizons)
Cambic horizon - from a depth of about 20 inches to 80 inches. (Bss, Bssy, Bssyg, and Bssg horizons)
Gypsic horizon - from a depth of about 42 to 60 inches. (Bssy and Bssyg horizon)
Vertisol feature - slickensides at a depth of 20 to 80 inches. Cracks that are 1/2 to about 1 inch wide at a depth of 12 inches or more when dry.
Oxyaquic feature - water is perched from the surface to about 20 inches for 30 days or more during the winter and early spring in most years. This layer has redoximorphic features but does not have aquic soil conditions or test positive to a,a'-dipyridyl in most years.
SOIL INTERPRETATION RECORD NUMBER: TX1172.
ADDITIONAL DATA: Jefferson County, Texas; NSSL sample S90TX-245-022 and S90TX-245-023.