LOCATION ICHUSA MS+AL
Established Series
Rev. RMT:MEL
10/2018
ICHUSA SERIES
The Ichusa series consists of very deep, somewhat poorly drained soils that formed in clayey marine sediments. Permeability is very slow. They are on uplands of the Jackson Prairie. Near the type location, the average annual air temperature is about 63 degrees F. and the average annual precipitation is about 52 inches. Slopes range from 1 to 8 percent.
TAXONOMIC CLASS: Fine, smectitic, thermic Aquic Dystruderts
TYPICAL PEDON: Ichusa silty clay loam--forested. (Colors are for moist soil.)
A--0 to 4 inches; very dark grayish brown (10YR 3/2) silty clay loam; moderate fine granular structure; friable; sticky, slightly plastic; many fine and medium roots; few worm channels; very strongly acid; clear smooth boundary. (2 to 7 inches thick)
AB--4 to 11 inches; yellowish brown (10YR 5/4) silty clay loam; moderate medium subangular blocky and angular blocky structure; firm; sticky, plastic; many fine roots and few medium roots; many medium distinct dark grayish brown (10YR 4/2) and few medium distinct grayish brown (10YR 5/2) iron depletions; very strongly acid; clear wavy boundary. (0 to 12 inches thick)
Bt--11 to 31 inches; 40 percent light brownish gray (10YR 6/2), 30 percent yellowish brown (10YR 5/4), 20 percent red (2.5YR 5/8), and 10 percent yellowish red (5YR 5/6) clay; weak coarse prismatic structure parting to strong fine and medium angular blocky; firm; sticky, plastic; common fine roots; few cracks up to 0.5 cm wide; common faint clay films on faces of peds; common pressure faces; the areas of light brownish gray are iron depletions and the areas of red and yellowish red are iron accumulations; very strongly acid; clear wavy boundary. (10 to 30 inches thick)
Btss--31 to 40 inches; brownish yellow (10YR 6/8) clay; large wedge-shaped aggregates which part to strong fine and medium angular blocky structure; very firm, very sticky, very plastic; few fine roots; common large intersecting slickensides with distinct polished and grooved surfaces; grooves are 4 to 7 inches wide and 0.5 to 1.5 inches deep; many medium distinct light brownish gray (10YR 6/2) iron depletions; very strongly acid; clear wavy boundary. (5 to 20 inches thick)
Bkss1--40 to 53 inches; light olive brown (2.5Y 5/4) clay; large wedge-shaped aggregates which part to strong fine and medium angular blocky structure; very firm, very sticky, very plastic; few fine roots; common large intersecting slickensides with distinct polished and grooved surfaces; grooves are 4 to 7 inches wide and 0.5 to 1.5 inches deep; many fine distinct grayish brown (2.5Y 5/2) iron depletions; few fine concretions of calcium carbonate; slightly acid; clear wavy boundary.
Bkss2--53 to 80 inches; 30 percent yellowish brown (10YR 5/8), 25 percent light brownish gray (2.5Y 6/2), 25 percent grayish brown (10YR 5/2), and 20 percent brownish yellow (10YR 6/8) clay; large wedge-shaped aggregates which part to strong fine and medium angular blocky structure; very firm, very sticky, very plastic; few fine roots; common large intersecting slickensides with distinct polished and grooved surfaces; grooves are 4 to 7 inches wide and 0.5 to 1.5 inches deep; few fine concretions of calcium carbonate; many medium distinct dark gray (10YR 4/1) iron depletions on faces of slickensides; the areas of light brownish gray and grayish brown are iron depletions and the areas of yellowish brown and brownish yellow are iron accumulations; slightly alkaline. (Combined thickness of the Bkss horizon is 25 to 50 inches.)
TYPE LOCATION: Smith County, Mississippi; about 4.9 miles north of Pineville on State Highway 501, then right at Carr Church sign onto gravel road for about 1 mile to fork, then right on FS 520 gravel road for about 2 miles, then 60 feet north of road into woods; NE1/4NE1/4SW1/4 sec. 10, T.4 N, R.9 E; Clear Springs 7.5' quadrangle; longitude W 89 deg. 22' 59", latitude N 32 deg. 11' 56".
RANGE IN CHARACTERISTICS: The solum is more than 60 inches thick. Depth to alkaline clays ranges from 30 to 60 inches. The calcium-magnesium ratio is more than 1.0.
The A or Ap horizon has hue of 10YR or 2.5Y, value of 3 to 5, and chroma of 2 to 4. It is silty clay loam, clay, or silty clay. Reaction is very strongly acid or strongly acid.
The AB horizon, if it occurs, has hue of 10YR or 2.5Y, value of 4 or 5, and chroma of 2 to 6. Redox depletions in shades of gray and redox accumulations in shades of brown, yellow, and red are commmon or many. Texture is silty clay loam, silty clay, or clay. Reaction is very strongly acid or strongly acid.
The Bt or Btss horizon commonly has hue of 10YR or 2.5Y but includes hue of 7.5YR. Value ranges from 4 to 6, and chroma from 4 to 8. Redox depletions in shades of gray and redox accumulations in shades of brown, yellow, and red are common or many. Some pedons do not have a dominant matrix color and are multicolored in shades of brown, gray, red, yellow, and olive. Texture commonly is silty clay or clay, but thin subhorizons of silty clay loam occur in some pedons. Reaction is very strongly acid in the upper part, and ranges from very strongly acid to moderately acid in the lower part.
The Bkss horizon, present in most pedons, has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 3 to 6. Redox depletions in shades of gray and redox accumulations in shades of brown, yellow, and olive range from few to many. Some pedons do not have a dominant matrix color and are multicolored in shades of brown, olive, gray, and yellow. Texture is silty clay or clay. Soft masses and nodules or concretions of calcium carbonate range from few to many. Soft masses and/or concretions of iron and manganese oxides range from none to common. Reaction is commonly slightly acid to slightly alkaline, but ranges to moderately alkaline.
COMPETING SERIES: These are the
Louin series in the same family and the
Vaiden series in a closely related family. Louin soils do not have significant accumulations of secondary carbonates in the solum and have prominent gilgai. Vaiden soils are very-fine.
GEOGRAPHIC SETTING: Ichusa soils are on gently sloping to moderately sloping side slopes on uplands of the Jackson Prairie. They formed in thick beds of acid clays and the underlying alkaline clayey sediments. Slopes range from 1 to 8 percent. The average annual air temperature ranges from 60 to 65 degrees F., and the average annual precipitation ranges from 48 to 56 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing
Louin series, and the
Freest,
Leeper,
Maytag,
Oktibbeha, and
Urbo series. Louin soils are on broad, nearly level ridgetops with prominent gilgai. Freest soils are on higher ridgetops or on lower terraces and are fine-loamy. Leeper and Urbo soils are on adjacent flood plains. Maytag soils are on slightly higher positions than Ichusa soils and are alkaline to the surface. Oktibbeha soils are on similar positions as Ichusa soils and have hue of 5YR or redder in the upper part of the subsoil.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow to medium
runoff; very slow permeability. The water table is perched at a depth of 1.5 to 3.0 feet in late winter and early spring in most years.
USE AND VEGETATION: Principal uses are cropland, pasture, hayland, and woodland. Commonly grown crops are cotton, soybeans, grain sorghum, and corn. Common trees in wooded areas are loblolly pine, shortleaf pine, post oak, sweetgum, southern red oak, post oak, and hickory.
DISTRIBUTION AND EXTENT: Jackson Prairie of Alabama and Mississippi. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Auburn, Alabama
SERIES PROPOSED: Smith County, Mississippi; 1993.
REMARKS: These soils were formerly included within the Kipling and Louin series.
Diagnostic horizons and significant features recognized in this pedon are:
Ochric epipedon.......0 to 4 inches (A horizon)
Argillic horizon......11 to 40 inches (Bt and Btss horizons)
Slickensides..........31 to 80 inches (Btss and Bkss horizons)
MLRA(s): 135
National Cooperative Soil Survey
U.S.A.