LOCATION LOUIN MS+AREstablished Series
TAXONOMIC CLASS: Fine, smectitic, thermic Aquic Dystruderts
TYPICAL PEDON: Louin silty clay loam--forested in microknoll.
(Colors are for moist soil unless otherwise stated.)
A--0 to 2 inches; very dark grayish brown (10YR 3/2) silty clay loam; weak fine granular and subangular blocky structure; firm; sticky and plastic; many fine to coarse roots; very strongly acid; clear wavy boundary. (2 to 16 inches thick)
Bw1--2 to 7 inches; yellowish brown (10YR 5/6) silty clay; common medium distinct light brownish gray (10YR 6/2) and few medium faint strong brown (7.5YR 5/6) mottles; weak fine angular blocky structure; firm, sticky and plastic; common fine and medium roots; very strongly acid; clear wavy boundary.
Bw2--7 to 19 inches; mottled yellowish brown (10YR 5/6), light brownish gray (2.5Y 6/2) and strong brown (7.5YR 5/6) clay; weak fine angular blocky structure; very firm, very sticky, very plastic; common fine and medium roots; few pressure faces on peds; very strongly acid; gradual wavy boundary.
Bw3--19 to 29 inches; mottled light brownish gray (2.5Y 6/2), yellowish brown (10YR 5/6) and strong brown (7.5YR 5/6) clay; weak fine angular blocky structure; very firm, very sticky, very plastic; few fine and medium roots; many intersecting slickensides about one inch long; very strongly acid; gradual wavy boundary.
Bw4--29 to 43 inches; mottled light brownish gray (2.5Y 6/2), yellowish brown (10YR 5/6), and strong brown (7.5YR 5/6) clay; intersecting slickensides two to four inches in cross-section, that form wedge-shaped natural fragments; very firm, very sticky, very plastic; few fine and medium roots; very strongly acid; gradual wavy boundary.
Bw5--43 to 60 inches; mottled strong brown (7.5YR 5/6), light brownish gray (2.5Y 6/2), and yellowish brown (10YR 5/6) clay; intersecting slickensides, three to five inches in cross-section, that form wedge-shaped natural fragments; very firm, very sticky, very plastic; few fine roots; few medium pebbles of quartz; very strongly acid; gradual wavy boundary. (Combined thickness of the B horizon is 36 to 60 inches or more.)
C--60 to 90 inches; yellowish brown (10YR 5/6) clay; many medium distinct gray (10YR 5/1) mottles; intersecting slickensides, eight to ten inches in cross-section, that form wedge-shaped natural fragments; very firm, very sticky, very plastic; few fine roots; many medium black concretions; slightly acid.
TYPE LOCATION: Jasper County, Mississippi; 1.4 miles northeast of Montrose, Mississippi, on State Highway 15, 3.6 miles north, 1.0
mile west to railroad crossing, 0.1 mile northwest of railroad crossing, 100 feet southwest into forest; SE1/4SE1/4 sec. 11, T. 4 N., R. 10 E.
RANGE IN CHARACTERISTICS: Depth to the C horizon ranges from 38 to 60 inches or more. Depth to intersecting slickensides ranges from 14 to 38 inches. The soil is very strongly acid or strongly acid in the A and Bw horizons and ranges from medium acid to mildly alkaline in the C horizon. The 10- to 40-inch particle-size control section has from 40 to 60 percent clay. Surface configuration in undisturbed areas is a succession of microbasins and microknolls that is repeated at intervals of 7 to 18 feet. Microbasins are 4 to 10 inches lower than microknolls, range from 3 to 8 feet across, and occupy 35 to 45 percent of the pedon dimension.
In the microknolls--depth to the gray or mottled gray and brown upper part of the Bw horizon is 14 to 25 inches. The A horizon has hue of 10YR, value of 3 to 5, and chroma of 2 to 6. It is 2 to 6 inches thick. The upper part of the Bw horizon has hue of 10YR or 2.5Y, value of 4 to 6, and chroma of 4 to 6; mottles in shades of gray or brown are few to many. The lower part of the Bw horizon either is mottled in shades of gray and brown or has a gray matrix with mottles in shades of brown.
In the microbasins--depth to the gray or mottled gray and brown upper part of the Bw horizon is 6 to 16 inches thick. The A horizon has hue of 10YR, value of 3 to 6, and chroma of 1. It is 6 to 16 inches thick. The upper part of the Bw horizon has hue of 10YR or 2.5Y, value of 5 or 6, and chroma of 1 or 2; mottles, if present, are in shades of brown. The lower part of the Bw has the same color range as the Bw horizon in the microknolls.
The C horizon has hue of 10YR or 2.5Y, value of 5, and chroma of 4 to 6 with few to many mottles in shades of brown and gray, or it is mottled in shades of brown and gray. It is silty clay or clay.
COMPETING SERIES: These are the Naclina and Vamont series and the closely related Beaumont, Brooksville, Eutaw, Garner, Kipling, Morse, and Vaiden series. Naclina and Vamont soils have mean annual temperature of 65 degrees Fahrenheit or more. In addition, Naclina soils have carbonates in lower part of the solum, and the Vamont has a solum more than 70 inches thick. Beaumont and Garner soils are predominantly gray throughout. Brooksville soils have a color value of less than 3.5 to a depth greater than 12 inches in more than 50 percent of the pedon. Eutaw and Vaiden soils are very fine in the particle-size control section. Kipling soils have an argillic horizon and do not have intersecting slickensides within a depth of 40 inches. Morse soils do not have distinct or prominent mottles within a depth of 20 inches.
GEOGRAPHIC SETTING: Louin soils are on uplands and stream terraces of the Blackland Prairie Major Land Resource Area. These are nearly level soils with gilgai microrelief. Slopes range from 0 to 2 percent. The soils formed in thick beds of acid clays and the underlying medium acid to mildly alkaline clays. The climate is warm and humid. Near the type location, the mean annual temperature is 62 degrees to 64 degrees Fahrenheit and the mean annual precipitation is 52 inches.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Eutaw, Kipling, and Vaiden series and the Okolona and Sumter series. Poorly drained Eutaw soils are in similar positions as the Louin soils. Somewhat poorly drained Kipling and Vaiden soils are in similar positions as the Louin soils and more strongly sloping parts of the landscape. The well drained Okolona soils, which have color values less than 3.5 to a depth greater than 12 inches in more than 50 percent of the pedon and do not have distinct or prominent mottles within 20 inches of the surface, are in similar positions as the Louin soils and more sloping parts of the landscape. The well drained Sumter soils, which are calcareous throughout, mainly are on slopes above drainageways.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; very slow permeability. Water table ranges from near the surface to a depth of 2 feet late in winter and early in spring.
USE AND VEGETATION: Most of this soil is used for growing loblolly and shortleaf pines, pasture and hay.
DISTRIBUTION AND EXTENT: Mississippi and Arkansas. The series is
of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Auburn, Alabama
SERIES ESTABLISHED: Jasper County, Mississippi; 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - the zone from the surface to a depth of approximately 2 inches (A horizon).
Aquentic Chromuderts features - Gilgai; slickensides that intersect in the zone from approximately 19 to 43 inches (Bw3, Bw4, Bw5, horizons); matrix with chroma of 1.5 or more dominant in some subhorizon in the upper 20 inches in more than half of pedon (Bw1 horizon); prominent mottles within 20 inches of soil surface (Bw2 horizon); color value moist more than 3.5 in upper 12 inches in more than half of pedon (Bw1 horizon).