LOCATION DELCOMB LA+NC TX

Established Series
Rev. HLC-WLC-CLN
01/2018

DELCOMB SERIES

The Delcomb series consists of very deep, very poorly drained soils that are rapidly permeable in the organic layers and moderately slowly permeable in the mineral layers. These soils formed in herbaceous plant remains over silty sediments. They are in brackish coastal marshes. Slopes is less than 1 percent.

TAXONOMIC CLASS: Loamy, mixed, euic, hyperthermic Terric Haplosaprists

TYPICAL PEDON: Delcomb mucky peat, brackish marsh--wildlife habitat.
(Colors are for moist soil unless otherwise stated.)

Oi--0 to 3 inches; dense mat of live herbaceous roots; neutral. (0 to 6 inches thick)

Oe--3 to 12 inches; very dark grayish brown (10YR 3/2) muck, dark gray (10YR 4/1) pressed and rubbed; about 85 percent fiber; about 15 percent rubbed; massive; non-sticky; many medium and fine live roots; dominantly herbaceous fiber; mineral content about 30 percent; slightly acid; gradual smooth boundary. (0 to 10 inches thick)

Oa1--12 to 33 inches; very dark brown (10YR 2/2) muck, black (10YR 2/1) pressed and rubbed; about 50 percent fiber, about 8 percent rubbed; massive; flows easily between fingers when squeezed and leaves hand empty; non-sticky; common fine live roots; about 35 percent mineral content; neutral; gradual smooth boundary. (8 to 25 inches thick)

Oa2--33 to 39 inches; dark grayish brown (10YR 4/2) muck, black (10YR 2/1) pressed and rubbed; about 65 percent fiber, about 6 percent rubbed; massive; flows easily between fingers when squeezed and leaves small residue in hand; common fine roots; dominantly herbaceous fiber; about 40 percent mineral content; neutral; abrupt smooth boundary. (6 to 15 inches thick)

A1g--39 to 46 inches; black (5Y 2/1) mucky silty clay loam; massive; flows easily between fingers when squeezed and leaves small residue in hand; sticky; common fine roots; slightly alkaline; gradual smooth boundary. (4 to 8 inches thick)

A2g--46 to 52 inches; very dark gray (5Y 3/1) silty clay loam; weak coarse prismatic structure; will not flow between fingers when squeezed; firm; plastic and sticky; few fine roots; few fine distinct yellowish brown iron concentrations; slightly alkaline; gradual smooth boundary. (4 to 10 inches thick)

C1g--52 to 82 inches; greenish gray (5GY 6/1) silty clay loam; weak coarse prismatic structure; will not flow between fingers when squeezed; firm; plastic and sticky; common medium distinct dark gray (5Y 4/1) concentrations; slightly alkaline. (10 to 30 inches thick)

C2g--82 to 148 inches; greenish gray (5GY 6/1) silty clay loam; massive; firm; plastic and sticky; many medium distinct olive (5Y 4/4) concentrations; olive concentrations increase with depth and become dominant color at 120 inches; moderately alkaline.

TYPE LOCATION: Iberia Parish, Louisiana; 3 miles southeast of Delcambre; 134 yards east of canal; SW1/4SW1/4 sec. 11, T. 13 S., R. 5 E.

RANGE IN CHARACTERISTICS: Thickness of the control section is 51 inches and depth to loamy material ranges from 18 to 50 inches. Sodium content of the mineral horizon ranges from 8 to 25 percent or more.

The O horizons have color with hue of 7.5YR, 10YR or 2.5Y, or neutral, value of 2 to 4, and chroma of 0 to 2. The organic materials are dominantly sapric material that are derived mainly from herbaceous fiber. Most pedons have layers, particularly surface layers, that are hemic or fibric materials but their accumulative thickness is less than one half the total thickness of the organic material. Though the upper 32 inches is dominantly organic materials, some pedons have loamy or clayey mineral layers in this section with an accumulative thickness of up to 15 inches. The organic materials are moderately acid to slightly alkaline but become extremely acid (pH 4.0) or very strongly acid if drained.

The A horizon has color with hue 10YR to 5Y, or neutral, value of 2 or 3, and chroma of 0 or 1. Texture is mucky silt loam, mucky silty clay loam, silt loam, or silty clay loam. Reaction ranges from slightly acid to moderately alkaline but becomes very strongly acid if drained.

The C or B horizons, where present, have hue of 10YR to 5GY, value of 4 to 6, and chroma of 1. Texture is silt loam or silty clay loam. Reaction ranges from neutral to moderately alkaline. Some pedons have subhorizons with up to 10 percent calcium carbonate nodules.

COMPETING SERIES: There are no other series in the same family. Similar soils are the Allemands, Belhaven, Carlin, Kenner, Lafitte, Mattamuskeet, Maurepas, Pamlico, Ponzer, and Tomoka series. Allemands soils have clayey textures. Belhaven, Ponzer, and Tomoka soils are more acid throughout. Carlin, Kenner, Lafitte, and Maurepas soils have more than 50 inches of organic materials. Mattamuskeet and Pamlico soils have sandy textures.

GEOGRAPHIC SETTING: Delcomb soils are on low level brackish marshlands at elevations slightly above sea level. The water level is at or above the surface most of the time. These soils are subject to tidal action and are frequently flooded with slightly saline water. Slope gradients are less than 1 percent. The climate is humid subtropical. The average annual temperature near the type location is about 68 degrees F., and the average annual precipitation is about 60 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Kenner series and the Andry series. Andry soils are mineral soils.

DRAINAGE AND PERMEABILITY: Very poorly drained; surface runoff is negligible or is ponded; permeability is moderately rapid or rapid in organic layers and moderately slow in the mineral substratum.

USE AND VEGETATION: These brackish marsh soils are used for wetland wildlife habitat. The vegetation is water tolerant herbaceous plants and includes marshhay cordgrass, black needlerush, switchgrass, saltmarsh bulrush, olney bulrush, big cordgrass, and hairypod cowpea.

DISTRIBUTION AND EXTENT: Coastal marshes in Louisiana and possibly Mississippi, and Texas (MLRA 151).

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: AUBURN, ALABAMA

SERIES ESTABLISHED: Iberia Parish, Louisiana; 1973

REMARKS: The Delcomb series has been classified as a land type - Brackish marsh peat, moderately deep. These soils were formerly classified as Bog soils.
Diganostic horizons and features recognized in this pedon are:

Sapric soil materials-12 to 39 inches (Oa horizons).
Terric feature-mineral soil materials at 39 inches.

ADDITIONAL DATA: NSSL data (S69LA-23-6)(S69LA-23-7) from Iberia Parish, LA in SSIR 35, p156-159.

TAXONOMIC VERSION: Soil Taxonomy, Second Edition, 1999.

National Cooperative Soil Survey
U.S.A.