LOCATION FOMSENG            FM+PB
Established Series
RD:WEL
01/2006

FOMSENG SERIES


The Fomseng series consists of shallow, well drained soils on uplands. These soils formed in residuum derived from highly weathered basic igneous rock. Slope is 15 to 100 percent. The mean annual rainfall is about 206 inches, and the mean annual temperature is about 81 degrees F.

TAXONOMIC CLASS: Clayey, mixed, semiactive, isohyperthermic, shallow Typic Dystrudepts

TYPICAL PEDON: Fomseng gravelly silty clay loam - on a 35 percent convex slope in agricultural forest. When described (11/3/80) the soil was moist throughout. (Colors are for moist soil. All textures are apparent field textures.)

A11--0 to 2 inches; dark brown (10YR 3/3) gravelly silty clay loam; strong fine subangular blocky structure; friable, slightly sticky and slightly plastic; common very fine and fine roots; common fine and medium tubular and interstitial pores; about 20 percent pebbles; slightly acid (pH 6.5, 1:1 water); abrupt wavy boundary. (2 to 3 inches thick)

A12--2 to 5 inches; brown (10YR 4/3) silty clay loam; strong fine and medium subangular blocky structure; friable, slightly sticky and slightly plastic; common fine roots; common fine tubular pores; medium acid (pH 6.0, 1:1 water); clear wavy boundary. (2 to 3 inches thick)

B2--5 to 14 inches; dark yellowish brown (10YR 4/4) silty clay loam; moderate fine and medium subangular blocky structure; friable, slightly sticky and slightly plastic; few fine roots; common fine and medium tubular pores; strongly acid (pH 5.5, 1:1 water); gradual wavy boundary. (6 to 10 inches thick)

C1--14 to 18 inches; dark yellowish brown (10YR 4/6) silty clay loam; moderate medium and coarse angular blocky structure; friable, slightly sticky and slightly plastic; few fine roots; common fine tubular pores; strongly acid (pH 5.5, 1:1 water): abrupt wavy boundary. (0 to 5 inches thick)

C2r--18 to 59 inches; highly weathered basalt; can be dug with a spade; roots penetrate only along fracture planes.

TYPE LOCATION: Island of Kosrae, Federated States of Micronesia; about .6 mile up the Fomseng farm road on a cut bank; lat. 5 degrees 20 minutes 18 seconds N. and long. 163 degrees 0 minute 19 seconds E.

RANGE IN CHARACTERISTICS: The depth to the paralithic contact ranges from 10 to 20 inches.

The A horizon has moist color of 10YR 3/2, 3/3, or 4/3, or of 7.5YR 4/4. It is silty clay loam or clay loam and has 0 to 10 percent cobbles and 0 to 25 percent pebbles. The reaction in 1:1 water ranges from strongly acid to slightly acid.

The B horizon has moist color of 10YR 3/4, 4/4, or 4/6, or of 7.5YR 4/6. It is silty clay loam, clay loam, or silty clay and has 0 to 20 percent cobbles and 0 to 10 percent pebbles. The reaction in 1:1 water is strongly acid or medium acid.

The C horizon has moist color of 10YR 4/6 or 5/6, or of 7.5YR 5/6. It is silty clay loam or clay loam and has 0 to 30 percent saprolitic cobbles and 0 to 20 percent saprolitic pebbles.

COMPETING SERIES: These are the Aimeliik, Donen, Finol, and Tolonier series in other families. Aimeliik soils are very deep and have a CEC of less than 24 milligrams per 100 grams of clay. Dolen soils are deep. Finol soils are moderately deep to a paralithic contact. Tolonier soils are skeletal.

GEOGRAPHIC SETTING: Fomseng soils are on uplands. Slopes are 15 to 100 percent. These soils formed in residuum derived from highly weathered basic igneous rock. Elevation is 33 to 1,312 feet. The mean annual rainfall is 177 to 236 inches, and the mean annual temperature is 77 to 81 degrees F.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Dolokei, Oatuu, and the competing Dolen and Tolonier soils. Dolokei soils are moderately deep and Oatuu soils are very shallow. Also, both soils lack the high organic matter content of the Fomseng soils.

DRAINAGE AND PERMEABILITY: Well drained; medium or rapid runoff; moderately rapid permeability.

USE AND VEGETATION: Fomseng soils are used for subsistence agriculture, woodland, watershed, and wildlife habitat. The main crops are banana, tapioca, sugarcane and upland taro. The vegetation in areas not cultivated is mixed upland forest, ferns, and vines.

DISTRIBUTION AND EXTENT: Upland areas of the islands of Kosrae and Ponape, East Caroline Islands. The series is of small extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Kosrae, Federated States of Micronesia, 1981.


National Cooperative Soil Survey
U.S.A.