LOCATION KAGMAN MP+GU PBEstablished Series
TAXONOMIC CLASS: Very-fine, mixed, isohyperthermic Kandiustalfic Eutrustox
TYPICAL PEDON: Kagman clay, on a 2 percent slope under a forest of Leucaena leucocephala and Albizia lebbeck. (Colors are for moist soil unless otherwise stated. Textures are apparent field textures.)
A1--0 to 1 inch; very dark grayish brown (10YR 3/2) clay, very dark grayish brown (10YR 3/2) dry; strong fine granular structure, mostly wormcasts; friable, sticky and plastic; common very fine roots and few fine roots; many very fine and common fine interstitial pores; mildly alkaline (pH 7.4); abrupt smooth boundary. (1 to 2 inches thick)
A2--1 to 6 inches; dark brown (10YR 3/3) clay, dark brown (10YR 3/3) dry; moderate very fine and fine subangular blocky structure; friable, very sticky and very plastic; common very fine roots and few fine roots; common very fine and fine interstitial and common very fine tubular pores; few thin clay films on faces of peds; about 5 percent .04 to .08 inch manganese concretions; mildly alkaline (pH 7.4); abrupt smooth boundary. (3 to 8 inches thick)
Bt1--6 to 17 inches; strong brown (7.5YR 5/6) clay, with dark brown (10YR 3/3) on vertical ped faces; moderate medium prismatic structure parting to moderate fine subangular blocky; friable, very sticky and very plastic; common very fine roots and few fine roots; common very fine and fine tubular pores, continuous moderately thick clay films on faces of peds and lining pores; about 5 percent .04 to .08 inch manganese concretions; mildly alkaline (pH 7.4); gradual wavy boundary. (6 to 20 inches thick)
Bt2--17 to 28 inches; strong brown (7.5YR 5/6) clay; moderate medium prismatic structure parting to moderate medium subangular blocky; friable, very sticky and very plastic; few very fine and medium roots; common very fine and fine tubular and common very fine interstitial pores; continuous moderately thick clay films on faces of peds and lining pores; about 5 percent .04 to .08 inch manganese concretion; mildly alkaline (pH 7.4); gradual wavy boundary. (6 to 20 inches thick)
Bt3--28 to 38 inches; strong brown (7.5YR 5/6) clay, with few medium distinct red (2.5YR 4/8) patches; moderate medium prismatic structure parting to moderate medium subangular blocky; friable, very sticky and very plastic; few very fine and fine exped roots, flattened; common very fine and fine tubular pores; continuous moderately thick clay films on faces of peds and lining pores; 5 to 10 percent manganese staining in patches as a very fine pattern and along pores; mildly alkaline (pH 7.4); diffuse wavy boundary. (8 to 24 inches thick)
Bt4--38 to 60 inches; strong brown (7.5YR 5/6) clay, with few medium distinct red (2.5YR 4/8) patches; moderate medium prismatic structure parting to moderate medium subangular blocky; friable, very sticky and very plastic; few very fine roots; common very fine and fine tubular pores; continuous moderately thick clay films on faces of peds and lining pores; manganese staining in patches as a very fine pattern and along pores; mildly alkaline (pH 7.4).
TYPE LOCATION: Saipan, Commonwealth of the Northern Mariana Islands; along road south of Susupe golf course, south (right) fork about 2,100 feet from highway intersection, 650 feet further to next fork, then 45 feet west of road; lat. 15 degrees 9 minutes 35 seconds N. and long. 145 degrees 43 minutes 0 seconds E.
RANGE IN CHARACTERISTICS:
Soil moisture - Not continuously moist in all parts of the moisture control section for 90 to 120 cumulative days, primarily between February and May. The moisture control section is usually moist from July through December.
Soil temperature - 77 degrees to 86 degrees F., with less than 4 degrees F. variation between summer and winter.
Depth to bedrock - Ranges from 60 to over 80 inches.
Percent clay - 60 to 90 percent in the argillic horizon.
Al horizon - Color: N 2/0, or of 10YR 2/2, 3/2, or 4/2.
Texture: Range from silty clay loam, clay loam, silty clay, and clay. Rock fragments: 0 to 10 percent, mostly as pebbles, with a few cobbles.
A2 horizon - Color: 10YR 3/1, 3/2, 3/3, or 4/3, or of 7.5YR 3/4. Rock fragments: 0 to 10 percent, mostly as pebbles, with a few cobbles.
Transitional horizon - AB, BA, A/B or B/A may be present in some pedons.
B horizon - Color: Dominantly 7.5YR 5/6, 5/8, or 4/6, or 10YR 5/6 or 5/8, but ranges to 7.5YR 4/4, of 10YR 6/8 or 4/4, or of 5YR 4/6 and on Guam, 2.5YR 4/6. Color mottles: 2.5YR 3/6, 4/6, 4/8, or 5/8, of 5YR 4/6 or 5/8.
Structure: Prismatic parting to subangular blocky.
Reaction: Neutral to strongly acid.
COMPETING SERIES: This is the Chacha series, which is somewhat poorly drained, has many manganese concretions and has a BC horizon with thin seams of low chroma colors.
GEOGRAPHIC SETTING: Level to rolling limestone plateaus. Slopes range from 0 to 15 percent. Elevation is 10 to 800 feet. These soils formed in residual and alluvial sediments derived mostly from argillaceous coralline limestone, possibly with some volcanic ash. Mean annual precipitation ranges from 80 to 100 inches, most of which falls between June and November. Mean annual temperature is 78 degrees F., with less than 4 degrees F. difference between summer and winter.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chinen, Guam, Pulantat, Saipan, Takpochao, and the competing Chacha soils. Chinen, Guam, Pulantat, and Takpochao soils are very shallow and shallow to limestone. Saipan soils have an argillic horizon with less than 60 percent clay.
DRAINAGE AND PERMEABILITY: Well drained; very slow or slow runoff; moderately slow permeability.
USE AND VEGETATION: Most areas are in forest dominated by Leucaena leucocephala. Large areas are grazed or are used for vegetable cropping. Some areas are urbanized.
DISTRIBUTION AND EXTENT: Kagman soils are on Guam and the Commonwealth of the Northern Mariana Islands. The series is not extensive, with about 2,000 acres mapped.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Saipan, Commonwealth of the Northern Mariana Islands, 1985.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - from the surface to 8 inches.
Argillic horizon from the top of the Btl horizon in cultivated pedons to the limestone contact. Pale Great Group, with little or no clay decrease throughout the argillic horizon.
ADDITIONAL DATA: The Kagman soil was characterized on Guam by the National Soil Survey Laboratory (sample S83-GU-066-013).