LOCATION KACHEMAK AK

Established Series
Rev. RBH-SR-DVP
8/95

KACHEMAK SERIES

The Kachemak series consists of moderately deep, well drained soils on dissected uplands. Kachemak soils formed in volcanic ash mixed with silt overlying moderately consolidated shale and sandstone. Slopes range from 0 to 45 percent. The mean annual temperature is about 36 degrees F., and the average annual precipitation is about 38 inches.

TAXONOMIC CLASS: Medial over loamy, mixed Typic Vitricryands

TYPICAL PEDON: Kachemak silt loam -- grassland (All colors are for moist soil)

Oi--3 inches to 0; mat of roots, leaves, and stems; much charcoal; thin lens of white sand grains at base of horizon; extremely acid; abrupt smooth boundary. (2 to 8 inches thick)

C1--0 to 1 inch; recent volcanic ash; dark brown (7.5YR 3/3) silt loam; weak very fine granular structure; very friable; common roots; extremely acid; abrupt smooth boundary. (0 to 2 inches thick)

C2--1 to 2 inches; recent volcanic ash; dark reddish brown (5YR 3/4) silt loam; weak fine granular structure; very friable; common roots; very strongly acid; abrupt smooth boundary. (0 to 2 inches thick)

Oab--2 to 2 1/2 inches; black (5YR 2/1) mat of burned grass and woody materials; thin lens of sandy material, probably volcanic ash; common roots; abrupt wavy bounday. (1 to 3 inches thick) Eb--2 1/2 to 5 inches; dark brown (7.5YR 3/2) silt loam; weak very fine granular structure; very friable, smeary; common roots; very strongly acid; abrupt wavy boundary. (1 to 3 inches thick)

Bwb1--5 to 7 inches; very dusky red (2.5YR 2/2) silt loam; weak very fine granular structure; very friable, smeary; common roots; very strongly acid; clear wavy boundary. (1 to 3 inches thick)

Bwb2--7 to 11 inches; dark reddish brown (5YR 3/3) silt loam; weak very fine granular structure; very friable, smeary; common roots; strongly acid; gradual boundary. (2 to 5 inches thick)

BCb--11 to 14 inches; dark reddish brown (5YR 3/3) silt loam; weak fine subangular blocky structure; very friable, smeary; patches of dark brown (7.5YR 4/4); common roots; strongly acid; gradual boundary. (2 to 6 inches thick).

C'1--14 to 17 inches; dark brown (10YR 4/3) silt loam; weak medium subangular blocky structure; very friable, smeary; fine pores; strongly acid; abrupt wavy boundary. (3 to 7 inches thick)

2C2--17 to 23 inches; olive gray (5Y 5/2) silt loam; moderate thin platy structure breaking to weak very fine angular blocks; friable; streaks of dark grayish brown (2.5Y 4/2); few pebbles; fine pores; strongly acid; gradual boundary. (3 to 12 inches thick)

2C3--23 to 39 inches; olive gray (5Y 5/2) silt loam; moderate thin platy structure; friable; common medium faint mottles of olive brown; fine pores; strongly acid; abupt smooth boundary. (6 to 20 inches thick)

Cr--39 inches; moderately consolidated shale.

TYPE LOCATION: Homer - Ninilchik Area, Alaska. SE 1/4, SE 1/4 of section 7, T.6 S., R. 13 W., Seward Meridian. About 1 1/2 miles northwest of Homer.

RANGE IN CHARACTERISTICS: Thickness of the eolian mantle over residual soil ranges from 14 to 30 inches. In places, gravelly glacial till occurs with 30 inches. Soft, unconsolidated sedimentary bedrock is within 40 inches. The exchange complex of the upper control section is dominated by amorphous materials over sand and gravel.

The O horizon ranges up to 8 inches in thickness and is commonly underlain by thin deposits of relatively recent volcanic ash.

The A horizon has hue of 7.5YR or 10YR, value of 2 or 3, and chroma from 1 to 4.

The Bw horizons have hue from 2.5YR to 10YR, value from 2 to 4, and chroma from 2 to 6. The 2C horizon is commonly sandy loam but includes silt loam and loam. Coarse fragments range from 0 to 15 percent.

COMPETING SERIES: These are the Edds, Tenas and Whitehorse series. These series are all medial throughout the control section.

GEOGRAPHIC SETTING: Kachemak soils are on undulating to hilly dissected uplands. The soils formed in eolian silt and ash overlying weathered sandstone and shale. The climate is maritime with cool summers and long moderately cold winters. The average annual precipitation is about 28inches. Mean anuual temperature ranges from 34 to 36 degrees F. Slopes range from 0 to 45 percent.

DRAINAGE AND PERMEABILITY: Well drained. Slow to medium runoff. Permeability is moderate.

USE AND VEGETATION: Used for vegetables, hay production, rangeland, wildlife habitat, recreation, and residential development. Native vegetation is dominantly bluejoint grass, fireweed, and associated grasses and forbs. Clumps of Sitka spruce and alder thickets are common.

DISTRIBUTION AND EXTENT: Western Kenai Peninsula, Alaska. The series is extensive.

MLRA OFFICE RESPONSIBLE: Anchorage, Alaska

SERIES ESTABLISHED: Bennett, H.H., "Report on a Reconnaissance of the Soils, Agriculture, and Other Resources of the Kenai Peninsula of Alaska", 1918. (Advance Sheets -- Field Operations of the Bureau of Soils, 1916)

REMARKS: Mapping concepts of the Kachemak series have included soils with incipient spodic horizons and/or the lack of a Cr horizon within 40 inches with variable substratum material below 40 inches. It is recommended that Kachmak series be inactivated and several new series defined (jpm, 1/87).

National Cooperative Soil Survey
U.S.A.

Contact: Mike Gracz Kenai Watershed Forum  PO Box 15301 Fritz Creek, AK  99603 907-235-2218

04 May 2007 10:20