LOCATION TRUULI              AK

 Tentative Series

DVP

5/99                             DRAFT                                              DRAFT

TRUULI SERIES   

The Truuli series consists of very deep, poorly drained soils formed in a mantle of ash-influenced loess overlying loamy material. Truuli soils are on wet terraces, depressions, and discharge slopes.  Slopes range from 0 to 4 percent.  The mean annual precipitation is about 25 inches, and the mean annual temperature is about 35 degrees F.

TAXONOMIC CLASS: Medial over loamy, Histic Cryaquands.

TYPICAL PEDON: Truuli silt loam - on a west facing slope of 3 percent at 175 meter elevation under a mixed forest of Lutz spruce, birch, and water tolerant shrubs and forbs. (All colors are for moist soil)

    Oi—0 to 11 cm; mat of roots and peat; clear smooth boundary.  (2 to 14 cm thick)

    Oa—11 to 22 cm; mixture of muck and weathered volcanic ash; clear smooth boundary.  (6 to 15 cm thick)

     A—22 to 49 cm; very dark grayish brown  (10YR 3/2) silt loam; weak fine granular structure; very friable, nonsticky and nonplastic; many very fine and fine roots; smeary; extremely acid; abrupt wavy boundary.  (10 to 30 cm thick)

     2Bg—49 to 66 cm; olive brown (2.5Y 4/3) silt loam moderate fine granular structure; very friable; many fine roots; slightly smeary; 5 percent gravel; 20 percent 6 mm dark yellowish brown (10YR 4/6) high chroma concentrations, 5 percent 3 mm dark grayish brown (2.5Y 4/2) low chroma concentrations; extremely acid; clear wavy boundary.  (10 to 25 cm thick)

     2Cg1—66 to 110 cm; light olive brown (2.5Y 5/3) silt loam; weak fine granular structure; very friable, nonsticky and nonplastic; nonsmeary; 20 percent 6 mm dark yellowish brown (10YR 4/6) high chroma concentrations, 50 percent 10 mm grayish brown (10YR 5/2) low chroma concentrations; extremely acid; clear wavy boundary.  (31 to 48 cm thick)

    3Cg2—110 to 120 cm; light olive brown (2.5Y 5/3) gravelly sandy loam; weak fine granular structure; very friable, nonsticky and nonplastic; nonsmeary; 25 percent gravel; 20 percent 6 mm dark yellowish brown (10YR 4/6) high chroma concentrations, 50 percent 10 mm grayish brown (10YR 5/2) low chroma concentrations; extremely acid; clear wavy boundary. 

TYPE LOCATION: Western Kenai Peninsula, Alaska; about 7 miles southeast of Ninilchik, Alaska; 2500 feet west and 250 feet north of the southeast corner of sec. 32, T.2S., R.13W., USGS Seldovia D-5 NE quadrangle; UTM Zone 5 coordinates 581025 E, 6647038 N., NAD 27 Alaska.

RANGE IN CHARACTERISTICS: Depth to the 2Bg horizon ranges from 45 to 90 cm.  The silty solum ranges in thickness from 40 to 60 cm. The upper part of the control section formed in loess dominated by amorphous material.  Reaction throughout the profile is strongly acid to extremely acid .

The A horizon has hue of 10YR or 7.5YR, value moist from 2 or 3, and chroma moist of 2 or 3.  Texture is very fine sandy loam, silt loam, or mucky silt loam.

The 2Bg horizon has hue of 10YR or 2.5Y value moist of 3 or 4, and chroma moist of 3 or 4.  Texture is silt loam. High chroma concentrations are present. This horizon is not present in all profiles.

The 2Cg horizon has hue of 2.5Y to 10YR, value moist of 4 or 5, and chroma moist of 1 or 2.  Coarse fragment content ranges from 0 to 15 percent gravel and 0 to 5 percent cobble.  Texture is sandy loam or silt loam.  High chroma concentrations commonly exceed 30 percent.

The 3Cg horizon has hue of 2.5Y to 10YR, value moist of 4 or 5, and chroma moist of 1 or 2.  Coarse fragment content ranges 15 to 40 percent gravel and 0 to 15 percent cobble.  Texture is sandy loam, or loamy sand.

COMPETING SERIES: These are the Chunilna and Tuxedni series.  Chunilna soils have a surface organic mat less than 20 cm in thickness and have more than 35 percent coarse fragments in the lower part of the control section.  Tuxedni soils have a surface organic mat less than 20 cm in thickness and have redoximorphic features below 61 cm.

GEOGRAPHIC SETTING: The Truuli soils occur on wet terraces and depressions.  Slopes range from 0 to 4 percent.  The soils formed in loess, mixed with volcanic ash, over loamy alluvium over sandy materials.  Mean annual temperature ranges from 33 to 36 degrees F.  Mean annual precipitation ranges from 20 to 35 inches.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Cohoe and Redoubt soils. They are well drained, have spodic horizons, and occupy recharge positions of till plains and terraces.

DRAINAGE AND PERMEABILITY: Poorly drained, negligible to very low runoff, moderately rapid permeability.

USE AND VEGETATION:  Forestry, wildlife habitat, and recreation. Mixed forest of Lutz spruce and birch, with an understory of water tolerant shrubs and forbs.  

DISTRIBUTION AND EXTENT:  Southcentral Alaska; MRLA 17.  The series is of minor extent.

MLRA OFFICE RESPONSIBLE:  Anchorage, Alaska.

REMARKS:  Diagnostic features and horizons recognized in this profile include: Histic epipedon 0 to 22 cm. Andic soil properties between 11 and 49 cm; redoximorphic features within 50 cm of the surface.

SERIES PROPOSED:  Western Kenai Peninsula Area, Alaska, 1999.

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 10:35