LOCATION PITTPLACE CA

Established Series
Rev: ACF/JPS/ET
03/2017

PITTPLACE SERIES

The Pittplace series consists of very deep, well drained soils formed in colluvium and residuum derived from sandstone, mudstone, metasedimentary rocks and schist. Pittplace soils are on mountains and have slopes of 9 to 30 percent. The mean annual precipitation is about 2290 millimeters (90 inches) and the mean annual temperature is about 12 degrees C (54 degrees F).

TAXONOMIC CLASS: Fine, mixed, semiactive, isomesic Ustic Palehumults

TYPICAL PEDON: Pittplace clay loam - on a northeast-facing, slightly convex slope of 20 percent under tanoak, Douglas fir, Pacific madrone, Pacific rhododendron, California huckleberry, Oregon grape, and brackenfern at 623 meters (1900 feet) elevation. (Colors are for moist soil unless otherwise stated. When described October 12, 2004, the soil was moist throughout.)

A--0 to 17 centimeters (0 to 7 inches); dark brown (7.5YR 3/4) clay loam, brown (7.5YR 5/4) dry; weak and moderate fine subangular blocky structure; slightly hard, friable, slightly sticky and moderately plastic; common very fine, fine and medium roots; common very fine and fine irregular and common very fine, fine, medium and coarse tubular pores; 10 percent gravel; very strongly acid (pH 4.7); clear smooth boundary. (6 to 32 centimeters thick)

Bt1--17 to 36 centimeters (7 to 14 inches); strong brown (7.5YR 4/6) gravelly clay loam, strong brown (7.5YR 5/6) dry; moderate fine and medium subangular blocky structure; hard, very firm, moderately sticky and moderately plastic; common very fine, fine, medium roots; common very fine and fine irregular and common very fine, fine, medium and coarse tubular pores; few distinct clay films on faces of peds; 20 percent gravel and 10 percent paragravel; very strongly acid (pH 4.5); clear wavy boundary.

Bt2--36 to 60 centimeters (14 to 24 inches); strong brown (7.5YR 4/6) gravelly silty clay loam, strong brown (7.5YR 5/6) dry; moderate fine subangular blocky structure; slightly hard, friable, moderately sticky and moderately plastic, common very fine, fine, medium and coarse roots; common very fine and fine irregular and common very fine, fine, medium and coarse tubular pores; few distinct clay films on faces of peds and on rock fragments; 15 percent gravel and 10 percent paragravel; very strongly acid (pH 4.5); clear smooth boundary.

Bt3--60 to 78 centimeters (24 to 31 inches); strong brown (7.5YR 5/6) paragravelly silty clay loam, reddish yellow (7.5YR 7/6) dry; moderate medium subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common fine and medium roots; moderately few very fine and fine irregular and common fine and medium tubular pores; many distinct clay films on faces of peds and on rock fragments; 5 percent gravel and 20 percent paragravel; very strongly acid (pH 4.5); clear wavy boundary.

Bt4--78 to 109 centimeters (31 to 43 inches); yellowish red (5YR 5/6) paragravelly silty clay loam, reddish yellow (7.5YR 7/6) dry; moderate fine subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common fine and medium roots; common very fine and fine irregular and common fine and medium tubular pores; many distinct clay films on faces of peds and on rock fragments; 5 percent gravel and 25 percent paragravel; very strongly acid (pH 4.5); gradual smooth.

Bt5--109 to 143 centimeters (43 to 56 inches); yellowish red (5YR 5/6) gravelly clay loam, reddish yellow (7.5YR 7/6) dry; moderate fine and medium subangular blocky structure; hard, very firm, moderately sticky and very plastic; common fine and medium roots; common very fine and fine irregular and common fine and medium tubular pores; many distinct clay films on faces of peds and on rock fragments; 20 percent gravel and 20 percent paragravel; very strongly acid (pH 4.5); clear wavy.

Bt6--143 to 160 centimeters (56 to 63 inches); yellowish red (5YR 5/6) very gravelly clay loam, reddish yellow (7.5YR 7/6) dry; weak medium and coarse subangular blocky structure; hard, very firm, moderately sticky and very plastic; very few fine roots; moderately few very fine irregular and common very fine and fine tubular pores; many distinct clay films on faces of peds and on rock fragments; 35 percent gravel, 1 percent cobbles and 20 percent paragravel; very strongly acid (pH 4.5). (Combined thickness of Bt horizons is 100 to 225 centimeters).

TYPE LOCATION: Redwood National and State Parks, Del Norte County, California; located approximately 20 kilometers southeast of the town of Crescent City, cutbank on Wilbur Spur Road, Rock Creek Watershed; northwest quarter, northeast quarter, Section 26, T. 15 N., R. 1 E., WGS84 Decimal degrees 41.6712222 latitude and -124.0315556 longitude; HBLM; USGS Childs Hill Quadrangle, CA.; UTM Zone 10 414131mE 4613787mN; NAD83.

RANGE IN CHARACTERISTICS:

Soil moisture: The soil is continuously moist in all parts in the soil moisture control section in most years, but it becomes nearly dry in the upper part from about July 15 to October 15 in most years. The soils have an ustic moisture regime.

Soil temperature: The mean annual soil temperature is 10 to 13 degrees C (50 to 55 degrees F). The difference between mean summer and mean winter temperature is 2 to 4 degrees C.

Organic Matter: There is 12 to 20 kg per square meter of organic carbon to a depth of one meter.

Reaction is strongly or very strongly acid throughout. Base saturation is 5 to 35 percent between depths of 25 to 200 centimeters.

Particle-Size Control Section (weighted average):

Rock fragments: 0 to 25 percent gravel and 0 to 20 percent paragravel.
Clay content: 35 to 50 percent clay.

Some pedons have O horizons

O horizon

Hue: 10YR.
Value: 2 through 6 dry and moist.
Chroma: 1 through 4 dry and moist.

Texture: slightly decomposed organic material.
Wood fragments: 0 to 35 percent.
Reaction: moderately to very strongly acid.

A horizon

Hue: 7.5YR or 10YR.
Value: 5 through 7 dry, 3 through 5 moist.
Chroma: 3 through 6 dry and 6 moist.

Texture of fine earth: clay loam.
Rock fragments: 0 to 13 percent gravel.
Clay content: 27 to 35 percent.

Upper Bt horizon

Hue: 7.5YR, 10YR, or 2.5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 4 through 6 dry, 4 through 8 moist.

Texture of fine earth: clay loam, silty clay loam, silty clay or clay.
Rock fragments: 0 to 25 percent gravel.
Para rock fragments: 0 to 20 percent paragravel.
Clay content: 35 to 50 percent clay.

Lower Bt horizon

Hue: 7.5YR, 10YR, or 2.5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 4 through 6 dry, 4 through 8 moist.

Texture of fine earth: clay loam, silty clay loam, silty clay or clay.
Rock fragments: 5 to 35 percent gravel.
Para rock fragments: 0 to 25 percent paragravel.
Clay content: 35 to 50 percent clay.

COMPETING SERIES: At this time there are no other series in this family.

GEOGRAPHIC SETTING: Pittplace soils occur on broad ridges and upper, mountain slopes. Slopes are 9 to 30 percent. Elevations are 303 to 848 meters (990 to 2780 feet). The soils formed in colluvium and residuum derived from sandstone, mudstone, metasedimentary rocks and schist. The climate is humid with cool, foggy summers and cool, moist winters. Coastal influence limits the annual and diurnal range in temperature. Mean annual precipitation ranges from 2030 to 2550 millimeters (80 to 100 inches). Mean January temperature is about 9 degrees C; mean July temperature is about 14 degrees C; and the mean annual temperature is 10 to 13 degrees C (50 to 55 degrees F). Frost-free season is 240 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ahpah, Rockysaddle, Trailhead, and Wiregrass soils. Ahpah and Wiregrass soils are fine-loamy. Ahpah soils are 50 to 102 centimeters (20 to 40 inches) deep to a lithic contact and lack an argillic horizon. Rockysaddle soils are loamy-skeletal. Trailhead soils have parasesquic mineralogy and hues redder than 7.5YR throughout the argillic horizon. The Ahpah soils are on convex slopes and on narrow ridge crests above the Pittplace soils. The Wiregrass soils are on concave areas and on steeper slopes below the Pittplace soils. The Rockysaddle soils are on linear to convex areas on steeper slopes below the Pittplace soils. The Trailhead soils are on broad, gentler slopes above the Pittplace soils.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; high to very high runoff; moderately low saturated hydraulic conductivity.

USE AND VEGETATION: This soil has been used for commercial timber, recreation, wildlife, and watershed. Natural vegetation consists of Douglas-fir, tanoak, Pacific madrone, scattered redwood, rhododendron, evergreen huckleberry, and salal.

DISTRIBUTION AND EXTENT: California Coastal Redwood Belt; MLRA 4B. The series is not extensive.

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

SERIES ESTABLISHED: Humboldt Del Norte area, California 2007. Source of name is from the Pitt Place prairie, a prairie in the Bald Hills near the headwaters of Mettah Creek and Tectah Creek.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

1. Ochric epipedon - the zone from 0 to 17 centimeters (A horizon)
2. Argillic horizon - the zone from 17 to 160 centimeters (Bt1, Bt2, Bt3, Bt4, Bt5 & Bt6 horizons)
5. Palehumults feature - Clay does not decrease by as much as 20 percent of its maximum within 150 centimeters of the ground surface.
6. Particle-size control section - the zone from 17 to 67 centimeters, averages 36 percent clay, by weight, and 27 percent rock fragments, by volume.

ADDITIONAL DATA: NASIS User Pedon ID: 04CA605REDW140

Soil classified using the 12th Edition of the Keys to Soil Taxonomy.

National Cooperative Soil Survey
U.S.A.