LOCATION KNEERIDGE CAEstablished Series
The Kneeridge series consists of very deep, moderately well and well drained soils that formed in colluvium and/or till derived from andesite and andesitic lahar. The Kneeridge soils are on footslopes and side slopes of glaciated valleys in the mountains. Slopes range from 2 to 15 percent. The mean annual precipitation is about 1194 millimeters and the mean annual air temperature is about 6 degrees C.
TAXONOMIC CLASS: Medial, mixed, frigid Humic Vitrixerands
TYPICAL PEDON: Kneeridge gravelly medial loamy coarse sand on a southeast facing (150 degree), 14 percent slope at an elevation of 1948 meters. When described on 08/05/2003 the soil was dry throughout. Colors are for dry soils unless otherwise noted.
Oi--0 to 4 cm; Slightly decomposed plant material consisting of pine and fir needles.
A1--4 to 20 cm; dark grayish brown (10YR 4/2) crushed, gravelly medial loamy coarse sand, very dark brown (10YR 2/2) crushed moist; 96 percent sand; 4 percent clay; weak fine granular structure; loose, friable, nonsticky and nonplastic; common fine and medium roots; many fine interstitial pores; 7 percent subrounded gravel 2 to 5 millimeters and 15 percent subrounded gravel 5 to 75 millimeters; slightly acid, pH 6.6; abrupt wavy boundary.
A2--20 to 40 cm; olive brown (2.5Y 4/3) crushed, gravelly medial coarse sandy loam, very dark grayish brown (10YR 3/2) crushed moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; few very fine and fine roots and common medium roots throughout; common fine interstitial pores; 10 percent subrounded gravel 2 to 5 millimeters and 10 percent subrounded gravel 5 to 75 millimeters; slightly alkaline, pH 7.4; gradual smooth boundary. (the combined thickness of the A horizons is 25 to 61 cm thick)
Bw--40 to 100 cm; light olive brown (2.5Y 5/3) crushed, gravelly medial coarse sandy loam, dark olive brown (2.5Y 3/3) crushed moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; few fine, many medium, and common coarse roots throughout; common medium tubular pores; 8 percent subrounded gravels 5 to 75 millimeter and 9 percent subrounded gravels 2 to 5 millimeters; neutral, pH 7.2; gradual smooth boundary. (38 to 76 cm inches thick)
C--100 to 200 cm; brown (10YR 5/3) crushed, gravelly sandy loam, dark brown (10YR 3/3) crushed moist; massive; soft, very friable, nonsticky and nonplastic; few fine and common medium and coarse roots throughout; 1 percent subrounded cobbles and 6 percent subrounded gravels 5 to 75 millimeter and 10 percent subrounded gravels 2 to 5 millimeter; slightly alkaline, pH 7.6;
TYPE LOCATION: Placer County, CA, North of the road before the bridge in Blackwood Canyon, 232.5 meters E and 83.2 meters N of the SW corner of Section 26, Township 15N, Range 16E, 39 degrees, 6 minutes, 44 seconds North latitude and 120 degrees, 11 minutes, 16 seconds West longitude, NAD83 - U.S.G.S Quad: Homewood, California.
RANGE IN CHARACTERISTICS:
Soil moisture: Usually dry 45 to 75 consecutive days in late summer and early fall, moist the rest of the year. The soils have a xeric moisture regime.
Water features:
Seasonal high water table: 100 to 200 cm in the form of lateral flow in the lower part of the profile during spring snow melt
Surface rock fragment content:
10 to 40 percent consisting of: 5 to 25 percent gravels, 2 to 10 percent cobbles, and 0 to 5 percent stones
Organic matter: 8 to 15 percent in the A horizons and dropping off to 0.5 to 1 percent in the C horizon
Reaction: slightly acid to slightly alkaline
Acid-oxalate extractable Al plus 1/2 Fe: 2 to 3 percent (by weight) to a depth of 36 centimeters below the bottom of any O horizon that is present.
Control section:
Rock fragments: 10 to 35 percent, with 10 to 30 percent gravel, 0 to 5 percent
cobbles and 0 to 5 percent stones.
Mineralogy: amorphic
A horizons:
Hue: 10YR, 2.5Y
Value: 3 through 5 dry; 2 or 3 moist
Chroma: 2 or 3 dry; 2 or 3 moist
Organic matter: 8 to 15 percent
Texture of the fine earth fraction: Loamy coarse sand, coarse sandy loam, sandy loam
Clay content: 3 to 13 percent
Rock fragments: 10 to 35 percent
Reaction: slightly acid to slightly alkaline
Bw horizons:
Hue: 10YR, 2.5Y
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4 dry; 3 or 4 moist
Organic matter: 2 to 8 percent
Texture of the fine earth fraction: Coarse sandy loam, sandy loam
Clay content: 3 to 15 percent
Rock fragments: 10 to 35 percent
Reaction: slightly acid to slightly alkaline
C horizon(s):
Hue: 10YR, 2.5Y
Value: 4 or 5 dry; 3 or 4 moist
Chroma: 3 or 4 dry; 3 or 4 moist
Organic matter: 0.5 to 1 percent
Texture of the fine earth fraction: Loamy coarse sand, coarse sandy loam, sandy loam
Clay content: 1 to 10 percent
Rock fragments: 10 to 35 percent
Reaction: pH slightly acid to slightly alkaline
COMPETING SERIES: These are the Paige soils. The Paige soils have dense till at 100 to 150 cm.
GEOGRAPHIC SETTING: The Kneeridge soils are on footslopes and side slopes of glaciated valleys in the mountains. Slopes range from 2 to 15 percent. These soils formed in colluvium and/or till derived from andesite. Elevation is 1895 to 2170 meters. The climate is subhumid with warm dry summers and cold wet winters. The mean annual precipitation is 790 to 1550 millimeters and the mean annual air temperature is 4.5 to 7.9 degrees C. The frost free season is 40 to 90 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Waca and Paige soils. The Waca soils are moderately deep to bedrock and the Paige soils are 100 to 150 cm to dense till.
DRAINAGE AND PERMEABILITY: Moderately well to well drained, rapid permeability, very low to low runoff. No flooding or ponding
USE AND VEGETATION: This soil is used for wildlife, recreation and urban development. Vegetation is mixed conifers.
DISTRIBUTION AND EXTENT: Kneeridge is of minor extent in California in MLRA 22A
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Placer County, (Tahoe Basin area), California and Nevada 2007. Source of name from the name of a local ridge.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle Size Control Section for this pedon: from the mineral soil surface to 100 cm below the starting point (the A1, A2 and Bw horizons)
Andic properties: 4 to 100 cm (the A1, A2 and Bw horizons)
Umbric Epipedon: 4 to 100 cm (the A1, A2 and Bw horizons)