LOCATION POVO ID
Established Series
Rev. BDG/EMM
07/2013
POVO SERIES
The Povo series consists of very deep, well drained soils on mountain side slopes and ridges. They formed in loess over colluvium and/or residuum from rhyolite and dacite of the Potato Hill Volcanics that is blanketed by a thick mantle of volcanic ash. Saturated hydraulic conductivity is moderately high. Slope ranges from 5 to 55 percent. The average annual temperature is about 5 degrees C. and the average annual precipitation is about 915 mm.
TAXONOMIC CLASS: Medial over loamy, amorphic over mixed, active, frigid Alfic Udivitrands
TYPICAL PEDON: Povo ashy silt loam, forested, on a west facing ridge summit with 11 percent slope at 1,091 meters elevation. (Colors are for moist soil unless otherwise noted.) When described on July 28, 2004 the soil was dry throughout.
Oi--0 to 1 cm; slightly decomposed plant material. (5 to 8 cm thick)
A--1 to 9 cm; very dark grayish brown (10YR 3/2) ashy silt loam, brown (10YR 4/3) dry,; weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine, and few medium and coarse roots; common very fine tubular pores; 1 percent subangular very strongly cemented dacite gravel; slightly acid (pH 6.2); abrupt wavy boundary. (5 to 18 cm thick)
Bw1--9 to 26 cm; dark yellowish brown (10YR 4/4) ashy silt loam, light yellowish brown (10YR 6/4) dry; weak fine and medium subangular blocky structure parting to weak very fine and fine granular structure; soft, very friable, nonsticky and nonplastic; common very fine and fine and common medium and coarse roots; common very fine and fine tubular pores; 1 percent subangular very strongly cemented dacite gravel; slightly acid (pH 6.5); clear wavy boundary. (combined thickness of Bw horizons is 30 to 53 cm)
Bw2--26 to 48 cm; dark yellowish brown (10YR 4/4) ashy silt loam, very pale brown (10YR 7/4) dry; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine, common medium and coarse, and few very coarse roots; common very fine and fine tubular pores; 1 percent subangular very strongly cemented dacite gravel; slightly acid (pH 6.3); abrupt wavy boundary.
2EBt--48 to 66 cm; yellowish brown (10YR 5/4) silt loam, very pale brown (10YR 7/4) dry; moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and very plastic; common very fine and fine roots between peds and common medium and coarse roots; common very fine and fine tubular and common very fine irregular pores; 5 percent faint clay films on surfaces along pores and 15 percent distinct skeletans on surfaces along pores; 8 percent subangular very strongly cemented dacite gravel; strongly acid (pH 5.3); clear wavy boundary. (0 to 18 cm thick)
2Bt1--66 to 99 cm; brown (7.5YR 5/4) silt loam, light brown (7.5YR 6/4) dry; weak medium and coarse prismatic structure parting to moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and very plastic; common very fine and fine roots between peds and few medium and coarse roots; common very fine tubular pores; 10 percent distinct clay films on all faces of peds, 15 percent distinct skeletans on all faces of peds, and 15 percent distinct clay films on surfaces along pores; 10 percent subangular very strongly cemented dacite gravel; strongly acid (pH 5.3); gradual wavy boundary.
2Bt2--99 to 119 cm; brown (7.5YR 4/4) silt loam, light yellowish brown (10YR 6/4) dry; weak medium and coarse prismatic structure parting to moderate fine and medium subangular blocky structure; hard, friable, moderately sticky and very plastic; common very fine and fine roots between peds and few medium roots; common very fine tubular pores; 10 percent distinct clay films on surfaces along pores, 20 percent distinct clay films on all faces of peds, and 20 percent distinct skeletans on all faces of peds; 2 percent manganese coatings on faces of peds; 10 percent subangular very strongly cemented dacite gravel; strongly acid (pH 5.2); clear wavy boundary. (Combined thickness of 2Bt horizons is 15 to 66 cm)
3Bt3--119 to 135 cm; yellowish brown (10YR 5/4) gravelly silty clay loam, very pale brown (10YR 7/4) dry; moderate very fine and fine subangular blocky structure; hard, friable, moderately sticky and very plastic; few very fine, fine and medium roots; common very fine tubular pores; 10 percent prominent clay films on surfaces along pores, 15 percent prominent skeletans on all faces of peds, and 20 percent prominent clay films on all faces of peds; 15 percent subangular very strongly cemented dacite gravel; strongly acid (pH 5.2); clear wavy boundary.
3Bt4--135 to 163 cm; yellowish brown (10YR 5/4) very gravelly silt loam, yellow (10YR 7/6) dry; weak very fine and fine subangular blocky structure; hard, friable, moderately sticky and very plastic; common very fine tubular pores; 10 percent prominent clay films on surfaces along pores, 15 percent prominent skeletans on all faces of peds, and 30 percent prominent clay films on all faces of peds; 45 percent subangular very strongly cemented dacite gravel; strongly acid (pH 5.2).
TYPE LOCATION: Latah County, Idaho; about 2 miles north and 0.5 miles east of Deary, Idaho; about 20 feet (71 meters) north and 100 feet (36 meters) west of the southeast corner of Sec. 2, T.40 N., R.2 W.; Latitude 46 degrees, 49 minutes, 50.5 seconds North; Longitude 116 degrees, 32 minutes, 27.5 seconds West (NAD83); UTM zone 11, Easting 535010 meters, Northing 5186449 meters, NAD83. USGS Deary Quadrangle
RANGE IN CHARACTERISTICS:
Soil moisture - usually moist year round, and not dry for 45 consecutive days between June and October. Udic moisture regime
Average annual soil temperature - 3.9 to 7.2 degrees C. Frigid temperature regime
Volcanic ash mantle - 36 to 58 cm thick
Estimated properties of the volcanic ash layer:
Volcanic glass content in the 0.02 to 2 mm fraction - 25 to 60 percent
Acid-oxalate extractable Al plus 1/2 Fe - 1.3 to 2.7 percent
Phosphate retention - 75 to 90 percent
15-bar water retention on air dried samples - 9 to 25 percent (weighted average is more than 12 percent)
Moist bulk density - 0.62 to 1.00 g/cc
A horizon(s):
Hue - 7.5YR or 10YR
Value - 4 to 6 dry, 2.5 to 4 moist
Chroma - 3 or 4 dry, 2 to 4 moist
Texture - ashy-silt loam
Clay content: 8 to 10 percent
Content of rock fragments: 0 to 2 percent gravel
Reaction: 5.2 to 6.2
Bw horizon(s):
Hue - 7.5YR or 10YR
Value - 5 to 7 dry, 3 to 5 moist
Chroma - 4 or 6, dry or moist
Texture - ashy-silt loam
Clay content: 8 to 10 percent
Content of rock fragments: 0 to 5 percent gravel
Reaction: 5.4 to 6.5
2EBt and 2BtE horizon(s):
Value - 4 or 5 moist
Texture (less than 2mm): silt loam
Clay content: 17 to 21 percent
Content of rock fragments: 0 to 10 percent gravel
Reaction: 5.2 to 6.1
2E, 2E/B and 2B/E horizon(s): (present in some pedons)
E part:
Value - 4 or 5 moist
Chroma - 2 to 4 dry, 3 or 4 moist
Texture (less than 2mm): silt loam
Clay content: 14 to 19 percent
B part:
Hue - 7.5YR or 10YR
Value - 5 or 6 dry
Chroma - 4 or 6 dry
Texture (less than 2mm): silt loam, silty clay loam
Clay content: 18 to 27 percent
Content of rock fragments: 0 to 10 percent gravel
Reaction: 5.3 to 6.1
2Bt horizon(s):
Hue - 7.5YR or 10YR
Value - 6 or 7 dry, 3 to 5 moist
Chroma - 3 or 4, dry or moist
Texture (less than 2mm): Silt loam
Clay content: 19 to 23 percent
Content of rock fragments: 0 to 20 percent gravel
Reaction: 5.2 to 6.2
3Bt horizon(s):
Value - 5 to 7 dry, 4 or 5 moist
Chroma - 3 to 6 dry
Texture (less than 2mm): silt loam, silty clay loam, loam
Clay content: 20 to 28 percent
Content of rock fragments: 10 to 45 percent gravel, 0 to 20 percent cobbles,
15 to 45 percent total rock fragment content
Reaction: 4.7 to 6.2
3C horizon(s): (present in some pedons)
Value - 5 dry, 4 or 5 moist
Chroma - 4 dry or moist
Texture (less than 2mm): loam
Clay content: 17 to 20 percent
Content of rock fragments: 0 to 15 percent gravel, 0 to 20 percent cobbles, 0
to 35 percent total rock fragment content
Content of pararock fragments: 0 to 45 percent paragravel
Reaction: 5.2 to 5.8
COMPETING SERIES:
Lado soils: do not contain fragments of rhyolite or dacite rocks in the 3Bt horizons.
Lostpete soils: do not have 3Bt horizons
Odonnell soils: do not have 3Bt horizons; have albic materials within 100 cm of the soil surface
Spacecreek soils: do not have 3Bt horizons; have redox concentrations (noncemented masses of iron) within 100cm of the soil surface.
GEOGRAPHIC SETTING: The Povo soils are on mountain sides and ridge summits. Slopes range from 5 to 55 percent. These soils formed in loess over rhyolite and dacite with a thick mantle of volcanic ash at elevations of 840 to 1,226 meters. The average annual temperature ranges from 5.0 to 8.0 degrees C, with an average annual precipitation of 840 to 990 mm. The frost free season is 85 to 120 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Threebear soils. Threebear soils are on hills and are moderately deep to a fragipan.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; medium to rapid runoff; moderately high saturated hydraulic conductivity.
USE AND VEGETATION: These soils are used for timber production, livestock grazing, wildlife habitat, watershed, and recreation. Potential natural vegetation is western red cedar, grand fir, western larch, western white pine, Douglas-fir, and ponderosa pine, with an understory of queencup beadlily, coolwort foamflower, pioneer violet, prince's pine, and fool's huckleberry.
DISTRIBUTION AND EXTENT: North-central Idaho. MLRA 43A. The series is not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Latah County, Idaho, 2013.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 9 cm (Oi and A horizons).
Cambic horizon - The zone from 9 to 48 cm (Bw1 and Bw2 horizons).
Argillic horizon - The zone from 99 to 163 cm (2Bt1, 2Bt2, 3Bt3 and 3Bt4 horizons).
Andic soil properties - The zone from 1 to 48 cm (A, Bw1 and Bw2 horizons).
Particle-size control section - The zone from 1 to 101 cm (A, Bw1, Bw2, 2Bt1 and part of the 2Bt2 horizons).
ADDITIONAL DATA: Laboratory data exists for this pedon:
Laboratory pedon number - 04N1100 and soil survey pedon ID number - S04ID-057-007
National Cooperative Soil Survey
U.S.A.