LOCATION POUJADE OREstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Durinodic Xeric Natrargids
TYPICAL PEDON: Poujade very fine sandy loam--on a 2 percent slope at 1,256 meters elevation--rangeland. (Colors are for dry soil unless otherwise noted.)
A1--0 to 10 cm; light brownish gray (10YR 6/2) very fine sandy loam, very dark grayish brown (10YR 3/2) moist; moderate medium platy structure with a vesicular surface crust; moderate medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine interstitial pores; neutral (pH 7.0); clear smooth boundary. (5 to 10 cm thick)
2A2--10 to 15 cm; light brownish gray (10YR 6/2) loam, very dark grayish brown (10YR 3/2) moist; moderate very fine platy structure; soft, very friable, nonsticky and nonplastic; common fine roots; many very fine tubular pores; slightly alkaline (pH 7.8); clear smooth boundary. (5 to 10 cm thick)
2Btn1--15 to 23 cm; light brownish gray (10YR 6/2) silty clay loam, dark brown (10YR 3/3) moist; moderate very fine prismatic structure parting to strong fine angular blocky; very hard, friable, moderately sticky and moderately plastic; common fine and medium roots; few fine tubular pores; many prominent clay films in pores and on faces of peds; strongly effervescent with disseminated carbonates; SAR is 13; very strongly alkaline (pH 9.5); clear wavy boundary.
2Btn2--23 to 33 cm; light yellowish brown (10YR 6/4) silty clay loam, dark yellowish brown (10YR 4/4) moist; moderate fine subangular blocky structure; hard, friable, moderately sticky and slightly plastic; few fine roots; few very fine tubular pores; common distinct clay films in pores and on faces of peds; strongly effervescent with disseminated lime; SAR is 48; very strongly alkaline (pH 10.0); gradual wavy boundary. (Combined thickness of the 2Btn horizons is 13 to 30 cm)
3Bqn1--33 to 64 cm; light gray (10YR 7/2) loam, dark yellowish brown (10YR 4/4) moist; massive; hard, firm and brittle, slightly sticky and nonplastic; few very fine roots; strongly effervescent with disseminated lime; SAR is 95; very strongly alkaline (pH 10.0); gradual wavy boundary.
3Bqn2--64 to 102 cm; light gray (10YR 7/2) loam, brown (10YR 5/3) moist; massive; slightly hard, firm and brittle, nonsticky and nonplastic; few medium roots; strongly effervescent with disseminated lime; SAR is 167; very strongly alkaline (pH 10.0); clear smooth boundary. (Combined thickness of the 3Bqn horizons is 53 to 81 cm)
4Bn--102 to 117 cm; very pale brown (10YR 8/2) silty clay loam, brown (10YR 5/3) moist; massive; hard, friable, slightly sticky and slightly plastic; few medium roots; strongly effervescent with disseminated lime; very strongly alkaline (pH 10.0); gradual smooth boundary. (10 to 20 cm thick)
4C1--117 to 147 cm; very pale brown (10YR 8/2) loam, brown (10YR 5/3) moist; massive; hard, friable, slightly sticky and nonplastic; strongly effervescent with disseminated lime; strongly alkaline (pH 8.8); clear smooth boundary. (25 to 36 cm thick)
4C2--147 to 165 cm; light gray (10YR 7/2) fine sandy loam, grayish brown (10YR 5/2) moist; massive; slightly hard, very friable, nonsticky and nonplastic; strongly effervescent; strongly alkaline (pH 8.8).
TYPE LOCATION: Harney County, Oregon; about 2 miles north of Warm Springs Butte near Crane; approximately 300 feet north and 600 feet west of the southeast corner of section 23, T. 24 S., R. 33 E.; USGS Crane 7.5 minute topographic quadrangle; 43 degrees 27 minutes 54 seconds north latitude and 118 degrees 36 minutes 41 seconds west longitude, NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture - Usually moist in the moisture control section in winter and spring, dry in summer and fall; Aridic moisture regime that borders on xeric.
Mean annual soil temperature - 7 to 8 degrees F.
Depth to horizons with firm rupture resistance and brittle manner of failure - 25 to 50 cm.
Depth to bedrock - more than 152 cm.
Particle-size control section - Clay content: Averages 27 to 35 percent.
A horizon
Value: 5 through 7 dry, 3 or 4 moist.
Chroma: 2 or 3, dry or moist.
Reaction: Neutral through moderately alkaline.
2Btn horizons
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 3 or 4 moist.
Chroma: 3 or 4, dry or moist.
Texture: Silty clay loam or clay loam.
Clay content: 27 to 35 percent.
Rock fragments: 0 to 10 percent fine gravel.
Calcium carbonate equivalent: 1 to 5 percent.
Sodicity (SAR): 13 to 50.
3Bqn horizons
Hue: 10YR or 2.5Y.
Value: 6 or 7 dry, 4 or 5 moist.
Chroma: 2 through 4, dry or moist.
Texture: Loam or clay loam.
Clay content: 20 to 30 percent.
Sodicity (SAR): 50 to 170.
4Bn and 4C horizons
Hue: 10YR or 2.5Y.
Value: 6 through 8 dry, 4 or 5 moist.
Chroma: 2 through 4, dry or moist.
Texture: Stratified silty clay loam, loam and very fine sandy loam.
Clay content: 10 to 30 percent.
Calcium carbonate equivalent: 1 to 5 percent.
Sodicity (SAR): 30 to 170 decreasing with depth.
Reaction: Strongly alkaline or very strongly alkaline decreasing with depth.
COMPETING SERIES: There are currently no other series in this family.
GEOGRAPHIC SETTING: Poujade soils are on low lake terraces. These soils formed in lacustrine deposits derived from volcanic rocks with surficial eolian mantles of loess or sand. Slopes are 0 to 5 percent. Elevations range from 1,219 to 1,372 meters. The climate is semiarid and characterized by cold, moist winters and warm, dry summers. The mean annual precipitation is 200 to 300 mm, the mean annual temperature is 6 to 7 degrees C., and the frost-free period is 50 to 80 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ausmus, Crowcamp, Lawen, and Lolak soils. Ausmus soils are fine-silty and are on low lake terraces. Crowcamp soils are on depressions on low lake terraces and have mollic epipedons. Lawen soils are coarse-loamy and are on high lake terraces. Lolak soils are in drainageways and depressions on low old lake terraces and are poorly drained.
DRAINAGE AND PERMEABILITY: Moderately well drained; moderately slow permeability (moderately high saturated hydraulic conductivity). Endosaturation is present with an apparent seasonal high water table between 76 and 122 cm (moderately deep or deep free water occurrence classes) from March through May. Cumulative annual duration class is Transitory. The water table is not above 100 cm for over one month.
USE AND VEGETATION: Poujade soils are used for livestock grazing. Some areas are irrigated and used for hay and grain. Potential native vegetation is basin big sagebrush, black greasewood, and basin wildrye.
DISTRIBUTION AND EXTENT: South-central Oregon. These soils are moderately extensive. MLRA 23.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California.
SERIES ESTABLISHED: Harney County, Oregon, 1997.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to 15 cm (A1 and 2A2 horizons).
Natric horizon - The zone from 15 to 33 cm (2Btn1 and 2Btn2 horizons).
Duric feature - The zone from 33 to 102 cm (3Bqn1 and 3Bqn2 horizons).
Particle-size control section - The zone from 15 to 33 cm (2Btn1 and 2Btn2 horizons).
ADDITIONAL DATA: The typical pedon at the series type location has partial characterization by the Soil Survey Laboratory (SSL), Lincoln, NE, as user pedon ID 88OR025001 (pedon # 88P0706).