LOCATION MENDIAN WATentative Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Ultic Argixerolls
TYPICAL PEDON: Mendian very fine sandy loam - irrigated cropland, on a 1 percent northwest-facing slope at an elevation of 1,770 feet. (Colors are for dry soil unless otherwise stated.)
Ap--0 to 6 inches; dark grayish brown (10YR 4/2) very fine sandy loam, very dark brown (10YR 2/2) moist; weak fine medium and coarse granular structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular pores; strongly acid (pH 5.5); abrupt smooth boundary. (6 to 11 inches thick)
AB--6 to 13 inches; dark grayish brown (10YR 4/2) very fine sandy loam, very dark brown (10YR 2/2) moist; weak medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; many very fine roots; many very fine irregular and common very fine tubular pores; moderately acid (pH 5.8); clear wavy boundary. (5 to 10 inches thick)
Bt1--13 to 16 inches; brown (10YR 4/3) sandy clay loam, very dark grayish brown (10YR 3/2) moist; moderate medium and coarse prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine irregular and tubular pores; few coarse vertical tubular pores lined with dark grayish brown (10YR 4/2) surface material; many distinct pressure faces on peds, common faint clay bridging in pores, and few faint brown (7.5YR 4/4) clay films on ped faces and in pores; 10 percent very coarse cylindrical cicada casts; 5 percent gravel; neutral (pH 6.8); clear wavy boundary. (3 to 6 inches thick)
Bt2--16 to 22 inches; brown (10YR 4/3) sandy clay loam, dark brown (10YR 3/3) moist; moderate medium and coarse prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine tubular and common very fine irregular and few very coarse vertical tubular pores lined with dark grayish brown (10YR 4/2) surface material; many distinct pressure faces on peds, common faint clay bridging in pores and few faint brown (7.5YR 4/4) clay films on ped faces and in pores; 10 percent very coarse cylindrical cicada casts; 5 percent gravel; neutral (pH 6.8); clear wavy boundary. (4 to 14 inches thick)
2Btb1--22 to 38 inches; dark yellowish brown (10YR 4/4) sandy clay loam, dark brown (7.5YR 3/3) moist; moderate medium prismatic structure parting to moderate medium subangular blocky; slightly hard, friable, moderately sticky and moderately plastic; common very fine roots; many very fine tubular and common very fine irregular and few very coarse vertical tubular pores lined with dark grayish brown (10YR 4/2) surface material; many distinct pressure faces on peds and common distinct strong brown (7.5YR 4/6) clay films on ped faces and in pores; 10 percent very coarse cylindrical cicada casts; 10 percent gravel; neutral (pH 6.8); abrupt wavy boundary. (7 to 17 inches thick)
3Btb2--38 to 46 inches; dark yellowish brown (10YR 4/4) very gravelly sandy clay, dark brown (7.5YR 3/3) moist; moderate medium and coarse subangular structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; many distinct pressure faces on peds and common distinct strong brown (7.5YR 4/6) clay films on ped faces, on rock fragments and in pores; stone line at upper boundary; 45 percent gravel, 10 percent cobbles and 10 percent paragravel; neutral (pH 6.8); clear wavy boundary. (7 to 18 inches thick)
3Btb3--46 to 60 inches; dark yellowish brown (10YR 4/4) extremely gravelly sandy clay loam, dark brown (7.5YR 3/3) moist; moderate fine subangular blocky structure; hard, firm, moderately sticky and moderately plastic; few very fine roots; common very fine tubular pores; many distinct pressure faces on peds and common distinct strong brown (7.5YR 4/6) clay films on faces of peds, on rock fragments and in pores; 50 percent gravel, 15 percent cobbles and 10 percent paragravel; neutral (pH 6.8).
TYPE LOCATION: Kittitas County, Washington, about 1 mile northwest of Thorp, about 2,400 feet east and 2,500 feet north of the southwest corner of section 3, T. 18 N., R. 17 E.; USGS Thorp, Wash. topographic quadrangle; Latitude 47 degrees, 04 minutes, 46 seconds N, and Longitude 120 degrees, 41 minutes, 53 seconds W.
RANGE IN CHARACTERISTICS: The mean annual soil temperature at a depth of 20 inches is 47 to 52 degrees F. These soils are usually moist but are dry in all parts of the moisture control section for 90 to 100 consecutive days following summer solstice. Thickness of the mollic epipedon is 14 to 20 inches and includes part of the argillic horizon. Although dark colors extend below this depth, the organic matter content is below 1 percent. Base saturation is 50 to 72 percent throughout the upper 30 inches. The particle-size control section averages 22 to 33 percent clay in the fine earth fraction, 58 to 68 percent sand and 0 to 15 percent rock fragments. Organic matter is estimated to range from 2 to 3 percent in the Ap horizon. Depth to a very gravelly 3Btb horizon ranges from 25 to 60 inches.
The Ap horizon is strongly acid through slightly acid.
The AB horizon has value of 2 or 3 moist. It is fine sandy loam or very fine sandy loam. It is strongly acid through slightly acid.
The Bt horizon has value of 4 or 5 dry, and chroma of 2 through 4 dry or moist. It is sandy clay loam, fine sandy loam or very fine sandy loam. It is moderately acid through neutral.
The 2Btb and 3Btb horizons have value of 4 or 5 dry, 3 or 4 moist and chroma of 3 or 4 dry or moist. The upper part 3Btb horizon is very gravelly sandy clay or very gravelly sandy clay loam and the lower part is extremely gravelly sandy clay loam, extremely gravelly sandy clay or very gravelly sandy clay loam.
COMPETING SERIES: These are the Alterpoint (T), Annum, Brownlee, Chirpchatter, Dryfalls (T), Ebadlow, Felton, Fisherhill, Goldendale, Hellake, Lompico, Lorena, Meland, Meystre, Quiden, Rehfield, Robbscreek, Schumacher, Stacker, Stardust, Updegraff, and Van Horn series.
Alderpoint soils - no OSD available for competing.
Annum soils - 40 to 60 inches deep to paralithic contact (granodiorite)
Brownlee soils - 40 to more than 60 inches deep to paralithic contact (granite); dry for 60 to 90 consecutive days following the summer solstice; few to common lamellae in lower part of argillic horizon
Chirpchatter soils - dry for more than 100 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Dryfalls soils - 40 to more than 60 inches deep to lithic contact (basalt); dry for 60 to 75 consecutive days following the summer solstice; ash influence in the upper 7 to 14 inches
Ebadlow soils - depth to top of argillic horizon is 8 to 12 inches; lack 7.5 YR hue in lower part of the argillic horizon; silt loam textures with 1 percent pumice paragravel in upper 17 to 27 inches of the argillic horizon (Bt)
Felton soils -40 to 60 inches deep to paralithic contact (shale); MAST is 56 to 59 degrees F.
Fisherhill soils - MAST is 52 to 54 degrees F; silt loam, silty clay loam, or clay loam textures with less than 50 percent sand in the pscs of loess origin
Goldendale soils - 40 to more than 60 inches deep to bedrock; dry for 75 to 90 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Hellake soils - dry for 60 to 90 consecutive days following the summer solstice; depth to sandy loam or loamy sand substratum is 30 to 60 inches
Lompico soils - 20 to 40 inches deep to paralithic contact (sandstone); MAST is 56 to 58 degrees F.
Lorena soils - 20 to 40 inches deep to lithic contact (basalt); dry for 75 to 90 consecutive days following the summer solstice
Meland soils - 20 to 40 inches deep to lithic contact (basalt); dry for 45 to 70 consecutive days following the summer solstice
Meystre soils - dry for 60 to 75 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb); solum thickness ranges from 35 to 53 inches
Quiden soils - dry for 60 to 75 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Rehfield soils - 40 to more than 60 inches deep to lithic contact (basalt); argillic horizon is 15 to 30 inches thick; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Robbscreek soils - 20 to 40 inches deep to lithic contact (granodiorite); dry for 60 to 90 consecutive days following the summer solstice
Schumacher soils - dry for 45 to 60 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Stacker soils - 20 to 40 inches deep to lithic contact (basalt); lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Stardust soils - dry for 60 to 90 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
Updegraff soils - 40 to 60 inches deep to lithic contact (schist and graywacke); dry for more than 100 consecutive days following the summer solstice
Van Horn soils - dry for 60 to 80 consecutive days following the summer solstice; lack a skeletal discontinuity in the lower part of the argillic horizon (3Btb)
GEOGRAPHIC SETTING: Mendian soils are on terraces and have slopes of 0 to 2 percent. These soils formed in loess and outwash. Elevation is 1,650 to 1,860 feet. These soils are in a semiarid climate with warm dry summers and cool moist winter. The mean annual precipitation is 12 to 16 inches. The average January temperature is about 25 degrees F. and the average July temperature is about 69 degrees F. The mean annual temperature is 46 to 50 degrees F. The frost-free season is 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Ackna, Metser, Umtanum and Vanderbilt soils. Ackna soils are on terraces (Lakedale-Wisconsin Age) and alluvial fans, are loamy-skeletal and lack 7.5YR hues in the argillic horizon. Metser soils are on terraces and alluvial fans and have more than 40 percent clay in the particle-size control section. Umtanum soils are on terraces and alluvial fans and have more than 35 percent clay in the particle-size control section. Venderbilt soils are on terraces (Lakedale-Wisconsin Age) and alluvial fans, have mollic epipedons greater than 25 inches thick and lack 7.5YR moist hues in argillic horizon.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately slow permeability.
USE AND VEGETATION: These soils are used for irrigated cropland, livestock grazing and wildlife habitat. Native vegetation is bluebunch wheatgrass, Idaho fescue, Wyoming big sagebrush and bitterbrush.
DISTRIBUTION AND EXTENT: Kittitas County, Washington; MLRA 8, 44. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES PROPOSED: Kittitas County, Washington, 1999. The name is coined.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Mollic epipedon - 0 to 16 inches (Ap, AB and Bt1 horizons)
Agrillic horizon - 13 to 60 inches (Bt, 2Btb and 3Btb horizons)
PSCS - the zone from 13 to 36 inches (Bt and most of the 2Btb horizons)
Base saturation throughout the upper 30 inches is 50 to 72 percent.
Bt horizon is considered Lakedalel-Wisconsin Age. 2Btb is considered Indian John pre-Wisconsin Age.