LOCATION PLATNER CO+WYEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Paleustolls
TYPICAL PEDON: Platner loam - grassland. (Colors are for dry soil unless otherwise noted.)
A--0 to 23 centimeters (0 to 9 inches); grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate very fine granular structure; soft, very friable; 5 percent pebbles; neutral; clear smooth boundary. (13 to 30 centimeters (5 to 12 inches) thick)
E--23 to 25 centimeters (9 to 10 inches); light brownish gray (10YR 6/2) very fine sandy loam, dark grayish brown (10YR 4/2) moist; weak thin platy structure parting to moderate very fine granular; soft, very friable; 5 percent pebbles; neutral; abrupt smooth boundary. (0 to 8 centimeters (0 to 3 inches) thick)
Bt--25 to 46 centimeters (10 to 18 inches); grayish brown (10YR 5/2) clay, very dark grayish brown (10YR 3/2) moist; strong fine prismatic structure parting to strong fine angular blocky; extremely hard, firm, sticky, plastic; common distinct clay films on faces of peds; 10 percent pebbles; slightly alkaline; clear smooth boundary. (13 to 38 centimeters (5 to 15 inches) thick)
Btk--46 to 64 centimeters (18 to 25 inches); light brownish gray (10YR 6/2) loam, grayish brown (10YR 5/2) moist; weak and moderate medium prismatic structure parting to weak and moderate medium subangular blocky; very hard, friable; few faint clay films on the vertical faces of peds; concretions of calcium carbonate; 5 percent pebbles; strongly effervescent; moderately alkaline; gradual smooth boundary. (13 to 25 centimeters (5 to 10 inches) thick)
Bk1--64 to 91 centimeters (25 to 36 inches); light gray (10YR 7/2) sandy loam, pale brown (10YR 6/3) moist; very weak coarse subangular blocky structure; slightly hard, very friable; 10 percent pebbles; calcium carbonate occurring as concretions, in seams and streaks, and in finely divided forms; strongly effervescent; moderately alkaline; gradual wavy boundary. (18 to 30 centimeters (7 to 12 inches) thick)
Bk2--91 to 152 centimeters (36 to 60 inches); very pale brown (10YR 7/3) sandy loam, pale brown (10YR 6/3) moist; massive; slightly hard, very friable; 10 percent pebbles; some accumulation of calcium carbonate but less than in the horizon above; strongly effervescent; moderately alkaline.
TYPE LOCATION: Washington County, Colorado; about 17.6 kilometers (11 miles) south of Akron, 30 meters (100 feet) north and 713 meters (2340 feet) west of the southeast corner of Sec. 32, T. 1 N., R. 52 W.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 9 to 12 degrees C. (48 to 54 degrees F.)
Soil temperature 51 centimeters (20 inches), 5 degrees C. (41 degrees) or greater: 195 to 240 days
The mollic epipedon: 18 to 51 centimeters (7 to 20 inches) thick
Depth to calcareous material: 23 to 76 centimeters (8 to 30 inches)
Solum: 38 to 102 centimeters (15 to 40 inches) thick
Organic carbon in the mollic epipedon: .8 to 2.5 percent
Base Saturation: 90 to 100 percent
Rock fragments: 0 to 35 percent by volume but typically 3 to 10 percent
A horizon:
Hue: 2.5Y or 10YR
Value: 4 or 5, 2 or 3 moist
Chroma: 2 or 3
Structure: granular or crumb structure but subangular blocky in some pedons
Soil Moisture status: soft or slightly hard
Reaction: neutral or slightly alkaline
E horizon is absent in some pedons.
Hue: 2.5Y or 10YR
Value: 4 to 6, 3 to 5 moist
Chroma: 2 or 3
Reaction: neutral or slightly alkaline
Bt horizon:
Hue: 2.5Y to 7.5YR
Value: 4 to 6, 3 to 5 moist
Chroma: 2 to 4
Texture: clay and clay loam
Clay content: 35 to 50 percent
Silt content: 5 to 40 percent
Sand content: 20 to 55 percent, with more than 15 percent fine sand or coarser.
Reaction: neutral or slightly alkaline
Bk or C horizon:
Hue: 2.5Y or 10YR
Value: 5 to 7, 4 to 6 moist
Chroma: 2 to 4
Texure: loam, sandy clay loam, clay loam, or sandy loam
Reaction: slightly alkaline to strongly alkaline
Calcium carbonate equivalent: 5 to 20 percent with areas having more than 15 percent calcium carbonate occurring discontinuously
Gravelly modifiers: common in some pedons
COMPETING SERIES: These are the
Dawes,
Fondis,
Iliff,
Jonpol,
Platmak, and
Platsher series.
Dawes soils have course sand in the 2C horizon
Fondis soils have less than 15 percent fine or coarser sand in the upper part of the control section and have solums more than 40 inches thick.
Iliff soils have a lithic contact at depths of 20 to 40 inches.
Jonpol soils have a paralithic contact at 20 to 40 inches.
Weld soils contain less than 15 percent fine or coarser sand in the solum and C horizons, and contain less coarse fragments.
Platmak soils have soil temperature of 41 degrees F. or warmer at 20 inches for less than 192 days.
Platsher soils have a calcic layer.
GEOGRAPHIC SETTING:
Parent material: pedisediments of Ogallala or similar age in mixed eolian material and alluvium
Landform: broad table lands and plains
Slope: 0 to 25 percent
Mean annual precipitation is 14 to 18 inches, 12 inches of which falls during April through September
Mean annual temperature: 8 to 11 degrees C. (47 to 52 degrees F.)
Mean summer temperature: 20 to 23 degrees C. (68 to 74 degrees F.)
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ascalon,
Satanta and
Weld soils.
Ascalon and Satanta soils have a fine-loamy control section.
Weld soils have less than 15 percent fine and coarser sand in the argillic horizon.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well drained
Runoff: low or moderately low
Saturated hydraulic conductivity: moderately low
USE AND VEGETATION: These soils are used as dry and irrigated cropland or as native pastureland.
Native vegetation is principally short grasses of which blue grama predominates.
DISTRIBUTION AND EXTENT: Eastern Colorado and southeastern Wyoming. The series is of large extent. MLRA 67
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Akron Area, Washington County, Colorado, 1941.
REMARKS: Diagnostic horizons and features include in this pedon
Mollic epipedon: 0 to 46 centimeters (0 to 18 inches)
Albic horizon: 23 to 25 centimeters (9 to 10 inches)
Argillic horizon: 18 to 64 centimeters (7 to 25 inches)
Last updated by the state 3/94
Modified format by LRM in 10/2005 to include metric conversion and change permeability to saturated hydraulic conductivity.