LOCATION VONA CO+KS MT OK TX WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aridic Haplustalfs
TYPICAL PEDON: Vona fine sandy loam, rangeland. (Colors are for dry soil unless otherwise noted)
A--0 to 13 centimeters (0 to 5 inches); light brownish gray (10YR 6/2) fine sandy loam, dark grayish brown (10YR 4/2) moist; moderate fine granular structure; soft, very friable; neutral (pH 7.0); clear smooth boundary. (10 to 20 centimeters (4 to 8 inches) thick)
AB--13 to 20 centimeters (5 to 8 inches); brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist; weak medium subangular blocky structure parting to moderate medium granular; slightly hard, very friable; neutral (pH 7.0); clear smooth boundary. (0 to 15 centimeters (0 to 6 inches) thick)
Bt--20 to 61 centimeters (8 to 24 inches); brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist; weak very coarse prismatic structure parting to moderate coarse subangular blocks; hard, friable; few distinct clay films on both horizontal and vertical faces of peds, and clay bridging between sand grains; neutral (pH 7.2); clear smooth boundary. (10 to 66 centimeters (4 to 26 inches) thick)
Bk1--61 to 76 centimeters (24 to 30 inches); pale brown (10YR 6/3) sandy loam, brown (10YR 5/3) moist; weak and moderate coarse subangular blocky structure; slightly hard, very friable; few faint clay films and a small amount of clay bridging between sand grains; few fine calcium carbonates occurring as concretions; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (8 to 23 centimeters (3 to 9 inches) thick)
Bk2--76 to 127 centimeters (30 to 50 inches); very pale brown (10YR 7/3) sandy loam, brown (10YR 5/3); moist; massive; slightly hard, very friable; few fine secondary calcium carbonate occurring as concretions, and in thin seams and streaks; violently effervescent; moderately alkaline (pH 8.2); gradual wavy boundary. (15 to 51 centimeters (6 to 20 inches) thick)
Bk3--127 to 152 centimeters (50 to 60 inches); pale brown (10YR 6/3) loamy sand, yellowish brown (10YR 5/4) moist; single grain; loose; few fine secondary calcium carbonate concretions but less than in the horizon above; strongly effervescent; moderately alkaline (pH 8.2).
TYPE LOCATION: Morgan County, Colorado; approximately 518 meters (1,700 feet) south and 305 meters (1,000 feet) east of the northwest corner of Sec. 22, T. 5 N., R. 59 W.
RANGE IN CHARACTERISTICS:
Soil moisture: moist intermittently April through September, and moist in some part for 45 consecutive days from July 15th to September
Moisture regime: ustic bordering on aridic
Mean annual soil temperature: 9 to 12 degrees C. (48 to 53 degrees F.)
Mean summer soil temperature: 19 to 23 degrees C. (67 to 74 degrees F.)
Depth to secondary calcium carbonate: 20 to 81 centimeters (8 to 32 inches)
Depth to the argillic horizon base: 25 to 102 centimeters (10 to 40 inches)
Weighted average organic carbon content in the upper 15 inches: exceeds .5 percent and decreases uniformly with depth
Rock fragment content: 0 to 15 percent
A horizon:
Hue: 10YR or 2.5Y
Value: 4 to 6, 3 to 5 moist
Chroma: 2 to 4
Texture: fine sandy loam, sandy loam, or loamy sand
Reaction: neutral or slightly alkaline (pH 6.8 to 7.8)
Bt horizon: (Btk in some pedons)
Hue: 7.5YR to 2.5Y
Value: 4 to 6, 4 or 5 moist
Chroma: 2 to 4
Reaction: neutral to moderately alkaline (pH 7.0 to 8.4)
Texture: sandy loam, but includes fine sandy loam
Clay content: 8 to 18 percent
Silt content: 5 to 35 percent
Sand content: 52 to 85 percent with more than 35 percent fine sand or coarser.
Bk horizons: (C horizon in some pedons)
Hue: 10YR or 2.5Y
Value: 5 to 7, 4 to 6 moist
Chroma: 2 to 4
Texture: sandy loam, fine sandy loam, loamy sand, or loam
Reaction: moderately alkaline or strongly alkaline (pH 8.0 to 8.6)
Calcium carbonate equivalent: 2 to 15 percent.
COMPETING SERIES: These are the
Atalaya,
Eva,
Fragua,
Fraguni,
Vonalf and
Xema series.
Atalaya soils have a lithic contact at 102 to 152 centimeters (40 to 60 inches)
Eva soils are moist for at least 90 cumulative days from April to September, have buried horizons below a depth of 183 centimeters (72 inches), and do not have Bk horizons below the argillic horizon.
Fragua and Fraguni soils are driest during
May and June, and have maximum precipitation from July to October.
Vonalf soils are dry July to September.
Xema soils have a paralithic contact at depths of 51 to 102 centimeters (20 to 40 inches).
GEOGRAPHIC SETTING:
Landscape: upland and hills
Landform: hills, ridges and plains frequently paralleling major river channels.
Slopes: range from 0 to 30 percent.
Parent material: eolian or partly wind reworked alluvial parent materials.
Elevation: 1219 to 1981 meters (4,000 to 6,500 feet)
Mean annual precipitation: 36 to 43 centimeters (14 to 17 inches), 25 centimeters (10 inches) of which falls during the months of April to September.
Mean annual temperature: 8 to 12 degrees C. (47 to 53 degrees F.)
Mean summer temperature: 19 to 23 degrees C. (66 to 74 degrees F.)
Frost free period: 125 to 165 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Ascalon,
Olnest,
Otero,
Terry,
Valent and
Valentine soils.
Ascalon soils have a mollic epipedon.
Olnest soils have a fine-loamy particle-size control section.
Otero soils do not have an argillic horizon.
Valent and Valentine soils have sandy control sections and do not have an argillic horizon.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY:
Drainage: well or somewhat excessively drained
Runoff: low
Saturated hydraulic conductivity: high
USE AND VEGETATION: These soils are used as dry and irrigated cropland, as well as native pastureland.
Native vegetation consists of short and tall grass associations consisting of big bluestem, sand bluestem, little bluestem, prairie sandreed, sideoats grama, blue grama, sagebrush, and yucca.
DISTRIBUTION AND EXTENT: Eastern Colorado, western Kansas, and southeastern Wyoming. LRR G, MLRA's 67 and 72; The series is extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Washington County (Akron Area), Colorado, 1942.
REMARKS: Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon: 0 to 20 centimeters (0 to 8 inches) (A and AB horizons)
Argillic horizon: 20 to 61 centimeters (8 to 24 inches)(Bt horizon)
Revision documents a change in class from Ustollic Haplargids to Aridic Haplustalfs
This series is characterized by sample S61-Colo-44-1-(1-6).
Series was last updated by the state in 3/94.
Modified by MLRA Office 10 on 1/12/2000 to add the ranges of textures in the A and C horizons; and to expand the hue and value of the Bt and C horizons to include 4.
Modified in January 2002 by Lee Neve to update the semitab format, add to competing series and update geographically associated soils.
Taxonomic Version: Second Edition, 1999.
Modified format by LRM in 1/2006 to include metric conversion and change permeability to saturated hydraulic conductivity.