LOCATION VONALF WYEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, mesic Aridic Haplustalfs
TYPICAL PEDON: Vonalf fine sandy loam -- on a north facing slope of 4 percent, utilized as rangeland. (Colors are for dry soil unless otherwise stated)
A--0 to 6 inches; yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 3/4) moist; weak fine and medium subangular blocky structure parting to weak fine granular; soft, very friable, nonsticky and nonplastic; many fine and very fine roots; slightly alkaline (pH 7.4); clear smooth boundary. (2 to 8 inches thick)
Bt1--6 to 16 inches; yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak medium prismatic structure parting to weak medium subangular blocky; soft, very friable, slightly sticky and nonplastic; many very fine and fine roots; common distinct discontinuous brown (10YR 4/3) clay bridges between sand grains; slightly alkaline (pH 7.8); clear smooth boundary.
Bt2--16 to 34 inches; yellowish brown (10YR 5/4) fine sandy loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common distinct discontinuous brown (10YR 4/3) clay bridges between sand grains; slightly alkaline (pH 7.8); clear smooth boundary. (Combined Bt horizons 10 to 28 inches thick)
Bk--34 to 60 inches; light yellowish brown (2.5Y 6/4) fine sandy loam, olive brown (2.5Y 4/4) moist; weak fine subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; strongly effervescent, few fine irregular light gray (10YR 7/2) carbonate threads and few fine rounded light gray (10YR 7/2) carbonate masses; moderately alkaline (pH 8.2).
TYPE LOCATION: Campbell County, Wyoming; about 200 feet east and 2,440 feet north of the southwest corner of section 7, T. 48 N., R. 73 W. USGS Four Bar J Ranch, WY topographic quadrangle; 44 degrees 09 minutes 06 seconds north latitude and 105 degrees 41 minutes 18 seconds west longitude.
RANGE IN CHARACTERISTICS: Depth to effervescent horizons is commonly 30 to 40 inches, but some pedons may be noneffervescent to 40 to 80 inches or more. The moisture control section is moist in some or all parts in March through June. The average annual soil temperature is 47 to 50 degrees F. Rock fragments range from 0 to 15 percent.
The A horizon has hue of 10YR, value 4 or 5 dry and 3 or 4 moist, and chroma of 2 to 4. It is fine sandy loam, sandy loam, very fine sandy loam, loamy fine sand or loamy sand. It is neutral or slightly alkaline. Some pedons have a Bw horizon.
The Bt horizon has hue of 10YR or 7.5YR, value of 4 to 6 dry and 3 to 5 moist, and chroma of 3 through 6. Texture is sandy loam or fine sandy loam with 10 to 18 percent clay. It is neutral or slightly alkaline. Some pedons have Btk horizon.
The Bk horizon has hue of 10YR or 2.5Y, value of 5 to 7 dry and 4 to 6 moist, and chroma of 2 to 4. Texture is commonly sandy loam or fine sandy loam and less commonly loamy sand or loamy fine sand. It has 1 to 5 percent calcium carbonate equivalent. It is slightly alkaline or moderately alkaline.
Some pedons have a C horizon with properties similar to the Bk horizon. However, it is neutral or slightly alkaline and has a calciium carbonate equivalent of 0 to 3 percent. It is loam or sandy clay loam below a depth of 40 inches in some pedons.
COMPETING SERIES: These are the
Fragua,
Fraguni,
Vona and
Xema series.
The Fragua and Fraguni soils are usually dry in
May and June. Vona soils are not dry July through September. Xema soils are moderately deep.
GEOGRAPHIC SETTING: Vonalf soils are on fan remnants, alluvial fans, eolian ridges and hills. They are on backslopes, footslopes and toeslopes of hills. They formed in alluvium or eolian deposits derived primarily from sandstone. Slopes are 0 to 20 percent. Elevations are 3,500 to 5,200 feet. The mean annual precipitation ranges from 15 to 17 inches, half of which falls as rain or snow from March through June. The mean annual air temperature ranges from 44 to 50 degrees F. The frost-free season is about 105 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Mittenbutte and Xema soils and the Arwite and Elwop soils. Arwite and Elwop soils are fine-loamy.
DRAINAGE AND PERMEABILITY: Well drained; slow runoff; moderately rapid permeability.
USE AND VEGETATION: These soils are utilized as rangeland, hayland and pasture, nonirrigated cropland, and wildlife habitat. The native vegetation is mainly needleandthread, prairie sandreed, little bluestem, and Indian ricegrass. Winter wheat, oats, barley, and alfalfa are the principle cultivated crops.
DISTRIBUTION AND EXTENT: Vonalf soils occur in the Powder River basin of north-central and northeastern Wyoming. The series is of limited extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Campbell County, Wyoming, Southern Part; 1995
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 6 inches (A horizon)
Argillic horizon - 6 to 34 inches (Bt1 and Bt2 horizons)
SIR- WY1375
LRR- G