LOCATION MOLINARO CO NMEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, frigid Pachic Haplustolls
TYPICAL PEDON: Molinaro loam, on a south facing, convex, 5 percent slope in grass at an elevation of 7,100 feet. (Colors are for dry soil unless otherwise noted.) When described on September 9, 1981 the soil was moist from 0 to 41 inches.
A1--0 to 17 inches; very dark grayish brown (10YR 3/2) loam, very dark brown (10YR 2/2) moist; moderate fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine roots; neutral (pH 7.2); clear smooth boundary. (12 to 20 inches thick)
A2--17 to 31 inches; dark grayish brown (10YR 4/2) loam, very dark grayish brown (10YR 3/2) moist; weak medium subangular blocky structure; soft, friable, slightly sticky and slightly plastic; common very fine and fine roots; neutral (pH 7.2); clear smooth boundary. (10 to 20 inches thick)
Bw--31 to 41 inches; grayish brown (10YR 5/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak medium prismatic structure parting to moderate medium subangular blocks; hard, firm, slightly sticky and slightly plastic; few very fine roots; slightly effervescent; slightly alkaline (pH 7.4); gradual smooth boundary. (8 to 16 inches thick)
Bk--41 to 66 inches; grayish brown (10YR 5/2) loam, dark grayish brown (10YR 4/2) moist; massive; hard, firm, slightly sticky and slightly plastic; few very fine roots; slightly effervescent; few fine filaments of lime; slightly alkaline (pH 7.8).
TYPE LOCATION: Las Animas County, Colorado; about 2.0 miles northwest of Weston, Colorado; located about 100 feet east and 2,200 feet north of the southwest corner of sec. 23, T. 33 S., R. 67 W.; Weston USGS quad; lat. 37 degrees 9 minutes 21 seconds N. and long. 104 degrees 51 minutes 48 seconds W., NAD 1927
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is moist in some part from April through August, dry December through February; Ustic moisture regime.
Mean annual soil temperature: 43 to 45 degrees F
Mean annual summer soil temperature: 59 to 61 degrees F
Depth to secondary calcium carbonate: 30 to 56 inches.
Thickness of the mollic epipedon: 40 to 66 inches
Particle-size control section (weighted average):
Clay content: 20 to 30 percent
Sand content: 30 to 50 percent
Rock fragments: 0 to 5 percent, dominantly gravel
A horizons:
Hue: 7.5YR or 10YR
Value: 3 or 4 dry, 2 or 3 moist
Chroma: 1 to 3
Clay content: 18 to 27 percent
Rock fragments: 0 to 15 percent
Reaction: slightly acid to slightly alkaline
Bw horizon:
Hue: 7.5YR or 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: loam, clay loam
Clay content: 20 to 30 percent
Rock fragments: 0 to 15 percent
Calcium carbonate equivalent: 0 to 2 percent
Reaction: neutral or slightly alkaline
Bk horizon:
Hue: 7.5YR or 10YR
Value: 4 or 5 dry, 3 or 4 moist
Chroma: 2 to 4
Texture: loam, clay loam
Clay content: 18 to 30 percent
Rock fragments: 0 to 15 percent
Calcium carbonate equivalent: 1 to 5 percent
Reaction: slightly alkaline or moderately alkaline
COMPETING SERIES: These are the Arngard (ND),
Beman (CO),
Bowery (MT),
Falkirk (ND),
Garlips (CO),
Garza (WY),
Lonecone (CO),
Obrien (MT),
Roseglen (ND),
Shawa (CO),
Sheckle (UT), and
Yeoman (MT) series.
Arngard soils: have an mean annual temperature of 34 to 45 degrees F and have an aridic-ustic moisture regime with an mean annual precipitation of 12 to 18 inches.
Beman and Garza soils: have secondary carbonates above a depth of 15 inches.
Bowery, Shawa, and Sheckle soils: are greater than 40 inches to secondary carbonates.
Falkirk soils: have a lithologic discontinuity at depths of 16 to 40 inches.
Garlips soils: have a calcic horizon at depths of 18 to 35 inches and are dry in July.
Lonecone soils: have a paralithic contact at depths of 20 to 40 inches.
Obrien soils: have free carbonates above a depth of 30 inches and bulk density greater than 1.55
Roseglen soils: mollic epipedon 16 to 36 inches thick and secondary carbonates at depths of 15 to 30 inches.
Yeoman soils: average greater than 15 percent rock fragments in the control section.
GEOGRAPHIC SETTING:
Parent material: alluvium derived from noncalcareous sandstone and shale
Landform: terraces, fan remnants, and valley floors
Slopes: 2 to 15 percent
Elevation: 6,800 to 8,000 feet
Mean annual temperature: 45 to 47 degrees F
Mean annual precipitation: 17 to 22 inches
Precipitation pattern: continental
Wettest period: April through August
Driest period: December through February
Frost-free period: 70 to 100 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Allens Park, Bandarito, Gulnare, Rombo, Saruche, and Trujillo series. The Allens Park and Gulnare soils have a lithic contact above 60 inches and are on backslopes and summits of hills. The Bandarito soils average more than 35 percent clay in the control section and are on fans. The Rombo and Saruche soils have a paralithic contact above 40 inches and are on backslopes of hills. Trujillo soil soils have an argillic horizon and are on fans.
DRAINAGE AND PERMEABILITY: Well drained, medium runoff, moderate permeability, rarely flooded for brief periods during the months of June.
USE AND VEGETATION: Rangeland and wildlife habitat. The native vegetation is mainly western wheatgrass, green needlegrass, mountain muhly, blue grama and fringed sagebrush.
DISTRIBUTION AND EXTENT: Foothills of southeastern Colorado and northeastern New Mexico; LRR E, MLRA 49; moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana.
SERIES ESTABLISHED: Las Animas County, Colorado, 2007, Las Animas County Area soil survey area, Colorado. The name was taken from a canyon by Weston, Colorado.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Particle-size control section: The zone from 10 to 40 inches. (A1, A2, and part of the Bw horizons)
Mollic epipedon: The zone from 0 to 41 inches. (A1, A2, Bw horizons)
Other features:
secondary carbonates from 31 to 66 inches. (Bw and Bk horizons)
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
Taxonomic Version: Tenth Edition, 2006