LOCATION YANKEE NMEstablished Series
TAXONOMIC CLASS: Fine, smectitic, frigid Vertic Argiustolls
TYPICAL PEDON: Yankee silt loam - rangeland (colors are for dry soil unless otherwise noted)
Al--0 to 4 inches; dark grayish brown (10YR 4/2) silt loam, very dark grayish brown (10YR 3/2) moist; moderate fine granular structure; slightly hard, friable, slightly sticky, slightly plastic; many fine and very fine roots; neutral; abrupt smooth boundary. (3 to 7 inches thick)
A2--4 to 9 inches; dark grayish brown (10YR 4/2) silty clay loam, very dark grayish brown (10YR 3/2) moist; strong medium granular structure; hard, firm, slightly sticky, plastic; many fine and very fine roots; neutral; abrupt smooth boundary. (3 to 6 inches)
Bt1--9 to 14 inches; brown (10YR 4/3) clay, dark brown (10YR 3/3) moist; moderate coarse prismatic structure parting to moderate coarse angular blocks; very hard, very firm, slightly sticky, very plastic; few fine roots; common cracks; many prominent clay films on faces of peds; common cracks and pressure faces; less than 5 percent rounded basalt gravel; neutral; gradual smooth boundary. (9 to 15 inches)
Bt2-- 14 to 27 inches; brown (7.5YR 5/2) clay, dark brown (7.5YR 3/2) moist; weak coarse prismatic structure parting to moderate coarse subangular blocky; very hard, very firm, slightly sticky, very plastic; few fine roots; many prominent clay films on faces of peds; common cracks and pressure faces; less than 5 percent rounded basalt gravel; neutral; gradual smooth boundary (9 to 15 inches thick)
Btk--27 to 49 inches; brown (7.5YR 5/4) silty clay, dark brown (7.5YR 4/4) moist; weak coarse prismatic structure parting to weak coarse subangular blocks; very hard, very firm, slightly sticky, very plastic; few prominent clay films on faces of peds; common pressure faces; mildly alkaline; strongly effervescent; few, fine, rounded, soft masses of calcium carbonate; gradual smooth boundary. (18 to 24 inches think)
C-- 49 to 62 inches; brown (7.5YR 5/4) silty clay, dark brown (7.5YR 4/4) moist; many fine faint strong brown (7.5YR 5/6) mottles; massive; very hard, very firm, slightly sticky, very plastic; many pressure faces; strongly effervescent; mildly alkaline.
TYPE LOCATION: Colfax County, New Mexico; 340 feet west, 5 feet north at SE corner of sec. 22, T.31N., R.26E.
RANGE IN CHARACTERISTICS:
Soil moisture: The SMCS is usually moist, in some part, for more than 90 cumulative days from May through October. It is usually dry, in all parts, for less than 90 cumulative days during the same period. The period of maximum precipitation is July through October. The soil is driest during May and June. Typic ustic moisture regime.
Mollic epipedon - 20 to 60 inches thick.
Soil temperature - 44 to 46 degrees F.
A horizon - Value: 3 or 4 dry, 2 or 3 moist.
Chroma: 1 or 2 dry and moist.
Texture: loam, silt loam or silty clay loam.
Bt horizon - Hue: 5YR, 7.5YR or 10YR.
Value: 3 through 5 dry, 2 through 5 moist.
Chroma: 2 through 4 dry and moist.
Texture: clay and silty clay. This horizon has less than 5 percent rounded basalt gravel. In some pedons there is a Btk horizon.
C horizon - Hue of 5YR, 7.5YR or 10YR.
Value of 4 through 6 dry, 3 through 5 moist.
Chroma: 2 through 4 dry and moist.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Yankee soils are on nearly level to moderately sloping valley fill and fans on basalt capped mesas. Slopes range from 0 to 9 percent. Elevation ranges from 7,500 to 9,000 feet. The soils formed in fine textured material weathered from basalt and other volcanic debris with some influence from eolian materials. The climate is continental with mean annual temperature ranging from 40 to 45 degrees F. and a summer temperature of about 58 degrees F. Mean annual precipitation is about 15 to 20 inches. Frost-free period is 90 to 110 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Barela, Firo, Hillery, and Raton soils. Barela soils when dry lack cracks more than 1cm wide to a depth of 20 inches. Firo and Raon soils have lithic contacts at depths of less than 20 inches. Hillery soils have montmorillonitic mineralogy.
DRAINAGE AND PERMEABILITY: Well-drained; medium runoff; very slow or slow permeability.
USE AND VEGETATION: Native range, dry cropland, and wildlife. Principal plants are Arizona fescue, blue grama, and western wheatgrass. Small areas are cropped to hay and small grains and alternate fallow cropping.
DISTRIBUTION AND EXTENT: Northeastern New Mexico and southeastern Colorado. This soil is moderately extensive. MLRA 48A.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Bozeman, Montana
SERIES ESTABLISHED: Colfax County, New Mexico, 1974.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - The zone from the surface to 27 inches (A and Bt1 horizons)
Argillic horizon - The zone from 9 to 49 inches (Bt horizons)
Vertic feature - When dry, cracks form from the surface that are at least 1cm. wide at a depth of 20 inches and pressure faces in the 14 to 27 inch layer.