LOCATION MANZANST COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Aridic Haplustalfs
TYPICAL PEDON: Manzanst loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; dark grayish brown (10YR 4/2) clay loam, very dark grayish brown (10YR 3/2) moist; weak fine subangular blocky structure parting to moderate fine and medium granular; hard, firm, very sticky and very plastic; common very fine and fine roots; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.0); clear smooth boundary. (3 to 5 inches thick)
Bt--3 to 12 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate fine prismatic structure parting to moderate medium subangular blocks; extremely hard, extremely firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; many distinct clay films on faces of peds; slightly effervescent, carbonates are disseminated; moderately alkaline (pH 8.2); clear smooth boundary. (9 to 17 inches thick)
Btk--12 to 37 inches; grayish brown (10YR 5/2) clay, dark grayish brown (10YR 4/2) moist; moderate medium and coarse columnar structure parting to moderate medium angular blocks; extremely hard, extremely firm, very sticky and very plastic; few very fine and fine roots; few very fine tubular pores; common distinct clay films on faces of peds; EC is 1.8; slightly effervescent, few fine irregular filaments; moderately alkaline (pH 8.2); clear smooth boundary. (0 to 25 inches thick)
Bk1--37 to 52 inches; light brownish gray (10YR 6/2) clay, dark grayish brown (10YR 4/2) moist; weak coarse columnar structure parting to moderate medium and coarse subangular blocks; extremely hard, extremely firm, very sticky, very plastic; few very fine roots; few very fine tubular pores; few faint clay films on faces of peds; EC is 7.2; slightly effervescent, common fine and medium irregular soft masses and filaments; moderately alkaline (pH 8.2); clear smooth boundary. (5 to 15 inches thick)
Bk2--52 to 60 inches; light brownish gray (10YR 6/2) clay, dark grayish brown (10YR 4/2) moist; weak medium prismatic structure; extremely hard, extremely firm, very sticky and very plastic; few very fine roots; common very fine tubular pores; slightly effervescent, common fine and medium irregular soft masses and filaments; moderately alkaline (pH 8.2).
TYPE LOCATION: Kit Carson County, Colorado; approximately 2.5 miles south of Flagler; about 725 feet south and 175 feet west of the northeast corner of Sec. 23, T. 9 S., R. 51 W. U.S.G.S. quad Flagler Colo. Lat. 39 degrees, 15 minutes, 23 seconds N., and long. 103 degrees, 3 minutes, 42 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture: moist intermittently April through August; ustic moisture regime bordering on aridic.
Mean annual soil temperatures range from 49 to 54 degrees F.
Organic carbon ranges from 1 to 2 percent in the upper 4 inches.
Depth to the base of the argillic horizon ranges from 12 to 21 inches in the Bt horizon and 26 to 37 inches when a Btk is present.
A horizon:
Hue: 10YR or 2.5Y
Value: 4 to 6 dry, 3 to 5 moist
Chroma: 2 or 3
When the moist value and chroma is as dark as 3/3, the horizon is too thin to be mollic, and if mixed to 18 cm (7 inches) it is too light colored or contains too little organic carbon to qualify as a mollic epipedon.
Clay content: 25 to 40 percent
Reaction: neutral to moderately alkaline
Bt & Btk horizons:
Hue: 10YR or 2.5Y
Value: 4 to 7 dry, 4 or 5 moist
Chroma: 2 to 4
Texture: clay, silty clay, clay loam and silty clay loam
Clay content: 35 to 55 percent
Silt content: 20 to 50 percent
Sand content: 10 to 45 percent,with 8 to 25 percent fine sand and coarser in the Bt.
Calcium carbonate equivalent: 5 to 10 percent
Reaction: slightly alkaline or moderately alkaline.
Bk or C horizons:
Hue: 10YR or 2.5Y
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 4
Texture: clay, clay loam, and silty clay loam
Clay content: 30 to 45 percent
Silt content: 20 to 50 percent
Sand content: 10 to 45 percent
Calcium carbonate equivalent: 5 to 15 percent, but can range to 25 percent below a depth of 40 inches
Reaction: slightly alkaline to strongly alkaline.
COMPETING SERIES: These are the
Baca (CO),
Falfa (CO),
Hesper (MT),
Leiter (WY),
Norrest (SD), and
Ulmet (CO) series.
Baca soils: have accumulated calcium carbonate at depths of 8 to 20 inches.
Falfa soils: have hues 5YR or redder in the control section.
Hesper soils: have accumulated calcium carbonate at depths of 12 to 24 inches.
Leiter and Norrest soils: have a paralithic contact at depths of 20 to 40 inches.
Ulmet soils: have calcium carbonate accumulations at depths of 13 to 24 inches
GEOGRAPHIC SETTING:
Landform: plains, alluvial fans, terraces, drainageways, and valley sides.
Parent material: fine textured alluvium and loess.
Slopes: 0 to 8 percent.
Elevation: 4,400 to 6,500 feet
Mean annual precipitation: 13 to 17 inches with peak periods of precipitation in the spring and summer months.
Mean annual temperature: 45 to 53 degrees F.
The frost-free period: 135 to 155 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Baca,
Fort Collins,
Midway,
Razor,
Sampson,
Stoneham,
Weld, and
Wiley soils.
Baca Soils: do not have secondary carbonates in the surface and upper part of the argillic horizon.
Fort Collins soils: average less than 35 percent clay in the control section.
Midway soils: average less than 20 inches to paralithic contact.
Razor soils: have a paralithic contact at depths of 20 to 40 inches.
Sampson and Weld soils: have a mollic epipedon.
Wiley soils average less than 35 percent clay in the control section.
DRAINAGE AND PERMEABILITY: Well drained; runoff is low or medium; slow permeability.
USE AND VEGETATION: Manzanst soils are used primarily for rangeland. Native vegetation is mainly blue grama, western wheatgrass, switchgrass, big bluestem, bottlebrush squirreltail, fourwing saltbush, and green needlegrass.
DISTRIBUTION AND EXTENT: Eastern Colorado. LRR G, MLRA 67; This series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Kit Carson County, Colorado, 1997.
REMARKS: The name is coined from the Manzanola series. Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - 0 to 3 inches (A)
Argillic horizon - 3 to 37 inches (Bt and Btk)
Last updated by the state 7/99.
Modified by Lee Neve in January 2002 to make minor changes to the format.
Taxonomic Version: Second Edition, 1999.