LOCATION MANZANST           CO
Established Series
REV. LLC/LAN
06/2006

MANZANST SERIES


The Manzanst series consists of very deep, well drained, slowly permeable soils on alluvial fans, plains, terraces, drainageways, and valley side slopes. They formed in fine textured alluvium and loess. Slopes range from 0 to 5 percent. Mean annual precipitation is 14 inches, and mean annual temperature is 50 degrees F.

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.


National Cooperative Soil Survey
U.S.A.