LOCATION AGUILAR COEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Vertic Natrargids
TYPICAL PEDON: Aguilar very fine sandy loam, on a northeast facing, 1 percent slope in shrubs and grass at an elevation of 6,060 feet. (Colors are for dry soil unless otherwise noted.) When described on September 9, 1987 the soil was moist from 0 to 65 inches.
E--0 to 4 inches (0 to 10 cm); pale brown (10YR 6/3) fine sandy loam, dark grayish brown (10YR 4/2) moist; weak fine granular structure; slightly hard, very friable, nonsticky and nonplastic; many fine and medium roots; noneffervescent; moderately alkaline (pH 8.4); abrupt wavy boundary. (2 to 6 inches thick)
Btn1--4 to 10 inches (10 to 25 cm); brown (10YR 5/3) clay, brown (10YR 4/3) moist; moderate medium columnar structure parting to strong fine angular blocks; very hard, very firm, moderately sticky and moderately plastic; many very fine to medium roots; common continuous distinct clay films on faces of peds; few fine salt threads; noneffervescent, 23 percent sodium absorption ratio; strongly alkaline (pH 8.8); clear smooth boundary.
Btn2--10 to 14 inches (25 to 36 cm); brown (10YR 5/3), silty clay, brown (10YR 4/3) moist; moderate coarse columnar structure parting to strong medium subangular blocks; extremely hard, very firm, very sticky and very plastic; few very fine and fine roots; common continuous distinct clay films on faces of peds; common fine salt threads; slight effervescence, 21 percent sodium absorption ratio; strongly alkaline (pH 8.8); clear smooth boundary. (combined thickness of the Btn horizons is 8 to 14 inches)
Btny--14 to 23 inches (36 to 58 cm); brown (10YR 5/3) clay, brown (10YR 4/3) moist; moderate medium columnar structure parting to strong medium angular blocks; extremely hard, very firm, very sticky and very plastic; few very fine roots; common continuous distinct clay films on faces of peds; common medium salt and gypsum threads; strong effervescence, 21 percent sodium absorption ratio; strongly alkaline (pH 8.8); clear smooth boundary. (7 to 14 inches thick)
Btkny--23 to 29 inches (58 to 74 cm); brown (10YR 5/3) clay loam, brown (10YR 4/3) moist; strong medium subangular blocky structure; extremely hard, very firm, moderately sticky and moderately plastic; few patchy distinct clay films on faces of peds; common coarse carbonate threads and common coarse salt and gypsum masses; violent effervescence, 22 percent sodium absorption ratio; strongly alkaline (pH 8.6); clear smooth boundary. (2 to 10 inches thick)
Bkny--29 to 45 inches (74 to 114 cm); grayish brown (10YR 5/2) silty clay loam, brown (10YR 5/3) moist; 18 percent sand; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common medium salt and gypsum threads; common medium distinct carbonate threads; violent effervescence (3 percent calcium carbonate equivalent), 22 percent sodium absorption ratio; moderately alkaline (pH 8.4); gradual smooth boundary. (10 to 20 inches thick)
Bny--45 to 65 inches (114 to 165 cm); grayish brown (10YR 5/2) silty clay loam, brown (10YR 5/3) moist; weak medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common medium salt and gypsum threads; common medium carbonate threads; violent effervescence (2 percent calcium carbonate equivalent); 21 percent sodium absorption ratio; moderately alkaline (pH 8.2).
TYPE LOCATION: Las Animas County, Colorado; about 4.5 miles east of Aguilar; located about 400 feet east and 1400 feet south of the northwest corner of sec. 27, T. 30 S., R. 64 W.; The Hogback USGS quad; lat. 37 degrees 24 minutes 27 seconds N. and long. 104 degrees 33 minutes 20 seconds W., NAD 27
RANGE IN CHARACTERISTICS:
Soil moisture: The soil moisture control section is moist intermittently May through August; Aridic moisture regime bordering on ustic but is considered typic aridic due to natric properties.
Mean annual soil temperature: 48 to 54 degrees F. (8.9 to 12.2 degrees C)
Mean summer soil temperature: 68 to 74 degrees F. (20 to 23.2 degrees C)
Depth to secondary calcium carbonate: 2 to 10 inches (5 to 25 cm)
Depth to gypsum accumulations: 10 to 20 inches (25 to 51 cm)
Depth to natric horizon: 2 to 6 inches (5 to 15 cm)
Depth to salt accumulations: 2 to 6 inches (5 to 15 cm)
Thickness of the natric horizon: 22 to 44 inches (56 to 112 cm
Vertic features: linear extensibility is greater than 6.0 cm from 0 to 40 inches
Particle-size control section (weighted average):
Clay content: 40 to 50 percent
Sand content: 15 to 30 percent, dominantly very fine sand
Rock fragments: 0 to 5 percent gravel
E horizon: (A horizon is present in some pedons)
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 or 3
Texture: fine sandy loam, silty loam
Clay content: 10 to 25 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 0 to 1 percent
EC (mmhos/cm): 0 to 4
SAR: 0 to 8
Reaction: slightly alkaline or moderately alkaline
Btn horizon:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: clay, silty clay, silty clay loam
Clay content: 35 to 55 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 0 to 5 percent
EC (mmhos/cm): 8 to 16
Gypsum: 0 to 1 percent
SAR: 15 to 35
Reaction: moderately alkaline or strongly alkaline
Btny and Btkny horizons:
Hue: 7.5YR or 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: clay, silty clay, clay loam
Clay content: 35 to 55 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 1 to 5 percent
EC (mmhos/cm): 8 to 16
Gypsum: 1 to 5 percent
SAR: 15 to 35
Reaction: moderately alkaline or strongly alkaline
Bkny horizon:
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6
Texture: silty clay loam, clay loam, clay
Clay content: 27 to 45 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 1 to 4 percent
EC (mmhos/cm): 4 to 16
Gypsum: 1 to 5 percent
SAR: 15 to 35
Reaction: moderately alkaline or strongly alkaline
Bny horizon: (stratified horizons are present in some pedons)
Hue: 7.5YR or 10YR
Value: 5 to 7 dry, 4 to 6 moist
Chroma: 2 to 6
Texture: silty clay loam, clay loam, clay
Clay content: 27 to 45 percent
Rock fragments: 0 to 5 percent
Calcium carbonate equivalent: 1 to 5 percent
EC (mmhos/cm): 4 to 16
Gypsum: 1 to 5 percent
SAR: 5 to 25
Reaction: moderately alkaline or strongly alkaline
COMPETING SERIES: These are the
Churchill(NV),
Final(OR), and
Uzacol(CO) series.
Churchill soils: depth to the base of the natric hoizon is 14 inches or less.
Final soils: are somewhat poorly drained and are aridic bordering on xeric.
Uzacol soil: have a paralithic contact at depths of 40 to 60 inches.
GEOGRAPHIC SETTING:
Parent material: alluvium derived from sedimentary deposits
Landform: terrace, flood plain
Slopes: 0 to 5 percent
Elevation: 5,000 to 6,100 feet (1,524 to 1,875 m)
Mean annual temperature: 49 to 53 degrees F. (9.5 to 11.7 degrees C)
Mean annual precipitation: 12 to 15 inches (300 to 380 mm)
Precipitation pattern: continental with peak periods May through August and driest December through February
Frost-free period: 125 to 155 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Beckton, Haversid, and Manzanola series. The Beckton soils have a mollic epipedon and are on terraces and flood plains. The Haversid soils do not have a natric horizon and are on terraces. The Manzanola soils have argillic horizons and are on terraces and in drainageways.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: well drained, low saturated hydraulic conductivity, none to rarely flooded for brief periods during the months of June and July.
USE AND VEGETATION: Rangeland and wildlife habitat. Native vegetation is mainly alkali sacaton, western wheatgrass, greasewood, fourwing saltbush, and inland saltgrass.
DISTRIBUTION AND EXTENT: Southeastern Colorado; LRR G, MLRA 69; moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES ESTABLISHED: Las Animas County, Colorado, Las Animas County Area soil survey area, Colorado. The name is from a small town in the area.
REMARKS:
Diagnostic horizons and features recognized in this pedon are:
Series control section: The zone from 0 to 60 inches (0 to 74 cm).
Particle-size control section: The zone from 4 to 24 inches (10 to 61 cm). (Btn1, Btn2, Btny and part of the Btkny horizons)
Ochric epipedon: The zone from 0 to 4 inches (0 to 10 cm). (E horizon)
Natric horizon: The zone from 4 to 29 inches (10 to 74 cm). (Btn1, Btn2, Btny, Btkny horizons)
Vertic features: Linear extensibility exceeding 6.0 cm from 0 to 40 inches (0 to 100 cm). (E, Btn1, Btn2, Btny, Btkny, and part of the Bkny horizons)
Other features: Aridic moisture regime bordering on ustic but is considered typic aridic due to natric properties.
This soil was included in the Arvada series. Changes in the moisture control section (in the RIC) of the Arvada series excludes southeastern Colorado.
The assignment of the cation-exchange activity class is supported by lab sample(s) numbers S87CO-071-012.
10/2008 LAN WAW updated the format to include metric and updated horizon nomenclature during final correlation of Las Animas County soil survey.
Taxonomic Version: Second Edition, 1999
ADDITIONAL DATA: Hatch kit EC, SAR, gypsum, and calcium carbonate equivalent