LOCATION TIMPAS CO
Established Series
LAN
01/2014
TIMPAS SERIES
The Timpas series consists of deep, well drained soils that formed in alluvium. Timpas soils areon paleoterraces and strath terraces. The surface horizon formed in clayey alluvium from sediment-rich irrigation water. The subsoil and substratum formed in alluvium derived from mixed sedimentary materials over residuum weathered from limestone, chalk, and marl. Slopes range from 0 to 6 percent. The mean annual precipitation is about 305 millimeters (12 inches) and the mean annual temperature is about 11 degrees C (52 degrees F.).
TAXONOMIC CLASS: Fine-silty, mixed, superactive, mesic Aridic Calciustolls
TYPICAL PEDON: Timpas silty clay loam, on a northeast facing, linear, 2 percent slope in a cultivated field at an elevation of 1,283 meters (4,211 feet). (Colors are for dry soil unless otherwise noted.) When described on August 31, 2011 the soil was moist from 0 to 30 centimeters and slightly moist from 30 to 122 centimeters.
Ap1--0 to 15 centimeters (0 to 6 inches); brown (10YR 4/3) silty clay loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; moderately hard, firm, moderately sticky and moderately plastic; common fine roots; strongly effervescent; 6 percent calcium carbonate equivalent; slightly alkaline (pH 7.8); clear smooth boundary.
Ap2--15 to 30 centimeters (6 to 12 inches); dark grayish brown (10YR 4/2) silty clay loam, dark brown (10YR 3/3) moist; moderate medium subangular blocky structure; very hard, firm, moderately sticky and moderately plastic; common fine roots; strongly effervescent; 11 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); abrupt smooth boundary. (Combined thickness of the Ap horizons is 20 to 49 centimeters)
Bk--30 to 61 centimeters (12 to 24 inches); light yellowish brown (10YR 6/4) silty clay loam, yellowish brown (10YR 5/4) moist; moderate medium subangular blocky structure; moderately hard, friable, moderately sticky and moderately plastic; common fine roots; 2 percent medium, distinct, irregular carbonate masses in matrix; violently effervescent; 13 percent calcium carbonate equivalent; moderately alkaline (pH 8.4); clear smooth boundary. (25 to 46 centimeters thick)
Bky--61 to 84 centimeters (24 to 33 inches); very pale brown (10YR 8/3) silt loam, pale brown (10YR 6/3) moist; weak medium subangular blocky structure; few very fine roots; 20 percent medium distinct spherical carbonate masses in matrix; 3 percent fine distinct irregular gypsum masses in the matrix; violently effervescent; 35 percent calcium carbonate equivalent; moderately alkaline (pH 8.0); gradual wavy boundary.
BCky--84 to 122 centimeters (33 to 48 inches); very pale brown (10YR 7/3) loam, pale brown (10YR 6/3) moist; massive; 5 percent medium distinct irregular carbonate masses in matrix; 3 percent medium distinct irregular gypsum masses in matrix; violently effervescent; 30 percent calcium carbonate equivalent; moderately alkaline (pH 7.9). (Combined thickness of the Bky horizons is 70 to 86 centimeters)
Cr--122 to 200 centimeters (48 to 79 inches); weakly cemented Niobrara chalk, marl, shale and limestone; vertical fractures 10 to 40 centimeters apart.
TYPE LOCATION: Otero County, Colorado; approximately 3.5 miles south of Swink; 194 meters (638 feet) east and 213 meters (700 feet) south of the northwest corner of Sec. 13, T. 24 S., R. 56 W., Sixth Principle Meridian; Hawley, Colorado USGS topographic quadrangle; UTM zone 13 619826 E, 4202899 N; latitude 37 degrees, 57 minutes, 57 seconds N. and longitude 103 degrees, 38 minutes, 9.1 seconds W., NAD83.
RANGE IN CHARACTERISTICS:
Soil moisture: moist in some part March through May and intermittently moist June through October. It is driest December through February.
Moisture regime: aridic bordering on ustic.
Mean annual soil temperature: 9 to 12 degrees C. (49 to 54 degrees F.)
Mean summer soil temperature: 20 to 24 degrees C (68 to 75 degrees F.)
Depth to paralithic contact: 100 to 150 centimeters (40 to 59 inches)
Depth to secondary calcium carbonate: 20 to 51 centimeters (8 to 20 inches)
Depth to calcic horizon: 33 to 66 centimeters (13 to 26 inches)
Thickness of calcic horizon: 51 to 71 centimeters (20 to 30 inches)
Ap horizons have increases of clay and organic matter content due to prolonged irrigation, cultivation, and fertilization. Phosphorous content is not high enough for an anthropic epipedon.
Particle size control section (weighted average):
Clay content: 25 to 35 percent
Silt content: 50 to 65 percent
Sand content: 5 to 25 percent, with less than 15 percent fine or coarse sand.
Rock fragments: 0 to 5 percent, fine gravel
Ap horizons:
Hue: 10YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 2 or 3
Texture: clay loam, silty clay loam
Clay content: 27 to 35 percent
Calcium carbonate equivalent: 1 to 15 percent
Reaction: slightly alkaline or moderately alkaline
Bw horizons: (where present)
Hue: 10YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: clay loam, silty clay loam
Clay content: 27 to 35 percent
Calcium carbonate equivalent: 1 to 10 percent
Sodium Adsorption Ratio: 0 to 3 percent
Reaction: slightly alkaline or moderately alkaline
Bk horizon:
Hue: 10YR or 7.5YR
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 3 or 4
Texture: silt loam, silty clay loam
Clay content: 20 to 35 percent
Calcium carbonate equivalent: 5 to 15 percent
Electrical conductivity: 0 to 1.5
Sodium Adsorption Ratio: 0.5 to 5 percent
Reaction: moderately alkaline or strongly alkaline
Bky horizons:
Hue: 10YR or 7.5YR
Value: 6 through 8 dry, 5 or 6 moist
Chroma: 3 through 6
Texture: silt loam, loam
Clay content: 18 to 27 percent
Rock fragment content: 0 to 5 percent
Calcium carbonate equivalent: 15 to 40 percent with at least one horizon with 15 percent or more above 100 centimeters (40 inches)
Electrical conductivity: 1.5 to 6 dS/m
Gypsum content: 1 to 3 percent
Exchangeable sodium percentage: typically 2 to 6 percent, but can range to 13 percent in some pedons.
Sodium Adsorption Ratio: 1 to 6
Reaction: slightly alkaline or moderately alkaline
COMPETING SERIES: These are the
Cuevoland,
Rocky Ford and
Sophia series.
Cuevoland soils: are very deep
Rocky Ford soils: are very deep
Sophia soils: are very deep
GEOGRAPHIC SETTING:
Parent material: clayey alluvium from sediment-rich irrigation water over silty mixed alluvium over residuum weathered from soft limestone and shale.
Landform: strath terraces and paleoterraces
Slopes: 0 to 6 percent
Elevation: 1,158 to 1,585 meters (3,800 to 5,000 feet)
Average annual air temperature: 10 to 12 degrees C (50 to 54 degrees F.)
Average annual precipitation: 254 to 356 millimeters (10 to 14 inches)
Precipitation pattern:
Peak period: May through August
Driest period: December through February
Frost free season: 130 to 170 days
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Minnequa,
Numa, and the
Rocky Ford soils.
Minnequa soils: have a paralithic contact at depths of 51 to 100 centimeters (20 to 40 inches) and are on strath terraces
Numa soils: have a fine-loamy control section and are on paleoterraces
Rocky Ford soils: are very deep and are on paleoterraces and terraces
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Drainage: well drained
Saturated hydraulic conductivity: moderately high or high
USE AND VEGETATION: Used as irrigated cropland. Principal irrigated crops are alfalfa, small grains, sorghum, corn, truck crops, and melons. Native vegetation is mainly blue grama, galleta, and western wheatgrass. Loamy plains (R069XY006CO) ecological site.
DISTRIBUTION AND EXTENT: Arkansas River Valley, Colorado, LRR G, MLRA 69 and 67B. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Denver, Colorado
SERIES PROPOSED: Otero County, Colorado 2013
REMARKS: Diagnostic horizons and features in this pedon are:
Series control section: 0 to 150 centimeters (0 to 59 inches)
Particle size control section: 25 to 100 centimeters (10 to 40 inches).
Mollic epipedon: 0 to 30 centimeters (0 to 12 inches). (Ap1 and Ap2 horizons)
Calcic horizon: 61 to 122 centimeters (24 to 48 inches). (Bky1 and Bky2 horizons)
Paralithic contact: at 122 centimeters (48 inches).
The assignment of the cation-exchange activity class is inferred from lab data from similar soils in the surrounding area.
LAN 3/2013 This soil was previously described as a limestone bedrock phase of the Rocky Ford series. This phase is outside the range of characteristics and series control section of the Rocky Ford series.
Taxonomic Version: Eleventh Edition, 2010.
National Cooperative Soil Survey
U.S.A.