LOCATION LAPORTE                 CO+MT NM WY

Established Series
Rev. DM-GB-KLS
05/2023

LAPORTE SERIES

The Laporte series consists of shallow, well drained soils that formed in slope alluvium or colluvium over residuum weathered from limestone. Laporte soils are on upland hills, cuestas and ridges. Slopes of 2 to 60 percent. The mean annual precipitation is about 405 mm and the mean annual air temperature is about 9 degrees C.

TAXONOMIC CLASS: Loamy, carbonatic, mesic Lithic Haplustolls

TYPICAL PEDON: Laporte loam, rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 23 cm; grayish brown (10YR 5/2) loam, very dark grayish brown (10YR 3/2) moist; moderate fine crumb structure; slightly hard, very friable; 5 percent limestone fragments; calcareous; moderately alkaline; clear smooth boundary. (13 to 41 cm thick)

C--23 to 41 cm; light brownish gray (10YR 6/2) channery loam, dark grayish brown (10YR 4/2) moist; massive; slightly hard, friable; some secondary calcium carbonate occurring mostly as nodules; 30 percent limestone fragments; calcareous; moderately alkaline; gradual smooth boundary. (10 to 38 cm thick)

R--41 cm; weakly fractured limestone.

TYPE LOCATION: Larimer County, Colorado; approximately 520 meters north and 100 meters west of SE corner sec. 1, T. 4 N., R. 70 W.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature - 9 degrees C
Mean summer soil temperature - 20 degrees C
Mollic epipedon thickness - 13 to 39 cm
Depth to lithic contact - 25 to 50 cm
Depth to calcium carbonate - These soils are calcareous at or within a few centimeters of the surface.

Particle-size control section:
Clay content - 15 to 35 percent
Sand content - 15 to 60 percent, with more than 15 percent but less than 35 percent being fine sand or coarser
Rock fragment content - 5 to 35 percent channers that are dominantly less than 150 mm in length

A horizon
Hue: 2.5Y through 7.5YR
Value: 4 or 5 dry, 2 or 3 moist
Chroma: 1.5 to 3 dry or moist
Reaction: pH 7.4 to 8.4

C horizon
Hue: 2.5Y through 7.5YR
Texture: loam, clay loam
Calcium carbonate equivalent: 10 to 35 percent, but is typically about 16 percent. A considerable proportion of the calcium carbonate equivalent is derived from fine limestone gravel and sand-sized fragments, resulting in equivalent readings of the whole soil (2 cm and smaller) of 40 to 50 percent.
Reaction: pH 7.9 to 9.0

COMPETING SERIES:
Lanola (CO) - have more precipitation in July and August than any other months

GEOGRAPHIC SETTING:
Landform - upland hills, cuestas and ridges
Elevation - 1,550 to 2300 meters
Slope - 2 to 60 percent
Parent material - slope alluvium or colluvium over limestone residuum
Mean annual air temperature - 7 to 10 degrees C; 9 to 11 degrees C in central New Mexico
Mean annual precipitation - 360 to 460 mm; 305 to 380 cm in central New Mexico
Precipitation pattern - most precipitation falls during the spring and early summer, decreasing in July and August
Frost-free period - 110 to 150 days

GEOGRAPHICALLY ASSOCIATED SOILS: None listed.

DRAINAGE AND PERMEABILITY: Well drained; medium to rapid runoff; moderate permeability above the bedrock.

USE AND VEGETATION: Laporte soils are used mostly as rangeland; however, they are tilled locally. Principal native vegetation is blue grama, western wheatgrass, needle-and-thread grass, Russian-thistle, yucca, and cactus.

DISTRIBUTION AND EXTENT: The Laporte series is extensive in Colorado, Montana, New Mexico, and Wyoming; MLRAs 35, 36, 48A, 49, 70, and 70A.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Bozeman, Montana

SERIES ESTABLISHED: The Fort Collins Area, Colorado, 1927.

REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - 0 to 23 cm (A horizon)
Lithic contact - 41 cm to limestone bedrock (R horizon)
Particle-size control section - 25 to 41 cm (part of the C horizon)

Laporte soils have a mesic soil temperature regime and an aridic soil moisture regime bordering on ustic.

Converted to metric, formatting updated to current standards, and competing series section updated. 04/2020

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National Cooperative Soil Survey
U.S.A.