LOCATION DERECHO                 NM

Established Series
Rev. JOC/JAW/KLS
07/2022

DERECHO SERIES

The Derecho series consists of deep, well drained soils that formed in material weathered from shale and sandstone. These soils are on canyon and mountain slopes of 15 to 60 percent. Mean annual precipitation ranges from 640 to 890 mm. Mean annual air temperature is about 4 degrees C.

TAXONOMIC CLASS: Clayey-skeletal, smectitic, frigid Udic Haplustalfs

TYPICAL PEDON: Derecho cobbly loam, forested. (Colors are for dry soil unless otherwise noted.)

Oe--0 to 3 cm; moderately decomposed forest litter.

A11--3 to 11 cm; grayish brown (10YR 5/2) cobbly loam, very dark grayish brown (10YR 3/2) moist; weak very fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine and few medium and coarse roots; many very fine pores; 20 percent gravel, 15 percent cobbles; neutral (pH 7.2); abrupt smooth boundary. (5 to 13 cm thick)

A12--11 to 33 cm; light brownish gray (10YR 6/2) gravelly loam, dark grayish brown (10YR 4/2) moist; weak very fine granular structure; soft, friable, slightly sticky and slightly plastic; many very fine and fine few medium and coarse roots; many very fine pores; 35 percent gravel; neutral (pH 7.2); abrupt smooth boundary. (13 to 25 cm thick)

B21t--33 to 56 cm; brown (10YR 5/3) very cobbly heavy clay loam, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; slightly hard, friable, sticky and plastic; common very fine and fine, few coarse roots; many very fine tubular pores; many thin clay films on faces of peds; 40 percent gravel, 20 percent cobbles; slightly alkaline (pH 7.4); gradual smooth boundary. (25 to 50 cm thick)

B22t--56 to 94 cm; brown (10YR 5/3) extremely cobbly clay, brown (10YR 4/3) moist; moderate fine subangular blocky structure; hard, firm, sticky and plastic; few very fine, fine and medium roots; many very fine tubular pores; many thin clay films on faces of peds; 40 percent gravel, 20 percent cobbles, 10 percent stones; slightly alkaline (pH 7.4); gradual smooth boundary. (25 to 50 cm thick)

B23t--94 to 133 cm; yellowish brown (10YR 5/4) extremely stony clay, dark yellowish brown (10YR 4/4) moist; weak fine subangular blocky structure; very hard, very firm, sticky and plastic; few very fine roots; common very fine tubular pores; many thin clay films on faces of peds; 30 percent gravel, 30 percent cobbles, 20 percent stones; slightly alkaline (pH 7.6); clear wavy boundary. (25 to 50 cm thick)

C--133 to 155 cm; grayish brown (10YR 5/2) extremely stony sandy clay loam, dark grayish brown (10YR 4/2) moist; massive; hard, firm, sticky and plastic; 60 percent gravel, 20 percent cobbles, 15 percent stones; slightly alkaline (pH 7.6).

TYPE LOCATION: Taos County, New Mexico; NW1/4 NE1/4 section 31, T.24N., R.14E.

RANGE IN CHARACTERISTICS:
Mean annual soil temperature--4 degrees to 7 degrees C
Mean summer soil temperature--warmer than 8 degrees C
Thickness of the solum--115 to 150 cm
Total rock fragments--40 to 80 percent in a major part of the solum and the C horizon.
Reaction--pH 6.6 to 7.6, but in some pedons the C horizon is calcareous

A1 horizon
Value--4 through 6 dry, 2 or 3, moist
Chroma--2 through 4
Texture--loam or light sandy clay loam
Rock fragment content--20 to 35 percent gravel; 5 to 40 percent cobbles

B2t horizon
Hue--7.5YR or 10YR
Value--5 through 7 dry, 4 or 5 moist
Chroma--2 through 6
Texture--clay, sandy clay and heavy clay loam
Rock fragment content--10 to 40 percent gravel, 20 to 60 percent cobbles and 10 to 60 percent stones

C horizon
Hue--7.5YR or 10YR
Value--5 or 6 dry, 4 or 5 moist
Chroma--2 through 6
Texture--sandy clay loam or clay loam
Rock fragment content--40 to 60 percent gravel, 20 to 40 percent cobbles and 10 to 60 percent stones

COMPETING SERIES: These are the Bignell (T), Crest (T), Pinata, and Ring series. Bignell, Crest and Pinata soils have Ap horizons with moist value of 4 or more or dry value of 6 or more. Ring soils have sola less than 45 inches thick.

GEOGRAPHIC SETTING:
Landform--sides of mountains and canyons
Elevations--2450 to 3200 meters
Slope--10 to 60 percent, mostly on southerly aspects
Parent material--colluvium from interbedded shale and sandstone of the Pennsylvanian Formation
Mean annual precipitation--640 to 890 mm, with peak periods in winter and late summer
Mean annual air temperature--3 degrees to 4 degrees C
Mean summer air temperature--10 degrees C

GEOGRAPHICALLY ASSOCIATED SOILS: None listed

DRAINAGE AND PERMEABILITY: Well drained; moderately slow permeability.

USE AND VEGETATION: These soils are used for timber production, range, recreation, water production and wildlife habitat. Native vegetation is Gambel oak, mountain-mahogany, and various grasses with widely spaced Douglas-fir, white fir and ponderosa pine.

DISTRIBUTION AND EXTENT: Derecho soils are of moderate extent in the high mountains of north-central and northern New Mexico; MLRAs 48A, 48B

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

SERIES ESTABLISHED: Taos Area, New Mexico, 1976.

REMARKS: Control of fire favors Gambel oak and grasses.

Converted to metric, updated formatting, and O horizons were updated to start at zero. 3/2022

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National Cooperative Soil Survey
U.S.A.