LOCATION TOADLENA NMEstablished Series
TAXONOMIC CLASS: Loamy, mixed, active, mesic, shallow Leptic Haplogypsids
TYPICAL PEDON: Toadlena channery loam -- on a slightly convex footslope of a structural bench sloping 8 percent to the southeast at 6,220 feet elevation -- rangeland. (Colors are for dry soil unless otherwise noted. When described, the soil was slightly moist from 2 to 6 inches and otherwise dry throughout.)
A--0 to 1 inch; light yellowish brown (10YR 6/4) channery loam, yellowish brown (10YR 5/4) moist; moderate very coarse platy structure parting to weak fine granular; slightly hard, very friable, slightly sticky and nonplastic; few fine and very fine roots; common very fine vesicular pores; 20 percent channers; secondary sand-size gypsum crystals segregated in very few fine filaments; strongly effervescent; moderately alkaline (pH 8.0); abrupt smooth boundary. (1 to 3 inches thick)
By1--1 to 5 inches; light yellowish brown (10YR 6/4) gypsiferous loam, brown (10YR 4/3) moist; moderate fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and common very fine roots; common very fine irregularly shaped pores; 5 percent soft siltstone fragments; secondary sand-size gypsum crystals segregated in many fine irregularly shaped soft masses; strongly effervescent; moderately alkaline (pH 8.0); abrupt wavy boundary. (3 to 7 inches thick)
By2--5 to 12 inches; pale brown (10YR 6/3) gypsiferous loam, brown (10YR 4/3) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and common very fine roots; common very fine irregularly shaped pores; 40 percent soft siltstone fragments; secondary sand-size gypsum crystals segregated in many medium irregularly shaped soft masses and as accumulations on rock fragments; slightly effervescent; slightly alkaline (pH 7.8); clear smooth boundary. (3 to 7 inches thick)
BCy--12 to 18 inches; light brownish gray (2.5Y 6/2) and light yellowish brown (2.5Y 6/4) gypsiferous silty clay loam, grayish brown (2.5Y 5/2) and light olive brown (2.5Y 5/4) moist; massive; slightly hard, friable, sticky and plastic; few fine and very fine roots; 70 percent soft shale and siltstone fragments; secondary sand-size gypsum crystals segregated in few medium irregularly shaped accumulations on rock fragments; slightly effervescent; slightly alkaline (pH 7.8); clear wavy boundary. (4 to 10 inches thick)
Cr--18 inches; interbedded siltstone and shale bedrock
TYPE LOCATION: San Juan County, New Mexico; on the Navajo Indian Reservation about 5.5 miles north of Toadlena; 1,500 feet west and 2,150 feet north of the southeast corner of section 16, T.24N., R.19W.; Latitude 36 degrees 18 minutes 45 seconds N and Longitude 108 degrees 52 minutes 5 seconds W.
RANGE IN CHARACTERISTICS:
Soil moisture - Typically, the soil moisture control section (SMCS) is intermittently moist in some part from July through October and December to April 15. The SMCS is dry in all parts 50 to 75 percent of the time (cumulative) that the soil temperature at the bedrock contact is greater than 41 degrees F. Ustic aridic moisture regime.
Soil temperature - 52 to 54 degrees.
Soil depth - 10 to 20 inches.
Depth to gypsic horizon - 1 to 3 inches.
Particle-size control section - apparent clay content: 18 to 35 percent.
Reaction - slightly to moderately alkaline.
A horizon
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 3 or 4.
Organic carbon content: 0.4 to 0.6 percent.
Calcium carbonate equivalence: 5 to 10 percent.
Rock fragments: Total range is 15 to 25 percent; 15 to 20 percent channers; 0 to 5 percent pebbles.
Salinity, mmhos/cm: 2 to 4.
Sodicity, SAR: 5 to 13.
By horizons
Hue: 10YR or 2.5Y.
Value: 5 through 7 dry, 4 or 5 moist.
Chroma: 2 through 4.
Organic carbon content: 0.2 to 0.4 percent.
Texture: gypsiferous loam or gypsiferous clay loam.
Calcium carbonate equivalence: 1 to 10 percent.
Salinity, mmhos/cm: 2 to 4.
Sodicity, SAR: 5 to 13.
Gypsum content: 15 to 25 percent.
Other features: 5 to 50 percent soft siltstone and shale fragments.
BCy horizon
Hue: 10YR or 2.5Y.
Value: 5 or 6 dry, 4 or 5 moist.
Chroma: 2 through 4.
Organic carbon content: 0.1 to 0.2 percent.
Texture: gypsiferous silty clay loam or gypsiferous clay loam. Salinity, mmhos/cm: 8 to 16.
Sodicity, SAR: 5 to 13.
Gypsum content: 5 to 10 percent.
Other features: 30 to 70 percent soft siltstone and shale fragments.
COMPETING SERIES: This is the Picliff series. Picliff soils are in a typic aridic moisture regime.
GEOGRAPHIC SETTING: Toadlena soils are on footslopes of structural benches. They formed in alluvium and residuum derived from Cretaceous siltstone and shale. Slopes are 2 to 20 percent. Elevations range from 6,100 to 6,900 feet. The mean annual precipitation is 8 to 12 inches about half of which falls as rain from high-intensity convective thunderstorms between July and September. The mean annual temperature is 50 to 52 degrees F. The average frost-free period is 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Eagleye, Farview, and Sanostee soils. Eagleye soils are fine textured, lack gypsic horizons, and occur on backslopes. Farview soils are very shallow over hard sandstone bedrock and occur on structural benches and dipslopes of cuestas. Sanostee soils are moderately deep to sandstone and occur on toeslopes.
DRAINAGE AND PERMEABILITY: Well drained, rapid runoff, moderately slow permeability.
USE AND VEGETATION: Toadlena soils are used for livestock grazing. Present vegetation is galleta, blue grama, Bigelow sagebrush, shadscale, Bigelow rubber rabbitbrush, winterfat, and widely scattered Utah juniper and relict pinyon.
DISTRIBUTION AND EXTENT: Toadlena soils are of small extent on the Four Corners Platform portion of the Colorado Plateau province in northwest New Mexico. MLRA 35.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: San Juan County, New Mexico; Shiprock Area Soil Survey, 1993. Toadlena is a local place name.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from the soil surface to a depth of about 1 inch. (A horizon)
Gypsic horizon - The zone from 1 to about 12 inches. (By1 and By2 horizons)
Paralithic contact - The presence of soft siltstone and shale bedrock at about 18 inches.
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Tenth Edition, 2006.
ADDITIONAL DATA: Organic carbon and gypsum values are estimated. Calcium carbonate equivalence determined with a field volume calcimeter.