LOCATION SILVER NMEstablished Series
TAXONOMIC CLASS: Fine, mixed, superactive, mesic Ustic Haplargids
TYPICAL PEDON: Silver very fine sandy loam - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 3 inches; brown (10YR 5/3) very fine sandy loam, dark brown (10YR 3/3) moist; moderate thick platy and weak fine granular structure; soft, very friable, nonsticky and nonplastic; many fine roots; many very fine and fine pores; slightly alkaline; clear smooth boundary. (2 to 6 inches thick)
Bt--3 to 14 inches; grayish brown (10YR 5/2) silty clay loam, dark brown (7.5YR 4/2) moist; moderate medium prismatic and strong medium subangular blocky structure; very hard, very firm, sticky and plastic; common very fine and fine roots; many very fine and fine pores; many thin clay films on faces of peds and lining pores; slightly alkaline; clear smooth boundary. (6 to 30 inches thick)
Btk--14 to 30 inches; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; moderate medium subangular blocky structure; hard, firm, sticky and plastic; few very fine and fine roots; common very fine and fine pores; few thin clay films on faces of peds and lining pores; strongly effervescent; few medium calcium carbonate masses; moderately alkaline; clear smooth boundary. (8 to 25 inches thick)
Bk1--30 to 45 inches; light brown (7.5YR 6/4) silty clay loam, brown (7.5YR 5/4) moist; weak medium subangular blocky structure; hard, friable, sticky and plastic; few fine roots; few fine pores; approximately 5 percent fine pebbles; strongly effervescent; few fine to medium calcium carbonate masses and filaments; moderately alkaline; abrupt smooth boundary. (12 to 20 inches thick)
2Bk2--45 to 68 inches; pinkish gray (7.5YR 7/2) gravelly very fine sandy loam, pinkish gray (7.5YR 6/2) moist; massive; very hard, friable, nonsticky and nonplastic; approximately 25 percent pebbles; strongly effervescent; many medium calcium carbonate masses and filaments; moderately alkaline.
TYPE LOCATION: Santa Fe County, New Mexico; unsurveyed area about 2 miles northeast of Tetilla Park within the La Majada and Caga Del Rio Grants; if survey lines are projected, location would be in northeast quarter, Sec. 9, T. 16 N., R. 7 E.; 106 degrees, 11 minutes, 53 seconds west longitude; 35 degrees, 37 minutes, 54 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: Usually dry, intermittently moist in some part of the soil moisture control section July through October and December through March.
Soil Temperature: 47 to 57 degrees F.
Depth to carbonates: 10 to 40 inches or more.
Calcium carbonate equivalent: less than 15 percent; greater than 15 percent below 40 inches in some pedons.
Rock fragments: less than 15 percent, mostly pebbles on a weighted average.
A horizon - Hue: 7.5YR or 10YR. Value: 4 to 6 dry, 3 to 5 moist.
Chroma: 2 to 4.
Texture: very fine sandy loam, silt loam, loam, cobbly silty clay loam, silty clay loam or clay loam, and fine sandy loam.
Reaction: slightly alkaline or moderately alkaline.
Bt and Btk horizons - Hue: 7.5YR or 10YR. Value: 4 to 7 dry, 3 to 6 moist. Chroma: 2 to 4.
Texture: clay loam, silty clay loam, clay or silty clay (averages 35 to 50 percent clay and less than 35 percent sand).
Bk and C horizons (where present) - Hue: 7.5YR or 10YR. Value: 6 to 8 dry, 5 to 7 moist.
Chroma: 2 to 4.
Texture: very fine sandy loam, loam, sandy clay loam and clay loam. Some pedons in Rio Arriba Soil Survey have cobbly sandy clay loam below 48 inches. Reaction: moderately alkaline or strongly alkaline.
COMPETING SERIES: These are the Bessemer (WY), Hawaikuh (T NM), Lonti (AZ), Padilla (T AZ), and Tobish (UT) soils. Bessemer soils have loamy-skeletal materials at 20 to 40 inches and are moist for longer periods in the spring. Hawaikuh soils have hue redder than 7.5YR. Lonti soils have more than 15 percent rock fragments. Padilla soils are effervescent to the surface. Tobish soils are 20 to 40 inches to a lithic or paralithic contact.
GEOGRAPHIC SETTING: The Silver soils are on convex positions of piedmont slopes, hills, fan terraces, mesas and plateaus. Slope ranges from 0 to 15 percent. The soils formed in calcareous material from sources of basalt, and sedimentary rock with some addition of eolian material. This unconsolidated material is more than 5 feet thick. The climate is semiarid continental. Mean annual temperature ranges from 49 to 55 degrees F. and mean annual precipitation ranges from 10 to 13 inches, with a marked summer maximum characterized by heavy thunderstorms of short duration. In a few areas the precipitation is higher. The frost-free season ranges from 120 to 170 days and elevation of ranges from 4,700 to 7,500 feet.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Calabasas, Clovis, Majada, Montosa, and Pojoaque soils. Calabasas and Pojoaque soils lack argillic horizons. Clovis soils have less than 35 percent clay in the control section. Majada and Montosa soils have mollic epipedons and contain more than 35 percent rock fragments in the control section.
DRAINAGE AND PERMEABILITY: Well drained. Permeability is moderately slow. Runoff is negligible on slopes less than 1 percent, very low on 1 to 3 percent slopes, low on 3 to 5 percent slopes, and medium on slopes greater than 5 percent.
USE AND VEGETATION: The principal use of these soils is grazing. Present vegetation is blue grama, galleta, sideoats grama, Indian ricegrass, black grama, and threeawn with widely spaced pinyon and juniper.
DISTRIBUTION AND EXTENT: North-central and west-central New Mexico and eastern Arizona. This soil is of large extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Navajo County (Holbrook-Show Low Area), Arizona, 1961.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon: 0 to 3 inches. (A horizon)
Argillic horizon: 3 to 30 inches. (Bt horizon)
When the ochric epipedon and part of the argillic horizon meet the color and organic carbon requirements of a mollic epipedon, they are less than 7 inches thick.