LOCATION PLACITAS                NM

Established Series
Rev. DRS/LWH/RJA/WWJ
10/2011

PLACITAS SERIES

The Placitas series consists of moderately deep, well drained soils that formed in material derived from conglomerate on fan terraces. Slopes are 8 to 40 percent. The mean annual precipitation is about 11 inches, and the mean annual temperature is about 53 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Ustic Haplocalcids

TYPICAL PEDON: Placitas gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 5 inches; pale brown (10YR 6/3) gravelly loam, brown (10YR 4/3) moist; weak fine and medium granular structure; soft, very friable, slightly sticky and slightly plastic; many fine, few very fine roots; 30 percent gravel; strongly effervescent; moderately alkaline; clear smooth boundary. (3 to 6 inches thick)

Bw--5 to 10 inches; very pale brown (10YR 7/4) very gravelly sandy loam, yellowish brown (10YR 5/4) moist; weak fine subangular blocky structure; soft, very friable, slightly sticky and slightly plastic; few fine and very fine roots; 40 percent gravel; violently effervescent; moderately alkaline; clear smooth boundary. (4 to 13 inches thick)

Bk--10 to 27 inches; very pale brown (10YR 7/3) very gravelly sandy loam, brown (10YR 5/3) moist; massive; soft, very friable, slightly sticky and slightly plastic; few fine very fine roots; 55 percent gravel; violently effervescent; calcium carbonate as many fine seams and filaments; moderately alkaline; clear smooth boundary. (7 to 21 inches thick)

2R--27 to 40 inches; conglomerate.

TYPE LOCATION: Sandoval County, New Mexico; about 2 miles northeast of Placitas; 400 feet north and 200 feet west of the southeast corner of the SE1/4 of SE1/4 of sec. 21, T. 13 N., R. 5 E.

RANGE IN CHARACTERISTICS:

Soil Moisture: Usually dry, intermittently moist in some part of the soil moisture control section winter and summer. The soil is driest during May and June. Ustic aridic moisture regime.

Soil Temperature: 54 to 57 degrees F.

Depth to lithic contact: 20 to 40 inches

Rock fragments: 35 to 60 percent, mostly gravel in the control section

A horizon
Hue: 10YR, 7.5YR, 5YR
Value: 5 or 6 dry, 3 or 5 moist
Chroma: 2 to 6 dry or moist

B horizon
Hue: 7.5YR, 10YR, 5 YR
Value: 4 to 7 dry, 4 or 5 moist
Chroma: 3 to 6 dry or moist

COMPETING SERIES: These are the Buffcreek (WY), Clapper (UT), Claprych (WY), Ildefonso (NM), Seis (NM) and Strych (UT) series. Buffcreek, Clapper, Claprych, and Ildefonso, and Strych soils are more than 40 inches deep. Seis soils have more than 18 percent clay. In addition, Buffcreek and Claprych soils are in the Great Plains (LRR-G MLRAs 58B & 67) and are moist in May and June.

GEOGRAPHIC SETTING: Placitas soils are over conglomerate on fan terraces that have slopes of 8 to 40 percent. Elevations are 5,600 to 6,400 feet. The climate is semiarid and mean annual precipitation is about 10 to 14 inches. Mean annual air temperature is about 52 to 54 degrees F. The frost-free period is about 120 to 165 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Ildefonso soils.

DRAINAGE AND PERMEABILITY: Well drained; moderate runoff; moderate permeability.

USE AND VEGETATION: Placitas soils are used for livestock grazing, wildlife habitat and for urban development. Native vegetation is threeawn, blue grama, sand dropseed, sideoats grama, yucca, pricklypear, cholla, and oneseed juniper.

DISTRIBUTION AND EXTENT: Northcentral New Mexico. MLRA 35. Series is inextensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona

SERIES ESTABLISHED: Sandoval County, New Mexico, 1987.

REMARKS: Diagnostic horizons and features recognized in this pedon are:

Ochric epipedon -the zone from 0 to 5 inches. (A horizon)

Calcic horizon - the zone from 10 to 27 inches. (Bk horizon)

Lithic contact - conglomerate at 27 inches. (2R horizon)

Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy Eleventh Edition, 2010

Update and revisions for the correlation of Little Colorado River Area (AZ707), Sept. 2011, CEM

---

National Cooperative Soil Survey
U.S.A.