LOCATION PENA NM+WY
Established Series
Rev. VGL/RJA/LWH
12/2014
PENA SERIES
The Pena series consists of very deep, well drained, moderately permeable soils formed in alluvial deposits derived from igneous and sedimentary rocks. These soils are on bajadas, terraces and knolls with slopes ranging from 0 to 65 percent. Mean annual precipitation is about 14 inches and the mean annual temperature is about 51 degrees F.
TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, mesic Aridic Calciustolls
TYPICAL PEDON: Pena gravelly loam--rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 8 inches; dark grayish brown (10YR 4/2) gravelly loam, dark brown (10YR 3/3) moist; weak fine granular structure; slightly hard, friable, slightly sticky and slightly plastic; many fine roots; common fine interstitial pores; 20 percent pebbles, 5 percent cobbles and a few stones; slightly effervescent; slightly alkaline; clear wavy boundary. (4 to 20 inches thick)
Bk1--8 to 18 inches; dark grayish brown (10YR 4/2) cobbly loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common fine roots; common interstitial pores; 10 percent pebbles; 20 percent cobbles, 5 percent stones; strongly effervescent with thin patchy calcium carbonate coatings on bottom of pebbles, cobbles and stones and few thin lime veins and finely divided calcium carbonates throughout; moderately alkaline; clear wavy boundary. (6 to 20 inches thick)
Bk2--18 to 30 inches; light gray (10YR 7/2) very cobbly sandy clay loam, pale brown (10YR 6/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few fine and medium interstitial pores; 15 percent pebbles, 30 percent cobbles, 10 percent stones; nearly continuous calcium carbonate coatings on coarse fragments; strongly effervescent of which about 30 percent of the fine earth is calcium carbonate that is finely divided throughout; moderately alkaline; gradual irregular boundary. (8 to 20 inches thick)
Bk3--30 to 65 inches; light gray (10YR 7/2) extremely cobbly loam, pale brown (10YR 6/3) moist; massive; slightly hard, friable, slightly sticky and slightly plastic; few fine interstitial pores; 15 percent pebbles, 40 percent cobbles, 20 percent stones; thin nearly continuous calcium carbonate coatings on coarse fragments, mostly in the upper 12 inches of this horizon; strongly calcareous with about 20 percent of the fine earth as calcium carbonate that is finely divided throughout, decreasing gradually in amount below 42 inches; moderately alkaline.
TYPE LOCATION: Otero County, New Mexico; 7,260 feet west and 1,850 feet south of Cambell Well; 105 degrees, 52 minutes, 36 seconds west longitude; 33 degrees, 14 minutes, 00 seconds north latitude.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section December through April and July through September. The soil is driest during May and June.
Soil Temperature: 47 to 59 degrees F.
Depth to calcic horizon: 10 to 40 inches
Mollic epipedon: 10 to 20 inches thick
Rock fragments: 35 to 85 percent in the particle-size control section and increasing with depth
A horizon
Hue: 7.5YR, 10YR
Value: 3 to 5 dry, 2 or 3 moist
Chroma: 2 or 3, dry or moist
Texture: sandy loam, loam
Reaction: slightly to moderately alkaline
Bk horizon
Hue: 7.5YR, 10YR
Value: 4 to 8 dry, 3 to 7 moist
Chroma: 1 to 4, dry or moist
Texture: sandy loam, loam, sandy clay loam, silt loam
Calcium carbonate equivalent: more than 15 percent in some part that is more than 6 inches thick.
COMPETING SERIES: These are the
Ayon(NM),
Curabith(CO),
Hogadero(NM), and
Modyon(NM) series. Ayon soils have dominantly basalt rock fragments and the majority are greater than 10 inches in size. Curabith soils have mollic epipedons less than 10 inches thick and are moist in some part of the soil moisture control section periodically during
May and June. Hogadero soils have a cemented calcic horizon with hardness of less than 3. Modyon soils have bedrock between depth of 20 to 40 inches.
GEOGRAPHIC SETTING: Pena soils formed in alluvial deposits derived from igneous and sedimentary rocks. These soils are on bajadas, terraces, and knolls. Recent washes and arroyos have dissected the old sediments. Slopes range from 0 to 65 percent. Elevations are 4,300 to 7,800 feet. Pena soils occur in a semiarid climate. Mean annual precipitation ranges from 12 to 17 inches with a maximum during July, August, September and October. Mean annual temperature is about 45 to 57 degrees F. The frost-free period is 100 to 180 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the
Dioxice,
Guy,
Irock,
Oro Grande,
Shanta and the competing
Hogadero soils. Dioxice, Guy and Shanta soils have less than 35 percent rock fragments in the 10 to 40 inch control section. Oro Grande soils have a lithic contact within 20 inches of the surface.
DRAINAGE AND PERMEABILITY: Well drained; medium runoff; moderate permeability.
USE AND VEGETATION: Pena soils are used primarily for livestock grazing and watershed. Principal vegetation is blue grama, black grama, sideoats grama, hairy grama and pinyon juniper.
DISTRIBUTION AND EXTENT: Southern New Mexico and southern Colorado; the series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Otero County (Mescalero-Apache Area), New Mexico, 1970.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon: The zone from the surface of the soil to a depth of 18 inches. (A, Bk horizons)
Calcic horizon: The zone between 18 and 30 inches. (Bk2 horizons)
Aridic feature: The soil is dry more than 0.6 of the time in some part of the SMCS.
Classified according to Soil Taxonomy Second Edition, 1999; Keys to Soil Taxonomy, Twelfth Edition, 2014.
Revised for the correlation of White Sands Missile Range, New Mexico; October, 2014, NMS
National Cooperative Soil Survey
U.S.A.