LOCATION PORVENIR                NM

Tentative Series
AJM / NS
06/2022

PORVENIR SERIES

The Porvenir series consists of well drained soils shallow to sandstone bedrock that formed in some loess over residuum weathered from sandstone. Porvenir soils are on plateau margins with slopes of 0 to 10 percent. The mean annual precipitation is about 17 inches and the mean annual soil temperature is 53 degrees F.

TAXONOMIC CLASS: Loamy, mixed, superactive, mesic Aridic Lithic Argiustolls

TYPICAL PEDON: Porvenir loam, rangeland. (Colors are for dry soil unless otherwise noted.)

A--0 to 9 centimeters (0.0 to 3.5 inches); brown (10YR 4/3), dark brown (10YR 3/3), moist; loam; weak fine subangular blocky structure parts to weak fine granular; soft, very friable, moderately sticky, moderately plastic; common very fine and fine and many medium roots; common very fine, few fine tubular and common very fine interstitial pores; 10 percent sandstone gravels; noneffervescent; clear smooth boundary; moist when described.

Bt1--9 to 21 centimeters (3.5 to 8.3 inches); brown (7.5YR 5/3), dark brown (7.5YR 3/3), moist; clay loam; moderate coarse angular blocky parts to moderate fine angular blocky structure; hard, friable, very sticky, very plastic; common very fine roots and few medium and fine roots; common very fine and few fine tubular pores; 20 percent distinct clay films on all faces of peds; 5 percent subangular sandstone gravels, and 7 percent subangular sandstone cobbles; noneffervescent; clear wavy boundary; moist when described.

Bt2--21 to 33 centimeters (8.3 to 13.0 inches); brown (7.5YR 4/4), dark brown (7.5YR 3/4), moist; very flaggy clay loam; moderate coarse subangular blocky parts to fine angular blocky structure; very hard, friable, very sticky, very plastic; common very fine roots and few medium and fine roots; few very fine interstitial and few fine tubular and interstitial pores; 50 percent distinct clay films on all faces of peds and 50 percent faint clay films on rock fragments; 10 percent subangular sandstone gravels and 40 percent angular sandstone flagstones; noneffervescent; abrupt wavy boundary; slightly moist when described.

R--33 centimeters (13.0 inches); common medium and fine roots along top of bedrock contact; indurated sandstone.

TYPE LOCATION: Mora County, New Mexico, south of headquarters for Fort Union Ranch; DD: 35.8760, -105.0314; Elevation 6932' (2113 m).

RANGE IN CHARACTERISTICS: Thickness of the solum and depth to bedrock range from 10 to 20 inches (25 to 50 cm). The soils formed in some amount of moderately fine-textured, noncalcareous, eolian material over residuum weathered from sandstone. Rock fragments range from few to about 15 percent of which 60 percent is gravel. The solum is neutral or mildly alkaline. The control section ranges from sandy clay loam to clay loam and averages 18 to 35 percent clay. Carbonates are usually absent throughout the profile but can occur in the immediate area of the lithic contact. Porvenir series is in a mesic soil temperature regime and an aridic-ustic soil moisture regime.

A horizon:
Hue of 10YR to 7.5YR,
Value of 3 through 5 dry, 2 or 3 moist,
Chroma of 2 or 3.
Texture of fine fraction: sandy clay loam, clay loam, loam, sandy loam, fine or very fine sandy loam
Fragments: 0 to 10 percent gravels, 0 to 15 percent cobbles

Bt1 horizon:
Hue of 10YR to 5YR
Value of 4 through 5 dry, 3 moist
Chroma of 2 through 4
Texture of fine fraction: clay loam, loam, sandy clay loam
Fragments: 0 to 30 percent gravels, 0 to 50 percent cobbles, 0 to 5 percent stones.

Bt2 horizon:
Hue of 10YR to 5YR
Value of 4 through 6 dry, 3 through 5 moist
Chroma of 2 through 4
Texture: clay loam, loam, sandy loam, or fine sandy loam
Fragments: 0 to 30 percent gravels, 0 to 50 percent cobbles, 0 to 10 percent stones.
Secondary Carbonates: 0 to 1 percent, when present, mostly hovering above the bedrock contact.

R horizon: Indurated sandstone bedrock

COMPETING SERIES: These are the Bernal (MLRA 70C), Frajillo (MLA 70
C), Joachem (MLRA 39), and Margosa (MLRA 70C) series.

Bernal and Frajillo soils have an ustic-aridic soil moisture regime where the monsoon season starts later, in July, rather than May-June.
Bernal soils may be aridic-ustic, but only above 2286 m (7500 feet) elevation
Joachem soils formed in rhyolitic tuff and therefore probably have a glassy sand fraction.
Joachem soils are very shallow with lithic contact at 28 centimeters (11 inches)
Margosa soils have a calcic horizon.
Margosa soils have a cooler mean annual air temperature ranging from 7.7 to 8.8 degrees C (46 to 48 degrees F).

GEOGRAPHIC SETTING: The Porvenir soils are found on plateau margins of the Canadian Plateaus LRU part of MLRA 70A. The formed mostly in residuum from sandstone bedrock-controlled landscapes supported by the Cretaceous aged Dakota Formation. They form a boundary to the Mosozioc Canyons and Breaks LRU of MLRA 70A from which some eolian materials can blow out of the canyons and deposit on the Porvenir soils of the plateau surface.

Slope range: from 0 to 30 percent.
Soil moisture: ustic moisture regime bordering on aridic.
Mean annual soil temperature: 9.4 to 14.4 degrees C (49 to 58 degrees F)
Mean annual air temperature: 8.3 to 12.8 degrees C (47 to 55 degrees F)
Mean annual precipitation: 381 to 457 mm (15 to 18 in)
Frost-free period: 130 to 175 days
Elevation: 1524 to 2195 m (5000 to 7200 ft)

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Carnero, and
Onava soils of MLRA 70A. Carnero soils are deep to sandstone bedrock while Onava soils are very deep. Both soils have notable secondary pedogenic carbonate accumulations at depth

DRAINAGE AND PERMEABILITY: Well drained; local runoff class ranges from low in nearly level soils to very high in soils with slopes approaching 10 percent or more; moderate permeability.

USE AND VEGETATION: Rangeland savannah. Principal native plants are blue grama, sideoats grama, little bluestem, and wolfstail, and commonly with an open savannah-type overstory of twoneedle pion and oneseed juniper.

DISTRIBUTION AND EXTENT: Northeastern New Mexico, LRR G, in MLRA 70A along the Canadian Plateaus of the Southwestern Great Plains; LRU 70A.1 (Canadian Plateaus). The series is extensive.

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

SERIES ESTABLISHED: Mora County, New Mexico, 2021.

REMARKS:
This soil was previously correlated to the Bernal series. The Bernal series is characteristic of MLRA 70C, a drier part of New Mexico with an ustic-aridic soil moisture regime. The name Porvenir is taken from the locality of El Porvenir, near Las Vegas, NM, and means "the future" in Spanish.

Mollic epipedon described from 0 to 21 cm
Argillic horizon described from 9 to 33 cm
Lithic contact identified at 33 cm

ADDITIONAL DATA:
KSSL Lab Pedon #: 20N0590
User Pedon ID S2021NM033002

Classified according to Keys to Soil Taxonomy Twelfth Edition, 2014.
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National Cooperative Soil Survey
U.S.A.