LOCATION MCNARY AZEstablished Series
TAXONOMIC CLASS: Very-fine, smectitic, mesic Aridic Haplusterts
TYPICAL PEDON: McNary clay - rangeland. (Colors are for dry soil unless otherwise noted.)
A--0 to 4 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; strong fine subangular blocky structure; very hard, very firm, very sticky and very plastic; many fine roots; many fine to coarse irregular pores; occasional small calcium carbonate nodules on the surface; noneffervescent; slightly alkaline (pH 7.6); abrupt smooth boundary. (2 to 6 inches thick)
Ass--4 to 18 inches; dark gray (10YR 4/1) clay, very dark gray (10YR 3/1) moist; weak medium prismatic parting to moderate fine subangular blocky structure; extremely hard, extremely firm, very sticky and very plastic; many roots; few slickensides; many fine and very fine pores; noneffervescent; slightly alkaline (pH 7.7); clear wavy boundary. (8 to 16 inches thick)
Css1--18 to 30 inches; brown (7.5YR 5/2) clay, grayish brown (10YR 5/2) moist; moderate medium subangular blocky structure; extremely hard, extremely firm, very sticky and very plastic; few to common roots; many slickensides; slightly to strongly effervescent becoming more calcareous with depth, violently effervescent on a few fine to medium prominent calcium carbonate flecks that occur in the lower part of this horizon; slightly alkaline (pH 7.6); gradual wavy boundary. (10 to 20 inches thick)
Css2--30 to 60 inches; brown (7.5YR 5/2) clay, brown (7.5YR 5/2) moist; moderate medium and fine subangular parting to angular blocky structure; extremely hard, extremely firm, very sticky and very plastic; few fine roots; many slickensides; strongly effervescent with many medium to large prominent white calcium carbonate accumulations and occasional medium or fine hard calcium carbonate nodules; slightly alkaline (pH 7.6).
TYPE LOCATION: Navajo County, Arizona; about 1 mile south of the town of Lakeside; near the northeast corner of section 35, T. 9 N., R. 22 E.
RANGE IN CHARACTERISTICS:
Soil Moisture: Intermittently moist in some part of the soil moisture control section during July-September and December-February. Driest during May and June. Aridic ustic soil moisture regime.
Soil Temperature: 47 to 59 degrees F.
Organic matter: 2 to 4 percent in the surface
Cracking: Deep, wide cracks are open more than 210 days cumulative
Reaction: slightly to moderately alkaline
A and Ass horizons
Value: 2 through 4, dry or moist
Css horizons
Hue: 5YR, 7.5YR
Value: 4 or 5, dry or moist
Chroma: 2 through 4, dry or moist
COMPETING SERIES: These are the Catman (NM), Kyle (SD), Swanboy (SD), Twotop (SD) and Venzuni (NM) series. Catman soils have hue 10YR and yellower. Kyle, Swanboy, and Twotop soils are in LRR-G and are more moist in May and June. Venzuni soils do not have visible secondary accumulations of calcium carbonate.
GEOGRAPHIC SETTING: McNary soils are on plateaus and have slopes of 0 to 1 percent. These soils formed in residuum from basalt or basaltic cinders. Elevations range from 6000 to 6800 feet. The mean annual precipitation ranges from 14 to 18 inches. The mean annual air temperature is about 45 to 57 degrees F. The frost-free period is 100 to 140 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Elledge, Showlow and Springerville series. Springerville soils have basalt bedrock at depths of 40 to 60 inches. Elledge and Showlow soils do not have intersecting slickensides.
DRAINAGE AND PERMEABILITY: Well drained; very slow runoff; very slow permeability.
USE AND VEGETATION: McNary soils are used for livestock grazing and wildlife habitat. The present vegetation is Western wheatgrass, bluegrass, occasional Gambel oak and Ponderosa pine.
DISTRIBUTION AND EXTENT: Northern Arizona. This series is not extensive. MLRA is 39.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Phoenix, Arizona
SERIES ESTABLISHED: Navajo County, Arizona. Soil survey of Holbrook-Show Low Area, Arizona; 1961. Name is from a nearby town.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - The zone from 0 to 18 inches (A, Ass horizons)
Intersecting slickensides - The zone from 18 to 60 inches (Ass, Css1, Css2 horizons)
Classified according to Soil Taxonomy, Second Edition, 1999; Keys to Soil Taxonomy, Tenth Edition, 2006.
Update and revisions for the competing series section 2/08 DWD