LOCATION MAGALLON WAEstablished Series
TAXONOMIC CLASS: Sandy, mixed, mesic Aridic Haploxerolls
TYPICAL PEDON: Magallon silt loam, grassland. (Colors are for dry soil unless otherwise stated.)
A--0 to 8 inches; grayish brown (10YR 5/2) silt loam, very dark grayish brown (10YR 3/2) moist; weak thick platy structure parting to weak fine granular; soft, very friable, slightly sticky and nonplastic; many roots; common coarse basalt sand grains; slightly alkaline (pH 7.6); clear wavy boundary. (7 to 10 inches thick)
Bw--8 to 17 inches; brown (10YR 5/3) sandy loam, dark brown (10YR 3/3) moist; weak subangular blocky structure; slightly hard, friable, slightly sticky and nonplastic; common roots; few very fine pores; occasional bands with thin clay films on sand grains and in some pores; common coarse basalt sand grains; slightly alkaline (pH 7.7); gradual wavy boundary. (7 to 15 inches thick)
C1--17 to 26 inches; brown (10YR 5/3) loamy sand, dark brown (10YR 4/3) moist; massive; soft, very friable, nonsticky and nonplastic; common roots; porous; slightly alkaline (pH 7.8); abrupt wavy boundary. (0 to 10 inches thick)
2C2--26 to 60 inches; light brownish gray (10YR 6/2) coarse sand (basalt), very dark gray (10YR 3/1) moist; single grain; loose; slightly alkaline (pH 7.7).
TYPE LOCATION: Adams County, Washington; 1/2 mile northeast of Washtucna; 450 feet south and 1,400 feet west of the northeast corner of sec. 28, T.15N., R.36E., W.M.
RANGE IN CHARACTERISTICS: The mean annual soil temperature is 50 to 55 degrees F. These soils are usually dry in all parts between depths of 4 and 12 inches for 90 consecutive days following the summer solstice. Thickness of the solum is 14 to 25 inches. Depth to coarse sand ranges from 20 to 35 inches. The upper part of the control section averages more than 50 percent fine or coarser sand. The mollic epipedon is 7 to 10 inches thick.
The A horizon has value of 4 or 5 dry and chroma of 2 or 3 moist and dry..
The Bw horizon has hue of 7.5YR or 10YR and value of 4 to 6 dry, 3 or 4 moist and chroma of 2 to 4 dry and moist. It is sandy loam, fine sandy loam, very fine sandy loam or silt loam. This horizon has weak subangular blocky or weak prismatic structure. Reaction is slightly alkaline or moderately alkaline. Organic matter is less than one percent.
The C horizon ranges from loamy fine sand to coarse sand and has 0 to 15 percent coarse fragments. The color is variable depending on the amount of basaltic sand. Reaction ranges from slightly alkaline to strongly alkaline.
COMPETING SERIES: There are no competing series.
GEOGRAPHIC SETTING: Magallon soils are on terraces and their sideslopes. Slopes are 0 to 65 percent. The soils formed in glacial outwash consisting mainly of sand with mantle of reworked loess and small amounts of volcanic ash. They are at elevations between 400 to 1,700 feet. The annual precipitation is 9 to 12 inches. These soils occur in a climate with warm dry summers and cool moist winters; an average July temperature of 71 degrees F.; an average January temperature of 30 degrees F.; a mean annual temperature of 49 to 53 degrees F.; and a frost-free season of 140 to 190 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Esquatzel, Farrell, Renslow, Ritzville, and Stratford soils. Esquatzel, Renslow and Ritzville soils are coarse-silty. Farrell soils are coarse-loamy. Stratford soils have a calcic horizon and have more than 35 percent coarse fragments in the lower part of the particle-size control section.
DRAINAGE AND PERMEABILITY: Somewhat excessively drained; slow to medium runoff; moderately rapid permeability in the upper part of the control section and very rapid in the lower part.
USE AND VEGETATION: Used for production of small grains and for grazing. Native vegetation is bluebunch wheatgrass, Sandberg bluegrass, balsamroot, western yarrow, and big sagebrush.
DISTRIBUTION AND EXTENT: Southeastern and Central Washington. Magallon soils are of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Walla Walla County, Washington, 1961.
REMARKS: Diagnostic horizons and features in this pedon include: Mollic epipedon - 0 to 8 inches (A horizon)
Cambic horizon - 8 to 17 inches (Bw horizon)
Particle-size control section - 10 to 40 inches (Bw and C1 horizon)