LOCATION HOOPAL OREstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, calcareous, mesic Typic Duraquolls
TYPICAL PEDON: Hoopal fine sandy loam, pasture. (Colors are for moist soil unless otherwise noted.)
A11--0 to 3 inches; very dark grayish brown (10YR 3/2) fine sandy loam, grayish brown (10YR 5/2) dry; weak thin platy and weak fine granular structure; soft, friable, nonsticky and nonplastic; common very fine and few fine roots; many very fine and few medium tubular pores; slightly effervescent; strongly alkaline (pH 8.6); clear smooth boundary. (2 to 4 inches thick)
A12--3 to 10 inches; very dark grayish brown (10YR 3/2) fine sandy loam, grayish brown (10YR 5/2) dry; moderate thin and medium platy structure; slightly hard, friable, nonsticky and nonplastic; few fine and medium roots; common very fine tubular pores; violently effervescent; very strongly alkaline (pH 9.2); clear wavy boundary. (5 to 10 inches thick)
B2--10 to 31 inches; dark brown (10YR 3/3) silt loam, brown (10YR 5/3) dry; weak medium subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few fine roots; few fine and common very fine tubular pores; violently effervescent; strongly alkaline (pH 9.0); abrupt smooth boundary. (13 to 26 inches thick)
C1casim--31 to 35 inches; dark brown (10YR 3/3) duripan, brown (10YR 5/3) dry; massive; very hard, extremely firm, weakly cemented, nonsticky and nonplastic; silica laminar coating on surface; common fine tubular pores; violently effervescent; very strongly alkaline (pH 9.2); abrupt smooth boundary. (1 to 20 inches thick)
C2--35 to 60 inches; brown (10YR 5/3) fine sandy loam, pale brown (10YR 6/3) dry; massive; soft, friable, nonsticky and nonplastic; common very fine tubular pores; violently effervescent; very strongly alkaline (pH 9.2).
TYPE LOCATION: Union County, Oregon; 300 feet west of gate in the NE1/4 SW1/4 section 19, T. 3 S., R. 39 E.
RANGE IN CHARACTERISTICS: These soils are saturated during the winter and spring. The exchangeable sodium exceeds 15 percent to a depth of 20 inches and decreases below with increasing depth. The mean annual soil temperature ranges from 48 to 50 degrees F. The mean summer soil temperature at a depth of 20 inches ranges from 62 to 65 degrees F. Depth to duripan ranges from 20 to 40 inches. Depth to bedrock is more than 60 inches.
The A horizon has value of 2 or 3 moist and chroma of 1 or 2 moist and dry.
The B horizon has value of 3 or 4 moist and chroma of 2 or 3 moist and dry. It is silt loam or loam and averages 10 to 18 percent clay and more than 15 percent coarser than very fine sand. It has weak or moderate subangular blocky structure.
The duripan is massive or platy and weakly to strongly cemented.
The C2 horizon is fine sandy loam, loam, or silt loam.
COMPETING SERIES: These are the Ahtanum, Poe and Winlo series in other families. Ahtanum soils are coarse-silty. Poe soils are sandy throughout. Winlo soils are clayey-skeletal.
GEOGRAPHIC SETTING: Hoopal soils are on old lake and river bottoms. Slope is 0 to 2 percent. The soils formed in mixed alluvium and volcanic ash. Elevation ranges from 2,600 to 3,000 feet. The mean annual precipitation is 12 to 17 inches with warm dry summers and cold moist winters. The mean annual temperature is 47 to 51 degrees F. The average frost-free period is 130 to 150 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Catherine, Hot Lake, La Grande, and Umapine series. All of these soils lack a duripan.
DRAINAGE AND PERMEABILITY: Somewhat poorly drained; slow runoff; moderate permeability through the solum and very slow through the duripan. A perched water table is above the duripan irrigation and the rainy season.
USE AND VEGETATION: Major uses are range, pasture, and irrigated crops. Native vegetation dominantly is greasewood, saltgrass and wildrye.
DISTRIBUTION AND EXTENT: These soils are in the Grande Ronde Valley of northeastern Oregon. The series is of small extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Union County, Oregon, 1978.