LOCATION NYSSA OREstablished Series
TAXONOMIC CLASS: Coarse-silty, mixed, superactive, mesic Xeric Haplodurids
TYPICAL PEDON: Nyssa silt loam, cultivated. (Colors are for dry soil unless otherwise noted.)
Ap--0 to 13 inches; light brownish gray (10YR 6/2) silt loam, dark grayish brown (10YR 4/2) moist; weak medium granular structure; slightly hard, friable, slightly sticky and slightly plastic; few roots; many very fine tubular pores; mildly alkaline (pH 7.5); clear smooth boundary. (5 to 13 inches thick)
Bw--13 to 20 inches; pale brown (10YR 6/3) silt loam, dark brown (10YR 3/3) moist; weak coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; few roots; many very fine tubular pores; neutral (pH 7.0); clear wavy boundary. (7 to 10 inches thick)
Bkq--20 to 25 inches; light gray (10YR 7/2) silt loam, grayish brown and brown (10YR 5/2 and 5/3) moist; massive; hard, firm, slightly sticky and slightly plastic; very few roots; common very fine tubular pores; 45 percent calcareous durinodes 1/4 to 1 inch by 1/4 to 1/2 inch; strongly calcareous; moderately alkaline (pH 8.1); abrupt wavy boundary. (3 to 8 inches thick)
Bkqm1--25 to 31 inches; light gray (10YR 7/2) indurated of silty material brown (10YR 5/3) moist; weak very thick platy structure; thin silica indurated lenses on top of plates with a matting of roots and reddish brown organic matter on top of silica lenses; extremely hard, extremely firm, nonsticky and nonplastic; no roots except for mats on lenses; many very fine and fine tubular pores; strongly calcareous; moderately alkaline (pH 8.4); clear wavy boundary. (4 to 15 inches thick)
Bkqm2--31 to 52 inches; similar to horizon above except being massive.
TYPE LOCATION: Malheur County, Oregon; 80 feet southeast of 4 foot vertical stand pipe turnout in NW1/4 SW1/4 SW1/4 section 11, T. 20 S., R. 46 E.
RANGE IN CHARACTERISTICS: The mean annual soil temperature ranges from 52 to 56 degrees F. The soils are usually dry but are moist for more than 60 days during the winter season. Depth to the duripan ranges from 20 to 40 inches. The A and B horizons above the duripan are slightly to moderately alkaline and commonly noncalcareous but some pedons are weakly calcareous in the B horizon. The A and B horizons above the duripan are silt loam or very fine sandy loam and have less than 18 percent clay and less than 15 percent fine sand and coarser.
The A horizon has value of 3 or 4 moist and chroma of 2 or 3 moist and dry.
The Bw and Bkq horizons have value of 3 or 4 moist. It has weak prismatic or subangular blocky structure.
The duripan is indurated in some part and the remaining part ranges from weakly to strongly cemented. It is massive or platy.
COMPETING SERIES: These are the Burke, Dolman, Minidoka, and Sluka series. Burke soils are calcareous below depth of 6 inches and lack durinodes above the duripan. Dolman soils have a calcic horizon. Minidoka soils have Bk (calcic) horizons at depths of 7 to 16 inches. Stanfield soils have high exchangeable sodium, are somewhat poorly drained and very strongly alkaline in some part above the duripan. Sluka soils have a calcic horizon.
GEOGRAPHIC SETTING: Nyssa soils are on nearly level to gently sloping terraces with gradients up to 20 percent but commonly less than 8 percent at elevations of 2,100 to 2,600 feet. The soils formed in lacustrine materials with the surface reworked by wind. The climate is semiarid and has hot dry summers and cold winters. Mean annual precipitation is 9 to 11 inches. The mean annual temperature is 50 to 54 degrees F., the mean summer temperature is 70 to 74 degrees F., and the mean winter temperature is 31 to 33 degrees F. The frost-free period ranges from 150 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Greenleaf, Owyhee and Virtue soils. Greenleaf soils have an argillic horizon and lack duripans. Owyhee soils lack duripans. Virtue soils have argillic horizons.
DRAINAGE AND PERMEABILITY: Well drained; slow to moderate runoff; moderate permeability to the duripan.
USE AND VEGETATION: Principal use is irrigated crops: sugar beets, potatoes, onions, small grain, specialty seed crops, mint, and alfalfa. Native vegetation is mainly big sagebrush, Atriplex spp., bud sagebrush, needlegrass, Sandberg bluegrass, annual fescue, and associated forbs.
DISTRIBUTION AND EXTENT: Southeastern Oregon and southwestern Idaho. The series is of moderate extent.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Portland, Oregon
SERIES ESTABLISHED: Malheur County, Oregon, 1975.
REMARKS: Diagnostic horizons and characteristics recognized in this pedon:
Ochric epipedon - the zone from 0 to 13 inches (Ap horizon)
Cambic horizon - the zone from 13 to 25 inches (Bw and Bkq horizons)
Duripan - the zone from 25 to 52 inches (Bkqm1 and Bkqm2 horizons)
Particle-size control section - the zone from 10 to 25 inches.
ADDITIONAL DATA: Characterization data for 2 pedons (S62Oreg-23-1 and S62Oreg-23-2) by Oregon State University.