LOCATION ESPERANZA CAEstablished Series
TAXONOMIC CLASS: Fine, smectitic, mesic Pachic Argixerolls
TYPICAL PEDON: Esperanza sandy loam on a north facing 5 percent slope under a cover of antelope bitterbrush, rabbitbrush, wheatgrass, and soft chess at an elevation of 3330 feet. (Colors are for moist soil unless otherwise noted.)
A1--0 to 3 inches; grayish brown (10YR 5/2) sandy loam, very dark grayish brown (10YR 3/2) moist; weak thin platy structure parting to moderate very fine subangular blocky; slightly hard, very friable, nonsticky and nonplastic; many very fine roots; many very fine tubular pores; neutral (pH 7.0); clear smooth boundary.
A2--3 to 6 inches; brown (10YR 5/3) sandy loam, very dark grayish brown (10YR 3/2) moist; moderate coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; many very fine roots; many very fine and fine tubular pores; mildly alkaline (pH 7.5); clear wavy boundary. (Combined thickness of the A horizon is 5 to 10 inches)
Bt1--6 to 12 inches; brown (10YR 5/3) loam, dark brown (10YR 3/3) moist; weak medium prismatic structure parting to moderate fine subangular blocky; very hard, friable, sticky and plastic; common very fine and few and medium roots; common very fine and fine tubular pores; common moderately thick clay films on peds and in pores; mildly alkaline (pH 7.5); abrupt smooth boundary. (5 to 10 inches thick)
Bt2--12 to 30 inches; yellowish brown (10YR 5/4) clay, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; very hard, friable, sticky and plastic; common very fine and few and medium roots; common very fine and fine tubular pores; common moderately thick clay films on peds and in pores; mildly alkaline (ph 7.5); gradual wavy boundary. (15 to 20 inches thick)
Bt3--30 to 44 inches; light yellowish brown (10YR 6/4) sandy clay loam, brown (7.5YR 4/4) moist; moderate medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few very fine roots; many very fine tubular pores; many moderately thick clay films on peds and common moderately thick clay films in pores; mildly alkaline (pH 7.5); gradual smooth boundary. (10 to 20 inches thick)
C1--44 to 53 inches; light yellowish brown (10YR 6/4) sandy loam, dark brown (10YR 3/3) moist; weak medium subangular blocky structure; slightly hard, very friable, nonsticky and nonplastic; few very fine roots; many very fine tubular pores; mildly alkaline (pH 7.5); abrupt smooth boundary.
C2--53 to 58 inches; very pale brown (10YR 7/4) sandy loam, dark brown (10YR 3/3) moist; moderate fine subangular blocky structure; hard, friable, nonsticky and nonplastic; few very fine roots; common very fine tubular pores; mildly alkaline (pH 7.5); abrupt smooth boundary. (Combined thickness of the C horizon is 5 to 15 inches)
2Cqm--58 to 61 inches; very pale brown (10YR 7/4) dark brown (7.5YR 3/4) moist; strong thin platy structure parting to strong fine angular blocky; extremely hard, slightly brittle; few very fine roots; many very fine tubular pores; mildly alkaline (pH 7.5).
TYPE LOCATION: Shasta County, California; about 1 mile northeast of Fall River Mills on a north facing slope; 100 feet south and 1,200 feet west of the northeast corner of sec. 25, 37 T. N., R. 5 E., Fall River Mills SW (Fall River Mills) quadrangle (7.5 minute series).
RANGE IN CHARACTERISTICS: Depth to duripan ranges from 40 to 60 inches. The mean annual soil temperature is 50 to 54 degrees F. The soil temperature exceeds 41 degrees f. from mid March to mid November (260 to 280 days) and exceeds 47 degrees F. from early April to early November. The soil moisture control section (7 to 19 inches) is dry in all parts from early July to mid October (120 to 130 days) and is moist in all parts from mid November to mid May. The particle-size control section (6 to 26 inches) averages 35 to 50 percent clay.
The A horizon color is 10YR 4/2, 4/3, 5/2, or 5/3. Moist color is 10YR 3/2, 2/2, 2/3; or 7.5YR 3/2. Organic matter ranges from 2 to 5 percent. Texture is loam or sandy loam. Clay content ranges from 15 to 27 percent. Rock fragments, mostly gravel range from 0 to 10 percent. Reaction is slightly acid or neutral.
The Bt horizon color is 10YR 5/2, 5/3, 5/4, 6/4, or 7/4. Moist color is 10YR 3/2, 3/3, 4/4; 7.5YR 3/2, 3/4, or 4/4. Organic matter ranges from 0.5 to 2 percent. Clay content ranges from 35 to 50 percent in the upper part and 25 to 35 in the lower part. Reaction is neutral or mildly alkaline.
The C horizon color is 10YR 6/4, or 7/4. Moist color is 10YR 3/3, 3/4; 7.5YR 4/4, or 3/4. Organic matter is less than 0.5 percent. Texture is sandy loam, coarse sandy loam, and loamy sand. Clay content ranges from 5 to 15 percent. Rock fragment, mostly gravel, range from 0 to 15 percent.
COMPETING SERIES: These are the Denbar (CA), Deshler (ID), Deter (OR), Deterson (ID), Jacknife (ID), Medford (OR), Mindego (CA), Nebeker (UT) and Patburn (T CA) series. Deshler soils are 20 to 40 inches deep to bedrock and are dry for 45 to 70 days. Denbar soils are mildly or moderately alkaline throughout and have a mollic epipedon 30 inches or less. Deter and Deterson soils have a combined A and Bt horizon thickness of 60 inches or more. Jacknife soils are moist in some part of the moisture control section for more than 90 days when the temperature is above 47 degrees F., are dry for 60 to 80 consecutive days and have a cobbly clay or cobbly clay loam argillic horizons with more than 15 percent rock fragments. Medford soils have a have a soil temperature of 54 to 57 degrees F. and are dry 45 to 80 days. Mindego soils have soil temperature of 55 degrees F. and have a comparatively small summer-winter temperature change. Nebeker soils have slightly or moderately calcareous C horizons, have a combined A and Bt horizon thickness of 40 to 60 inches and are dry for 60 to 75 days. Patburn soils are somewhat poorly drained and dry for less than 100 days.
GEOGRAPHIC SETTING: Esperanza soils are on stream terraces. Slopes are 0 to 5 percent. Elevations are 2,700 to 5,000 feet. These soils formed in alluvium weathered from tuff, basalt and diatomite. The climate is semiarid with warm dry summers and cold moist winters. Annual precipitation is 12 to 18 inches. Snowfall is 24 to 36 inches. The mean annual temperature is 48 to 52 degrees F. The mean January temperature is about 30 degrees F. The mean July temperature is about 60 degrees F. The frost-free period is 80 to 130 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Bieber, Cupvar, Dotta, Dudgen, Graven, and Pittville series. The Bieber and Dudgen soils are 10 to 20 inches deep to a hardpan in concave positions on terraces. The Dotta and Pittville soils have a fine-loamy textural control section. The Cupvar soils are 20 to 40 inches deep, fine throughout, and are in basins. The Graven soils are 20 to 40 inches deep to a hardpan on mounds.
DRAINAGE AND PERMEABILITY: Well drained; very slow or slow runoff; slow permeability.
USE AND VEGETATION: These soils are used for livestock grazing and irrigated crops. The vegetation is low sagebrush, antelope bitterbrush, rubber rabbitbrush, Lemmon needlegrass, and beardless wildrye.
DISTRIBUTION AND EXTENT: Northeastern, California. These soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Shasta County, Intermountain Soil Survey Area, California, 1994. Source of name is from Esperanza spring. MLRA is 21.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - the zone from the soil surface to 30 inches (A1, A2, Bt1, Bt2)
Argillic horizon - the zone from 6 to 44 inches (Bt1, Bt2, Bt3)
Duripan - the zone from 58 inches