LOCATION FERNANDEZ CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, thermic Ultic Palexeralfs
TYPICAL PEDON: Fernandez sandy loam, on a west facing 1 percent slope under a cover of annual grasses and forbs at an elevation of 190 feet, (58 m). When described on 4/30/1997 the soil was dry to 18 inches, (46 cm) and slightly moist from 18 to 73 inches, (46 to 185 cm). (Colors are for dry soil unless otherwise noted).
A--0 to 2 inches, (0 to 5 cm); brown (7.5YR 5/4) sandy loam, dark reddish brown (5YR 3/4) moist; 18 percent clay; strong fine platy parting to moderate fine subangular blocky structure; slightly hard, friable, nonsticky, slightly plastic; many very fine roots; few very fine tubular pores; 10 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; abrupt smooth boundary. (2 to 13 inches, (3 to 33 cm) thick)
Bt1--2 to 6 inches, (5 to 15 cm); yellowish red (5YR 5/6) sandy clay loam, dark red (2.5YR 3/6) moist; 24 percent clay; strong medium subangular blocky structure; extremely hard, friable, slightly sticky, moderately plastic; common very fine roots; few very fine tubular pores; 10 percent clay films on all faces of peds; 10 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; abrupt smooth boundary.
Bt2--6 to 18 inches, (15 to 46 cm); yellowish red (5YR 5/6) sandy clay loam, dark reddish brown (2.5YR 3/4) moist; 28 percent clay; moderate medium subangular blocky parting to strong fine granular structure; slightly hard, firm, slightly sticky, moderately plastic; few very fine and fine roots; few fine tubular and common very fine tubular pores; 10 percent clay films on faces of peds; 10 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; abrupt wavy boundary. (Combined thickness of the Bt horizon is 15 to 45 inches, (38 to 114 cm) thick)
2Bt3--18 to 28 inches, (46 to 71 cm); red (2.5YR 5/6) clay loam, dark reddish brown (2.5YR 3/4) moist; 38 percent clay; strong medium angular blocky structure; extremely hard, very firm, moderately sticky, very plastic; few very fine and fine roots; common very fine tubular pores; 40 percent clay films on faces of peds; 10 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; clear smooth boundary.
2Bt4--28 to 44 inches, (71 to 112 cm); red (2.5YR 5/6) clay loam, reddish brown (2.5YR 4/4) moist; 38 percent clay; strong medium angular blocky structure; extremely hard, very firm, moderately sticky, very plastic; few fine roots; few fine tubular and common very fine tubular pores; 50 percent clay films on faces of peds; 5 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; abrupt smooth boundary.
2Bt5--44 to 57 inches, (112 to 145 cm); red (2.5YR 5/6) clay, dark red (2.5YR 3/6) moist; 42 percent clay; strong medium angular blocky structure; extremely hard, very firm, moderately sticky, very plastic; few very fine roots; few very fine tubular pores; 60 percent clay films on faces of peds; 5 percent fine distinct threadlike iron depletions with diffuse boundaries lining pores; 10 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; clear smooth boundary.
2Bt6--57 to 65 inches, (145 to 165 cm); red (2.5YR 5/6) gravelly clay, dark red (2.5YR 3/6) moist; 45 percent clay; strong medium subangular blocky structure; extremely hard, very firm, moderately sticky, very plastic; few very fine roots; few very fine tubular pores; 40 percent clay films on faces of peds; 5 percent fine distinct threadlike iron depletions with diffuse boundaries lining pores; 20 percent well rounded gravel; moderately acid, pH 6.0 by Hellige-Truog; clear wavy boundary.
2Bt7--65 to 73 inches, (165 to 185 cm); red (10R 5/6) gravelly clay loam, dark red (10R 3/6) moist; 37 percent clay; strong medium subangular blocky structure; extremely hard, very firm, moderately sticky, very plastic; few very fine roots; few very fine tubular pores; 30 percent clay films on faces of peds; 20 percent very coarse distinct irregular iron depletions with diffuse boundaries around rock fragments; 25 percent well rounded gravel; slightly acid, pH 6.2 by Hellige-Truog; abrupt wavy boundary. (Combined thickness of the 2Bt horizon is 23 to 55 inches, (58 to 140 cm) thick)
3Btq--73 to 85 inches, (185 to 216 cm); duripan; yellowish red (5YR 5/6) gravelly sandy loam, dark reddish brown (5YR 3/4) moist; 5 percent clay; massive; extremely hard, very firm, weakly cemented, cemented by silica, nonsticky, nonplastic; few very fine tubular pores; 20 percent clay films on rock fragments; 20 percent fine mica flakes throughout; 20 percent well rounded gravel; slightly acid, pH 6.2 by Hellige-Truog; Does not slake in water after 2 hours. About 75 percent is weakly cemented, 25 percent moderately cemented.
TYPE LOCATION: Butte County, California, about 6.43 miles southeast of Nelson, approximately 500 feet west and 2700 feet south of the northeast corner of Section 8, Township 19 N., Range 3 E., 39 degrees, 30 minutes, 59 seconds North latitude and 121 degrees, 39 minutes, 8 seconds West longitude, NAD83 - U.S.G.S. Quad: Shippee, California.
RANGE IN CHARACTERISTICS: Depth to weakly cemented to moderately cemented duripan ranges from 60 to 80 inches (152 to 205 cm) or more and depth to 2Bt horizon ranges from 18 to 49 inches, (46 to 124 cm). The mean annual soil temperature is 61 to 64 degrees F, (16 to 18 degrees C). The particle-size control section averages 20 to 35 percent clay and 0 to 20 percent rock fragments, mostly gravel. Mineralogy is mixed. A fluctuating water table can occur between the top of the duripan and 40 inches, (102 cm) below the surface of the soil from December through April. Rock fragments on the surface range from 2 to 15 percent gravel.
The A horizon dry color is 7.5YR 5/4, 5/6 or 6/4. Moist color is 5YR 3/3, 3/4, 4/3, 7.5YR 3/4 or 4/4. Texture is sandy loam, fine sandy loam, gravelly sandy loam or gravelly loam. Clay content ranges from 15 to 18 percent. Rock fragments range from 5 to 20 percent gravel. Organic matter ranges from 0.5 to 1.2 percent. Reaction ranges from moderately acid to slightly acid.
The Bt horizon dry color is 5YR 5/6, 6/6, 7.5YR 6/4 or 6/6. Moist color is 2.5YR 3/4, 3/6, 4/4, 5YR 3/4, 4/4, 7.5YR 3/4 or 4/4. Texture is sandy clay loam, gravelly sandy clay loam, loam, clay loam or sandy loam. Clay content ranges from 18 to 30 percent. Rock fragments range from 5 to 33 percent gravel. Redoximorphic features range from 0 to 20 percent soft oxidized iron masses and 0 to 5 percent soft manganese masses. Organic matter ranges from 0.1 to 0.5 percent. Reaction ranges from moderately acid to neutral.
The 2Bt horizon dry color is 2.5YR 4/8, 5/6, 10R 5/6, 5YR 5/6, 6/6, 7.5YR 5/4, 6/6 or 7/6. Moist color is 2.5YR 3/4, 3/6, 4/4, 4/6, 10R 3/6, 4/6, 5YR 4/6, 7.5YR 4/4 or 4/6. Texture is clay loam, clay, sandy clay, gravelly clay or very gravelly sandy clay. Clay content ranges from 35 to 50 percent. Rock fragments range from 2 to 45 percent gravel. Redoximorphic features range from 0 to 5 percent iron depletions, 0 to 15 percent soft oxidized iron masses and 0 to 10 percent soft manganese masses. Organic matter ranges from 0.1 to 0.5 percent. Reaction ranges from moderately acid to neutral.
COMPETING SERIES: These are the Bruella, Natomas and Parkshill series. Bruella and Parkshill soils do not have a clayey subsoil. Natomas soils lack a duripan.
GEOGRAPHIC SETTING: Fernandez soils are on intermediate terraces. Slopes range from 0 to 9 percent. These soils formed in alluvium weathered from mixed rocks such as quartz-diorite, greenschist, diorite, tuff, andesite and basalt. Elevation is 110 to 258 feet, (33 to 79 m). Mean annual precipitation is 20 to 26 inches, (508 to 660 mm). The mean annual temperature is 60 to 62 degrees F, (16 to 17 degrees C). Frost free season is 250 to 255 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Oroville, Thermalito and Thompsonflat soils. The Oroville soils are moderately deep to duripan, are fine and are in swales. Thermalito soils are moderately deep to a duripan, are fine-loamy and are on mounds. Thompsonflat soils are very deep, are fine-loamy, have clay content that decreases by 20 percent from the maximum at a depth of 60 inches, (152 cm), lack a duripan and have noncemented to very weakly cemented substratum.
DRAINAGE AND PERMEABILITY: Moderately well drained; low runoff; moderate to moderately rapid saturated hydraulic conductivity in the A horizon, moderately slow to moderate in the Bt horizon, moderately slow in the upper 2Bt horizon, slow in the lower 2Bt horizon and very slow in the 3Btq horizon. A fluctuating water table can occur between the top of the duripan and 40 inches, (102 cm) below the surface of the soil from December through April.
USE AND VEGETATION: This soil is used for livestock grazing, wildlife habitat, home site development and in some areas, olive orchards. Vegetation is soft chess, ripgut brome, wild oat, Mediterranean barley, Italian ryegrass, annual fescue, filaree, rose clover, bluedicks, brodiaea, fiddleneck, vetch, bicolor lupine, medusahead, mullein and dandelion.
DISTRIBUTION AND EXTENT: Butte County, California and occurs in (262Ag) Hardpan Terraces subsection of the (262A) Great Valley section. MLRA 17 - Sacramento Valley. The soils are not extensive and are associated with the Laguna formation.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005. Source of name from Fernandez Land Grant.
REMARKS: Diagnostic horizons and features recognized in this pedon are:
Ochric epipedon - zone from 0 to 2 inches, (0 to 5 cm) (A)
Argillic horizon - zone from 2 to 73 inches, (5 to 185 cm) (Bt1, Bt2, 2Bt3, 2Bt4, 2Bt5, 2Bt6, 2Bt7)
Duripan - zone from 73 to 85 inches, (185 to 216 cm) (3Btq)
Particle-size control section for this pedon: 2 to 22 inches, (5 to 56 cm)
The soil moisture control section - zone from 7 to 21 inches, (18 to 53 cm) is dry in all parts from about June to October (about 180 days).
ADDITIONAL DATA: Based on data from S84-CA-115-001, NSSL, Lincoln, NE. Data indicates organic carbon is greater than 0.7 percent in the upper 6 inches and is less below. Base saturation (sum of cations) is less than 75 percent in the upper 19 inches and is greater than 75 percent below.