LOCATION OJAI CA
Established Series
Rev. RWK/LCL/RCH/RLR/JTW
02/2024
OJAI SERIES
The Ojai series consists of very deep, well drained soils that formed in alluvium derived from material weathering from mostly sandstone or related sedimentary rocks. Ojai soils are on alluvial fans and terraces and have slopes of 0 to 30 percent. The mean annual precipitation is about 600 millimeters and the mean annual air temperature is about 16 degrees C.
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Mollic Haploxeralfs
TYPICAL PEDON: Ojai soils in an area of Ojai very fine sandy loam on slope of less than 2 percent at 220 meters elevation in an orchard. (Colors are for dry soil unless otherwise noted).
A1--0 to 18 centimeters; brown (7.5YR 5/4) very fine sandy loam, dark brown (7.5YR 3/2), moist; massive and weak coarse platy structure; very friable, very hard, slightly sticky, slightly plastic; few very fine roots; and common fine and few very fine tubular and many very fine interstitial pores; moderately acid (pH 6.0); gradual wavy boundary.
A2--18 to 30 centimeters; brown (7.5YR 5/4) very fine sandy loam, dark reddish brown (5YR 3/3), moist; weak medium subangular blocky structure; very friable, very hard, slightly sticky, slightly plastic; common very fine roots; common fine and few medium and many very fine tubular and many very fine interstitial pores; moderately acid (pH 6.0); clear smooth boundary.
A3--30 to 41 centimeters; brown (7.5YR 5/4) very fine sandy loam, dark reddish brown (5YR 3/3), moist; weak medium subangular blocky structure, and weak coarse subangular blocky structure; very friable, very hard, slightly sticky, slightly plastic; few very fine roots; many very fine interstitial and common very fine tubular pores; slightly acid (pH 6.2); clear wavy boundary. (combined thickness of A horizons is 10 to 45 cm)
Bt1--41 to 64 centimeters; reddish brown (5YR 5/4) sandy clay loam, dark reddish brown (5YR 3/4), moist; weak medium angular blocky structure, and weak coarse angular blocky structure; firm, very hard, moderately sticky, moderately plastic; few very fine roots; common fine and few very fine tubular and many very fine interstitial pores; common distinct clay films on faces of peds; 2 percent gravels; slightly acid (pH 6.5); gradual smooth boundary.
Bt2--64 to 91 centimeters; reddish brown (5YR 5/4) sandy clay loam, reddish brown (5YR 5/4), moist; weak coarse prismatic structure, moderate medium and weak coarse angular blocky structure; firm, very hard, moderately sticky, moderately plastic; few very fine roots between peds; common very fine interstitial and few very fine tubular pores; 35 percent reddish brown (5YR 5/4), and dark reddish brown (5YR 3/4), moist, clay films on faces of peds and 35 percent distinct clay films on surfaces along pores; 2 percent gravels; slightly acid (pH 6.2); clear smooth boundary.
2Bt3--91 to 140 centimeters; light reddish brown (5YR 6/4) extremely cobbly clay, reddish brown (5YR 4/4), moist; weak medium subangular blocky structure; firm, very hard, very sticky, very plastic; few very fine tubular pores; common distinct clay bridges between sand grains and common distinct clay films on surfaces along pores; 30 percent gravels and 45 percent cobbles; slightly acid (pH 6.1). (combined thickness of the Bt horizons is 65 to 140 cm or more)
TYPE LOCATION: Ventura County, California, west of Meiners Oaks near Ventura River on terrace, 0.3 mile south of Roblar Drive on Rice Road, and 60 feet east of edge of road; 34.44593 degrees latitude, -119.28486 degrees longitude WGS84; UTM Zone 11, 3813969n, 290087e. U.S.G.S Quad Name: Matilija, California.
RANGE IN CHARACTERISTICS:
Mean annual soil temperature: 17 to 20 degrees C. Soil temperature is greater than 8 degrees C. the entire year.
Soil moisture: moist at a depth of 25 cm or more sometime from November or December and remains moist in some part until April or May.
Rock fragments: 0 to 25 percent gravels and cobbles in the upper part and 35 to 75 percent below a depth of 60 cm or more. Weighted average in the particle-size control section is less than 35 percent. Some pedons have parafragments.
Reaction: slightly acid to neutral throughout.
Clay content: 18 to 35 percent by average in the particle-size control section.
A horizons:
Dry color: 7.5YR or 5YR 6/4, 6/3, 5/2, 5/3, 5/4, 4/2, 4/4 or 10YR 5/2, 5/3, 4/2
Moist color: 7.5YR or 5YR or 10YR 3/3, 3/4, 4/2, 4/3
Texture: sandy loam, loam
Clay content: 12 to 18 percent
Rock fragments: 0 to 25 percent gravels and cobbles
Organic matter content: 1 to 3 percent at the surface and less than 1 percent in the lower part
Bt horizons:
Dry color: 7.5YR or 5YR 7/6, 7/4, 6/4, 6/3
Moist color: 7.5YR or 5YR 4/3, 4/4, 4/6, 5/4, 5/6
Texture: sandy clay loam, clay loam, or clay
Clay content: 22 to 35 percent in upper part and up to 45 percent in the lower part
Rock fragments: less than 35 percent in the upper part and 35 to 75 percent in the lower part. Fragments are dominantly cobbles but range from gravels to stones.
Some pedons have a BC horizon with 35 to 65 percent rock fragment and with sandy clay loam or sandy loam texture.
COMPETING SERIES:
Bellyspring soils: 50 to 102 centimeters to a paralithic contact of sandstone.
Coarsegold soils: 50 to 100 centimeters to a paralithic contact of schist.
Hicksville soils: less than 15 percent rock fragments in the lower part of the Bt horizon.
Olashes soils: less than 15 percent rock fragments throughout.
Padova soil: 100 to 150 cm to a lithic contact of gneiss.
Perkins soil: do not have cobbles in the Bt horizon within 100 centimeters of the mineral soil surface.
Pleasanton soils: have less than 35 percent rock fragments in the lower part of the Bt Horizon.
Redsluff soils: moderately well drained and are formed in alluvium derived from volcanic rock.
Rescue soils: less than 25 percent rock fragments throughout and are 100 to 200 cm to a paralithic contact of gabbrodiorite.
GEOGRAPHIC SETTING:
Landscape: valleys and canyons
Landform: alluvial fans and terraces
Parent Material: alluvium derived from mostly sandstone or related sedimentary rocks
Slope: 0 to 30 percent slopes
Elevation: 75 to 800 meters
Mean annual precipitation: 400 to 750 mm
Mean January temperature: about 12 degrees C.
Man July temperature: about 22 degrees C.
Mean annual temperature: 15.5 to 18.5 degrees C.
Frost-free season: 300 to 365 days
GEOGRAPHICALLY ASSOCIATED SOILS:
Anacapa soils: less than 18 percent clay throughout and are on slightly lower positions on alluvial fans.
Azule soils: have a fine particle-size class and are on hills.
Cortina soils: have a loamy-skeletal particle size class and are on slightly lower adjacent landforms of alluvial fans or floodplains.
Garretson soils: do not have an argillic horizon and are on slightly lower landforms of alluvial fans.
Kimball soils: have a fine particle-size class and are on lower terraces.
Saugus soils: 100 to 142 cm to a paralithic contact and are on dissected terraces and foothills.
Sespe soils: have are formed in residuum, have a mollic epipedon and are on adjacent hillslopes.
Sorrento soils: have secondary carbonates, a mollic epipedon and are on alluvial fans and fan skirts.
Zamora soils: have a fine-silty particle-size class and are on alluvial fans or stream terraces.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained; moderately slow saturated hydraulic conductivity.
USE AND VEGETATION: Used for citrus, avocado, hay, grains, pasture and scattered residential area. Native vegetation is live oak, grasses, forbs, sagebrush and various shrubs.
DISTRIBUTION AND EXTENT: Southern California Coastal Plains and Mountains, MLRA 19. This soil is moderately extensive.
SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: DAVIS, CALIFORNIA
SERIES ESTABLISHED: Ventura Area, California 1917.
REMARKS:
Diagnostic horizons and features recognized in this pedon include:
Ochric epipedon: the zone from 0 to 41 cm
Argillic horizon: the zone from 41 to 140 cm
Particle-size control section: the zone from 41 to 91 cm
Some pedons in Ventura County have stony or cobbly textures throughout due to eroded surfaces or turned up during farm operations, and are included in this concept.
Ojai soils correlated in Los Angeles County have less than 35 percent rock fragments in the lower part of the Bt horizons and are included in this concept
This series was reactivated in 2019 and updated to meet National Cooperative Soil Survey standards. The Ojai series was formerly combined with the Perkins series from Yuba County.
This soil was formerly classified as Noncalcic Brown soils.
ADDITIONAL DATA:
NASIS User Site/Pedon ID: 1968CA111001
Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)
National Cooperative Soil Survey
U.S.A.