LOCATION REYES                   CA

Established Series
Rev. TDC/ET/GML/RLR
05/2020

REYES SERIES

The Reyes series consists of very deep, poorly drained soils that formed in alluvium along the margin of bays. Reyes soils are on reclaimed and protected marsh areas. Slopes are 0 to 2 percent. The mean annual precipitation is about 650 millimeters. The mean annual temperature is about 14.5 degrees C.

TAXONOMIC CLASS: Fine, mixed, active, acid, thermic Typic Sulfaquents

TYPICAL PEDON: Reyes clay, on a gently undulating slope of 1 percent at 1 meter elevation. (Colors are for dry soil unless otherwise stated. When described (11/07/17). Water table at about 152 cm.)

Oi--0 to 3 cm; brown (10YR 5/3) slightly decomposed plant material, dark brown (10YR 3/3) moist; abrupt smooth boundary. (0 to 5 cm thick)

A--3 to 18 cm; light brownish gray (10YR 6/2) clay, brown (10YR 4/3) moist; moderate medium subangular blocky structure parting to moderate medium granular structure; moderately hard, friable, moderately sicky and very plastic; common fine and very fine roots; common very fine irregular and common very fine tubular pores; 5 percent fine distinct irregular oxidized iron masses on surfaces along pores with clear boundaries; very strongly acid (pH 4.6); gradual smooth boundary.

Ag--18 to 38 cm; brown (10YR 5/3) clay, dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; hard, friable, moderately sticky and very plastic; common very fine roots; common very fine irregular pores; 7 percent fine faint irregular oxidized iron masses on the surface along pores; extremely acid (pH 4.4); clear smooth boundary. (Combined thickness of A horizons is 15 to 50 cm)

Bjg1--38 to 60 cm; grayish brown (2.5Y 5/2) silty clay, very dark grayish brown (2.5Y 3/2) moist; moderate coarse angular blocky structure; very hard, firm, moderately sticky and very plastic; common very fine roots; common very fine irregular pores; 5 percent medium distinct irregular oxidized iron masses on surfaces of peds with clear boundaries and 4 percent fine prominent pale yellow (2.5Y 7/4) dendritic jarosite masses on surfaces along root channels with clear boundaries; extremely acid (pH 4.2); clear smooth boundary;

Bjg3--60 to 95 cm; grayish brown (2.5Y 5/2) clay, dark olive gray (5Y 3/2) moist; moderate coarse angular structure; very hard, friable, moderately sticky and very plastic; common fine and very fine roots; common very fine irregular pores; 7 percent oxidized iron masses, 7 percent fine prominent pale yellow (2.5Y 7/4) irregular jarosite masses and 3 percent manganese masses in the matrix; extremely acid (pH 4.0); gradual smooth boundary.

Bjg3--95 to 115 cm; clay dark grayish brown (2.5Y 4/2) moist; moderate medium subangular blocky structure; very hard, friable, moderately sticky and very plastic; 5 percent medium prominent moderately hard cylindrical oxidized iron concretions on surfaces of root channels with sharp boundaries and 5 percent medium prominent irregular pale yellow (2.5Y 7/4) jarosite masses in matrix with clear boundary; ultra acid (pH 3.3); gradual smooth boundary.

Bjg4--115 to 140 cm; clay dark gray (2.5Y 4/1) moist; moderate medium subangular blocky structure; very hard, friable, moderately sticky and moderately plastic; 5 percent medium prominent moderately hard cylindrical oxidized iron concretions on surfaces of root channels with sharp boundaries and 5 percent medium prominent irregular pale yellow (2.5Y 7/4) jarosite masses in matrix with clear boundary; extremely acid (pH 3.7); clear smooth boundary. (Combined thickness of B horizons is 75 to 180 cm)

2Cg--140 to 160cm; clay dark gray (N 4/) moist; massive; very hard, friable, moderately sticky and moderately plastic; 5 percent oxidized iron masses, 2 percent manganese masses and 2 percent oxidized iron concentrations in the matrix; ultra acid (pH 3.2);

TYPE LOCATION: Sonoma County, California; 90 meters east of Skaggs Island Road, and 1,000 meters north from Bridge over Napa Slough. USGS Sears Point topographic quadrangle; latitude 38 degrees, 10 minutes 8.80 seconds N. and longitude 122 degrees, 22 minutes 54.10 seconds W., WGS84.

RANGE IN CHARACTERISTICS:

Mean annual soil temperature: 15 to 16 degrees C.
Soil moisture: drained to a depth of 50 centimeters or more. Tidal saturation is restored in some locations.

Depth to redoximorphic features: at the soil surface or directly below the Ap horizon.

Organic matter: averages less than 15 percent in the control section. The profile contains major strata of mineral soil low in organic matter and thin strata of soil with 5 to 30 percent organic matter.
Clay content: 50 to 60 percent clay by weighted average in the particle-size controls section.
n value: 0.3 to 0.7.

Reaction: with cultivation/drainage the soil becomes oxidized and is slightly to extremely acid. The lower horizons (3Cg horizons) are commonly extremely acid but range from very strongly acid to ultra acid within a space of a few centimeters. Usually the more the soil is drained and oxidized, the more acid it becomes.

Salinity: non-saline to strongly saline; increasing with depth.
Sodicity: non sodic to slightly sodic; increasing with depth.
Sulfidic materials: throughout the profile.

A(p)(g) horizon
Hue: 10YR or 2.5Y dry and moist
Value: 5 to 7 dry; 3 to 5 moist
Chroma: 1 to 6 dry; 1 to 3 dry and moist
Texture: clay or silty clay
Clay content: 50 to 65 percent
Electrical conductivity (EC): 0 to 4 dS/m
Sodium adsorption Ratio (SAR): 0 to 6

B(j)(g) horizon
Hue: 10yr, 5Y or N dry and moist
Value: 5 or 6 dry, 4 or 5 moist
Chroma: 0, 1 or 2 dry; 0 or 1 moist.
Texture: clay or silty clay
Clay content: 50 to 65 percent
Electrical conductivity: 2 to 8 dS/m
Sodium adsorption ratio (SAR): 0 to 12

2Cg horizon (where is occurs)
Hue: 5Y or N
Texture: clay or silty clay
Clay content: 50 to 65 percent
Electrical conductivity (EC): 4 to 28 dS/m
Sodium adsorption ratio (SAR): 0 to 22

COMPETING SERIES: There are no competing series.

GEOGRAPHIC SETTING: The Reyes soils are on saltwater marshes which are adjacent to bodies of sea water and are now drained by large ditches and protected by levees and dikes. Slopes are 0 to 2 percent. Elevations are between 1 meter below sea level to about 3 meters above. The soils formed in mixed bay and stream alluvium under marsh type plants such as pickleweed, bulrush, and saltgrass. The climate is Mediterranean with hot, dry summers and cool moist winters. Mean annual precipitation is 480 to 735 millimeters. The mean annual air temperature is 14 to 15 degrees C; average January temperature is about 8 degrees C; average July temperature is about 22 degrees C. Frost-free season is 345 to 365 days.

GEOGRAPHICALLY ASSOCIATED SOILS:
Alviso soils: do not contain polysulfides and are nonacid.
Clear Lake soils: are not affected by sea water and lack high levels of polysulfides.
Joice soils: have 30 to 50 percent organic matter in the series control section.
Novato soils: have tidal influence and have neutral to alkaline reaction classes.
Suisun soils: have more than 50 percent organic matter in the series control section.

DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Poorly drained; low saturated hydraulic conductivity. Water table fluctuates from 1 to 1.5 meters. The soils are protected by levees and are flooded only during periods of severe storms and very high tides.

USE AND VEGETATION: Reyes soils have been reclaimed. Reyes soils are used for production of oat hay, grain, and livestock pasture. Other areas are used as game refuges or by duck clubs. Vegetation in uncultivated areas is annual grasses, saltgrasses, coyotebush, and lambsquarter.

DISTRIBUTION AND EXTENT: Along the edges of Suisun, San Francisco and San Pablo Bays and scattered in the Sacramento Delta in California. The series is of moderate extent.

SOIL SURVEY REGIONAL OFFICE (SSRO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Sonoma County, California, 1971

REMARKS: Diagnostic horizons and features recognized in this profile are:

Ochric epipedon: the zone from 3 to 18 cm
Aquic conditions: the zone from 3 to 160 cm
Redoximorphic concentrations: the zone from 3 to 160 cm
Sulfidic materials: the zone from 3 to 160 cm
Sulfuric horizon: the zone from 38 to 140 cm

The Reyes soils formerly were a part of the Alviso and Ryde series. The part of the Reyes soils mapped in other survey areas that are not protected by levees and are flooded daily by tides would now be recognized as the Novato series.

ADDITIONAL DATA:

User site/pedon ID: S2018CA097001

Type location relocated within Sonoma County in 2020 following a multi-year project to disentangle series concepts for Reyes and Novato soils.

Sampled by the Riverside Laboratory 6/28/61. Sample No. S61 Calif-49-13, SSIR No. 24, June, 1973.
Original User Pedon/Site ID S1961CA097013

Classified using the Twelfth Edition Keys to Soil Taxonomy (2014)

---

National Cooperative Soil Survey
U.S.A.