LOCATION AKAD CA

Established Series
PWB/PGN/MAV/JHR/ARF/KJO/KP
12/2022

AKAD SERIES

The Akad series consists of moderately deep, somewhat excessively drained soils on foothills and mountains. These soils formed in material weathered from mixed conglomerate rock or sandstone. Slope ranges from 30 to 75percent. The mean annual precipitation is about 279 millimeters (11 inches) and the mean annual temperature is 17 degrees C (62 degrees F).

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Mollic Haploxeralfs

TYPICAL PEDON: Akad sandy clay loam - on an east-facing slope of 48 percent, under soft chess, wild oats, red brome, filaree, and other annual grasses and forbs at an elevation of 244 meters (800 feet). (Colors are for dry soil unless otherwise stated. When described on July 5, 1978, the soil was dry throughout.)

A--0 to 8 centimeters (0 to 3 inches); brown (7.5YR 4/4) sandy clay loam, dark brown (7.5YR 3/4) moist; moderate fine and coarse subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; few very fine tubular and interstitial pores; 10 percent gravel; slightly acid (pH 6.5) clear smooth boundary. (8 to 15 centimeters (3 to 6 inches) thick)

BA--8 to 15 centimeters (3 to 6 inches); dark reddish brown (5YR 3/4) gravelly sandy clay loam, dark brown (7.5YR 3/4) moist; strong medium and coarse subangular blocky structure; hard, friable, slightly sticky and slightly plastic; common very fine roots; few very fine tubular pores; 30 percent gravel; continuous thin clay films on peds and bridging sand grains; neutral (pH 7.2); clear wavy boundary. (5 to 13 centimeters (2 to 5 inches) thick)

Bt1--15 to 25 centimeters (6 to 10 inches)-; dark reddish brown (5YR 3/4) dry and moist very gravelly sandy clay loam; weak fine and medium subangular blocky structure; hard, friable, slightly sticky and plastic; common very fine roots; few very fine tubular pores; many thin clay films on peds and bridging sand grains; 55 percent gravel 15 to 50 mm in size; neutral (pH 7.0); clear smooth boundary. (5 to 13 centimeters (2 to 5 inches) thick)

Bt2--25 to 43 centimeters (10 to 17 inches); dark red (2.5YR 3/6) extremely gravelly sandy clay loam, dark reddish brown (5YR 3/4) moist; massive; hard, friable, slightly sticky and plastic; common very fine roots between soil and rock fragments; few very fine tubular pores; many thin clay films on peds and bridging sand grains; 75 percent gravel 15 to 50 mm in size; neutral (pH 7.0); clear wavy boundary. (8 to 20 centimeters (3 to 8 inches) thick)

C--43 to 61 centimeters (17 to 24 inches); reddish brown (5YR 4/4) extremely gravelly sandy clay loam, dark reddish brown (5YR 3/4) moist; massive; hard, friable, slightly sticky and slightly plastic; few very fine roots between soil and rock fragments; few very fine tubular pores; 80 percent gravel 15 to 75 mm in size; neutral (pH 6.7); abrupt irregular boundary. (0 to 33 centimeters (5 0 to 13 inches) thick)

R--61 centimeters (24 inches); sandstone conglomerate rock.

TYPE LOCATION: Merced County, California; about 4.5 miles west of the community of Santa Nella; l,800 feet south and l,600 feet east of the SW corner of Section 33, T. 9 S., R.8 E. USGS San Luis Dam Quad., California; latitude 37 degrees, 05 minutes, 52 seconds N and long. 121 degrees, 05 minutes, 58
seconds W.

RANGE IN CHARACTERISTICS: Depth to sandstone conglomerate rock is 51 to 76 centimeters (20 to 30 inches). The mean annual soil temperature is 15 to 20 degrees C (59 degrees to 68 degrees F). The soil temperature is below 8 degrees C (47 degrees F) in parts of January and February. It is not below 5 degrees C (41 degrees F) at any time. The soil between the depths of 18 and 61 centimeters (7 and 24 inches) or between 18 centimeters (7 inches) and a lithic contact is moist in all parts from January 1 to April 1 and dry in all parts from May 15 to October 31.

The A horizon is 7.5YR 3/4, 4/4, 5/4; or 10YR 4/3, 5/4. Moist colors are 7.5YR 3/2, 3/3, 3/4 or 10YR 3/4. Some pedons have up to 80 percent gravel and cobbles 25 to 150 mm in size, covering the
surface. Organic matter ranges from 1 to 2 percent. It has 17 to 30 percent clay content. Gravel content is 0 to 10 percent. Texture is loam or sandy clay loam. Reaction ranges from slightly acid to mildly alkaline.

The Bt horizon is 2.5YR 3/6; 5YR 3/4, 4/3, 4/4, 5/4; 7.5YR 4/6, 5/6; or 10YR 4/4. Moist colors are 2.5YR 3/4; 5YR 3/4, 4/4; 7.5YR 3/4, 4/4; or 10YR 3/4. It has 27 to 35 percent clay content and is
at least 1.2 times that of the A horizon. It is gravelly through extremely gravelly (Gravel content ranges from 30 to 75 percent. Cobble content ranges from 0 to 20 percent.) clay loam or sandy clay loam.

The C horizon is 5YR 4/4; 7.5YR 3/4; or 10YR 4/3. Moist colors are 5YR 3/4; 7.5YR 4/6; or 10YR 4/4.

COMPETING SERIES: These are the Agua Dulce, Pluth and Ashokawna series in the same family and the Conosta and Quinto soils in other families. Agua Dulce soils have a paralithic contact at 102 to 152 centimeters (40 to 60 inches) and a medium acid or slightly acid reaction in the texture control section. Pluth soils have not been described according to soil taxonomy but appear to be moist for a longer period than Akad soils. Ashokawna soils are dry in the 10 to 31 centimeter (4 to 12 inch) moisture control section from June 1 to October 1 and are strongly acid to slightly acid in the texture control section. Conosta soils have a fine texture control section. Quinto soils have a lithic contact within 51 centimeters (20 inches) of the surface.

GEOGRAPHIC SETTING: Akad soils are formed in material weathered from conglomerate rock or sandstone on hills and mountains and have slopes from 30 to 75 percent. Elevations range from 91 to 884 meters (300 to 2,900 feet). The climate is semiarid with hot dry summers and cool moist winters. The mean annual precipitation is 254 to 305 millimeters (10 to 12 inches). Mean January temperature is 7 degrees C (44 degrees F), mean July temperature is 24 degrees C (76 degrees F), and the mean annual temperature is 14 to 17 degrees C (58 to 62 degrees F). The frost-free season is 175 to 280 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Conosta soils and the Arburua, Oneil, and Wisflat soils. Arburua, Oneil, Saucito and Wisflat soils do not have an argillic horizon and have less than 35 percent coarse fragments in the texture control section. Saucito soils are shallow to hard bedrock.

DRAINAGE AND PERMEABILITY: Somewhat excessively drained, very high runoff, and moderately slow permeability.

USE AND VEGETATION: These soils are used as annual rangeland and as wildlife habitat. The vegetation is soft chess, wild oats, red brome, filaree, foxtail fescue, burclover,
tarweed, and other annual grasses and forbs.

DISTRIBUTION AND EXTENT: These soils are in the Coast Range foothills bordering the western edge of the Central San Joaquin Valley of California, MLRA 15. They are not extensive.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California

SERIES ESTABLISHED: Merced County, California 1984. Name is coined.

REMARKS: These soils were mapped as Contra Costa in the Los Banos Area, series 1939 report. They are being differentiated by having more than 35 percent coarse fragments and
less than 35 percent clay content in the texture control section which is typical of Contra Costa soils. pH determined by colormetric method using Thymol blue and Hellige-Truog Triplex
indicators. Texture determined by hydrometer method. Organic carbon estimated to be 0.7 percent in upper 10 cm based on dark colors and by organic carbon in nearby soils using Walkley-Black digestion method.

Last revised by the state on 4/85.

National Cooperative Soil Survey
U.S.A.