LOCATION LOCKWOOD CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, thermic Pachic Argixerolls
TYPICAL PEDON: Lockwood shaly loam, orchard. (Colors are for dry soil unless otherwise noted.)
Ap1--0 to 3 inches; gray (10YR 5/1) shaly loam, very dark grayish brown (10YR 3/2) moist; moderate fine and medium subangular blocky structure; slightly hard, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine interstitial pores; about 18 percent fine gravel-size fragments; very strongly acid (pH 5.0); abrupt smooth boundary. (2 to 5 inches thick)
Ap2--3 to 16 inches; gray (10YR 5/1) shaly loam, very dark brown (10YR 2/2) moist; weak very coarse angular blocky structure parting to moderate medium granular; slightly hard, friable, slightly sticky and slightly plastic; few very fine and fine roots; common very fine interstitial and very few tubular pores; horizon compacted due to tillage; about 18 percent fine gravel-size shale fragments; slightly acid (pH 6.5); gradual smooth boundary. (6 to 13 inches thick)
AB--16 to 26 inches; gray (10YR 5/1) shaly loam, very dark brown (10YR 2/2) moist; strong medium granular structure; slightly hard toward soft, very friable, slightly sticky and slightly plastic; few very fine roots; many very fine interstitial, common fine and medium tubular pores; about 18 percent fine gravel-size shale fragments; neutral (pH 7.0); gradual smooth boundary. (9 to 12 inches thick)
BA--26 to 40 inches; gray (10YR 5/1) shaly heavy loam, very dark grayish brown (10YR 3/2) moist; moderate medium granular structure; soft, very friable, slightly sticky and slightly plastic; few fine and medium roots; many very fine interstitial pores and common fine tubular worm holes; about 26 percent shale fragments 3/4 to 3 inches diameter; neutral (pH 7.0); clear irregular boundary. (10 to 16 inches thick)
Bt1--40 to 57 inches; brown (10YR 5/3) shaly clay loam, dark yellowish brown (10YR 4/4) moist; massive; slightly hard, very friable, sticky and plastic; many very fine interstitial pores; continuous thin clay films on shale fragments and few moderately thick films lining pores; suggestion of 1/2 inch dark brown horizontal lamellae; about 25 percent fine to coarse shale fragments; slightly alkaline (pH 7.5); gradual wavy boundary. (8 to 20 inches thick)
Bt2--57 to 82 inches; brown (10YR 5/3) shaly clay loam, dark brown (10YR 4/3) moist; massive; slightly hard, very friable, sticky and plastic; many very fine interstitial pores; continuous thin clay films lining pores; suggestion of 1/2 inch thick dark brown horizontal lamellae; about 25 percent fine to coarse shale fragments; slightly alkaline; gradual wavy boundary (10 to 25 inches thick)
2Bt3--82 to 90 inches; pale brown (10YR 6/3) heavy loam, dark brown (10YR 4/3) moist; massive; slightly hard, very friable, slightly sticky and slightly plastic; few thin clay films lining pores; slightly alkaline (pH 7.5).
TYPE LOCATION: Monterey County, California; about 7 miles NW of King City; 100 feet SW, 50 feet NW from corner of Teague and Central Avenue.
RANGE IN CHARACTERISTICS: The solum is more than 40 inches thick. The soil between depths of about 5 and 15 inches becomes moist in some part in November or early December and remains moist until May. The mean annual soil temperature is 59 degrees to 62 degrees F. The average summer soil temperature is 64 degrees to 72 degrees F. and the average winter soil temperature is 50 degrees to 54 degrees F. Rock fragments, mostly pebble sized angular or subangular shale fragments, make up 15 to 35 percent of the soil between depths of 10 and 40 inches and make up 15 to 60 percent of the soil below 40 inches. Organic matter content is 2 to 5 percent in the upper 20 inches and decreases regularly to less than 1 percent between depths of 24 to 40 inches. The lithologic discontinuity may not occur in all pedons.
The A horizon is gray, dark gray, grayish brown or dark grayish brown (10YR 5/1,k 4/1, 5/2, 4/2). It is loam or clay loam, and has 15 to 35 percent shale fragments. The A1 horizon has weak to strong granular or weak to moderate subangular blocky or angular blocky structure. It is generally slightly acid to slightly alkaline although some areas may be strongly acid or moderately acid in the surface as a result of amendments, fertilizers, or other cultural practices. An AB or BA horizon separates the A and Bt horizons.
The Bt horizon is grayish brown, light brownish gray, dark brown, brown, pale brown, very pale brown, dark yellowish brown, yellowish brown, or light yellowish brown (10YR 5/2, 6/2, 4/3, 5/3, 6/3, 7/3, 4/4, 5/4, 6/4). It is heavy loam or clay loam and has 5 to 10 percent more clay absolute, than the A horizon. It is neutral to moderately alkaline, and is not calcareous. The Bt horizon is massive or it has weak to moderate subangular blocky structure.
The C horizon, when present, is variable but on the average it is loamy and stratified. It is pale brown, very pale brown or light yellowish brown (10YR 6/3, 7/3, 6/4, 7/4).
COMPETING SERIES: These are the Arujo (T), Botella, Chico, Corona, Elkhorn, Havala, McCoy and Saltcanyon series. Arujo and McCoy soils are underlain by a paralithic contact. Botella and Elkhorn soils have less than 15 percent rock fragments in the solum. Elkhorn soils also have shot or concretions in the solum.
GEOGRAPHIC SETTING: The Lockwood soils are on alluvial fans and bench terraces in alluvium from dominantly siliceous shale. Slopes are 0 to 15 percent. Elevations are 100 to 2,000 feet. The climate is dry subhumid mesothermal with warm dry summers and cool moist winters. Annual precipitation is 12 to 35 inches. The average January temperature is about 48 degrees to 51 degrees F., average July temperature is 62 degrees to 70 degrees F., and the mean annual temperature is 58 degrees to 60 degrees F. The freeze-free season is 210 to 310 days. Coastal phases of this soil exist which have average January temperature of about 54 degrees to 58 degrees F. and frost free seasons of 310 to 350 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Chamise, Metz, Mocho, Rincon, Salinas and Santa Lucia soils. Chamise soils have a base saturation of 50 to 74 percent and more than 35 percent clay in the Bt horizon. Metz soils are sandy throughout and have value of 6 or more and less than 1 percent organic matter in the A horizon. Mocho soils lack a Bt horizon and are calcareous throughout. Rincon soils have hard and massive A horizons and have more than 35 percent clay in the B2t horizon. Salinas soils lack a Bt horizon and have secondary lime within depth of one meter. Santa Lucia soils lack a Bt horizon, contain more than 35 percent rock fragments and are underlain at depths of 20 to 40 inches by a lithic contact.
DRAINAGE AND PERMEABILITY: Well drained; low to high runoff; moderately slow permeability.
USE AND VEGETATION: Used for growing irrigated row crops, truck crops, truck crops, alfalfa, some orchards, and extensive areas used for growing dryland grain, and some used as rangeland. Naturalized and native vegetation is annual grasses and forbs, a few scattered oak, and some brush.
DISTRIBUTION AND EXTENT: Valleys of the central and southern part of the coast Range in California particularly in the Salinas River watershed. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Monterey County (King City Area), California, 1924.
REMARKS: Riverside Laboratory, Pedon No. S65-Calif-27-1.
OSED scanned by SSQA.