LOCATION MODJESKA CA

Established Series
Rev. JKW/LAB/GMK
01/2017

MODJESKA SERIES

The soils of the Modjeska series are deep, well-drained soils formed in mixed alluvium. They are on terraces in the Coastal plain of southern California. The mean annual precipitation is 14 to 20 inches and the mean annual temperature is about 62 degrees F.

TAXONOMIC CLASS: Loamy-skeletal, mixed, superactive, thermic Typic Haploxerepts

TYPICAL PEDON: Modjeska gravelly loam, cultivated. (Colors are for dry soil unless otherwise noted.)

Ap--0 to 5 inches, brown (10YR 5/3) gravelly loam, dark brown (7.5YR 3/2) when moist; moderate, medium and coarse, granular structure; slightly hard, friable, slightly sticky and slightly plastic; many very fine and fine roots; few very fine tubular pores; about 15 to 20 percent gravel by volume; slightly acid (pH 6.5); abrupt, smooth boundary. 3 to 11 inches thick.

B1--5 to 14 inches; brown (7.5YR 5/2) gravelly loam, dark brown (7.5YR 3/2) when moist; weak, fine and medium, subangular blocky structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular pores; about 15 to 20 percent gravel by volume; slightly acid (pH 6.5); gradual, smooth boundary. 6 to 12 inches thick.

B2--14 to 28 inches; reddish-brown (5YR 5/3) very cobbly loam, dark reddish brown (5YR 3/3) when moist; moderate, fine and medium, granular structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular and many fine interstitial pores; common thin clay films in pores and many moderately, thick clay films around cobblestones and pebbles; about 30 percent by volume cobblestones and 20 percent by volume gravel; slightly acid (pH 6.5); gradual, smooth boundary. 6 to 14 inches thick.

B3--28 to 47 inches; reddish-brown (5YR 5/3) very cobbly loam, dark reddish brown (5YR 3/3) when moist; moderate, fine and medium structure; slightly hard, friable, slightly sticky and slightly plastic; common very fine roots; common very fine tubular and many fine interstitial pores; many thin clay films as bridges, many moderately thick clay films around cobblestones and pebbles; about 35 percent by volume cobblestones and 25 percent by volume gravel; slightly acid (pH 6.5); gradual, smooth boundary. 11 to 18 inches thick.

C--47 to 71 inches; light-brown (7.5YR 6/4) very gravelly loamy sand, brown (7.5YR 5/4) when moist; single grained; loose; few very fine roots; about 50 percent gravel by volume and 30 percent cobblestones by volume; slightly acid (pH 6.5).

TYPE LOCATION: Orange County, California; on Rancho Mission Viejo, Plano Trabuco, approximately 0.9 miles north, northeast of triangulation point 1,116; NW 1/4 sec. 22, T.6S., R.7W.

RANGE IN CHARACTERISTICS: The solum is 41 to 80 inches thick. Pebbles or cobblestones or both are present throughout the soil. They make up 35 to 60 percent by volume of the 10- to 40-inch control section. The mean annual soil temperature is about 63 degrees F. The soil is continuously dry from late April or May until November; it is moist in some parts between depths of 8 and 24 inches all the rest of the year.

The A horizon is grayish brown or brown in 10YR or 7.5YR hue. It is gravelly loam, gravelly very fine sandy loam, or gravelly fine sandy loam and has granular or subangular blocky structure. This horizon is slightly acid to medium acid. It has less than 1 percent organic matter.

The B horizon is reddish brown or brown in 7.5YR or 5YR hue. It is very gravelly to very cobbly loam and has 2 to 3 percent more clay than the A horizon. This horizon has granular or subangular blocky structure. It is slightly or medium acid.

COMPETING SERIES: These are the Agua Dulce, Anderson, Arbuckle, Cortina, Olivenhain, Soboba, and Soper series. Agua Dulce, Arbuckle,Olivenhain, and Soper soils have argillic horizons. Anderson and Cortina soils lack cambic horizons and the organic matter decreases irregularly with depth. Soboba soils lack cambic horizons and have sandy-skeletal control sections.

GEOGRAPHIC SETTING: The Modjeska soils are nearly level to strongly sloping and are on terraces at elevations from 200 to 1,500 feet. They formed in mixed gravelly and cobbly sandy alluvium high in metabasic, metasedimentary, and granitic rocks. The climate is dry subhumid, mesothermal with cool moist winters and somewhat foggy dry summers. The mean annual precipitation is 14 to 20 inches. Average January temperature is about 52 degrees F., average July temperature is about 71 degrees F.; and mean annual temperature is about 62 degrees F. The average frost-free season is 280 to 330 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the Corralitos and Solano soils and the competing Soboba and Olivenhain soils. Corralitos soils are sandy, lack a cambic horizons, and have less than 35 percent rock fragments in the control section. Solano soils have an abrupt A-B horizon boundary, a natric horizon, and have less than 35 percent rock fragments.

DRAINAGE AND PERMEABILITY: Well-drained; slow to medium runoff; moderate permeability.

USE AND VEGETATION: Used mainly for growing dryland small grain, pasture, and irrigated citrus. Some areas are now being used for urban development. Vegetation in uncultivated areas is chamise, flattop buckwheat, sumac, California sagebrush, and annual grasses and forbs.

DISTRIBUTION AND EXTENT: The series is inextensive and occurs on the coastal plain in southern California in MLRA 19.

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

SERIES ESTABLISHED: Orange and Western Part of Riverside Counties, California, 1974. Presumably, the name refers to Helena Modjeska, a renowned Polish Shakespearean Actress.

REMARKS: The Modjeska soils would have been classified as (minimal) Noncalcic Brown soils. Initially, the Modjeska series was regarded as having a mollic epipedon and an argillic horizon. Summation of data show an ochric epipedon and a cambic horizon.

ADDITIONAL DATA: NSSL pedon S71CA-059-011 (type location) and S71CA-059-002 (range in characteristics)

OSED scanned by SSQA. Last revised by state on 7/74.

National Cooperative Soil Survey
U.S.A.