LOCATION NISENE CAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, superactive, mesic Pachic Ultic Argixerolls
TYPICAL PEDON: Nisene loam, forested. (Colors are for dry soil unless otherwise noted.)
0--2 inches to 0; mat of leaves, needles and twigs, variably decomposed.
A1--0 to 10 inches; dark grayish brown (10YR 4/2) loam, black (10YR 2/1) moist; strong medium and coarse granular structure; slightly hard, friable, slightly sticky and slightly plastic; common fine, many medium and coarse roots; many fine and medium interstitial and tubular pores; neutral (pH 6.6); clear wavy boundary. (9 to 14 inches thick)
B21t--10 to 22 inches; brown (7.5YR 5/2) clay loam, dark brown (7.5YR 3/2) moist; moderate medium and coarse subangular blocky structure; hard, friable, sticky and plastic; common fine, many medium and coarse roots; many fine, common medium and many coarse tubular and common fine interstitial pores; common thin clay films on faces of peds, and few thin clay films lining pores; estimated 10 percent by volume angular pebbles; slightly acid (pH 6.3); gradual wavy boundary. (10 to 16 inches thick)
B22t--22 to 32 inches; brown (7.5YR 5/2) clay loam, dark brown (7.5YR 3/2) moist; moderate medium and coarse subangular blocky structure; hard, friable, sticky and plastic; common fine, many medium and coarse roots; common fine, many medium and coarse tubular pores; common and few thin clay films lining pores; estimated 10 percent angular pebbles, about 1/2 crushing under hand pressure; slightly acid (pH 6.1); gradual wavy boundary. (9 to 14 inches thick)
B23t--32 to 48 inches; brown (7.5YR 5/2) clay loam, dark brown (7.5YR 3/2) moist; moderate medium subangular blocky structure; hard, friable, sticky and plastic; common fine and many medium and coarse roots; common fine and many medium and coarse tubular pores; few thin clay films lining pores, common thin clay films on faces of peds; estimated about 10 percent angular pebbles most crushing under hand pressure; slightly acid (pH 6.1); diffuse irregular boundary. (12 to 18 inches thick)
B3t--48 to 58 inches; yellowish brown (10YR 5/4) loam, dark yellowish brown (10YR 4/4) rubbed moist; weak and moderate fine and medium subangular blocky structure; hard, friable, slightly sticky and slightly plastic; few fine and common medium and coarse roots; few fine tubular and common very fine interstitial pores; common thin clay films as bridges between mineral grains; estimated 15 percent pebbles most crushing under hand pressure; slightly acid (pH 6.1); clear irregular boundary. (0 to 10 inches thick)
Cr--58 inches; highly weathered fine grained sandstone; slightly acid (pH 6.1).
TYPE LOCATION: Santa Cruz County, California; 7,000 feet due east of intersection of Olive Springs Road and Hinckley Creek Road on Hinckley Creek Road; SW1/4 SE1/4 section 18 (projected), T.10S., R.1W.
RANGE IN CHARACTERISTICS: Depth to a paralithic contact of soft fine grained sandstone or shale is 40 to 60 inches. The soil between depths of 6 and 17 inches is usually moist between the end of December and the end of April. The mean annual soil temperature is about 56 to 58 degrees F. Organic matter content is more than 1 percent at a depth of 22 to 34 inches. Base saturation is more than 50 percent in all parts and less than 75 percent in some or all parts of the profile to a depth of 30 inches. Pebbles range from 0 to 15 percent by volume.
The A horizon is very dark gray, very dark grayish brown, dark gray, dark grayish brown or grayish brown (10YR 3/1, 3/2, 4/1, 4/2, 5/2). It is sandy loam, fine sandy loam, or loam. This horizon is slightly acid or neutral.
The B2t horizon is dark brown, grayish brown, brown (10YR 4/3, 5/2, 5/3; 7.5YR 5/2), and in places, at a depth greater than 20 inches, light brownish gray, light yellowish brown, or light brown (10YR 6/2, 6/4; 7.5YR 6/4). It is sandy clay loam or clay loam and has 20 to 35 percent clay. This horizon is moderately acid or slightly acid. Some pedons have a B3t horizon that is yellowish brown or light yellowish brown (10YR 5/4, 6/4) and is loam or sandy clay loam.
Some pedons have a C horizon, 5 to 10 inches thick, having a color of light yellowish brown or very pale brown (10YR 6/4, 7/4). It is loam or sandy clay loam.
COMPETING SERIES: These are the Aptos and Roseburg series in the same family and the Felton, Lompico, and Soquel series in other families. Aptos soils have a paralithic contact at depths of 20 to 40 inches. Roseburg soils have a mean annual soil temperature of 52 to 55 degrees F. and a 160 to 200 dry frost free growing season. Felton and Lompico soils have value of 6 or more, moist chroma of 4 or more within 10 to 20 inches of the soil surface. Soquel soils have an irregular decrease in organic carbon to a depth below 20 inches.
GEOGRAPHIC SETTING: Nisene soils are on uplands and have slopes of 15 to 75 percent. They formed in material weathered from fine grained sandstone and shale at elevations from 400 to 3,000 feet. The climate is humid mesothermal having warm, dry but foggy summers and cool, moist winters. The mean annual precipitation is 35 to 60 inches. The average January temperature is 45 degrees F.; the average July temperature is 65 degrees F.; and the mean annual temperature is 54 to 57 degrees F. The frost free season is 220 to 240 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Aptos, Felton, Lompico and Soquel soils and the Ben Lomond, Catelli, and Sur soils. Ben Lomond and Catelli soils lack a B2t horizon and have less than 18 percent clay. Sur soils have more than 35 percent rock fragments and a base saturation of more than 75 percent throughout.
DRAINAGE AND PERMEABILITY: Well drained; rapid to very rapid runoff; moderate permeability.
USE AND VEGETATION: Used for timber production, recreation, wildlife,watershed and in some areas, homesites and orchards. Vegetation is redwoods, Douglas fir, madrone, tanoak, ferns and poison oak.
DISTRIBUTION AND EXTENT: Central part of the Coastal Range of California. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Santa Cruz County, California, 1976.
REMARKS: The base saturation is marginal for a Ultic subgroup.
The activity class was added to the classification in February of 2003. Competing series were not checked at that time. - ET