LOCATION IGNORD CAEstablished Series
TAXONOMIC CLASS: Coarse-loamy, mixed, superactive, thermic Pachic Haploxerolls
TYPICAL PEDON: Ignord fine sandy loam on a less than one percent slope under a cover of valley oak, yellow starthistle, and annual grasses at an elevation of 131 feet, (40 m). When described on 8/24/94, the soil was moist from 4 to 77 inches, (10 to 196 cm). (Colors are for dry soil unless otherwise noted).
Akp--0 to 4 inches, (0 to 10 cm); dark grayish brown (10YR 4/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; 10 percent clay; single grain and weak fine and medium granular structure; soft, very friable, nonsticky and nonplastic; many very fine and fine roots; many very fine interstitial pores; slightly effervescent, carbonates disseminated; moderately alkaline, pH 8.0 by Hellige-Truog; clear smooth boundary.
Ak1--4 to 14 inches, (10 to 36 cm); dark grayish brown (10YR 4/2) fine sandy loam, very dark grayish brown (10YR 3/2) moist; 8 percent clay; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine roots; common very fine interstitial, and common very fine and fine and few medium tubular pores; violently effervescent, carbonates disseminated; moderately alkaline, pH 8.0 by Hellige-Truog; clear smooth boundary.
Ak2--14 to 25 inches, (36 to 64 cm); dark grayish brown (10YR 4/2) sandy loam, very dark grayish brown (10YR 3/2) moist; 10 percent clay; weak fine and medium subangular blocky structure; soft, very friable, nonsticky and nonplastic; common very fine and fine and few medium roots; common fine interstitial and many very fine and fine tubular pores; violently effervescent, carbonates disseminated; moderately alkaline, pH 8.2 by Hellige-Truog; abrupt smooth boundary.
Ak3--25 to 32 inches, (64 to 81 cm); brown (10YR 5/3) fine sandy loam, very dark grayish brown (10YR 3/2) moist; 8 percent clay; weak fine and medium subangular blocky; soft, very friable, nonsticky and nonplastic; common very fine roots; common fine interstitial pores; violently effervescent, carbonates disseminated; moderately alkaline, pH 8.2 by Hellige-Truog; clear wavy boundary. (Combined thickness of the Akp and Ak horizon is 20 to 35 inches, (51 to 89 cm) thick.).
Bk--32 to 53 inches, (81 to 135 cm); brown (10YR 5/3) sandy loam, brown (10YR 4/3) moist; 8 percent clay; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine and fine tubular pores; violently effervescent, carbonates disseminated; moderately alkaline, pH 8.0 by Hellige-Truog; clear wavy boundary. (15 to 30 inches, (38 to 76 cm) thick)
Bkq--53 to 58 inches, (135 to 147 cm); brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; 10 percent clay; massive; soft, very friable, nonsticky and nonplastic; few very fine roots; common very fine and fine and few medium tubular pores; 20 percent weakly cemented with silica; violently effervescent, carbonates disseminated; moderately alkaline, pH 8.0 by Hellige-Truog; clear smooth boundary. (3 to 6 inches, (8 to 15 cm) thick)
Bk'--58 to 77 inches, (147 to 196 cm); brown (10YR 5/3) fine sandy loam, brown (10YR 4/3) moist; 10 percent clay; massive; soft, very friable, nonsticky and nonplastic; few very fine and medium roots; many very fine and fine and few medium tubular pores; very slightly effervescent, carbonates disseminated; moderately alkaline, pH 8.0 by Hellige-Truog. (15 to 30 inches, (38 to 76 cm) thick)
TYPE LOCATION: Butte County, California; about 2 miles west of Chico; approximately 1400 feet west of the Mt. Diablo Meridian, and approximately 2750 feet south of the line separating Township 22 N. and Township 21 N.; in an unsectionized area in the Rancho de Farwell Land Grant; 39 degrees, 42 minutes, 10 seconds North latitude and 121 degrees, 55 minutes, 22 seconds West longitude, NAD27. U.S.G.S. Quad: Ord Ferry, California.
RANGE IN CHARACTERISTICS: Depth of the solum is over 72 inches, (183 cm). The mean annual soil temperature is 60 to 62 degrees F, (16 to 17 degrees C). The soil moisture control section is moist from approximately December 1 to March 31 (about 110 to 140 days), and is dry in all parts from approximately May 1 to September 31 (about 150 to 170 days). The particle-size control section averages 8 to 15 percent clay. Mineralogy is mixed. Disseminated lime ranges from the surface to at least 40 inches, (102 cm) deep and the soil is very slightly effervescent to violently effervescent. Calcium carbonate ranges from 1 to 4 percent throughout. Organic matter ranges from 1 to 4 percent at the surface, and decreases regularly with depth. A fluctuating water table can occur below 72 inches, (183 cm) from December through March. Some pedons have a thin (3 to 8 inches, (8 to 20 cm) thick) weakly cemented layer within the Bk horizon. This silica cementation comprises less than 20 percent of the layer.
The Akp horizon dry color is 10YR 4/2, 5/2 or 5/3. Moist color is 10YR 2/2, 3/2 or 3/3. Clay content ranges from 8 to 20 percent. Reaction ranges from slightly alkaline to moderately alkaline.
The Ak horizon dry color is 10YR 4/2, 5/2 or 5/3. Moist color is 10YR 2/2, 3/2 or 3/3. Texture is fine sandy loam or sandy loam. Clay content ranges from 8 to 15 percent. Reaction ranges from slightly alkaline to moderately alkaline.
The Bk and Bkq horizons dry color is 10YR 5/3, 6/2, 6/3 or 6/4. Moist color is 10YR 3/3, 3/4, 4/2, 4/3 or 4/4. Texture is fine sandy loam or sandy loam. Clay content ranges from 8 to 15 percent. Reaction ranges from slightly alkaline to moderately alkaline.
COMPETING SERIES: These are the Sheridan and Vina soils. Sheridan soils have a paralithic contact at 25 to 40 inches, (64 to 102 cm). Vina soils have less than 1 percent calcium carbonate.
GEOGRAPHIC SETTING: Ignord soils are on distal alluvial fans, on low ridges and mounds. These soils formed in alluvium weathered from mixed rocks. They are on slightly higher positions than the surrounding soils, and they have been extensively modified and leveled for agriculture. Slopes range from 0 to 2 percent. Elevation is 115 to 158 feet, (35 to 48 m). Mean annual precipitation is 20 to 22 inches, (508 to 559 mm). The mean annual temperature is 60 to 62 degrees F, (16 to 17 degrees C). Frost free season is 240 to 250 days.
GEOGRAPHICALLY ASSOCIATED SOILS: These are the Conejo, Almendra, Vina, and Bosquejo soils. Conejo and Almendra soils are fine-loamy and are in slightly lower positions on alluvial fans. Vina soils are coarse-loamy and have less than 1 percent calcium carbonate. Bosquejo soils are fine and are in interfan basins.
DRAINAGE AND PERMEABILITY: Well drained; negligible runoff; moderately rapid saturated hydraulic conductivity. A fluctuating water table can occur below 72 inches, (183 cm) from December through March.
USE AND VEGETATION: This soil is used for row crops, grain and orchards. Native vegetation was grasses and valley oak woodland.
DISTRIBUTION AND EXTENT: Butte County, California. MLRA 17 Sacramento Valley. The soils are not extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Davis, California
SERIES ESTABLISHED: Butte County, California 2005.
Diagnostic horizons and features recognized in this pedon are:
Mollic epipedon - zone from 0 to 32 inches, (0 to 81 cm) (Apk, Ak1, Ak2, Ak3)
Cambic horizon - zone from 32 to 77 inches, (81 to 196 cm) (Bk, Bkq, Bk)