LOCATION WATSON PAEstablished Series
TAXONOMIC CLASS: Fine-loamy, mixed, active, mesic Typic Fragiudults
TYPICAL PEDON: Watson silt loam - cultivated. (Colors are for moist soil unless otherwise noted.)
Ap--0 to 10 inches; dark brown (10YR 4/3) silt loam; weak fine granular structure; friable, slightly sticky, slightly plastic; 10 percent gravel; slightly acid; abrupt smooth boundary. (7 to 12 inches thick)
Bt1--10 to 16 inches; strong brown (7.5YR 5/6) gravelly silty clay loam; moderate fine subangular blocky structure; friable, sticky, plastic; few faint clay films on faces of peds; 15 percent gravel; moderately acid; gradual wavy boundary. (4 to 9 inches thick)
Bt2--16 to 23 inches; reddish yellow (7.5YR 6/6) gravelly silty clay loam; moderate medium and fine blocky structure; friable, sticky, plastic; few faint clay films on faces of peds; 15 percent gravel; moderately acid; clear wavy boundary. (4 to 12 inches thick)
Bt3--23 to 27 inches; reddish yellow (7.5YR 6/6) gravelly silty clay loam; common medium faint very pale brown (10YR 7/3)mottles; moderate medium blocky structure; firm, sticky, plastic; few distinct clay films on faces of peds; 20 percent gravel; moderately acid; abrupt wavy boundary. (0 to 8 inches thick)
Bx1--27 to 46 inches; yellowish red (5YR 5/6) gravelly clay loam, gray (10YR 6/1) coating on faces of prisms; many coarse prominent light gray (10YR 7/2) mottles; weak very coarse prismatic structure parting to moderate medium blocky; very firm, brittle, sticky, plastic; common distinct clay films on faces of peds and in pores; many black manganese stains; 30 percent gravel; strongly acid; gradual wavy boundary. (15 to 25 inches thick)
Bx2--46 to 65 inches; yellowish red (5YR 5/6) very gravelly loam, gray (10YR 6/1) coatings on faces of prisms; many coarse prominent light gray (2.5Y 7/2) and reddish yellow (7.5YR 6/8) mottles; weak very coarse prismatic structure parting to moderate medium blocky; very firm, brittle, sticky, plastic; common distinct clay films on faces of peds and in pores; many coarse black stains; 40 percent gravel; strongly acid.
TYPE LOCATION: Monroe County, Pennsylvania; Chestnut Hill Township; 0.5 mile east of Effort on Township Road 417, south of road in field.
RANGE IN CHARACTERISTICS: Solum thickness ranges from 40 to 72 inches. Bedrock is usually below 60 inches. Depth to fragipan ranges from 18 to 32 inches. Rock fragments of subrounded gravel or shale usually increase with depth and range from 5 to 20 percent in the surface, from 10 to 40 percent in individual horizons of the Bt, and from 10 to 50 percent in the Bx horizons. Reaction throughout the soil is very strongly acid or strongly acid where unlimed. Illite is the dominant clay mineral with smaller amounts of kaolinite, vermiculite, and montmorillonite.
The Ap horizon has hue of 10YR through 5YR, value of 3 or 4, and chroma of 2 through 4. Texture is silt loam or loam in the fine-earth fraction.
The Bt horizon has hue of 10YR through 5YR, value of 5 or 6, and chroma of 4 through 8. Low chroma mottles are within 30 inches of the soil surface. Texture is silt loam, silty clay loam, loam, or clay loam in the fine-earth fraction with less than 40 percent sand. Structure is weak or moderate, fine or medium subangular blocky and blocky with friable or firm consistence.
The Bx horizon has hue of 2.5YR through 7.5YR, value of 4 through 6, and chroma of 4 through 6. Mottle colors include gray, light gray, light brownish gray and pinkish gray. Texture is the same as the Bt horizon. Structure is weak very coarse prismatic that parts to medium to very thick platy or fine to coarse subangular blocky or blocky .
The C horizon, where present, has hue of 10YR through 2.5YR. Texture is silt loam, loam, or sandy loam in the fine-earth fraction commonly with 40 percent or more rock fragments.
COMPETING SERIES: The Annandale, Beltsville, Califon, Delassus, Hanover, Laidig, Meckesville, Monongahela, Tonti, and Trego series are in the same family. The Annandale, Hanover, Laidig, and Meckesville soils do not have low chroma mottles within 30 inches of the surface. Beltsville soils have less than 10 percent gravel in the argillic horizon. Califon soils contain fragments of granitic rocks. Delassus soils are formed in loess. Monongahela soils have water-worn rock fragments. Tonti soils have rock fragments dominated by chert. Trego soils have more than 40 percent sand in the particle-size control section.
GEOGRAPHIC SETTING: These soils are mainly in the glaciated section of the Ridge and Valley area. The slopes are nearly level to moderately steep. Gradients are dominantly 3 to 8 percent but range from 0 to 20 percent. The soils formed in loamy pre-Wisconsin glacial till derived from sandstone, siltstone and shale similar to that of the underlying rock. The climate is humid temperate, mean annual precipitation ranges from 38 to 48 inches, mean annual air temperature ranges from 50 to 55 degrees F., the frost-free season ranges from 140 to 170 days.
GEOGRAPHICALLY ASSOCIATED SOILS: The Watson soils are a member of a drainage sequence which includes the deep well drained Allenwood soils, the somewhat poorly drained Alvira soils, and the poorly drained Shelmadine soils. The nearby Bedington, Berks, Hartleton, and Weikert soils do not have fragipans. Berks, Hartleton and Weikert soils also have more than 35 percent rock fragments. Berks and Weikert soils, in addition, are less than 40 inches deep to shale bedrock.
DRAINAGE AND PERMEABILITY: Moderately well drained. Surface runoff is medium to slow and permeability is slow.
USE AND VEGETATION: Most of the soils are cleared and cultivated for hay, grain and other crops. Wooded areas are in mixed hardwoods.
DISTRIBUTION AND EXTENT: Glaciated portion of Ridge and Valley area in east central Pennsylvania. It is of moderate extent, with an estimated 25,000 acres.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Morgantown, West Virginia
SERIES ESTABLISHED: Northumberland County, Pennsylvania, 1941.
REMARKS: Diagnostic horizons and features recognized in this pedon are: a. Ochric epipedon - the zone from the surface of the soil to a depth of about 10 inches (Ap horizon).
b. Argillic horizon - the zone from 10 to 27 inches (Bt horizon). c. Fragipan - the zone from 27 to 65 inches (Bx horizon).