LOCATION POTSDAM NY+VT
The Potsdam series consists of very deep, well drained soils on till plains. They are nearly level to steep soils formed in an eolian or water deposited mantle that overlies dense till. Saturated hydraulic conductivity is moderately high through high in the layers above the substratum and moderately low through moderately high in the substratum. Slope ranges from 3 through 60 percent. Mean annual temperature is 44 degrees F, and mean annual precipitation is 40 inches.
TAXONOMIC CLASS: Coarse-loamy, isotic, frigid Typic Haplorthods
TYPICAL PEDON: Potsdam very fine sandy loam, on a 15 percent slope in a wooded area. (Colors are for moist soil unless otherwise noted.)
Oa -- 0 to 3 inches; black (5YR 2/1) well decomposed leaves and twigs. (0 to 6 inches thick.)
E -- 3 to 6 inches; pinkish gray (5YR 6/2) very fine sandy loam; weak fine subangular blocky structure; very friable; many Fine pores; many coarse and many medium roots; 2 percent gravel; extremely acid; abrupt irregular boundary. (0 to 9 inches thick.)
Bh -- 6 to 9 inches; dark reddish brown (5YR 2/2) silt loam; weak medium subangular blocky structure; friable; common fine pores; common fine and medium roots; 3 percent gravel; very strongly acid; gradual irregular boundary. (0 to 7 inches thick.)
Bs -- 9 to 19 inches; reddish brown (5YR 4/4) and strong brown (7.5YR 5/6) silt loam; few fine distinct dark reddish brown (5YR 3/4) root stains; moderate medium subangular blocky structure; friable; common fine pores; common fine and medium roots; 3 percent gravel; very strongly acid; clear smooth boundary. (5 to 18 inches thick.)
2BC -- 19 to 31 inches; light olive brown (2.5Y 5/4) gravelly sandy loam; very weak medium subangular blocky structure; friable; common fine pores; 10 percent fine gravel and 10 percent stones; very strongly acid; clear smooth boundary. (0 to 17 inches thick.)
2Cd -- 31 to 72 inches; light olive brown (2.5Y 5/4) gravelly sandy loam; massive; firm; few fine pores; 15 percent gravel and cobbles; strongly acid.
TYPE LOCATION: St. Lawrence County, New York, Town of Piercefield, 100 feet south of N.Y. Route 3 and 1 mile west of Conifer Road. Piercefield, NY topographic quadrangle; Latitude 44 degrees, 14 minutes, 21 seconds N. and Longitude 74 degrees, 35 minutes, 40 seconds W., NAD 1927.
RANGE IN CHARACTERISTICS: The thickness of the solum ranges from 20 to 40 inches. Depth to bedrock is more than 60 inches. Thickness of the silty mantle ranges from 16 to 40 inches over the dense till substratum. Rock fragments range from 0 to 15 percent, by volume, in the silty mantle and from 5 to 35 percent in the lower part of the subsoil and substratum that is in till. Rock fragments include gravel, cobbles, and stones. Stones occupy as much as 15 percent of some layers. The surficial mantle contains 50 through 80 percent silt plus very fine sand.
The O horizon has hue of 10YR through 5YR, value of 2 through 3, and chroma of 1 or 2. Some undisturbed pedons have an A horizon with hue of 10YR through 5YR, value of 2 through 3, and chroma of 1 or 2. Reaction ranges from extremely acid through moderately acid.
In cleared areas, an Ap horizon is present with hue of 5YR through 10YR, value of 2 through 4, and chroma of 1 through 3. Texture is very fine sandy loam, loam, or silt loam. It has weak or moderate fine or medium granular structure and friable or very friable consistence. Reaction ranges from extremely acid through moderately acid.
The E horizon has hue of 5YR through 10YR, value of 5 through 7, and chroma of l or 2. Texture is fine sandy loam, very fine sandy loam, loam, or silt loam. It has thin or medium platy or subangular blocky structure, or fine granular structure. Reaction ranges from extremely acid through moderately acid.
The Bh horizon has hue of 5YR or 7.5YR, value of 2 or 3, and chroma of 1 or 2. Texture is very fine sandy loam, loam, or silt loam. It has weak or moderate fine or medium subangular blocky structure and friable or very friable consistence. Reaction ranges from extremely acid through moderately acid. Some pedons have a Bhs horizon with a value and chroma of 3 or less.
The Bs horizon has hue of 5YR, value of 3 through 6 and chroma of 3 through 8; or hue of 7.5YR or 10YR, value 3 through 5 and chroma of 4 through 6. The lighter colors are more common in the lower part. Texture is very fine sandy loam, loam, or silt loam with subhorizons of loamy very fine sand in some pedons. The Bs horizon has very weak, weak, or moderate subangular blocky or granular structure and friable or very friable consistence. Reaction ranges from very strongly acid through moderately acid. Some pedons have a BC or C horizon under the Bs horizon.
The 2BC horizon has hue of 7.5YR through 2.5Y, value 3 through 5 and chroma of 2 through 4. Texture of the fine earth fraction ranges from silt loam through loamy sand. Reaction ranges from very strongly acid through neutral. Some pedons have a BC or C horizon under the Bs horizon.
The 2Cd horizon has hue of 10YR through 5Y, value of 3 through 5, and chroma of 2 through 4. It is sandy loam, fine sandy loam, loamy sand or loamy fine sand in the fine-earth fraction. It is massive, with or without plate-like divisions. In some pedons the upper part of the substratum is prismatic. Consistence is firm or very firm. Reaction ranges from strongly acid through slightly alkaline.
COMPETING SERIES: These are the
Welcome series in the same family. Bangor soils lack a lithologic discontinuity and have silt loam or loam textures in the substratum within the series control section. Berkshire, Groveton, and Houghtonville soils lack a Cd horizon in dense till within the series control section. DeKapen soils have more than 25 percent weathered pebbles in the solum. Elliottsville, Penquis, Revel, and Tunbridge soils have bedrock at a depth of 20 to 40 inches. Welcome soils have lower effective precipitation and are dry in the soil moisture control section for 45 to 60 consecutive days within the four month period that follows the summer solstice.
GEOGRAPHIC SETTING: Potsdam soils occupy undulating to steep, typically convex landforms of till plains and glaciated mountain sides. Slope ranges from 3 through 60 percent. The regolith is fine sandy loam through loamy sand till from sandstone, schist, or granite gneiss overlain by an 16 to 40 inch eolian or lacustrine mantle containing 50 to 80 percent silt plus very fine sand. Mean annual temperature ranges from 40 through 45 degrees F, mean annual precipitation ranges from 35 through 55 inches, and mean frost-free days ranges from 90 through 145 days. Elevation ranges from 500 through 2000 feet above sea level.
GEOGRAPHICALLY ASSOCIATED SOILS: They moderately well drained
Crary soils form a drainage sequence with Potsdam soils and occupy footslopes and other less convex areas. The competing
Marlow soils are in nearby areas that lack a nearly stone-free surficial mantle.
Worth soils occur in areas that have a fragipan.
Tunbridge soils are associated where bedrock is at a depth of 20 to 40 inches. Other geographically associated soils are the
Colton soils. Adams and Colton soils are in glaciofluvial sand and gravel deposits. The competing Berkshire soils are on associated till plains, but lack a dense substratum.
DRAINAGE AND SATURATED HYDRAULIC CONDUCTIVITY: Well drained. The potential for surface runoff is low to very high. Saturated hydraulic conductivity is moderately high through high in the layers above the substratum and moderately low through moderately high in the substratum.
USE AND VEGETATION: Many areas have been cleared and used for growing hay, oats, and limited acreage of corn for silage; however, most cleared areas have reverted to brush or woodland. Woodlots contain sugar maple, American beech, black ash, white ash, hop hornbeam, eastern hemlock, red oak, and eastern white pine.
DISTRIBUTION AND EXTENT: The Adirondack Mountains of New York and Green Mountains of Vermont. MLRA 141, 142, and 143. The series is moderately extensive.
MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Amherst, Massachusetts
SERIES ESTABLISHED: Hamilton County, New York, 1979.
REMARKS: Reclassification (1/89) of these soils from Fragiorthods to Haplorthods reflects the fact that in most areas the dense substratum was formerly identified as a Cx horizon which is now a Cd horizon.
Diagnostic horizons recognized in the typical pedon are:
a. Ochric Epipedon - the zone from 0 to 6 inches (Oa and E horizon).
b. Spodic horizon - the zone from 6 to 19 inches (Bh and Bs horizons).
National Cooperative Soil Survey