LOCATION HEMPSTEAD          NY
Established Series
Rev. JPW-JWW
02/2000

HEMPSTEAD SERIES


The Hempstead series consists of very deep, well drained soils on outwash plains. They are nearly level or gently sloping soils formed in a silty mantle overlying stratified sand and gravel outwash materials. Permeability is moderate in the solum and very rapid in the substratum. Mean annual temperature is 52 degrees F and mean annual precipitation is 42 inches.
TAXONOMIC CLASS: Coarse-silty over sandy or sandy-skeletal, mixed, active, mesic Humic Dystrudepts

TYPICAL PEDON: Hempstead silt loam, grassed area. (Colors are for moist soil.)

A--0 to 11 inches; black (10YR 2/1) silt loam; very dark grayish brown (10YR 3/2) dry; moderate fine and medium granular structure; friable; many fine roots; moderately acid; clear wavy boundary. (10 to 15 inches thick.)

AB--11 to 15 inches; dark brown (10YR 4/3) silt loam; moderate fine subangular blocky structure; friable; many fine roots; strongly acid; clear smooth boundary. (0 to 6 inches thick.)

Bwl--15 to 25 inches; yellowish brown (10YR 5/6) silt loam; moderate, medium subangular blocky structure; friable; common fine roots; strongly acid; clear wavy boundary. (7 to 13 inches thick.)

Bw2--25 to 29 inches; yellowish brown (10YR 5/8) silt loam; weak, medium subangular blocky structure; very friable; few fine roots; 5 percent fine gravel; strongly acid; abrupt smooth boundary. (3 to 6 inches thick.)

2BC--29 to 33 inches; strong brown (7.5YR 5/8) very gravelly loamy sand; very weak fine granular structure; very friable; 50 percent gravel; strongly acid; clear smooth boundary. (0 to 5 inches thick.)

2C--33 to 60 inches; very pale brown (10YR 7/3) stratified sand and gravel; single grain; loose; 60 percent gravel; strongly acid.

TYPE LOCATION: Nassau County, New York; Town of Hempstead, 1800 feet northwest of intersection of Clinton Road and Stewart Avenue.

RANGE IN CHARACTERISTICS: The solum thickness ranges from 20 to 40 inches and corresponds to the depth to stratified sand and gravel. Depth to bedrock is greater than 60 inches and is mainly several hundred feet. Rock fragment content ranges from 0 to 5 percent in the A and Bw horizons, and from 25 to 75 percent in the 2BC and 2C horizons. The rock fragments are mainly gravel of granitic origin with up to 20 percent cobblestones in the 2BC and 2C horizons. Reaction ranges from moderately acid to very strongly acid in the solum and it is strongly acid or very strongly acid in the substratum.

The A horizon has hue of 10YR, value of 2 or 3, and chroma of 1 or 2. It is silt loam or very fine sandy loam and has very weak to moderate, fine or medium granular structure.

The AB horizon has hue of 10YR, value of 3 or 4, and chroma of 2 or 3. It is silt loam or very fine sandy loam. It has weak or moderate subangular blocky structure.

The Bw horizon has hue of 7.5YR through 2.5Y, value of 4 or 5, and chroma of 4 through 8. It is silt loam or very fine sandy loam. Structure is weak or moderate subangular blocky, and is friable or very friable. The BC has colors similar to the Bw. It is loamy sand or sandy loam in the fine earth fraction. Coarse high chroma mottles occur at the contact with the 2C horizon in some pedons.

The 2C horizon has hue of 7.5YR through 2.5Y, value of 5 through 7, and chroma of 3 or 4. It is loamy sand or sand in the fine earth fraction.

COMPETING SERIES: There are no other known series in the same family. Allard, Enfield, Haven, Bridgehampton, and Mineola are similar soils in related families. All except Mineola lack the thick dark colored (umbric) surface of Hempstead. Mineola soils are wetter (moderately well drained.)

GEOGRAPHIC SETTING: Hempstead soils are nearly level to gently sloping soils on outwash plains. Slopes range from 0 to 3 percent. The soils formed in a silty or very fine sandy loam mantle over highly siliceous stratified sand and gravel. The climate is cool, temperate, and humid. Mean annual temperature is 48 degrees to 55 degrees F, mean annual precipitation is 40 to 44 inches and the growing season is 180 to 220 days.

GEOGRAPHICALLY ASSOCIATED SOILS: These are the competing Enfield and Mineola soils and the Montauk, Plymouth and Riverhead. Mineola soils are in a drainage sequence with Hempstead. Riverhead and Montauk soils are on nearby terraces or elevated moraines. Riverhead soils are sandier in the solum and Montauk soils have dense substrata. Plymouth soils have sand or loamy sand textures throughout and all lack the thick dark colored surface horizons that is typical for Hempstead.

DRAINAGE AND PERMEABILITY: Well drained. Surface runoff is slow to moderate. Permeability is moderate in the A and Bw horizons and rapid or very rapid in the 2BC C horizons. The lower part of the solum tends to retain higher than normal moisture for short periods due to change in pore space between the solum and substratum.

USE AND VEGETATION: Most areas were originally used for farming but most have been converted to housing developments and similar urban uses since 1940. Most underdeveloped areas are in parks or along older parkways.

DISTRIBUTION AND EXTENT: Only known areas of occurrence is central Nassau County, New York. It is a single contiguous area and is 12,000 to 15,000 acres in extent.

MLRA SOIL SURVEY REGIONAL OFFICE (MO) RESPONSIBLE: Amherst, Massachusetts

SERIES EXTABLISHED: Nassau-Suffolk soil survey, issued in 1928.


REMARKS: The soils were first mapped as Hempstead in the 1903 Soil Survey of the Long Island Area, New York and later in the 1928 Soil Survey of Nassau and Suffolk Counties, New York. The series is currently listed as inactive. This revision is to reactivate the series and assign a firm classification.
National Cooperative Soil Survey
U.S.A.