34 Glossary
Taken from: http://clic.cses.vt.edu/Ltpark/cover.html
A
Aggregation. Many soil particles being held together in a single aggregate or clod.
Alluvium. Soil parent material, such as sand, silt, clay, or gravel deposited on floodplains by streams.
Available water capacity. The ability of soils to hold water available for use by most plants; the difference
between the amount of soil water at field capacity and the amount at wilting point.
B
Baseflow. Water movement into streams from aquifers.
Biogeochemical. Interaction of biological, geologic, and chemical processes.
C
Clay. The electrically charged mineral soil particles less than 0.002 millimeter in diameter.
Cobble. A rock 3 to 10 inches across.
Complex (soil complex). A map unit with two kinds of soil intermixed so that it is not practical to
separate them at the map scale being used.
Corrosion. Soil-induced chemical action that dissolves or weakens concrete or uncoated steel.
D
Drainage class. Refers to the common depth of water tables or saturated zones that affect plant growth
and use of the soil for buildings and septic tanks. Seven classes are: excessively drained - Water
is removed very rapidly. The occurrence of internal free water commonly is very rare or very
deep; somewhat excessively drained - Water is removed from the soil rapidly. Internal free water
occurrence commonly is very rare or very deep; well drained - Water is removed from the soil
readily but not rapidly. Internal free water occurrence is common but is deep or very deep;
moderately well drained - Water is removed from the soil somewhat slowly during some periods
of the year. Internal free water occurrence commonly is moderately deep and temporary through
permanent; somewhat poorly drained - Water is removed slowly so that the soil is wet at a
shallow depth for significant periods during the growing season. The occurrence of internal free
water commonly is shallow to moderately deep and temporary to permanent; poorly drained Water is removed so slowly that the soil is wet at shallow depths periodically during the growing
season or remains wet for long periods. The occurrence of internal free water is shallow or very
shallow and common or persistent; and very poorly drained - Water is removed from the soil so
slowly that free water remains at or very near the ground surface during much of the growing
season. The occurrence of internal free water is very shallow and persistent or permanent.
E
Ecosystem. Interaction of the soils, plants, animals, and water that are part of the ecology of an area.
Estuary. The mouth of a freshwater river that is now filled with seawater due to rising sea levels.
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Excavation difficulty class. The ease of digging a pit or trench to 6 feet in moist soil. Classes are: Low Can be excavated with a spade using only arm-applied pressure; Moderate - Excavation can be
accomplished quite easily by foot pressure on a spade; High - Excavation with a spade can be
accomplished, but is easier with a full length pick using an over-the-head swing; Very high Excavation with hand tools is markedly difficult but is possible in a reasonable period of time
with a small backhoe; Extremely high - Excavation is nearly impossible without a large backhoe.
F
Field capacity. The moisture content of a soil a few days after a soaking rain, when there is no more free
drainage from the soil.
Fragipan. A dense subsoil horizon that restricts roots and severely limits water conductivity, except in a
few widely spaced vertical cracks.
Frost action. Freezing and thawing of moist soil that can damage roads, buildings, and plant roots.
G
Glacial drift (glacial deposits). Pulverized rock particles and other rock material transported by glacial ice
and then deposited.
Glacial outwash. Coarse-texture material such as gravel, sand, and silt, deposited (in thin layers) by fastmoving glacial meltwater.
Glacial till. Unsorted, nonlayered glacial drift consisting of clay, silt, sand, and gravel to boulder sized
rock fragments transported and deposited by glacial ice. Dense till restricts roots and severely
limits water conductivity. Friable till is not a barrier to roots or water.
Glaciofluvial deposits. Moderate- and fine-textured material such as fine sand, silt, and clay moved by
glaciers and then sorted and deposited in thin layers by slow-moving glacial meltwater.
Gravelly soil material. Material that is over 15 percent (volume) of rock fragments.
H
Hemic soil material. Same as mucky peat, but used in unsaturated soils.
Horizon (soil horizon). A layer of soil, approximately parallel to the surface, having distinct
characteristics produced by soil-forming processes. An uppercase letter represents the major
horizon types. Numbers or lowercase letters that follow represent subdivisions of the major
horizons. Major horizons are:
O horizon. An organic layer of freshly fallen and decaying plant parts.
A horizon. The mineral horizon at or near the surface with an accumulation of organic matter.
E horizon. Mineral horizon in which the main feature is loss of clay, iron, and/or organic matter.
B horizon. The mineral horizon below an A horizon. Horizons with (1) accumulation of clay,
sesquioxides, and/or organic matter; (2) more strongly expressed soil structure; or (3)
redder or browner colors relative to those in the A and C horizons.
C horizon. The mineral horizon or layer, that is little affected by soil-forming processes and does
not have the properties of the overlying B horizon.
Cr horizon. Soft, weathered bedrock beneath the soil.
R layer. Consolidated, usually hard, unweathered bedrock beneath the soil.
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Hydrologic group. Refers to soils grouped according to their runoff potential. The soil properties that
influence this potential are depth to a seasonal high water table, the infiltration rate and
permeability after prolonged wetting, and depth to a very slowly permeable layer. The slope and
the kind of plant cover are not a factor. The classes are:
A - Saturated hydraulic conductivity is very high or in the upper half of high and internal free
water occurrence is very deep;
B – Saturated hydraulic conductivity is in the lower half of high or in the upper half of
moderately high and free water occurrence is deep or very deep;
C - Saturated hydraulic conductivity is in the lower half of moderately high or in the upper half of
moderately low and internal free water occurrence is deeper than shallow;
D – Saturated hydraulic conductivity is below the upper half of moderately low, and/or internal
free water occurrence is shallow or very shallow and transitory through permanent.
I
Interflow. Rapid water movement into a stream mainly by runoff.
L
Leaching. The removal of dissolvable and suspendable material from soil by downward moving water.
Limitations for Use. Limits for soil use as sites of local roads, paths, motorcycle trails, lawns, turfgrass,
and picnic areas. Some limiting feature phrases are:
Area Reclaim - area is difficult to establish good vegetation on after soil is removed from it;
Low strength (or Subsidence) - soil is not strong enough to support heavy vehicles or buildings;
Small stones (or rock fragments) - too much gravel, not enough fine soil material;
Thin layer - the suitable layer of soil is too thin;
Restricted layer - a layer occurs within 20 inches that restricts root growth;
Frost action - the upper soil is susceptible to expansion and collapse from frost formation and
melting;
Wetness - water table is high enough to affect land use;
Depth to garbage - Household garbage occurs within 20 inches;
Methane gas emissions - methane gas is emitted as household garbage decomposes;
Thin layer - the suitable topsoil is too thin;
Excess humus - soil organic matter is destroyed readily by vehicle traffic;
Organic soil - tree seedlings require mineral soil for root stability;
Large stones - stones must be removed for lawns and recreation areas;
Seepage - water moves very rapidly into aquifers and deep layers.
M
Metabolizes. Chemically changing (inside a living organism) of food into living cell material, and also
dead cell material into food and energy.
Mineral soil material. A mixture of mineral particles with less than 20 to 30 percent organic matter in
commonly saturated soil horizons and less than 35 percent organic matter if the horizon is rarely
saturated.
Muck. Dark, finely divided, highly decomposed organic soil material in saturated soil. The term "Sapric"
is used in unsaturated soils.
Mucky (texture). A modifier to surface texture to indicate high organic matter content (>10 percent) in a
mineral soil.
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Mucky Peat. Organic soil material in saturated soils, intermediate in degree of decomposition between the
less decomposed peat and the more decomposed muck. The term "Hemic" soil material is used in
unsaturated soils.
O
Organic soil material. A mixture of mineral particles with 20 to 30 percent or more organic matter in a
soil horizon if the horizon is saturated at times and 35 percent or more organic matter if the
horizon is never saturated.
Ornamental Trees, Shrubs, and Ground Covers. The following plant lists apply to the Group number in
the Map Unit Description section. These groups are general and apply to acid, unlimed soils. If
the soil has been limed, occurs next to a building, where a building once stood, or the natural
reaction is neutral or higher (pH 6.6 or higher), the following plants should not be planted without
checking the pH and consulting a specialist: American holly, lowbush and higbush blueberry,
azalea, cotoneaster, winterberry, inkberry, Japanese holly, Mugo pine, English holly, Japanese
andromeda, leucothoe, pachysandra, rhododendron, and periwinkle.
Group 1 - Loamy, acid soils with bedrock or dense till at less than 20 inches. Deciduous Trees:
Honeylocust, hawthorn, amur maple, Tallhedge, glossy buckthorn, white poplar, black locust,
white ash, crabapple, green ash, alder, plane tree, sycamore, sweet gum, black gum, hackberry.
Evergreen Trees: Japanese black pine, eastern white pine, eastern redcedar. Deciduous Shrubs
and Ground Cover: Sumac, bristly locust, Rugosa rose, redtwig dogwood, forsythia, bush
honeysuckle, Japanese honeysuckle, lowbush blueberry, sweetfern, Japanese barberry, Scotch
broom, aralia, California privet, autumn olive, cotoneaster, spiraea, fragrant sumac, highbush
blueberry, witchhazel, bayberry, Virginia creeper. Evergreen Shrubs and Ground Cover:
Mountain laurel, Juniper.
Group 2 - Deep, loamy, acid soils. Deciduous Trees: European beech, dawn redwood, flowering
crabapple, ginkgo, Turkish Filbert, sweetbay magnolia, American basswood, littleleaf linden, pin
oak, Japanese pagodatree, Bradford pear, golden raintree, larch, yellowwood, zelkova, sawtooth
oak, Crimean linden, honeylocust, sourwood, Kousa dogwood, tuliptree, amur corktree, Chinese
elm, northern red oak, flowering dogwood, shadbush, sweetgum, white ash, green ash, red maple,
river birch, horse chestnut, katsura tree, mountain ash, green ash, American hornbeam, scarlet
oak. Evergreen Trees: Atlas cedar, white fir, eastern hemlock, eastern white pine, Norway spruce,
Oriental spruce, Douglas fir, Nordmann fir, Himalayan pine, Swiss stone pine, American holly.
Deciduous Shrubs and Ground Cover: redosier dogwood, forsythia, amur honeysuckle,
winterberry, fringetree, chokeberry, abelia, cornelian cherry dogwood, viburnum, Washington
hawthorn, deciduous azalea, winged euonymus, witchhazel, highbush blueberry, cotoneaster,
plantain lily, fothergilla, hydrangea, winged euonymous, redbud, Siberian cypress, spiraea,
weigela. Evergreen Shrubs and Ground Cover: Inkberry, Japanese holly, mountain laurel, Mugo
pine, rhododendron, yew, English holly, Japanese andromeda, leucothoe, evergreen euonymus,
pachysandra, English ivy, juniper, Periwinkle.
Group 3 - Wet, loamy, neutral soils with water table less than 18 inches deep. Deciduous Trees: Willow
oak, sweetgum, tuliptree, swamp white oak, willow, shadbush, sourgum, red maple, sycamore,
plane tree, silver maple, green ash, bald cypress. Evergreen Trees: Eastern arborvitae. Deciduous
Shrubs and Ground Cover: Shrub willow, winged euonymus, redtwig dogwood, European and
American cranberry bush, bottlebrush buckeye, winterberry, fringetree, chokeberry, buttonbush,
fern, yellow root, plantain lily, summersweet, fothergilla, grey dogwood, false spiraea,
arrowwood. Evergreen Shrubs and Ground Cover: Inkberry, Christmas fern, rosebay, bugleweed,
lilyturf.
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Group 4 - High marsh organic soils. Deciduous Shrubs and Ground Cover: Groundsel-tree, marshelder,
bayberry, smooth cordgrass, salt meadow cordgrass. None others recommended.
Group 5 - Low marsh organic soils. Deciduous Shrubs and Ground Cover: Smooth cordgrass, salt
meadow cordgrass. None others recommended.
Group 6 - Deep, very sandy, very acid soils. Deciduous Trees: Honeylocust, golden raintree, hawthorn,
hedge maple, Amur maple, tallhedge glossy buckthorn, osage orange, white poplar, black locust,
chestnut oak, white ash, crabapple, Chinese elm, hackberry, Kentucky coffeetree, ginko.
Evergreen Trees: Japanese black pine, lacebark pine, eastern white pine, red pine, eastern
redcedar. Deciduous Shrubs and Ground Cover: Sumac, Arnot bristly locust, Rugosa rose,
forsythia, diervilla, Japanese honeysuckle, Japanese barberry, Scotch broom, fiveleaf aralia,
Regel’s amur or California privet, Autumn-olive, dwarf flowering quince, cotoneaster, cinquefoil,
fragrant sumac, highbush blueberry, bayberry, redtwig dogwood, grey dogwood, woadwaxen,
rose of Sharon, Nanking cherry, beach plum, peashrub, Virginia creeper. Evergreen Shrubs and
Ground Cover: Skimmia, azalea, Japanese holly, mountain laurel, Mugo pine, rhododendron,
yew, inkberry, evergreen euonymus, juniper, bearberry, American arborvitae, trumpet vine.
P
Parent material. The rocks and small particles that the soil develops in; often the geologic deposit C soil
horizons and R layers of the substratum.
Pedon. The smallest three dimensional volume that can be called "a soil."
Pesticide losses. Hazard classes from movement of pesticides with soil and water in runoff or with
groundwater in leaching.
R
Reaction (soil reaction, pH). A measure of acidity or alkalinity of a soil, expressed in pH values. The
classes are: Extremely acid, pH below 4.5; Very strongly acid, pH 4.5 to 5.0; Strongly acid, pH
5.1 to 5.5; Moderately acid, pH 5.6 to 6.0; Slightly acid, pH 6.1 to 6.5; Neutral, pH 6.6 to 7.3;
Mildly alkaline, pH 7.4 to 7.8; Moderately alkaline, pH 7.9 to 8.4; Strongly alkaline, pH 8.5 to
9.0; Very strongly alkaline, pH 9.1 and higher.
Reconstruction materials. Potential of soil for use as a source of fill material.
Reduction. Change in oxidation state of iron and manganese that changes the color of their compounds
and how soluble the compounds are.
Runoff class. Potential runoff hazard from a soil based on plant cover, slope, and surface texture. Higher
classes have more chance of causing erosion.
S
Salinity. A measure of soluble salts in soil based on electrical conductivity. Only salt tolerant plants can
grow in soil with high salinity levels.
Sand. Individual rock or mineral fragments from 0.05 millimeter to 2.0 millimeters in diameter. Most
sand grains consist of quartz.
Sapric soil material. Same as muck but used in unsaturated soils.
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Saturation. Water will flow from the soil into an open hole when the soil is saturated, and all the air
spaces in the soil are filled with water.
Saturated hydraulic conductivity. Rate (inches/hour) of water movement through a saturated horizon.
14.17 in/hr is equal to 0.01 cm/sec. The classes are: Very High - >14.17; High - 14.17 to 1.417;
Moderately High - 1.417 to .1417; Moderately Low - .1417 to .01417; Low - .01417 to .001417;
Very Low - <.001417.
Series (soil series). A group of soils that have profiles that are almost alike except for differences in
texture of the surface layer.
Silt. Individual rock fragments that range in diameter from the upper limit of clay (0.002 millimeter) to
the lower limit of very fine sand (0.05 millimeter).
Soil. A natural, three-dimensional body at the earth’s surface, capable of supporting plants, with
properties resulting from climate and living plants and animals acting on earthy parent material,
as controlled by relief over periods of time.
Solum. The upper part of a soil profile, above the C horizon, in which the processes of soil formation are
active.
Structure (soil structure). The aggregates (clods) of numerous sand, silt, clay, and organic matter
particles.
Subsoil. The E and B soil horizons below the topsoil that have some soil development.
Substratum. The C horizons and R layers below the depth of noticeable soil development; often the parent
material of the soil above.
T
Terrace. An old alluvial floodplain, usually level, that borders a river, a lake, or the sea, and is higher than
modern floodplains.
Texture (soil texture). The relative proportions of sand, silt, and clay particles. The basic textural classes
are: sand, loamy sand, sandy loam, loam, silt loam, silt, sandy clay loam, clay loam, silty clay
loam, sandy clay, silty clay, and clay. The dominant sand size (very fine to coarse) is described in
sand, loamy sand, and sandy loam classes. Gravel content modifiers are added when gravel
content is greater than 15 percent.
Tilth (soil tilth). The physical condition of the soil as related to tillage, seedbed preparation, seedling
emergence, and root penetration.
Topsoil. Potential of soil for use as a source of topsoil. Topsoil is the upper part of the soil which is the
darkest color (most organic matter) and most favorable part for growing plants in.
U
Udortherts. A broad level classification of non wetland, poorly developed soils in the northeast U.S.
Urbanization. Change from undeveloped land into cities and towns.
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W
Wilting point. The moisture content of soil at which a plant (specifically a sunflower) wilts so much that
it does not recover.
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List of Anthropogenic Features
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
Artificial collapsed depression (e. g., arising from subsurface)
Mining subsidence
Artificial levees
Borrow pit
Burial mound
Cut (road, railroad)
Ditch
Fill
Gravel pit
Landfill
Leveled land
Midden
Pond (human-made)
Quarry
Railroad bed
Rice paddy
Road bed
Sand pit
Sanitary landfill
Sewage lagoon
Spoil bank
Surface mine
Conservation terrace (modern)
Double- bedding mound; i.e., bedding mound used for timber; lower Coastal Plain
Drainage ditch
Furrow
Hillslope terrace (e. g., archeological features; China, Peru)
Inter-furrow
Urban land
Reference
Schoeneberger, P. J., Wysocki, D. A., Benham, E. C., and Broderson, W. D. 1998. Field book for
describing and sampling soils. Natural Resources Conservation Service, USDA, National Soil
Survey Center, Lincoln, NE.
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List of Anthropogenic Definitions
Proposed Terms to Describe Human Activities and Products
http://clic.cses.vt.edu/icomanth/
Anthric (Anthropic) saturation - (already in Soil Taxonomy) episaturation by human-controlled
flooding or irrigation which results in reduction and oxidation of iron and manganese compounds
and long term changes in soil properties (Anthraquic conditions), a type of Anthropopedogenesis.
Anthropic compaction – the reduction in the volume of pores per unit mass of soil by human activity or
machinery. (a type of Anthropopedogenesis)
Anthropic deposition – the deposition, reclamation, or replacement of artifacts, rock, organic and
mineral soil material. Deposition of more than 50cm constitutes
Anthropocompacted material - material with reduced volume of pores per unit mass of soil as a result
of human activity.
Anthropogenic (also appears as Anthrogenic in some papers) activities - Human actions that control soil
forming processes. Examples are: excavation and deposition of soil and rock, contamination with
pollutants, long term alteration of soil reaction by liming, artificial flooding, long term drainage
alteration, long term protection from natural flooding, mechanical mixing and soil compaction,
and accelerated erosion.
Anthropogeomorphic (appears as Anthrogeomorphic in some papers) activities - Excavation and
Anthropic deposition (cutting, filling, and leveling) that results in alteration of the shape of a
natural landform or creation of an artificial landform.
Anthropotransported material - Artifacts deposited on the landscape; and manure, soil, and rock with
evidence of being transported by human activity or machinery, including dredged sediment and
sediment in irrigation water.
Anthropoturbated material - organic material, artifacts, soils, or rocks with evidence of being mixed by
human activity or machinery.
Anthropoturbation - mixing of different horizons or mixing within a horizon that occurs because of
human activity or machinery. (A type of Anthropopedogenesis).
Artifacts - human altered material such as coal ash, iron ore slag, asphalt, human refuse such as garbage
or sewage sludge, human processed natural materials such as lumber, and human manufactured
material such as plastic, fiberglass, brick, cinder block, concrete, iron and steel, organic
byproducts, and other building debris. Garbage or refuse fragments include: food and household
cooking waste, soiled rags and paper cleaning products, broken household objects, empty glass,
paper, and plastic containers and bags, mail, magazines, and newspapers, and simple household
construction materials normally disposed of by homeowners and transported to dumps and
landfills.
Artificial drainage - lowering of a ground water table.
Artificial landform - an area in the landscape as large or larger than a polypedon that has evidence of
mining or reclamation, excavation more than 50cm deep, or Anthropic deposition more than
50cm thick. Evidence may be morphological, chemical, mineralogical, historical, or comparative
polypedon/landform study.
Excavation – the removal of rock and earthy material. Removal of more than 50 cm by human activity or
machinery constitutes creation of an artificial landform.
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