This section identifies words, terms, or phrases that
are used within the National Handbook of Conservation Practices. These terms best represent the technical information presented in the
standards. All significant terms that may have a meaning more specialized or more restrictive
than the common dictionary meaning are defined here for clarification for
the user of the standards and to best represent the intended use of terms
within the NRCS standards.
Absorption
|
The physical integration of a liquid into the pore spaces of a solid, such
as water being absorbed into a sponge.
|
Aeration
|
A process causing intimate contact between air and a liquid by one or more
of the following methods: (a)
spraying the liquid in the air, (b) bubbling air through the liquid,
and (c) agitating the liquid to promote absorption of oxygen through
the air liquid interface.
|
Aeration, soil
|
The
exchange of air in soil with air from the atmosphere. The air in a well-aerated soil is similar to that in the atmosphere; the air
in a poorly aerated soil is considerable higher in carbon dioxide and lower
in oxygen.
|
Aerobic
|
Having
or occurring in the presence of free oxygen.
|
Agricultural
waste management system
|
A
combination of conservation practices to collect, transport, store or treat,
and apply animal waste, and the management that, when applied, will protect
the resource base.
|
Agricultural
wastes
|
Wastes normally associated with the production and processing of food and fiber
on farms, feedlots, ranches, ranges, and forests which may include animal
manure, crop residues, and dead animals; also, agricultural chemicals,
fertilizers, and pesticides which may find their way into surface and subsurface
water. |
Alluvium
|
Sediment
deposited by streams and rivers.
|
Ammonia
volatilization
|
The loss of ammonium to the atmosphere
|
Ammonium
|
Anion (NH4+)
derived from ammonia (NH3)
|
Anaerobic
|
The
absence of molecular oxygen, or growing in the absence of oxygen.
|
Anaerobic
digester
|
A
heated, airtight apparatus that facilitates anaerobic digestion.
|
Anaerobic
digestion
|
Conversion
of organic matter in the absence of oxygen under controlled conditions
to such gases as methane and carbon dioxide.
|
Anaerobic
lagoon
|
A
structure o treat animal waste by predominantly anaerobic biological action
using anaerobic or facultative organisms, in the absence of air, for the
purpose of reducing the organic matter in wastes.
|
Artesian
well
|
A
well deriving its water from a confined aquifer in which the water level
stands above the ground surface; synonymous with flowing well.
|
Available
forage
|
That
portion of the forage production that is accessible for use by a specified
kind or class of grazing animal. It is the consumable forage stated in digestible dry matter per land unit
area that can be removed by grazing livestock without damage to the forage
plants.
|
Available
nitrogen
|
Form
of nitrogen that is immediately available for plant growth (NO3-)
or (NH4+)
|
Available
phosphorus
|
Forms
of phosphorus that can be immediately used for plant growth.
|
Available
water capacity (available moisture capacity)
|
The
capacity of soils to hold water available for use by most plants. It is commonly defined as the difference between the amount of soil water
at field capacity and the amount at wilting point. It is commonly expressed as inches of water per inch of
soil. The capacity, in inches, in a 60-inch profile or to a limiting layer is expressed
as inches.
12 inches |
Base flow
|
Water
that, having infiltrated the soil surface, percolates to the ground water
table and moves laterally to reappear as surface runoff.
|
Bedrock
|
The
solid rock that underlies the soil and other unconsolidated material or
that is exposed at the surface
|
Benchmark
|
(1)
A permanent reference point.(2)
In range inventory, it is used as a point where changes in vegetation through
time are measured.(3) In
soils, it is used to designate a major soil series that is representative
of similar soils.(4) In economics,
data that are used as a base for comparative purposes with similar data.(5)
A surveyor’s mark made on a permanent landmark that has known position
and altitude.
|
Best
Management Practice(s) (BMP)
|
A practice or combination of practices
found to be the most effective, practicable (including economic and
institutional considerations) means of preventing or reducing the amount of
pollution generated by non-point sources to a level compatible with water
quality goals.
|
Biological
wastewater Treatment
|
Forms
of wastewater treatment in which bacterial or biochemical action is intensified
to stabilize or oxidize the unstable organic matter present. Oxidation ditches, aerated lagoons, anaerobic lagoons and anaerobic digesters are
examples.
|
Biomass
|
The
total amount of living material, plants and animals, above and below ground
in a particular area.
|
Boulders
|
Rock
fragments larger than 2 feet (60 cm) in diameter
|
Broadcast
seeding
|
Process
of scattering seed on the surface of the soil prior to natural or artificial
means of covering the seed with soil.
|
Cabling
|
The
use of a large cable pulled between two large tractors (usually crawler
tractors) to pull sown or uproot brush.
|
Carbonate
|
Sediment
formed by the organic or inorganic precipitation from aqueous solution
of carbonates of calcium, magnesium, or iron.
|
Certified
seed
|
Seed
produced from foundation or registered seed that is available for consumer use. It
carries a tag signifying
it is high quality seed.
|
Chiseling
|
Breaking
or loosening the soil, without inversion, with a chisel cultivator or chisel plow. A
practice used for cropland,
grassland or pasture renovation.
|
Clay
(size)
|
The
mineral soil particles less than 0.002 millimeters in diameter.
|
Clay
(texture class)
|
As
a soil textural class, soil material that is 40 percent or more clay, less
than 45 percent sand, and less than 40 percent silt.
|
Coarse-grained
soil
(textured
class)
|
In
the USDA Soil Classification System, a texture group consisting of the
sands and loamy sands texture classes.
|
Coarse-grained
soil (engineering)
|
The
minus 3-inch (75-mm) fraction of soil having a gradation such that more
than 50 percent by dry weight is retained on the No. 200 (75-um) sieve.
|
Coliform
bacteria
|
A
group of bacteria predominantly inhabiting the intestines of man or animal,
but also found in soil. It includes
all aerobic and facultative anaerobic, gram-negative, non-spore-forming
bacilli that ferment lactose with production of gas. This group of “total” coliforms includes Escherichia
coli, which is considered
the
|
Community
(Plant)
|
An
assemblage of plants occurring together at any point in time, while denoting
no particular ecological status. A unit of vegetation.
|
Composting
|
A
process of aerobic biological decomposition characterized by elevated temperatures
that, when complete, results in a material that is relatively inert, safe,
and makes an excellent soil conditioner.
|
Cone
of depression
|
A
depression in the ground water table or potentiometer surface that has
the shape of an inverted cone and develops around a well from which water
is being withdrawn. It defines the
area of influence of a well.
|
Confined
aquifer
|
A
formation in which the ground water is isolated from the atmosphere at
the point of discharge by impermeable geologic formations. Confined ground water is generally subject to pressure greater than atmospheric.
|
Conservation
cropping sequence
|
An
adapted sequence of crops designed to provide adequate organic residue
for maintenance or improvement of soil tilth and for other conservation
purposes.
|
Conservation
plan
|
A
record of the client’s decisions and supporting information, for treatment
of a unit of land or water as a result of the planning process, that meets
FOTG quality criteria for each natural resource (soil, water, air, plants,
and animals) and takes into account economic and social considerations. The plan describes the schedule of operations and activities needed to solve
identified natural resource problems, and take advantage of opportunities,
at a resource management system level. The needs of the client, the resources, and Federal, State and local requirements
will be met.
|
Conservation
practice
|
A
specific structural, managerial, or cultural treatment of natural resources
commonly used to meet a specific need in planning and carrying out soil
and water conservation programs.
|
Contamination
|
The
degradation of water quality as result of natural processes and/or the
activities of people. No specific
limits are established because the degree of permissible contamination
depends upon the intended end use or uses of water.
|
Conventional
tillage
|
Those
primary and secondary tillage operations that are considered standard for
the specific location and crop.
|
Cost
effectiveness
|
A
term used to economically compare agricultural no point source control alternatives. It
is generally expressed
as dollars per unit pollutant load reduction.
|
Cover
crop
|
A
close-growing crop, whose main purpose is to protect and improve the soil
and use excess nutrients or soil moisture during the absence of the regular
crop, or in the no vegetated areas of orchards and vineyards.
|
Critical
area
|
An
area to be treated with special consideration because of inherent site
factors, size, location, condition, values, or significant potential conflicts
among uses.
|
Crop
residue
|
The
portion of a crop remaining after harvest of seed or other primary plant parts. It
may be managed for grazing
and/or ground cover and to replenish soil organic matter levels.
|
Crop
rotation
|
A
planned sequence of crops.
|
Cropland
|
Land
used primarily for the production of cultivated crops.
|
Deciduous
(plant)
|
A
plant whose parts, particularly leaves, are shed at regular intervals or
at a given stage of development.
|
Decision
maker
|
An
individual, group, unit of government, or other entity that has the authority
by ownership, position, office, delegation, or otherwise to decide on a
course of action.
|
Deep
percolation
|
The
downward movement of water through the soil and below the root zone.
|
Denitrificaiton
|
The
chemical or biological reduction of nitrate or nitrite to gaseous nitrogen,
either as molecular nitrogen (N2)
or as an oxide of nitrogen (N20).
|
Detention
pond
|
A
water impoundment made by constructing a dam or an embankment, or by excavating
a pit or dugout usually to provide temporary storage of runoff.
|
Direct
runoff
|
Both
surface flow and the interflow component of subsurface flow
|
Dissolved
oxygen (DO)
|
The
molecular oxygen dissolved in water, wastewater, or other liquid; generally
expressed in milligrams per liter, parts per million, or percent of saturation.
|
Diversity
|
A
measure of the number of species and their relative abundance in a community.
|
Dormant
|
(1)
A living plant that is not actively growing aerial shoots.(2) A pesticide application made on crop plants that are not actively growing.
|
Dormant
seeding
|
Planting
seed during the fall when seeds will not germinate until next spring.
|
Drill
seeding
|
Planting
seed directly into the soil with a drill in rows, usually 6 to 24 inches
apart.
|
Drip line
|
The
area under the outermost branches of a tree or shrub.
|
Drouth
(drought)
|
(1) A prolonged chronic shortage of water. (2) A period with below
normal precipitation during which the soil water content is reduced such
an extent that plants suffer from lack of water; frequently associated
with excessively high temperatures and winds during spring, summer, and
fall in many parts of the world.
|
Effluent
|
The
liquid discharge of a waste treatment process.
|
Erosion
|
The
wearing away of the land surface by water, wind, ice or other geologic
agents and by such processes such as gravitational creep.
|
Erosion
(accelerated)
|
Erosion
occurring more rapidly than geologic erosion, mainly as a result of the
activities of man or other animals or of a catastrophe in nature, for example,
fire that exposes the surface.
|
Eutrophicution
|
A
natural or artificial process of nutrient enrichment whereby a water body
becomes abundant in plant nutrients and low in oxygen content.
|
Evapotranspiration
|
The
loss of water from an area by evaporation from the soil or snow cover and
transpiration by plants.
|
Exotic
|
An
organism or species that is not native to the region in which it is found.
|
Fault
|
A
fracture or a zone of fractures along which there has been displacement
of the sides relative to one another parallel to the fracture.
|
Fertilizer
value
|
An
estimate of the value of commercial fertilizer elements (N, P, K) that
can be replaced by manure or organic waste material. Usually expressed as dollars per ton of manure or quantity of nutrients per ton
of manure.
|
Field
moisture capacity
|
The
moisture content of a soil, expressed as a percentage of the oven-dry weight,
after the gravitational, or free, water has drained away.
|
Fine
textured soil
|
Sandy
clay, silty clay, and clay.
|
Flooding
|
The
temporary covering of the soil surface by water that flows over it from
any source, such as a stream, irrigation canal, tidal action, or runoff
from adjacent or surrounding slopes.
|
Flushing
system
|
A
system that collects and transports or moves waste material with the use
of water, such as in washing of pens and flushing confinement livestock
facilities.
|
Fluvial
|
Pertaining
to or produced by the action of a stream or river.
|
Forage
|
All
browse and herbage that is available and acceptable to grazing animals
or that may be harvested for feeding purposes. Act of consuming forage. Syn. graze.
|
Ford
|
A
constructed or natural stream crossing for equipment, humans, or animals
at a point where water is shallow, footing is firm, and banks are low or
inclined for easy approach and exit. The bottom of the channel and approaches are either naturally or artificially
paved to facilitate ease of crossing and to reduce muddying of the water.
|
Geographic
Information System (GIS)
|
A
spatial type of information management system that provides for the entry,
storage, manipulation, retrieval and display of spatially oriented data.
|
Global
Positioning System (GPS)
|
A
computer based receiver system that uses satellite transmissions to determine
precise latitude and longitude readings at any location in a field. This system is used to map crop yield, soil fertility, weed infestations, soil
type, and other yield influencing differences. It then forms the basis for variable rate applications of fertilizer and
pesticides. Application equipment is guided by a georeferenced program to deliver different application
rates as it traverses back and forth across a field.
|
Grassed
infiltration area
|
An
area with vegetative cover where runoff water infiltrates into the soil
|
Green
manure
|
Any
crop or plant grown and not harvested that is used to improve the soil’s
organic matter content and structure. It may or may not be incorporated by tillage.
|
Ground
water
|
Subsurface
water that is in the zone of saturation. The top surface of the ground water is the water
table. Source of water for wells, seepage, and springs.
|
Ground
water table
|
The
surface between the zone of saturation and the zone of aeration. The surface of an unconfined aquifer.
|
Guide
|
A
detailed summary of information or series of options that does not recommend
a specific course of actions.
|
Head
|
Energy
contained in a water mass; expressed in elevation (feet) or pressure (pounds
per square feet).
|
Head
loss
|
That
part of head energy, which is lost because of friction as water flows.
|
Herbaceous
|
Vegetative
growth with little or no woody component. Non-woody
vegetation, such as graminoids and forbs.
|
Herbicide
|
A
chemical used to kill or inhibit the growth of plants.
|
Horizon,
soil
|
A
layer of soil, approximately parallel to the surface, having distinct characteristics
produced during soil-forming processes.
|
Hydraulic
conductivity
|
The
rate of flow of water in gallons per day through a cross section of one
square foot under a unit hydraulic gradient, at the prevailing temperature (gpd/ft2).
In the SI system, the units are m3/day/m2 or
m/day.
|
Hydraulic
gradient
|
The
rate of change in total head per unit of distance of flow in a given direction.
|
Hydrologic
condition
|
Description
of the moisture present in a soil by amount, location, and configuration.
|
Hydrologic
soil groups
|
A
classification system used by the Natural Resources Conservation Service
to group soils according to their runoff producing characteristics. The chief consideration is the inherent capacity of soil bare of vegetation
to permit infiltration. The slope
and kind of plant cover are not considered, but are separate factors in
predicting runoff. Soils are assigned to four groups. In-group A is soils having a high infiltration rate when thoroughly wet and
having a low runoff potential. They are mainly deep, well drained, and sandy or gravelly. In-group
D, at the other extreme, are soils having a very slow infiltration
rate and thus a high runoff potential. They have a clay pan or clay layer at or near the surface, have a permanent high
water table, or are shallow over nearly impervious bedrock or other material.
|
Indicator
species
|
(1)
Species that indicate the presence of certain environmental condition,
range condition, previous treatment, or soil type. (2)
One or more plant species selected to indicate a certain level of grazing
use.
|
In filtration
rate
|
The
rate, at which water penetrates the surface of the soil at any given instant,
usually expressed in inches per hour. The rate can be limited by the infiltration capacity of the soil or the rate
at which water is applied at the surface.
|
Karst
topography
|
A
type of topography that is formed in limestone, gypsum, and other similar
type rock by dissolution and are characterized by sinkholes, caves, and
rapid underground water movement.
|
Lagoon
|
A
shallow impoundment made by excavation or earthfill for the purpose of
waste treatment.
|
Landscape
|
The
environment, both natural and built, that surrounds us.
|
Landscape
quality
|
A
composite of those landscape conditions and perceived values that provide
diverse and pleasant surroundings for human use and appreciation. Recognized components of landscape quality include visual resource, landscape use,
viewscape, and visibility.
|
Leaching
|
(1)
The removal of soluble constituents, such as nitrates or chlorides, from
soils or other material by the movement of water.(2)
The removal of salts and alkali from soils by irrigation combined with
drainage.(3) The removal
of a liquid through a non-watertight artificial structure, conduit, or
porous material by downward or lateral drainage, or both, into the surrounding
permeable soil.
|
Limestone
|
A
sedimentary rock consisting chiefly of calcium carbonate.
|
Limiting
nutrient
|
Nutrient
that restricts plant growth.
|
Liquid
manure
|
A
mixture of water and manure that behaves more like a liquid than solid,
generally less than 5 percent solids.
|
Livestock
waste
|
A
term sometimes applied to manure that may also contain bedding, spilled
feed, eater, or soil. It also includes
wastes not particularly associated with manure, such as milking center
or washing wastes, and milk, hair, feathers, or other debris.
|
Manure
|
The
fecal and urinary excretions of livestock and poultry.
|
Mechanical
solids separation
|
The
process of separating suspended solids from a liquid-carrying medium by
trapping the particles on a mechanical
|
Microclimate
|
Climate
as experienced at the scale of a particular site. Includes such elements as solar orientation, wind direction, temperature, and precipitation.
|
Monitoring
|
Systematic
collection of data on a routine basis and the analysis of these data for
an understanding of the changes that may occur in the sampled environment.
|
Mulch
|
Any
substance that is spread on the soil surface to decrease the effects of
raindrop impact, runoff, and other adverse conditions and to retard evaporation.
|
Municipal
waste
|
Solid
and liquid fractions of wastes produced by a municipality. Municipal wastes may be treated or untreated and may be either used or disposed of.
|
Native
species
|
A
species, which is a part of the original fauna or flora of the area in
question.
|
Nitrogen
|
A
chemical element commonly used in fertilizer as a nutrient, which is also
a component of animal wastes. As one of the major nutrients required for plant growth, nitrogen can promote
algae blooms that cause water body eutrophication if it runs off or leaches
out of the surface soil. Nitrogen is immediately usable for plant growth in available forms (NO3-)
or (NH4+)
|
Nitrogen cycle
|
The succession of biochemical reactions that nitrogen undergoes as it is converted
to organic or available nitrogen from the elemental form. Organic nitrogen in waste is oxidized by bacteria into ammonia (NH3).If
oxygen is present, ammonia is bacterially oxidized first into nitrite (NO2-)
and then into nitrate (NO3-).If
oxygen is not present, nitrite and nitrate are bacterially reduced to nitrogen
gas, completing the cycle.
|
No point source
(NPS)
|
Entry
of effluent into a water body in a diffuse manner so there is no definite
point of entry.
|
No-till
|
A
planting procedure that requires no tillage except that done by a coulter
or disk opener in the immediate area of the crop row.
|
Noxious weed
|
An
unwanted plant specified by Federal or State laws as being especially undesirable,
troublesome, and difficult to control. It grows and spreads in places where it interferes with the growth and production
of the desired crop.
|
Nutrients
|
Elements
required for plant or animal growth, including the macronutrients (nitrogen,
phosphorus, and potassium), which are the major nutrients required and
micronutrients, which include a number of other elements that are essential
but needed in lesser amounts.
|
Organic matter
|
The
organic fraction of the soil exclusive of undecayed plant and animal residue.
|
Overgrazing
|
Grazing
that exceeds the recovery capacity of the individual species or the plant
community.
|
Pasture
|
(1)
Grazing lands comprised of introduced or domesticated native forage species
that are used primarily for the production of livestock. They receive periodic renovation and/or cultural treatments such as tillage,
fertilization, mowing, weed control, and may be irrigated. They are not in rotation with crops.(2)
A grazing area enclosed and separated from other areas by fencing or other barriers. The
management unit for
grazing land.(3) Forage plants
used as food for grazing animals.(4)
Any area devoted to the production of forage, native or introduced, and
harvested by grazing.
|
Percolation
|
The
downward movement of water through soil.
|
Percolation
rate
|
The
rate of movement of water under hydrostatic pressure down through the interstices
of rock, soil, or filtering media except movement through large openings,
such as caves.
|
Permanent wilting
point
|
The
moisture content of soil, on an oven-dry basis, at which a plant (specifically
a sunflower) wilts so much that it does not recover when
|
Permeability
|
The quality of the soil
that enables water to move downward through the profile. Permeability
is measured as the number of inches per hour that water moves downward
through the saturated soil. Terms
describing permeability are:
- Very slow less than 0.06
inches/hr
- Slow 0.06 to 0.2 inches/hr
- Moderately slow 0.2 to 0.6
inches/hr
- Moderate 0.6 to 2.0 inches/hr
- Moderately rapid 2.0 to 6.0
inches/hr
- Rapid 6.0 to 20 inches/hr
|
Pesticide
|
Any
chemical agent such as herbicide, fungicide, or insecticide, used for control
of specific organisms.
|
pH
|
The
negative logarithm of the hydrogen ion concentration. The
pH scale ranges from zero to 14.Values
below 7 are considered acidic and those above
|
Phosphate
|
Phosphate
ions exist in water as H2PO4
– or HPO4-2Otherwise
phosphate is an ester or salt of phosphoric acid, such as calcium phosphate
rock.
|
Phosphorus
|
One
of the primary nutrients required for the growth of plants. Phosphorus
is often the limiting nutrient for the growth of aquatic plants and algae.
|
Point source
|
The
release of a contaminant or pollutant, often in concentrated form, from
a conveyance system, such as a pipe, into a water body.
|
Pollution/polluted
|
The
presence in a body of water (or soil or air) of a substance (contaminant)
in such quantities that it impairs the body’s usefulness or renders it
offensive to the senses of sight, taste, or smell. In
general, a public health hazard may be created, but in some instances only
economic or aesthetics are involved, such as when foul odors pollute the
air.
|
Pond
|
A
water impoundment made by constructing a dam or an embankment, or by excavating
a pit or dugout usually to supply drinking water for livestock and or wildlife.
|
Ponding
|
Standing
water on soils in closed depressions. Unless
the soils are artificially drained, the water can be removed only by percolation
or evapotranspiration.
|
Porous dam
|
A
runoff control structure that reduces the rate of runoff so that solids
settle out in the settling terrace or basin. The
structure may be constructed of rock, expanded metal, or timber arranged
with narrow slots.
|
Potassium
|
One
of the primary nutrients required for the growth of plants.
|
Profile, soil
|
A
vertical section of the soil extending through all its horizons and into
the parent material.
|
Pumping test
|
A
test that is conducted to determine aquifer or well characteristics
|
Rangeland
|
Land
on which the historic climax plant community is predominantly grasses,
grasslike plants, forbs, or shrubs. Includes
lands revegetated naturally or artificially when routine management of
that vegetation is accomplished mainly through manipulation of grazing. Rangeland
includes natural grasslands, savannas, shrublands, most deserts, tundra,
alpine communities, coastal marshes, and wet meadows.
|
Reclamation
|
Restoration
of a site or resource to a desired condition to achieve management or stated
goals.
|
Reduced tillage
|
A
management practices whereby the use of secondary tillage operations is
significantly reduced.
|
Resource base
|
The
combination of soil, air, water, plants, and animals that makes up the
natural environment
|
Resource Management
System (RMS)
|
A
combination of conservation practices and resource management, for the
treatment of all identified resource concerns for soil, water, air, plants,
and animals, that meets or exceeds the quality criteria in the FOTG for
resource sustainability.
|
Ridge planting
|
The
practice of growing a row crop on the ridges between the furrows.
|
Riparian
|
Area,
zone, and/or habitat adjacent to streams, lakes, or other natural free
water, which have a predominant influence on associated vegetation or biotic
communities.
|
Root zone
|
The
part of the soil that can be penetrated by plant roots.
|
Ruminant
|
Even-toed,
hoofed mammals such as cow, goat, or sheep, having a 4-chamber stomach;
and chewing a cud consisting of regurgitated, partially digested food,
i.e., ruminantia
|
Runoff
|
The
part of precipitation or irrigation water that appears in surface streams
or water bodies; expressed as volume (acre-inches) or rate of flow (gallons
per minute, cubic feet per second).
|
Salt
|
A
compound made up of the positive ion of a base and the negative ion of
an acid.
|
Salvage value
|
The
value remaining in a piece of equipment or other asset at the end of its
intended useful life.
|
Sampling
|
Collection
of a small part of an entity and drawing conclusions about the whole. In water quality considerations, sampling consists of collecting a representative
part of a water body for testing from which conclusions can be drawn about
the water body as a whole.
|
Sediment delivery
|
Sediment
arriving at a specific location.
|
Sediment yield
|
Quantity
of sediment leaving a specified land area.
|
Seed inoculation
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Treatment
of legume seed with rhizobium bacteria before planting to enhance subsequent
nitrogen fixation.
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Seep
|
Wet
areas, normally not flowing, often created when the elevation of the lateral
flow of underground water intersects ground level, as on a hillslope.Occasionally
seeps occur from water arising from water arising from an underground source.
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Sewage sludge
|
Settled
sewage solids combined with varying amounts of water and dissolved materials
that are removed from sewage by screening, sedimentation, chemical precipitation,
or bacterial digestion.
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Sheet erosion
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Soil
erosion occurring from a thin, relatively uniform layer of soil particles
on the soil surface. Also called
inter-rill erosion.
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Site design
|
A
careful search among physical elements to plan for human and animal occupation
and utilization of a site so that comfort, profitability, and usefulness
are maximized and harmful stress is reduced.
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Slope
|
The
inclination of the land surface from the horizontal. Percentage of slope is the vertical distance divided by horizontal distance, then
multiplied by 100.Thus, a slope
of 20 percent is a drop of 20 feet in 100 feet of horizontal distance.
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Sodicity
|
The
degree to which a soil is affected by exchangeable sodium. Sodicity is
expressed as a sodium adsorption ratio (SAR) of a saturation extract.
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Soil
|
A
natural, three-dimensional body at the Earth’s surface. It
is capable of supporting plants and has properties resulting from the integrated
effect of climate and living matter acting on earthy parent material, as
conditioned by relief over time.
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Soil amendment
|
Any
material, such as lime, gypsum, sawdust, or synthetic conditioner that
is worked into the soil to make it more amenable to plant growth. Amendments may contain important fertilizer elements, but the term commonly refers
to added materials other than fertilizer.
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Soil and water
conservation practices
|
The
manipulation of such variables as crops, rotation, tillage, management,
and structures to reduce the loss of soil and to conserve water.
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Soil organic
matter
|
The
organic fraction of the soil that includes plant and animal residue at
various stages of decomposition, exclusive of undecayed plant and animal residue. Often
used synonymously
with humus.
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Soil reaction
|
Numerical
expression in pH units of the relative acidity or alkalinity of a soil. The range in soil pH is 0 to 14.0A pH
of 7.0 is neutral.
|
Soil test
|
A
chemical and physical analysis of a soil used to estimate its nutrient
supplying power. It must use chemical
extraction techniques appropriate for the elements being extracted and
the soil being examined. For the
results to be interpreted properly, the test procedures must also be calibrated
against nutrient rate experiments in the field and in the greenhouse.
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Solid manure
storage
|
A
storage unit in which accumulations of bedded manure or solid manure is
stacked before subsequent handling and field spreading. The liquid parts, including urine and precipitation, may or may not be drained
from the unit.
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Spatial
|
The
occupied space relationship between a soil and soil map unit to the landscape
or geomorphic surface on which the soil or map unit is located.
|
Specification
|
An
explicit set of requirements to be satisfied by a material, product, system,
or service, such as construction. It also identifies the methods for determining whether each of the requirements
is satisfied.
|
Standard
|
A
statement of acceptable quality or technical excellence in terms of both
form and function (performance), usually expressed in terms of limits,
i.e. minimum or maximum.
|
State Technical
Committee
|
A
technical committee in each State to assist in the technical considerations
and to develop the technical guidelines necessary to implement the conservation
provisions of the Food Security Act of 1985, as amended. The State Technical Committee is composed of representatives from Federal Agencies,
Private Interest members, State Departments, Agencies and Other outside
Groups.
|
State Technical
Guide Committee (STGC)
|
The
STGC is a committee of principal NRCS staff responsible for the approval
and distribution of State-developed, State-supplemented, or field office-supplemented
FOTG materials. The STGC is also
responsible for quality assurance activities to ensure the completeness
and currency of FOTG materials
|
Stock pond
|
A
water impoundment made by constructing a dam or by excavating a dugout
or both, to provide water for livestock and/or wildlife.
|
Stream classification
|
The
identification of specific channel categories, types, or characteristics
so that consistent descriptions and assessments of the conditions and potential
for the stream can be developed.
|
Structural
controls
|
Candidate
measures that require capital investment, construction activities, and
consequently, certain economic risks.
|
Subsoil
|
Technically,
the B-horizon; roughly, the part of the solum below plow depth.
|
Subsurface
runoff
|
Water
that infiltrates the soil and then moves laterally below the surface; includes
baseflow and interflow.
|
Succession
|
The
progressive replacement of plant communities on an ecological site that
leads to the climax plant community.
|
Suitability
|
(1)
The adaptability of an area to grazing by livestock or wildlife.(2)
The adaptability of a particular plant or animal species to a given area.
|
Surface layer
|
The
soil ordinarily moved in tillage, or its equivalent in uncultivated soil,
ranging in depth from about 4 to 10 inches (10 to 25 centimeters). Frequently designated as the “plow layer,” or the “A
horizon." Some water quality models refer to surface layer as the first few centimeters
of soil.
|
Suspended solids
|
(1)
Undissolved solids that are in water, wastewater, or other liquids, and
are largely removable by filtering or centrifuging.(2)
The quantity of material filtered from wastewater in a laboratory test,
as prescribed in APHA Standard Methods for the Examination of Water and
Wastewater or similar reference.
|
Texture, soil
|
The
relative proportions of sand, silt, and clay particles in a mass of soil.
|
Tilth, soil
|
The
physical condition of the soil as related to tillage, seedbed preparation,
seedling emergence, and root penetration.
|
Total solids
|
The
total amount of solids in a waste, both in solution and suspension.
|
Toxicity
|
Degree
of harmful affects an element or compound may have on a living organism,
plant, or animal. Excessive amount
of toxic substances, such as sodium or sulfur that severely hinder establishment
of vegetation or severely restrict plant growth.
|
Understory
|
Plants
growing beneath the canopy of other plants. Usually refers to grasses, forbs, and low shrubs under a tree or shrub canopy.
|
Universal Soil
Loss Equation (USLE)
|
An
empirical equation estimating the amount of soil loss. Used for the evaluation of a resource management system for water erosion
control. The revised equation is called RUSLE.
|
Vadose zone
|
The
zone containing water under less pressure than that of the atmosphere,
including soil water, intermediate vadose water, and capillary water. This zone is limited above by the land surface and below by the surface of the
zone of saturation, that is, the water table.
|
Vector
|
A
bearer or carrier such as an organism (often an insect) that carries and
transmits disease-causing microorganisms.
|
Vegetative
practices
|
Practices
that are directly concerned with the use and growth of plants. These include such practices as prescribed grazing and livestock exclusion.
|
View
|
A
scene observed from a given vantage point; can be preserved, neutralized,
modified, or accentuated.
|
Viewshed
|
All
the land and landscape elements that make up or affect a view from a given
location or point; delineated by the horizon/silhouette line, enclosure
by built or natural elements.
|
Vista
|
A
confined view generally toward a terminal or dominant element or feature;
may be natural or structural; may be created in its entirety and is therefore
subject to close control.
|
Volatile solids
|
Readily
vaporizable solids. Those solids
that are combustible at 6000C.
|
Volatilization
|
The
loss of gaseous components, such as ammonium nitrogen, from animal manure.
|
Warm-season
plant
|
(1) A plant that makes most or all its growth during the spring, summer,
or fall and is usually dormant in winter.(2)
A plant that usually exhibits the C-4 photosynthetic pathway.
|
Waste management
system
|
See
Agricultural waste management system.
|
Waste storage
pond
|
An
impoundment made by excavation or earthfill for temporary storage of animal
or other agricultural waste.
|
Waste treatment
lagoon
|
An
impoundment made by excavation or earthfill for biological treatment of
animal or other agricultural wastes. Lagoons can be aerobic, or facultative, depending on their loading and design.
|
Water budget
|
An
irrigation tool that keeps track on a daily basis of the amount of plant
available water in the soil over a 12-month period. It sums soil water depletion by evapotranspiration using one of the climatonomic
estimators and deducts water inputs from precipitation or irrigation. This yields the amount of irrigation water that needs to be applied to bring
the soil back to field capacity within the root zone of the crop being irrigated. Water
applications in
excess of field capacity are assumed lost to percolation or rum-off.
|
Water management
system
|
A
planned system in which the available water supply is effectively used
by managing and controlling the moisture environment of crops to promote
the desired crop response, to minimize soil erosion and loss of plant nutrients,
to control undesirable water loss, and to protect water quality.
|
Water quality
|
The
excellence of water in comparison with its intended use or uses.
|
Water table
|
The
surface between the vadose zone and the ground water; that surface of a
body of unconfined ground water at which the pressure is equal to that
of the atmosphere.
|
Watershed
|
(1)
A total area of land above a given point on a waterway that contributes
runoff water to the flow at that point.(2)
A major subdivision of a drainage basin.
|
Wetlands
|
Areas
characterized by soils that are usually saturated or ponded; i.e., hydric
soils, and that support mostly water-loving plants; i.e., hydrophytic plants.
|
Yield
|
(1)
The quantity of a product in a given space and/or time.(2)
The harvested portion of a product.
|
Zoning (rural)
|
A
means by which governmental authority is used to promote a specific use
of land under certain circumstances. This power traditionally resides in the state, and the power to regulate land
uses by zoning is usually delegated to minor units of government, such
as towns, municipalities, and counties, through an enabling act that specifies
powers granted and the conditions under which these are to be exercised.
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