Glossary
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # Select the first letter of the word from the list above to jump to appropriate section of the glossary. If the term you are looking for starts with a digit or symbol, choose the '#' link.
Absorb The physical entrapment of a fluid by a porous medium, such as a sponge absorbing water.
Aerobic
Requiring oxygen or in the presence of oxygen.
Adsorb
The attachment of a gas, liquid, or dissolved substance on a surface by way of chemical or molecular action. (Positively charged pesticide molecules may be adsorbed to negatively charged clay particles.)
Aggregation (soil)
Many soil particles held in a single mass or cluster such as a clod, crumb, block, or prism.
Algae
Simple, usually microscopic, rootless plants that grow in water. (adjective form: algal)
Algal blooms
A large population of algae that is obvious to the naked eye; usually caused by an abundance of nutrients in the water.
Anaerobic
Requiring no free oxygen or in the absence of free oxygen.
Animal unit
The equivalent of 1,000 pounds of animal live weight; thus one 1,200 pound dairy cow would represent 1.2 animal units and one 200 pound hog would be 0.2 animal units.
Aquifer
A sand, gravel, or rock stratum capable of storing or conveying water below the surface of the land.
Aquatic
Associated with water; living or growing in or near water.
Artificial wetland
Land that would not have been classified as a wetland under natural conditions but now exhibits wetland characteristics because of human activities.
Available water capacity (AWC)
The amount of water held by the soil between field capacity and the permanent wilting point. The AWC of a soil is measure of its capacity to make water available for plant growth.
Baseflow
Normal stream flow resulting from ground water drainage.
Bedrock
A rock formation that is overlain in most places by soil or rock fragments.
Concentrated flow
Runoff water from sheet or uniform flow that converges at a common area. Concentrated flow can cause gullies on unprotected soil surfaces.
Concentrated flow erosion
Erosion resulting when concentrated water flows across land and removes the soil during runoff. The eroded area is usually shallow enough to be crossed with farm equipment, but can develop into a gully.
Contour farming
The practice of farming in which the row patterns follow the contours of the landscape.
Converted wetland
A wetland that was drained, dredged, filled, leveled, or otherwise manipulated, including the removal of woody vegetation, or any activity that results in impairing or reducing the flow, circulation or reach of water, and makes the production of an agricultural commodity possible.
Crop residue
The portion of a plant or crop left in the field after harvest.
Denitrification
The process of converting the nitrate (NO3) and nitrite (NO2) forms of nitrogen to atmospheric nitrogen under anaerobic conditions. Usually accomplished by anaerobic bacteria.
Detention basin
A basin such as a small pond or reservoir that temporarily stores runoff water and released the water downstream in such a manner that reduced the peak flow.
Ecosystem
A biological community and its interaction with its environment.
Eutrophication
The natural or artificial process of nutrient enrichment often resulting in a water body becoming filled with algae and other aquatic plants.
Eutrophic lake A lake that has high level of plant nutrients, especially phosphorus and nitrogen, and a high level of biological productivity; oxygen content may be extremely high during sunny days and very low at night and on overcast days due to a high level of photosynthetic action.
Fecal coliforms
A group of bacteria found in the intestinal tract of all warm-blood animals, including humans. While most species are harmless in themselves, coliform bacteria are commonly used as indicators of the presence of pathogenic (disease causing) organisms.
Feedlot
Paved or unpaved land area upon which a high density of animals are confined.
Filter feeders
Any aquatic organisms that obtain their food from the surround water by continuously filtering the water through especially equipped mouth parts or gill slits.
Forb
A herbaceous broad leaf plant that is not a grass or is not glass like (i.e. sedge, rush).
Ford
A shallow stream crossing; the stream bed is often surfaced with stone or other material.
Grazing capacity
The maximum stocking rate possible without inducing damage to vegetation, water, or related resources.
Green manure crop
An annual grass or legume which is planted as a cover crop and which later dies or is killed with herbicides to become a source of organic matter, nutrients and soil cover for a following crop. The green manure crop may be plowed under conventional tillage or be the cover for conservation tillage.
Ground water
That portion of the soil or rock where all pore spaces are completely saturated; the water that occurs in the earth below the depth to which water will rise in a well.
Gully
A channel or void in the landscape associated with erosion and concentrated form of water. A gully is distinguished from a rill by its depth - a gully is too deep to be crossed by farm equipment while a rill can be crossed and may be smoothed by ordinary tillage methods (i.e. breaking or disking). Active gullies are usually significant producers of sediment.
Half-life
The measure of pesticide persistence. The time (days) required for the original concentration of a compound to be reduced to 50 percent of the original concentration.
Herbicides
Chemicals used to kill selected vegetation.
Hydraulics
The science of laws governing the motion of water and other liquids and their practical applications in engineering.
Hydrophytic
Water tolerant or water loving.
Infiltration
The downward entry of water into the soil.
Inorganic Not organic; see "organic"
Intermittent stream
A watercourse that flows only at certain times of the year, receiving water from springs or surface sources; also, a watercourse that does not flow continuously, when water losses from evaporation or seepage exceed available stream flow.
Karst
Geologic formation characterized by sinkholes, underground caverns, solution channels, and surface depressions without external drainage.
Leach
To percolate or migrate downward by force of gravity through a porous medium such as soil.
Leachate
The liquid, often contaminated, that leaches from a porous medium, such as a manure pile, a silage pit , or the soil.
Legume
A member of the Luguminasae family, one of the most important and widely distributed plant families. The fruit is a pod that opens along two sutures when ripe. Leaves are alternate, have stipules, and are usually compound. Includes many valuable food and forage species, such as peas, beans, peanuts, clovers, alfalfas, sweet clovers, lespedezas, and vetches. Many legumes are nitrogen-fixing plants.
Moisture control zone
The upper portion of the root zone in which moisture is controlled. Usually the top two feet of the soil profile.
Nitrogen fixing
The ability of a plant, such as certain legumes, to convert atmospheric nitrogen into soil nitrogen through a symbolic relationship with specific microorganisms located throughout the root zone. Can also be accomplished in water by certain algae.
Nonpoint source pollution
Pollution arising from an ill-defined and diffuse source, such as runoff from cultivated fields, grazing land, or urban areas.
No-till
Planting a crop without prior seedbed preparation into sod, crop residue, or an existing cover crop.
NPDES permit
National Pollution Discharge Elimination System permit that may be required by EPA regulations for certain livestock facilities. In the case of confined animal feeding operations (CAFOs), the need for a NPDES permit is based on the number and size of animals on hand and whether or not a discharge is planned. (See Agricultural Pollution)
Nutrients
Chemical elements and compounds needed by plants. Major nutrients include nitrogen, phosphorous, and potassium in different chemical compounds. Minor nutrients include such elements as zinc and copper.
Organic
Of, pertaining to, or derived from living organisms (i.e., plants, animals, animal waste, decaying vegetation); compounds that contain carbon in combination with one or more other elements. Most organic compounds can serve as a food source for bacteria, unlike inorganic compounds.
Pathogens
Disease-causing organisms.
Peak flow
The maximum rate of runoff that occurs from a watershed during a storm event.
Percolation
Movement of water through soil or other porous media.
Perennial stream
Water course that flows continuously throughout the year.
Permeable
A soil in which water can easily pass through the pores of the soil.
Persistence time
The time required for a pesticide to become inert. Arbitrarily assumed to equal four half-lives when measured persistence time is not available.
Pesticide
A chemical substance used to kill or control pests such as weeds, insects, fungus, mites, algae, rodents, and other undesirable agents.
pH
An expression of the intensity of the acid or alkaline condition of a solution; an indirect measure of the concentration of hydrogen ions in a solution, having a scale from zero (extremely acidic) to 14 (extremely alkaline) with 7 being neutral.
Photosynthesis
The process occurring in green plants that converts the radiant light energy of the sun into chemical energy that is stored in plants. Besides providing energy for plants by converting water and carbon dioxide into sugar, the process supplies practically all of the oxygen needed for live. During sunny days carbon dioxide is absorbed and oxygen is given off; at night the process is reversed.
Photosynthetic
The adjective form of photo synthesis; see photosynthesis.
Phytoplankton
Free-floating, microscopic algae.
Point row
A row that does not end at the edge of a cultivated field.
Point source pollution
Pollution coming from a well-defined origin, such as the discharge from a pipe at an industrial plant.
Pollutants
Any of the various noxious chemicals and refuse materials that impair the purity of water, soil or the atmosphere.
Pond
A small body of water, usually artificially created by damming, diking or excavating.
Protozoan
Any single celled, usually microscopic organism in the Phylum Protozoa; plural: protozoa or protozoa's.
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Restoration
Term used when the wetland functions and values that were lost on converted wetland are restored on the same site.
Rill erosion
An erosion process in which numerous small channels only several inches deep are formed; occurs mainly on recently cultivated soils and /or recent cuts and fills.
Rinstate
The mixture of water or other liquid used to rinse a container and any residues or pollutants rinsed from the container by that liquid.
Riparian
The bank, shoreline or edge of the rising ground bordering a natural, modified, or man-made watercourse or water area.
Rock riprap
Loose rock, usually limestone, that is used to stabilize slopes, watercourses, shorelines, etc.
Root zone
The depth of soil penetrated by plant roots.
Runoff
The portion of precipitation or irrigation water that flows off a field, feedlot or other impermeable or saturated surface. The water that flows off the surface of the land without infiltration onto the soil is called surface runoff.
Sediment
Solid material that is in suspension, is being transported, or has been moved from its original location; usually refers to soil sediment.
Sediment yield
The quantity of sediment arriving at a specific location; usually refers to soil sediment.
Seepage
Percolation of water through the soil from water contained in unlined canals, ditches, laterals, watercourses, or water storage facilities.
Sheet erosion
The removal of a fairly uniform layer of soil material from the land surface by the action of rainfall and surface runoff.
Sheet flow
Runoff water that flows uniformly over the soil surface.
Sink
A depression in the landscape where underlying limestone has been dissolved.
Sinkhole
A natural depression or opening on the land surface which often includes a channel or hole leading directly to ground water; usually in areas underlain by cavernous limestone.
Spillway
A designed surface passageway for excess runoff water to pass.
Spring development
The improvement of a natural spring or seep to collect and store water for a use such as livestock water.
Substrate
The medium on which or within which an organism grows (i.e., the rock surface on which bacteria or moss grow or the rock bed or soil in which the roots of wetland plants grow).
Sump
A pit, concentrate box or similar structure in which a liquid collects.
Surface layer
The soil ordinarily disturbed in tillage, or its equivalent in uncultivated soil, ranging in depth from 4 to 10 inches. Also called the plow layer.
Sward
The grassy surface of land or growth of grass such as a pasture or hay field.
Tilth
The physical condition of soil as related to its ease of tillage, fitness as a seedbed, and its impedance to seedling emergence and root penetration.
Tank
A large container or box used for holding water for livestock to drink.
Topography
The surface configuration of the landscape.
Trough
A usually long and narrow box used to hold water for livestock to drink.
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Water quality management plan
A set of decisions related to management of natural resources that addresses problems, both identified and predicted, associated with surface and/or ground water. A plan provides criteria for installation, operation and maintenance of the practices needed.
Watercourse
A natural or man-made channel that conveys water.
Watershed
The land area that drains to a particular point or area in the landscape (i.e., to a pond, lake, river, etc.)
Watershed protection plan
A resource plan developed to address identified and/or predicted resource problems within a drainage basin. Typically, the plan is made by sponsors for land on which they have jurisdiction but do not own or control.
Water table
The top of the saturated zone in soil or rock.
Well
A hole drilled or bored into the earth to serve as a water supply from an underground aquifer.
Wetland
An area that has a predominance of hydric soils and that is inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and, under normal circumstances, does support a prevalence of hydrophytic vegetation typically adapted for life in saturated soil conditions.
