Important Terms

Adsorption – The adhesion of one substance to the surface of another.

Aquifer – A geologic formation or structure that transmits water in sufficient quantity to supply the needs for a water development; usually saturated sands, gravel, fractures, and cavernous and vesicular rock.

Composting – A controlled process of degrading organic matter by microorganisms.

Conservation management system (CMS) – A generic term that includes any combination of conservation practices and management that achieves a level of treatment of the five natural resources that satisfies criteria contained in the Field Office Training Guide (FOTG), such as a resource management system or an acceptable management system.

DDT (dd-t) – Short for dichlorodiphenyltrichloroethane. A powerful insecticide that is also poisonous to humans and animals. It remains active in the environment for many years and has been banned in the United States for most uses since 1972 but is still in use in some countries in which malaria is endemic.

Denitrification – The chemical or biochemical reduction of nitrate or nitrite to gaseous nitrogen, either as molecular nitrogen or as an oxide of nitrogen.

Deposition – The accumulation of material dropped because of a slackening movement of the transporting material water or wind.

Diversion – A channel, embankment, or other man-made structure constructed to divert water from one area to another.

EPA – Environmental Protection Agency.

Erosion – Wearing away of the land surface by running water, glaciers, winds, and waves. The term erosion is usually preceded by a definitive term denoting the type or source of erosion such as gully erosion, sheet erosion, or bank erosion.

Eutrophication – the process where a waterbody, such as a lake or a soil solution, becomes loaded with dissolved nutrients. This can be natural, but is often due to pollution. Algal blooms can remove oxygen in the water, harming fishlife.

Evaporation – The process by which a liquid is changed to a vapor or gas.

Fallow – Allowing cropland to lie idle, either tilled or untilled, during the whole or greater portion of the growing season.

Fertilizer – Any organic or inorganic material of natural or synthetic origin that is added to a soil to supply elements essential to plant growth.

Food chain – A graphical representation of the sequence of organisms, each of which uses the next, lower member of the sequence, as a food source. The chain starts with plants or other autotrophs (an organism that satisfies its need for organic food molecules by using the energy of the sun, or of the oxidation of inorganic substances, to convert inorganic molecules into organic molecules. Green plants are autotrophs), which are eaten by herbivores. The herbivores are eaten by carnivores. These are eaten by other carnivores. When any organism dies, it is eaten by tiny microbes (detrivores) and the exchange of energy continues.

Herbicide – A chemical substance designed to kill or inhibit the growth of plants, especially weeds.

Incineration – The controlled process by which solids, liquid, or gaseous combustible wastes are burned and changed into gases; the residue produced contains little or no combustible material.

Inert – A substance that does not react with other substances under ordinary conditions.

Infiltration – The penetration of water through the ground surface into subsurface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls.

Insecticide – A pesticide compound specifically used to kill or control the growth of insects.

Irrigation – Application of water to lands for agricultural purposes.

Leachate – Liquids that have percolated through a soil and that contain substances in solution or suspension.

Leaching – The removal from the soil in solution of the more soluble materials by percolating waters.

Nutrients – Elements, or compounds, essential as raw materials for organism growth and development, such as carbon, nitrogen, phosphorus, etc.

Pasture – Grazing lands planted primarily to introduced or domesticated native forage species that receives periodic renovation and/or cultural treatments such as tillage, fertilization, mowing, weed control, and irrigation. Not in rotation with crops.

Percolation – The downward movement of water through the soil.

Pesticide – Any chemical agent used for control of plant or animal pests. Pesticides include insecticides, herbicides, fungicides, nematocides, and rodenticides.

Pollutant – Dredged spoil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, cellar dirt, and industrial, municipal, and agricultural waste discharged into water.

Root zone – The part of the soil that is, or can be, penetrated by plant roots.

Salinity – The concentration of dissolved solids or salt in water.

Sediment – The product of erosion processes; the solid material, both mineral and organic, that is in suspension, is being transported, or has been moved from its site of origin by air, water, gravity, or ice.

Sludge – The material resulting from chemical treatment of water, coagulation, or sedimentation. Soil profile: A vertical section of the soil from the surface through all its horizons, including C horizons.

Soil water depletion volume – The amount of plant-available water removed from the soil by plants and evaporation from the soil surface.

Surface water – All water whose surface is exposed to the atmosphere.

Suspended sediment – The very fine soil particles that remain in suspension in water for a considerable period of time.

Sustainability, sustainable development – Meeting the needs of the present generation without compromising the ability of future generations to meet their own needs or the health of the planet. Essentially it is about living, working and ordering society in ways which are environmentally "sustainable", encouraging reduction of pollution, re-use of resources, promoting biodiversity etc. The term originally applied to the exploitation of natural resources, where the focus was long-term.

Waste – Material that has no original value or no value for the ordinary or main purpose of manufacture or use; damaged or defective articles of manufacture; or superfluous or rejected matter or refuse.

Watershed – A drainage area or basin in which all land and water areas drain or flow toward a central collector such as a stream, river, or lake at a lower elevation.