6 
 Agriculture and Food Production
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GLOSSARY

This glossary is provided as a tool for studying this chapter. Keep it handy while you read, in order to find definitions of unfamiliar words, or of familiar words that may have an unfamiliar meaning in the context of this chapter.

If you do not find the term you are looking for on this page, try the complete glossary.
  • Agribusiness: Large-scale, organized production of food, farm machinery, and supplies as well as the storage, sale, and distribution of farm commodities, for profit.
  • Animal unit month: The amount of forage needed to support a certain number of grazing animals for one month.
  • Arable land: Land that is capable of being cultivated and supporting agricultural production. 
  • Bureau of Land Management (BLM): The U.S. Bureau of Land Management, located in the Department of the Interior, established in 1946 to administer federal lands not reserved for military, park, national forest, or other special uses.
  • Conservation tillage: An agricultural system using tillage techniques designed to reduce soil erosion and overland flow. Most conservation tillage techniques involve less manipulation of the soil than conventional techniques, leaving more plant matter on the soil surface.
  • Contour plowing: A soil conservation technique involving plowing parallel to the contour, across a slope rather than up and down it.
  • Crop rotation: A soil conservation technique involving changing crops grown on a given parcel of land from year to year. Crop rotations may include fallow periods.
  • Decreaser: A plant species in a range community that declines in importance as a result of grazing pressure. Usually, decreasers are the most palatable to the grazing animals.
  • Desertification: A process of land becoming more desertlike as a result of human-induced devegetation and related soil deterioration, sometimes aggravated by drought.
  • Domesticate: A species that has been bred for specific characteristics that humans value, thereby rendering the species dependent on humans for its continued survival.
  • Drip irrigation: An irrigation method involving small pipes placed at the base of plants delivering water slowly to the plant roots.
  • Drought: A period of time with unusually low precipitation.
  • Dry farming: Agricultural production in climatically marginal lands without the use of irrigation.
  • Energy efficiency: The amount of utility, either work performed or income generated, gained per unit of an energy resource.
  • Erosion: Removal of soil by running water or wind.
  • Erosivity: The ability of rainfall to cause erosion. Erosivity is a function of rainfall intensity and drop size.
  • Farmland: Land that is part of farm units, including cropland, pasture, small woodlots, and areas used for small farm roads and buildings.
  • Federal Land Policy and Management Act (FLPMA): Passed in 1976 this law consolidated diverse regulations of public land management and strengthened the power of the BLM to manage public lands.
  • Fertilizer: A substance added to the soil to improve plant growth. The most commonly used fertilizers are those containing large amounts of nitrogen, potassium, and phosphorus.
  • Flood irrigation: A means of irrigation whereby entire fields are occasionally inundated.
  • Food security: The condition of having both physical and economic access to the basic food that people need to function normally.
  • Furrow irrigation: A type of irrigation in which water is allowed to flow along the furrows (troughs) between rows of crops.
  • Geographic Information System (GIS): A computer database and data-manipulation system designed to use geographically organized data.
  • Green Revolution: A variety of agricultural systems developed for application in developing countries, involving the introduction of improved seed varieties, fertilizers, and irrigation systems. 
  • Gully: A steep-walled stream channel incised in the soil by accelerated erosion.
  • Horizon: A layer in the soil with distinctive textural, mineralogical, chemical, or structural characteristics.
  • Increaser: A range plant species that is present in a range ecosystem prior to grazing and that increases in numbers or coverage as a result of grazing.
  • Invader: A range plant species not present in a given area before grazing but entering the area as a result of the ecological changes caused by grazing.
  • Irrigation: The artificial application of water to a crop or pasture beyond that supplied by direct precipitation.
  • Land Capability Classification System: A scheme used by the U.S. Natural Resource Conservation Service for assessing and classifying the productivity of land units.
  • Maximum sustainable yield: The largest average harvest of a species that can be indefinitely sustained under existing environmental conditions.
  • Minimum tillage: A soil and water conservation technique that leaves the crop residue or stubble on the surface rather than plowing it under to minimize the number of times a field is tilled. Weeds are controlled by herbicides.
  • Mixed cropping: An agricultural system in which several different crops are grown in close proximity, in a rotation system, or both.
  • Monoculture: An agricultural system in which a single crop is grown repeatedly over a large area.
  • Multiple use: The use of lands for as many different purposes as possible in order to gain maximum benefit from them.
  • Overgrazing: Grazing by a number of animals exceeding the carrying capacity of a given parcel of land.
  • Overland flow: Water flowing on the soil surface and unchannelized, usually derived from precipitation that has not infiltrated.
  • Parent material: The mineral matter from which soil is formed.
  • Pastoral nomad: A person who herds animals, and has no permanent place of residence.
  • Pastoralist: A person whose livelihood is based on grazing animals.
  • Pasture: In U.S. terminology, land on which the natural vegetation is not grass, but which is used primarily for grazing.
  • Pesticide: A general term used to refer to a chemical used to control harmful organisms such as insects, fungi, rodents, worms, and bacteria. Insecticides, fungicides, and rodenticides are kinds of pesticides.
  • Range condition: As defined by the U.S. Forest Service, an estimate of the degree to which the present vegetation and ground cover depart from that which is presumed to be the natural potential (or climax) for the site.
  • Rangeland: Land that provides or is capable of providing forage for grazing animals.
  • Rill: A small channel created by soil erosion and small enough to be obliterated by plowing. 
  • Ruminant: One of a group of grazing animals including cattle, bison, sheep, goat, which have digestive systems particularly adapted to grasses.
  • Sahel: A semiarid east-west swath across Africa, environmentally transitional between the Sahara Desert (to the north) and equatorial rainforests (to the south), in which recent desertification and drought have been particularly severe.
  • Sedentarization: Permanent settlement of once-nomadic people.
  • Soil: A porous layer of mineral and organic matter at the earth's surface, formed as a result of the action of chemical and biological processes on rocks over a period of time.
  • Soil erodibility: A measure of the inherent susceptibility of a soil to erosion, without regard to topography, vegetation cover, management, or weather conditions.
  • Soil fertility: The ability of a soil to support plant growth through providing water, nutrients, and a growth medium.
  • Soil structure: The way in which individual soil particles form aggregates, particularly the shapes and arrangement of such aggregates; especially important to soil hydrologic characteristics.
  • Soil texture: The mix of different sizes of particles in a soil.
  • Sprinkler irrigation: Irrigation by pumping water under pressure through nozzles and spraying it over the land.
  • Strip cropping: A soil conservation technique in which parallel strips of land are planted in different crops.
  • Stubble mulch: A soil covering composed of the unused stalks of crop plants.
  • Sustainable agriculture: An agricultural system that is dependent solely on renewable resources and that maintains the soil in such a condition so that it will continue to be productive indefinitely.
  • Sustained yield: Management of renewable resources conducted in such a way as to allow a constant rate of harvest indefinitely.
  • Taylor Grazing Act: An act passed in 1934 closing most United States public lands to homesteading and establishing controls on grazing use of federal lands.
  • Terracing: A soil and water conservation technique consisting of ridges on the contour, or level areas constructed on a slope.
  • Universal Soil Loss Equation: A statistical technique developed by the U.S. Department of Agriculture for predicting the average erosion rate by rainfall under a variety of climatic, soil, topographic, and management conditions.
  • Water-holding capacity: The ability of the soil to retain or store water.
  • Windbreak: A line of trees or shrubs planted perpendicular to the prevailing winds, designed to reduce wind velocities and thus reduce wind erosion.
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H O M E
 Exploitation, Conservation, Preservation
A Geographic Perspective on Natural Resource Use
Susan L. Cutter and William H. Renwick
Web site by James Hayes-Bohanan
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