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Bertrand Competition

An oligopoly in which each firm believes that its rivals are committed to keeping their prices fixed and that customers can be lured away by offering lower prices

Best management practices

Best management practices (BMP). A conservation practice or combination of practices designed to maintain agricultural productivity while reducing point- and nonpoint- source water pollution. State water quality agencies (or their designees) determine BMPs to fit local conditions and to make the most efficient use of natural resources and purchased inputs.

Bioaccumulation

The absorption and concentration of toxic chemicals, heavy metals, and certain pesticides in plants and animals. Toxicity can be expressed in several ways: lead that is ingested by calves can bioaccumulate in their bones, interfering with calcium absorption and bone development; stored chemicals may be released to the blood stream at a later time, for example, during gestation or weight loss; and chemicals may concentrate to lethal levels at upper ends of the food chain. Bioconcentration is a synonym for biaccumulation.

Biochemical oxygen demand

(BOD) — A measure of the amount of oxygen consumed by natural, biological processes that break down organic matter, such as those that take place when manure or sawdust is put in water. High levels of oxygen-demanding wastes in waters deplete dissolved oxygen (DO) thereby endangering aquatic life. Sometimes referred to as "biological oxygen demand. Chemical oxygen demand (COD) is a measure of the oxygen consumed when organic matter is broken down chemically rather than biologically. COD can be determined much more quickly than BOD and more accurately reflects the amount of organic matter in a water sample. BOD is a standard measure of water quality.

Biodegradable

Material that can be broken down into simpler substances (elements and compounds) by bacteria or other decomposers. Paper and most organic wastes such as animal manure are biodegradable. See nonbiodegradable.

Biodiversity

In general, the variety and variation among plants, animals, and microorganisms, and among their ecosystems. It has 3 levels: ecosystem diversity, species diversity, and genetic (within species) diversity. The concept of maintaining biodiversity holds that civilization should preserve the greatest possible number of existing species so that a highly diverse genetic pool, which can be tapped for useful and beneficial characteristics, will be available into the future. Genetic diversity provides resources for genetic resistance to pests and diseases. In agriculture, biodiversity is a production system characterized by the presence of multiple plant and/or animal species, as contrasted with the genetic specialization of monoculture.

Biofuel

Gas or liquid fuel made from plant material (biomass). Includes wood, wood waste, wood liquors, peat, railroad ties, wood sludge, spent sulfite liquors, agricultural waste, straw, tires, fish oils, tall oil, sludge waste, waste alcohol, municipal solid waste, landfill gases, other waste, and ethanol blended into motor gasoline.

Biogeochemical Cycle

Natural processes that recycle nutrients in various chemical forms from the environment, to organisms, and then back to the environment. Examples are the carbon, oxygen, nitrogen, phosphorus, and hydrologic cycles.

Biological control

The practice of using beneficial natural organisms to attack and control harmful plant and animal pests and weeds is called biological control, or biocontrol. This can include introducing predators, parasites, and disease organisms, or releasing sterilized individuals. Biocontrol methods may be an alternative or complement to chemical pest control methods. Biocontrol is part of the Animal and Plant Health Inspection Service program to control several economically important pests of food and fiber crops; it also is researched and used by other USDA agencies that promote integrated pest management.

Biological oxygen demand (BOD)

Amount of dissolved oxygen needed by aerobic decomposers to break down the organic materials in a given volume of water at a certain temperature over a specified time period. See BOD5.

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