Chapter 7: Unit 5: Land and Water Use (copy)

Conservation

the management or regulation of a resource so that its use does not exceed the capacity of the resource to regenerate itself.

Preservation

the maintenance of a species or ecosystem in order to ensure their perpetuation, with no concern as to their potential monetary value.

Renewable resources

resources that can be regenerated quickly, such as plants and animals.

consumption

day-to-day use of the environmental resources such as food, clothing, and housing

production

use of environmental resources for profit

Traditional subsistence agriculture

family relies on crops they planted themselves enough for the family’s survival

slash-and-burn

an area of vegetation is cut down and burned before being planted with crops

Green revolution

when farming became mechanized and crop fields in industrialized nations boomed

second green evolution

promoted integrated pest management and organic methods such as fertilizer that are not synthetic

integrated pest management (IPM)

uses a combination of several methods and is a more environmentally sensitive approach than chemical pesticides.

irrigation

allowed crops to be planted in areas that normally would not have enough precipitation to sustain them

salinization

flooding fields with massive amounts of water in order to move the salt deeper into the soil is referred to as ____________ of land

furrow irrigation

irrigation which involves cutting furrows between crop rows and filling them with water, is inexpensive but loses about 1/3 of the water used to evaporation and runoff

flood irrigation

irrigation which involves flooding a field with water, can lead to waterlogging and loses about 20% of the water to evaporation and runoff.

spray irrigation

irrigation which involves pumping water into spray nozzles and spraying fields; it only loses about 1/4 of the water but requires energy to run and can be expensive.

genetically engineered plants

adding genes from one species to another to encourage desirable characteristics, such as longer shelf life, disease/drought/pest resistance, faster growth, and higher crop yields

monoculture

just one type of plant is planted in a large area.

plantation farming

type of industrialized agriculture in which a monoculture cash crop such as bananas, coffee, or vegetables, is grown and then exported to developed nations

arable

soil suitable for plant growth to meet our agricultural needs

soil fertility

soil’s ability to provide essential nutrients (N, K, P) in O layer

loamy

this type of soil is the best for plant growth

soil aggregates

formed and held together by such substances as clay particles and organic matter—plants and roots, the root-like filaments of fungi, and sticky substances released by bacteria and fungi

contour plowing

rows of crops are plowed across a hillside, prevents the erosion that can occur when rows are cut up and down on a slope.

terracing

flat platforms that are cut into the hillside to provide a

level planting surface; this reduces the soil runoff from the slope

no-till methods

farmers plant seeds without using a plow to turn the soil. Soil loses most of its carbon content during plowing. Plowing accelerates the decomposition of organic matter in the soil, decreasing soil fertility and releasing carbon dioxide gas into the atmosphere.

perennial crops

crops that grow back without replanting each year—are another way to reduce the need to till (by eliminating replanting) and keep erosion at bay.

windbreak

made up of one or more rows of trees or shrubs planted near crops in such a way as to provide shelter from eroding winds.

crop rotation

provide soils with nutrients when legumes are part of the cycle of crops in an area.

intercropping

the practice of planting bands of different crops in a field. This type of planting can also prevent some erosion by creating an extensive network of roots.

green manure

made by leaving plants (uprooted or simply sown) to wither and then serve as mulch: they are plowed under and incorporated into the soil before they can rot, providing valuable nutrients.

deforestation

removal of trees for agricultural purposes