APES Unit 4: Ch. 9 & 10

Agriculture

practice of raising crops & livestock for human use & consumption

Crop land

land use to raise plants for human & animal use

Rangeland or pasture

land use for grazing livestock

Soil

a complex plant-supporting system

Soil degradation

a decline in quality & productivity

Industrialized agriculture

uses large-scale mechanization & fossil fuels to boost yields

monoculture

uniform planting of a single crop

Green revolution

new technology, crop varieties & farming practices were introduced to developing countries

Parent material

the base geological material of soil

bedrock

solid rock comprising the Earth's crust

Weathering

processes that form soil

humas

spongy, fertile material formed by partial decomposition of organic matter

Physical weathering

wind, rain thermal expansion & contraction, water freezing

Chemical weathering

water & gasses

Biological weathering

tree roots & lichens

horizon

each layer of soil

Soil profile

the cross-section of soil as a whole

leaching

dissolved particles move down through horizons

topsoil

inorganic & organic material most nutritious for plants

Soil color

indicates its composition & fertility

Soil texture

determined by size of particles

Loam

solid with a mixture of the three; clay, silt, and clay

Soil structure

a measure of soils “clumpiness”

Soil PH

affects a soils ability to support plant growth

Cation exchange

process that allows plants to gain nutrients

Cation exchange capacity

a soils ability to hold cation

Swidden agriculture

traditional used in tropical areas

Land degradation

a general deterioration of land, decreasing its product, & biodiversity

erosion

removal of material from one place to another

deposition

arrival of eroded material at a new location

desertification

a loss of more than 10% productivity

Dust bowl

1930s drought & erosion caused “black blizzards” of sand

Conservation districits

operate with federal direction, authorization, & funding

Natural resources conservation services

also includes water quality protection & pollution control

Agriculture extension agents

agency or university experts who advise & help farmers

Crop rotation

growing different crops from one year to the next

Contour farming

plowing perpendicular across a hill

terracing

platforms cut into steep hillsides

intercropping

planting different crops in alternating band

shelterbelts

rows of trees planted along edges of fields

Conservation tillage

reduces the amount of tilling

no-till

farming disturbs the soil even less

irrigation

artificially providing water to support agriculture

waterlogging

over irrigated soils

salinization

the buildup of salts in the surface soil layers

fertilizers

substances containing essential nutrients

Inorganic fertilizers

mined or synthetically manufactured mineral supplements

Organic fertilizers

the remains or waste of organisms

compost

produced when decomposers break down organic matter

undernutrition

people receive fewer calories than their minimum requirements

Food security

guarantee of an adequate, safe, nutritious & reliable food supply

overnutrition

receiving too many calories each day

malnutrition

a shortage of nutrients the body needs

kwashiorkor

diet lacks protein or essential amino acids

marasmus

protein deficiency & insufficient calories

monoculture

large expanse of a single crop

biofuels

are derived from organic materials

ethanol

a biofuel deprived from corn

pest

any organism that damages valuable crops

weed

any plant that competes with crops

pesticides

poisons that target pest organisms

insecticides

kill insects

herbicides

kill plants

fungicides

kill fungi

Seed banks

institutions that preserve seed types as living museums of genetic diversity

Pesticide treadmill

chemists increase chemical toxicity to compete with resistant pests

biotechnology

the application of biological science to create products derived from organisms

Transgenic organism

an organism that contains DNA from another species

transgene

the genes that have moved between organisms

Traditional breeding

changes organisms through selective breeding of the same or similar species

Genetic engineering

mixes genes of different species

Precautionary principle

don't undertake a new action until the effects of that action are understood

Feedlots (factory farms)

also called concentrated animal feeding operations (CAFOs); Huge warehouses or pens deliver food to animals living at extremely high densities

Air pollution

odors, ammonia (acid rain)

aquaculture

raising aquatic organisms in a controlled environment

Sustainable agriculture

does not deplete soil, pollute water, or decrease genetic diversity

Low-input agriculture

uses smaller amounts of pesticides, fertilizers, growth hormones, water, & fossil fuels than industrial agriculture

Organic agriculture

uses no synthetic fertilizers, insecticides, fungicides, or herbicides

Farmer’s markets

provide fresh, locally grown food

Community-supported agriculture (CSA)

Consumers pay farmers in advance, Consumers get fresh food, Farmers get a guaranteed income