Studied by 6 people
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
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Flashcard (26)