Chapter 12 – Soil and Agriculture
12.2
Erosion- movement of land or soil due to weathering,
carrying away of soil particles after weathering
happens all the time, however process is so slow we hardly notice
ex: Grand Canyon
Causes – water, wind, ice, organism, chemicals, sand
Soil degradation – Destroying soil needed for plants growth
Intercropping – diversity of planting, planting multiple types of crops next to each other,
one could provide viable nutrients, one could keep pests off the other crop, one might
become mature and give the vegetable first, giving the other crop second, allowing efficient
use of land.
Crop rotation – every couple of planting seasons changing the crop to put nutrients back
into the soil
Shelterbelts/windbreaks – lines of trees to protect against wind erosion
Tilling – turning over the soil before planting, blend the dirt; bring up more nutrients from
soil, allowing water/gas from atmosphere to get into the soil
Terracing – a series of steps on hillsides to combat erosion, this makes land more arable,
we are using as much land as possible. Plowing along a hillside to prevent erosion
Irrigation – providing water to crops
Pesticide – chemical we put on crops to stop
Overgrazing – allowing animals to eat all vegetation in area
Salinization – messes with the pH, land getting too salty
Farming – erosion and depletion of nutrients
Forestry – clear-cutting farming, cutting everything in sight
In 1935 US came up with Soil Conservation Service, in response to Dust Bowl, government
worked with farmers to develop plans for their farming. This then became the National
Resource Conservation Service. This program dealt with land, water quality, and pollution
amount.
In order for farmers to get $ from government now, they have to adopt a conservation plan.
The government will pay farmers $ not to plant crops, perhaps trees instead, to keep the
soil from eroding. For every $1 spent = 1 ton of topsoil.
Intercropping
Crop rotation
Shelterbelts
Tilling
Terracing
Contour farming
Good vs. bad
erosion (made by humans)
degradation
overgrazing
clear cutting
desertification
salinization
(pesticides, irrigation)
Yield – the amount of a crop produced in a given area
Pollinator – ex: insects, hummingbirds, bats. Feed on flower nectar; collect pollen on their
bodies taking it to the next flower, which might then be fertilized.
Selective breeding – planting seeds from the fruit you like best, artificial selection
Traditional Agriculture
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Industrial
Revolution
Biologically powered
agriculture
Cultivating, harvesting,
storing, distributing
crops by human and
animal muscle power,
hand tools
Does not require fossil
fuels
Uses organic fertilizer,
teams of worker animals,
and irrigation
Industrial Agriculture
Green Revolution
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Mechanized farming
technology,
manufactured chemicals,
use of fossil fuels, and
irrigation
Produces huge amounts
of crops and livestock –
Monoculture
High-input agriculture
because it relies on
people to put in
enormous quantities of
energy, water, and
chemicals
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Norman Borlaug – father
of green revolution
Agricultural scientists
from developed nations
introduced new
technology, crop
varieties, and farming
practices to the
developing world.
Synthetic fertilizers,
chemical pesticides,
liberal irrigation of crops,
use of heavy equipment
powered by fossil fuels
Food production rose
150%, prevented
deforestation, habitat
loss, and preserved the
biodiversity of some
ecosystems