Chp. 2 Earth’s
Resources
2-1 Soil
• Natural Resources are
materials removed from
Earth & used by people.
• Fossil Fuels, Minerals, Trees
•There are 2 types
of natural
resources:
Nonrenewable
resources &
Renewable resources
Nonrenewable
Resources
• Resources that can’t be
replaced by nature.
Fossil Fuels (coal, oil, gas),
Minerals (copper, iron…)
Renewable
Resources
• Resources that can be
replaced by nature.
Wood, Water, Soil
Land Uses
•Land is used for cities,
highways, forests,
pastures, farms,
industry, & recreation.
• Farmland must be used to
its fullest potential. Must
use productive methods.
We have to use the same
farmland year after year.
• Land for raising animals
(pigs,chickens, cattle) is
important. We must feed
them in order to get beef
from them.
•Process of supplying water
to dry regions. It makes
regions with dry land more
suitable for farming.
Land Management
• Although soil is renewable, nature
takes hundreds of years to replace
3 cm of topsoil.
• We have limited land resources.
Different land provides different
purposes.
• Farming must be planned so that
the land will stay productive.
Land Management
Techniques
To prevent depletion To prevent erosion
1) Crop Rotation
1) contour
plowing
2) strip cropping
3) terracing
4) wind breaks
Depletion
• Occurs when nutrients are
removed from the soil.
• Planting corn removes nitrogen
from soil. If you continue to plant
the same thing year after year the
soil will become depleted and
won’t be as productive.
Crop Rotation
• A method of farming where
rotating crops yearly will keep
nutrients in the soil.
Year 1 plant corn- takes
nitrogen out of soil
Year 2 plant peanuts or clover
which puts nitrogen back in the
soil.
Continue to
alternate every
year.
Contour Plowing
• Planting crops across the face
of the slope of the land. It
prevents water & wind from
taking away big chunks of
topsoil.
• If you plant straight up and
down, water will rush down
the land taking the topsoil
with it. Contour Plowing will
slow the water runoff which
will save the topsoil.
Strip Cropping
• Farming method where cover
crops (hay, wheat) are planted
in between strips of other
crops to help hold down the
soil.
Terracing
• Plowing a slope of land into
a series of steps to prevent
erosion. It slows down water
runoff.
Windbreaks
• Planting rows of trees in
between fields of crops to
prevent erosion. It holds down
the soil better.
EROSION
•The carrying off of soil by
water and wind.
•Crops are grown in topsoil
(the rich upper layer of
soil). Topsoil is being lost
by erosion.
Overgrazing
• Land that is too dry for crops may
be used as a grassland for animals.
• If too many animals are on the
grassland:
–1. Animals eat all the grass
–2. Topsoil is exposed to erosion
This will lead to the grassland
becoming a desert.
Desertification
•Process where dry
grassland becomes
a desert.
Land Reclamation
•Restoring mining
land back to its
original condition.
•Ex: river dredge in
Hazleton.
Section 2-2
WATER
Where can we get new
sources of fresh water?
1.Desalination- process where we
remove salt from the ocean water.
(Boil water) Expensive to build,
costly to operate, what do you do
with the left over waste.
2. Icebergs/Glaciers- tow to
coast, mine fresh water.
MUST CONSERVE OUR FRESH
Section 2-3
MINERAL
•A naturally occuring
chemical substance
found in soil or rocks.
Nonrenewable
resource.
2 types of minerals
• Metallic Minerals- (copper, iron,
aluminum) shiny surfaces, can
conduct heat, can be hammered into
thin sheets w/out breaking.
• Nonmetallic Minerals- (quartz,
limestone, sulfur). Not shiny, poor
conductors of heat, can’t be
hammered into thin sheets w/out
breaking.
Ore & Alloy
•Ore- minerals that can be
mined for a profit.
•Alloy- a substance made
of 2 or more metals. Brass
or Steel.
Open Pit Mining
1. Located mineral
deposit
2. Mine the ore
3. Remove impurities
4. Processed in plants
5. Plants make the final
product
Negatives with
Mining
• Scars the land
• Topsoil buried under tons of
rock and is exposed to
erosion
What can we do if we run
out of minerals?
1. Recycle or reuse minerals
2. Find other materials to take
their place
3. Search the ocean floor- found
nickel, manganese, cobalt, &
copper.