Types of Land Use

1
Types of Land Use

• Agriculture-Source of most food
• Development-Construction of buildings, roads,
  bridges, dams, etc.
• Mining-removal of nonrenewable resources such as
  iron, copper, and coal from the land

2
Why Isnt All Land Suitable for Farming?

• Much of Earths land is to dry, too wet, too
  salty, or too mountainous to be farmed

3
Protecting the Soil

• Litter-top layer of dead leaves and grass
• Topsoil-mixture of rock fragments, nutrients,
  water, air, and decaying animal and plant matter
• Subsoil-rock fragments, water, airless plant and
  animal matter
• Bedrock-Rock that makes up Earths crust

4
Poor soil management can result in three
problems Erosion, Nutrient Depletion, and
Desertification
5
Erosion

• The process by which water, wind, or ice moves
  particles of rocks or soil
• Many uses of land expose soil and can cause
  erosion mining, logging, farming

6
Nutrient Depletion

• When the soil becomes less fertile
• The plants use more nutrients than the
  decomposers can replace.

7
Ways to Prevent Nutrient Depletion

• 1. Leave fields fallow-unplanted with crops
• 2. Leave unused parts of crops in the fields
  rather than clearing them away
• 3. Crop rotation-when a farmer plants different
  crops in a field each year. Each absorbs
  different nutrients

8
Desertification

• The advance of desert-like conditions into areas
  that were previously fertile
• Causes
• Climate (drought)
• Overgrazing by cattle and sheep
• Cutting down trees

9
Restoring the Land

• Land reclamation-Restoring an area of land to a
  more natural, productive state
• Restores land for agriculture and habitats for
  wildlife
• More difficult and expensive to restore damaged
  land and soil than it is to protect them in the
  first place

10
Soil Conservation

• Farming practices that can help reduce soil
  erosion
• Conservation plowing
• Strip cropping and contour plowing
• Windbreaks
• Terracing

11
Conservation Plowing

• Break up only the subsoil
• Leaves dead stalks and weeds from previous years
  crop in the ground to hold the topsoil in place

12
Strip Cropping and Contour Plowing

• Alternate tall crops with short crops
• Planted in curving rows that follow the slope of
  the land
• Reduces soil erosion as much as 50

13
Windbreaks

• Rows of trees are planted along the edges of
  fields
• Block wind and trap eroding soil

14
Terracing

• Steep hillsides are built up into a series of
  flat terraces
• Slows down run-off and catches eroding soil