Conserving Land and Soil

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Conserving Land and Soil
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Conserving Land and Soil

• Less than a 1/4 of Earth's surface is dry land.
• Except for the small amount added when volcanoes
  erupt, new land cannot be created.
• All the people on Earth must share this limited
  amount of land to
• Produce their food
• Build shelter
• Obtain other resources
• Land is a precious resource!

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Types of Land Use

• People use land in many ways.
• Three uses that change the land are agriculture,
  development, and mining.
• There are many other types of land use

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Agriculture

• Since land is the source of most food,
  agriculture is an important land use.
• New farmland must be created by clearing forests,
  draining wetlands, and irrigating deserts.

5
Development

• A type of land use that changes the land even
  more than agriculture is development.
• Development is the construction of homes, stores,
  office buildings, roads, bridges, and other
  structures.
• The process continues as what?...
• Population grows.
• Development not only reduces the amount of
  farmland, but can also destroy wildlife habitats.

6
Mining

• Mining changes the land as mineral resources such
  as iron, copper, and coal are removed.
• Once land has been mined, it is often difficult
  to use the land for another purpose.

7
The Value of Soil

• Soil is one of Earth's most valuable resources
  because everything that lives on land depends
  directly or indirectly on soil.
• It can take hundreds of years for just a few
  centimeters of soil to form.
• The thick, fertile soil may take thousands of
  years to develop.
• Fertile soil is valuable because there is a
  limited supply.
• Less than one eighth of the land on Earth has
  soils that are well suited for farming.

8
Soil Damage and Loss

• Soil is one of Earth's most important resources.
• But soil can be lost or damaged.
• It can become exhausted.
• Lose its fertility
• Polluted by human activities such as mining or
  chemical spills.
• It can be lost to erosion by water and wind.

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Soil Damage and Loss
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Soil Conservation

• Soil conservation is the management of soil to
  prevent its destruction.
• Ways that soil can be conserved include
• Contour plowing
• Conservation plowing
• Leaving the soil to lie fallow
• Crop rotation