Agrosystems (Farms)

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Agrosystems (Farms)

• ExpectationsB2, B3.5

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Non-native Species

• Introduced from other parts of the world
• Domesticated by humans over thousands of years
• Highly productive, nutritious and easy to produce
  in large quantities
• Examples corn, wheat, carrots, cattle, pigs,
  sheep
• Some of the native species strawberries, turkeys

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How do Agrosystems differ from Natural Ecosystems?
Agrosystem Natural Ecosystem
-non-native species -native species
-more uniform abiotic features -less uniform abiotic features
-lower biodiversity -higher biodiversity
-requires humans to maintain -do not require humans
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Impact of Agrosystems

• Farmers needs fertile soil to grow plants.
  Plants depend on soil for their physical support
  and to provide water, nutrients and oxygen to
  their roots.
• Plants need nitrogen, phosphorus and potassium,
  these nutrients are cycled through ecosystems.
  On farmland, the cycles are interrupted. HOW??

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Cycle interruption

• As crops grow, they take the nutrients from the
  soil. Farmers remove the crop (remove the
  nutrients). The nutrients arent returned to the
  soil.

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How to replace nutrients?

• Fertilizers!
• Two types
• Natural and Synthetic
• Advantage
• Increases crop yields and farm profitability.

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Disadvantages

• Nutrients are highly concentrated.
• Impact on ground water.
• Runoff into aquatic ecosystems.

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Alternative Farming Practices

1. No-tillage Agriculture
2. Crop Rotation

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HOMEWORK?Read page 120-122 6, 8, 9, 11 on
page 122Read page126-127 5, 6