1. Agrosystems (Farms)
Expectations:B2, B3.5

2. 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

3. How do Agrosystems differ from Natural Ecosystems?
-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

4. 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??

5. Cycle interruption
As crops grow, they take the nutrients from the soil. Farmers remove the crop (remove the nutrients). The nutrients aren’t returned to the soil.

6. How to replace nutrients?
Fertilizers!
Two types:
Natural and Synthetic
Advantage:
Increases crop yields and farm profitability.

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

8. Alternative Farming Practices
No-tillage Agriculture
Crop Rotation

9. HOMEWORK Read page 120-122 # 6, 8, 9, 11 on page 122 Read page126-127 # #5, 6