1. Agriculture and Nutrient Cycles Chapter 2.7

2. Agriculture and Nutrient Cycles The seeds, leaves, flowers and fruits of plants all contain valuable nutrients. As crops are ______________, the valuable __________________ and __________________ are removed and do not return to the field. This diversion of nitrates and phosphate from the local cycles would soon ________________the soil unless the farmer replaced the missing nutrients.

3. What plants need! There are many other elements/nutrients that plants need, other than carbon. The most important other nutrients are ________________ (N), _________________(P), and _______________________ (K) As plants grow, they remove these nutrients from the ____________. __________________________________are materials used to restore nutrients and increase production form land.

4. Fertilizer… However, adding too much fertilizer is not always better. Extra, unused fertilizer can end up in _______________and _____________.

5. The pH Scale

6. Fertilizer and Ecosystems Read the first paragraph of “Fertilizer and ecosystems” on page 70 ( 10 minutes ) Question What can happen to organisms when too much fertilizer is used? Answer: ______________________________________

7. Class Questions (20 minutes) Answer questions on Page 71 # 1, 2, 4 &5 ( may work with a partner – but please make sure you BOTH answer questions your books..)

8. SOLUTIONS TO QUESTIONS Q1 – Why do the levels of nitrogen and phosphorus in fields decline when crops are harvested? Answer:__________________________ __________________________________

9. SOLUTIONS TO QUESTIONS Q2 – Explain how excess fertilizers might affect decomposing organisms. ANSWER:_______________________ __________________________________

10. SOLUTIONS TO QUESTIONS Q4 – What dangers do high levels of nitrates in the drinking water present for infants? ANSWER:_______________________ __________________________________

11. SOLUTIONS TO QUESTIONS Q5 – Explain why not planting a crop and then ploughing in the fall might help a framer restore nitrogen and phosphorus levels in the soil. ANSWER:______________________ __________________________________