Fertilizers | Chemistry for Grade 11 (IGCSE) PDF Download

Fertilisers

N, P, K Fertilisers

• Fertilisers contain nitrogen, potassium, and phosphorus.
• Nitrogen is essential for making chlorophyll and proteins, promoting healthy leaves. For example, in plants like spinach, nitrogen is crucial for the vibrant green color of the leaves.
• Potassium plays a key role in promoting growth and ensuring the health of fruits and flowers. An example is how potassium aids in the development of strong apple trees with healthy fruit.
• Phosphorus is vital for promoting healthy roots. It helps plants establish a strong root system, such as in carrots where phosphorus contributes to robust root growth.
• Fertilizer compounds consist of water-soluble ions, including:
  • Ammonium ions (NH₄⁺) and nitrate ions (NO₃^-) as sources of soluble nitrogen. These ions are readily absorbed by plants for growth.
  • Phosphate ions (PO₄^3-) as a soluble phosphorus source, crucial for energy transfer in plants.
  • Common potassium compounds dissolve in water to produce potassium ions (K⁺), which are essential for various plant functions.
• Some common fertilizer compounds are:
  • Ammonium nitrate (NH₄NO₃)
  • Ammonium phosphate ((NH₄)₃PO₄)
  • Potassium sulfate (K₂SO₄)
• Ammonium salts and nitrates are widely used as fertilizers due to their nutrient-rich composition.
• Different fertilizers contain varying proportions of nitrogen, potassium, and phosphorus based on their intended use and plant requirements.