Composition of Fertilisers

Specification Point 5.22C:
  • Recall that fertilisers may contain nitrogen, phosphorus and potassium compounds to promote plant growth.
  • Compounds containing nitrogen, potassium and phosphorus are used as fertilisers to increase crop yields.
  • NPK fertilisers contain compounds of all three elements.
  • Nitrogen promotes healthy leaves, potassium promotes growth and healthy fruit and flowers and phosphorus promotes healthy roots.
  • Fertiliser compounds contain the following water soluble ions:
    • Ammonium ions, NH4+ and nitrate ions, NO3, are sources of soluble nitrogen.
    • Phosphate ions, PO43-  are a source of soluble phosphorus.
    • Most common potassium compounds dissolve in water to produce potassium ions, K+.
  • An advantage of artificial fertilisers is that they can be designed for specific needs whereas natural fertilizers, such as manure and seaweed, cannot.

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Morgan Curtin Chemistry

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.