Achievement Standard 90766: Describe the properties and effects of fertilisers


Achievement Criteria

Achievement
Achievement with Merit
Achievement with Excellence
Describe the properties and effects of fertilizers.
Explain the effects of fertilizers in terms of their properties.
Discuss the effects of fertilizers in terms of their properties.

Explanatory Notes


1. Fertilizers include but are not limited to inorganic: superphosphate, urea, ammonium nitrate, ammonium sulfate, potassium sulfate; and organic: manures, blood and bone.

2. The properties of fertilizers will be limited to:
  • ionic bonding โ€“ in a crystal lattice
  • pH โ€“ measurement, release of H+ ions
  • solubility โ€“ relationship to polarity of water molecule, effect on formulation for application (eg slow release fertilizers)
  • melting point and boiling point
  • percentage composition
  • availability of ions to plants.

3. The effects of fertilizers will be limited to the chemistry of the: ยท
  • elements in plant growth (N, P, K, S, Mg, Co, Mo, B)
  • soil particle charge in holding and releasing ions
  • ions in pollution and eutrophication.

Past exam papers and assessment schedules:

2008: Exam paper Marking schedule
2007: Exam paper Marking schedule
2006: Exam paper Marking schedule
2005: Exam paper Marking schedule