Nutrient Cycles

• The Nitrogen Cycle:

  • ammonification = breaking down amino acid compound by saprobionts
  • nitrogen fixing bacteria = convert nitrogen to ammonia
  • nitrification = ammonium ions to nitrites
  • Denitrification = convert nitrate back to nitrogen gas

  
• Phosphorus Cycle:

  • mycorrhizae = fungi that increase SA for absorption of water and phosphate ions
  • saprobionts = break dead organic matter to release phosphate ions

  
• Mycorrhizae

  fungi associate with roots of plants to increase the surface area for absorption of water and mineral ions, including phosphate ions.
• saprobionts (micro-organisms)

  break down dead organic matter to release phosphate ions back into soil
• nitrifying bacteria (nitrification)

  in soil

  oxidise ammonium ions --> nitrite --> nitrates
• nitrogen-fixing bacteria

  In soil

  reduce nitrogen gas into ammonium ions
• denitrifying bacteria

  anaerobic conditions

  convert nitrates back to nitrogen gas