Nitrogen Cycle Summary Know all about Nitrogen Cycle

Step 1: N2 Fixing Nitrogen (N2) from the atmosphere is converted into Ammonia (NH3) or Ammonium Ions (NH4+) by nitrogen-fixing bacteria. Step 2: Nitrification Ammonia (NH3) or Ammonium Ions (NH4+) are converted into Nitrite (NO2–) and then into Nitrate (NO3–) by nitrifying bacteria. Step 3: Ammonification Dead organic matter and animal waste (like urea and uric acid) decompose, releasing Ammonia (NH3) or Ammonium Ions (NH4+). Most of the ammonia escapes into the atmosphere. The rest undergoes nitrification (Step 2) and becomes nitrate. Step 4: Denitrification Nitrate (NO3–) is converted back into atmospheric Nitrogen (N2) by denitrifying bacteria. Summary Flow Nitrogen (N2) → Ammonia/Ammonium Ions (NH3/NH4+) → Nitrite (NO2–) → Nitrate (NO3–) → Denitrification → Nitrogen (N2)