The Nitrogen Cycle

By Emily, Steph and Chloe

Nitrogen in air

Nitrites

Ammonia

Nitrates in soil and water

Nitrites

Dead plants and

animals

Animal protein

Animal waste

Ammonia

Plant protein

Denitrifying bacteria

Nitrogen-fixing bacteria

Nitrifying bacteria

Decomposers

The nitrogen cycle Nitrogen atoms can be present in inorganic matter

such as nitrogen gas in the atmosphere and as nitrate, nitrite and ammonium ions in the soil and water. Nitrogen atoms are also present in organic matter, mainly in the proteins and amino acids of living things and in waste products, such as urea.

Nitrogen-fixing bacteria

converts atmospheric nitrogen (N2) to ammonium ions (NH4+)

Nitrifying bacteria

Oxidise ammonium ions to produce nitrates (NO3-) and nitrites (NO2-)

Denitrifying bacteria

Convert nitrates and nitrites to gaseous nitrogen

Decomposer bacteria

Convert organic nitrogen to inorganic form