The Nitrogen Cycle

• Nitrogen gas from the air is converted to nitrate compounds by nitrate fixing bacteria
• Lighting also converts nitrogen to nitrate compounds
• The Haber Process is a man made process that converts nitrogen to ammonia for use in fertilisers
• Ammonia is converted to nitrates by nitrifying bacteria in the soil
• Plants absorb nitrates from the soil and use them to build proteins
• The plant may be eaten by an animal and the biomass used to build animal proteins
• Decomposers break down waste to ammonia
• Decomposers break down the bodies of dead organisms, faeces, and urine, and returns it to the soil as ammonia
• the ammonia is converted to nitrates by nitrifying bacteria
• In some conditions, denitrifying bacteria in the soil break down nitrates and release nitrogen into the air
• improving drainage reduces the effect of denitrifying bacteria, and results in more nitrates in the soil for the plants, because the bacterica are happy in waterlogged soil