Nitrates are essential for plant growth and are absorbed through the root hair cells by active transport
the nitrogen cycle is the process of nitrogen being recycled in the environment
Nitrogen gas from the air is converted to nitrate compounds by nitrogen-fixing bacteria in soil or root nodules. Lightning also converts nitrogen gas to nitrate compounds
Ammonia is converted to nitrates by nitrifying bacteria in the soil
Plants absorb nitrates from the soil and use these to build up proteins.
Decomposers break down the bodies of dead organisms, urine and faeces resulting in nitrogen being returned to the soil as ammonia
