Nitrogen cycle

The availability of fixed nitrogen in the soil limits the productivity in an ecosystem Nitrogen fixing bacteria in the roots of leguminous plants reduce atmospheric nitrogen to ammonium using ATP + NADH2 The ammonium ions released into the soil are oxidised by nitrifying bacteria into nitrite,and then to nitrate plants can use nitrates to produces many useful molecules including amino acids, DNA and ATP The formation of these ions forms part of the ecological nitrogen cycle which plays a key role in sustaining life on this planet