About 80% of the atmosphere is dinitrogen gas, which is more or less unavailable to most plants. Nitrogen gas in the atmosphere is basically unusable by most of biology – plants and animals – but there are a few species of microbes in conjunction with plants that can convert the dinitrogen gas into usable forms of nitrogen like ammonium, and then that will turn into organic nitrogen or nitrate, and that can then enter the biological system.
The conversion of nitrogen gas into biologically available forms of nitrogen is critical for the functioning of the ecosystem.
Dr Kristine A Nichols
Professor Louis Schipper, University of Waikato