NITROGEN is a magic ingredient in healthy crops, fruit and vegetables, but its overuse is contributing to global warming and environmental damage.
Excess nitrogen transforms into nitrous oxide, a greenhouse gas with 300 times the potency of CO2.
Now scientists from Southern Cross University and the Wollongbar Department of Primary Industries have joined farmers and industry groups across the Northern Rivers to trial some cutting-edge methods to cut fertiliser use.
It's part of a $2.6 million project funded until 2017 by the Federal Government to introduce practical strategies to reduce agricultural carbon emissions.
At Tony and Bonnie Walker's Tuckombil avocado farm, the team will study the use of a groundcover plant known as a "nitrogen fixer".
The Walkers have been growing the pretty legume, pintoi or forage peanut, almost as long as they have been avocado farming.
"Since we've been using the pintoi we've probably been using 70% less nitrogen," Bonnie Walker estimated.
The legume study will also be extended to local coffee and tea tree plantations.
"We want to quantify exactly how much nitrogen these legumes are putting into the soil," SCU professor Lukas Van Zwieten said.
With nitrogen retailing about $2000 a tonne, it's also a way of saving farmers money while minimising the impact on the environment.