A $US2.8 million war chest has been established to help US researchers combat the environmental impacts of nitrogen.

Tom Tomich, director of the Agricultural Sustainability Institute at the University of California, says while nitrogen is ‘a hero of the agricultural revolution’, it is increasingly viewed as a worrisome source of water and air pollution.

‘This is one of the most important but least publicised environmental issues we face: escaped nitrogen from agriculture affects the quality of our air, water and soil and has huge potential to contribute to climate change,’ he says.

Tomich says many US politicians and members of the public are unaware of the challenge in mitigating nitrogen’s environmental impact – ‘and many farmers are unaware that nitrogen management can save them money’.

It is estimated nitrogen-based fertilisers help Californian farmers produce 400 agricultural commodities – vegetables, fruits, meats and dairy products – valued at $US36 billion a year.

But excess nitrogen is emitted from soils, seeps into groundwater and runs off into surface waterways. Waste from cattle, chickens and other livestock includes nitrogen, and farm machinery burning oil, petrol and diesel release nitrogen into the air.

The resulting environmental impacts include: trapping solar radiation in the atmosphere, contributing to climate change; decreased high-altitude ozone, which causes skin cancer; increased smog and ground-level ozone, leading to respiratory ailments; and aquatic environment ‘dead zones’ that can’t support fish life.

But Tomich says the environmental impacts of nitrogen are still not fully documented.

‘With this funding we can start to fill in the blanks and improve management of nitrogen, carbon and water to help move agriculture toward sustainability in significant ways.’

Tomich also admits that data on agricultural nitrogen pollution is limited and some forms of nitrogen pollution are difficult to monitor.

Fellow researcher Johan Six says new studies made possible with the funding should improve data collection: ‘It’s urgent we know how much nitrous oxide and other greenhouse gases are released during irrigation and fertilisation of farmland in California.

‘The good news is we know it is economically feasible to reduce these emissions. The first step is quantifying the necessary reductions.’