Researchers from the University of East Anglia have found a novel way of reducing Nitrous Oxide (N2O) emissions from farming.

Worldwide, agriculture is the main source of Nitrous Oxide emissions, through the cultivation of soils and use of nitrogen-based fertilisers and manure. Global agricultural emissions of the gas have increased by 20 percent over the last century as a result of increasing synthetic fertiliser use. The greenhouse gas has a global warming potential 310 times that of carbon dioxide.

Now though, UEA researchers believe they may be able to help reduce emissions N2O by incorporating copper into crop fertilisation processes. Research into the processes of nutrient cycling, published this week, suggests that farmers could mitigate the effects of N2O by boosting copper levels in their fields.

Lead researcher Prof David Richardson, from UEA's school of Biological Sciences, explained the problems associated with Nitrous Oxide emissions, "The increase in nitrous oxide in the atmosphere is largely the result of changing agricultural practices to more intensive, large scale production systems. Rapid population growth and the constant need for greater crop yields have fuelled the change.

"Agricultural N2O emissions have increased significantly and continue to rise. It is a big problem because [N2O] is a potent greenhouse gas... And it is behind almost one tenth of global radiative forcing by greenhouse gasses. But how to regulate these emissions has been poorly understood until now."

The research team investigated a process called denitrification – a series of chemical reactions in bacteria that happen in conditions where oxygen levels are low and quantities of nitrate are high.

Prof Richardson elaborated on the process, "Farmed soil is a prime example of such a condition, and what happens is that bacteria respire nitrate as a substitute for oxygen. We found that the gene in nitrate-utilising soil bacteria, responsible for the destruction of nitrous oxide, can be regulated when copper is added.

"So farmers could control N2O emissions by judicious use of copper in fertiliser regimes. Copper fertiliser is already used in areas where soil is copper deficient so it is already on the market. The next stage of research will be to compare N2O emissions from soil that is naturally high in copper, with that which is naturally low. We will also look at quantity and frequency of application."

Working as part of a trans-European effort to tackle N2O emissions (called the Nitrous Oxide Research Alliance, or NORA) the team will continue to study the role of bacteria in producing and consuming N2O.