"On a pound for pound basis, it is really worthwhile to figure how to limit our emissions of N2O and methane," she said. "Limiting N2O emissions can buy us a little more time in figuring out how to reduce CO2 emissions."
One approach, for example, is to time fertilizer application to avoid rain, because wet and happy soil microbes can produce sudden bursts of nitrous oxide. Changes in the way fields are tilled, when they are fertilized and how much is used can reduce N2O production.
Boering's studies, which involve analyzing the isotopic fingerprints of nitrous oxide from different sources, could help farmers determine which strategies are most effective. It could also help assess the potential negative impacts of growing crops for biofuels, since some feedstocks may require fertilizer that will generate N2O that offsets their carbon neutrality.
"This new evidence of the budget of nitrous oxide allows us to better predict its future changes and therefore its impacts on climate and stratospheric ozone depletion - for different scenarios of fertilizer use in support of rising populations and increased production for bio-energy," said coauthor David Etheridge of the Centre for Australian Weather and Climate Research in Aspendale, Victoria.
Finding the fingerprint of fertilized microbes
Boering was able to trace the source of N2O because bacteria in a nitrogen rich environment, such as a freshly fertilized field, prefer to inco
|Contact: Robert Sanders|
University of California - Berkeley