Fertilized Soil Leads to Nitrous Oxide Increase in Atmosphere: Important Confirmation
Dr. David Etheridge, from the Commonwealth Scientific and Industrial Research Organization (CSIRO), is one of the authors of the study; he explains the importance of these findings to Decoded Science.
“Our results confirm what many people suspected, that the main source of the N2O increase is from fertilized soils. Although this was previously suggested, this work used new measurements and an independent modeling approach. It also detected trends over time in the position of the 15N isotope within the N2O molecule, which suggests that aerobic nitrification was the dominant process behind the increased emissions.
N2O variations due to the other sources and the removal processes of N2O have made subtle imprints on the annual cycles and interannual differences of the N2O isotopes, which also can be simulated by models.”
The Environment: Problems Associated with N2O
N2O is a very powerful greenhouse gas; it has Global Warming Power (GWP) 298 times higher than that of carbon dioxide. Furthermore, for the reaction in the upper atmosphere with ozone (see above), N2O can also be considered partly “responsible” for the depletion of the ozone layer. Now that researchers have isolated the reasons for the increase in N2O in the atmosphere, the next step is take action to avoid these problems in the future.
As Dr. Ethridge told Decoded Science, “Clearly the use of fertilizers is essential in agriculture; however, maybe they should be used in a way that minimizes their N2O emissions and at the same time is more economical. Ongoing research is identifying improved practices and technologies that can achieve this.”
Park, S. et al. Trends and seasonal cycles in the isotopic composition of nitrous oxide since 1940. (2012). Nature Geoscience, 5, 261-265. Accessed April 30, 2012.
Davidson, E.A. The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860. (2009). Nature Geoscience, 2, 659-662. Accessed April 30, 2012.
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