Greenhouse gases from farmland underestimated

(Phys.org)—Changes in agricultural practices could reduce soil emissions of the greenhouse gas nitrous oxide and the atmospheric pollutant nitric oxide, according to a new study by scientists at the University of California, Davis.

"Agriculture is the main source of nitrous oxide globally, so this study is a starting point to help us understand how to manage and control it," said UC Davis professor of soil biogeochemistry William Horwath, whose lab conducted the study.

Horwath holds the J.G. Boswell Endowed Chair in Soil Science at UC Davis. The work was published today in the journal Proceedings of the National Academy of Sciences.

The study was an effort to understand the sources of nitrous oxide and nitric oxide by different microbial processes, especially following the application of certain types.

Previous studies assumed that nitrous oxide production through ammonia oxidation occurs mainly when there is abundant oxygen in soils.

However, by manipulating oxygen levels and using isotopic analysis, the researchers found the reverse: The amount of nitrous oxide increased through this process when oxygen was extremely limited.

In their paper, the authors said their results imply that management practices such as fertilizer choice affect how much nitrous oxide is released. Specifically, to reduce nitrous oxide emissions, of urea should be avoided in soils where oxygen is limited, they wrote.

On the other hand, practices that increase soil aeration, reduce compaction, and enhance using organic matter could decrease from . Using nitrification inhibitors could help, as well.

"The results of this study will change the way we think about the source of nitrous oxide from soil," Horwath said. "It will help researchers and people making fertilizer recommendations begin to understand that they need to consider different soil processes more explicitly."


Explore further

Nitrous oxide emissions respond differently to no-till depending on the soil type

Provided by UC Davis
Citation: Greenhouse gases from farmland underestimated (2013, April 2) retrieved 21 September 2019 from https://phys.org/news/2013-04-greenhouse-gases-farmland-underestimated.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
0 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more