SOIL CARBON AND CLIMATE CHANGE NEWS
From Kansas State University's:
Consortium for Agricultural Soils Mitigation of Greenhouse Gases (CASMGS)
Charles W. Rice, K-State Department of Agronomy, National CASMGS Director
(785) 532-7217 firstname.lastname@example.org
Scott Staggenborg, K-State Department of Agronomy (785) 532-7214 email@example.com
Steve Watson, CASMGS Communications (785) 532-7105 firstname.lastname@example.org
Enhanced-efficiency fertilizers as mitigation options
for N2O and NO emissions from agriculturE
Agricultural fields are an important anthropogenic source of atmospheric nitrous oxide (N2O) and nitric oxide (NO). Although many field studies have tested the effectiveness of possible mitigation options on N2O and NO emissions, the effectiveness of each option varies across sites due to environmental factors and field management. In a recent article in the journal Global Change Biology, Hiroko Akiyama, of the National Institute for Agro-Environmental Sciences in Japan, and co-authors combined these results and evaluated the overall effectiveness of enhanced-efficiency fertilizers (nitrification inhibitors, polymer-coated fertilizers, and urease inhibitors) on N2O and NO emissions. They performed a meta-analysis using field experiment data (113 datasets from 35 studies) published in peer-reviewed journals through 2008.
The results indicated that nitrification inhibitors significantly reduced N2O emissions compared with those of conventional fertilizers. Polymer-coated fertilizers also significantly reduced N2O emissions, whereas urease inhibitors were not effective in reducing N2O. Nitrification inhibitors and polymer-coated fertilizers also significantly reduced NO.
The effectiveness of nitrification inhibitors was relatively consistent across the various types of inhibitors and land uses. However, the effect of polymer-coated fertilizers showed contrasting results across soil and land-use type. They were significantly effective for imperfectly drained Gleysol grassland, but were ineffective for well-drained Andosol upland fields. Because available data for polymer-coated fertilizers were dominated by certain regions and soil types, additional data are needed to evaluate their effectiveness more reliably.
Nitrification inhibitors were effective in reducing N2O emission from both chemical and organic fertilizers. Moreover, the consistent effect of nitrification inhibitors indicates that they are potent mitigation options for N2O and NO emissions.
-- Steve Watson, CASMGS Communications