Gauci, Vincent; Dise, Nancy B.; Howell, Graham and Jenkins, Meaghan E.
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|DOI (Digital Object Identifier) Link:||http://dx.doi.org/doi:10.1029/2007JG000501|
|Google Scholar:||Look up in Google Scholar|
Sulfate in acid rain is known to suppress methane (CH4) emissions from natural freshwater wetlands. Here we examine the possibility that CH4 emissions from rice agriculture may be similarly affected by acid rain, a major and increasing pollution problem in Asia. Our findings suggest that acid rain rates of SO2-4 deposition may help to reduce CH4 emissions from rice agriculture. Emissions from rice plants treated with simulated acid rain at levels of SO2-4 consistent with the range of deposition in Asia were reduced by 24% during the grain filling and ripening stage of the rice season which accounts for 50% of the overall CH4 that is normally emitted in a rice season. A single application of SO2-4 at a comparable level reduced CH4 emission by 43%. We hypothesize that the reduction in CH4 emission may be due to a combination of effects. The first mechanism is that the low rates of SO2-4 may be sufficient to boost yields of rice and, in so doing, may cause a reduction in root exudates to the rhizosphere, a key substrate source for methanogenesis. Decreasing a major substrate source for methanogens is also likely to intensify competition with sulfate-reducing microorganisms for whom prior SO2-4 limitation had been lifted by the simulated acid rain S deposition.
|Item Type:||Journal Article|
|Copyright Holders:||2008 by the American Geophysical Union|
|Academic Unit/Department:||Science > Environment, Earth and Ecosystems
|Interdisciplinary Research Centre:||OpenSpace Research Centre (OSRC)
Centre for Earth, Planetary, Space and Astronomical Research (CEPSAR)
|Depositing User:||Vincent Gauci|
|Date Deposited:||16 Dec 2010 10:11|
|Last Modified:||18 Nov 2012 10:25|
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