| 32781 |
Creator |
9afccdbe975e25965953e777bb4d6a5f |
| 32781 |
Creator |
4d225a76246d727394d191e1158c779c |
| 32781 |
Creator |
ext-ca6cdbd677b39610cf33c0e9610fa180 |
| 32781 |
Date |
2006-12 |
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Is Part Of |
repository |
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abstract |
Large individual applications of SO<sub>4</sub><sup>2-</sup>(10<sup>2</sup>-10<sup>3</sup>
kg SO<sub>4</sub><sup>2-</sup>-S/ha) are known to suppress methane emissions from
rice paddies by up to ~70%. The application of large quantities of SO<sub>4</sub><sup>2-</sup>
amendments to rice paddies has therefore been proposed as a greenhouse gas mitigation
strategy. In a similar system, natural peatlands, research has established that very
low rates of SO<sub>4</sub><sup>2-</sup> deposition (~25 kg SO<sub>4</sub><sup>2-</sup>
-S/ha/yr as small weekly pulses), similar to those of regions experiencing acid rain
pollution, suppress methane emissions by as much as 30-40%. It is thought that this
is due to stimulation of sulfate-reducing microbial populations that out-compete methane
producers for substrates. Given that acid rain S pollution is forecast to increase
in Asia, the major rice growing region, we sought to establish the potential for acid
rain to suppress CH<sub>4</sub> emission from rice agro-ecosystems by experimentally
simulating acid rain inputs of S deposition to rice mesocosms in the laboratory. We
used soils from Portuguese rice growing regions as they experience low ambient S deposition,
and investigated the effect of simulated sulfate deposition (small regular pulses)
on CH<sub>4</sub> emissions, pore- water concentrations of CH<sub>4</sub> and alternate
electron acceptors. We also applied an annual dose of S deposition as a single pulse
of sulfate to one set of replicate rice mesocosms. After a lag time of 7 weeks, CH<sub>4</sub>
emission from the mesocosms subjected to the small weekly applications of ‘acid rain'
sulfate as Na<sub>2</sub>SO<sub>4</sub> at a rate of 100 kg SO<sub>4</sub><sup>2-</sup>
-S/ha/yr (amounting to a total deposition of ~20 kg SO<sub>4</sub><sup>2-</sup> -S/ha
throughout the 10 week experiment) were reduced below the control by an average of
22%, and as much as 35% on a single date. CH<sub>4</sub> emissions from the ‘single
pulse' experiment were significantly suppressed by the applied sulfate as were pore-water
CH<sub>4</sub> concentrations. |
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authorList |
authors |
| 32781 |
presentedAt |
ext-0dee494d48bbf7ed2ca373dd454540be |
| 32781 |
status |
peerReviewed |
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type |
AcademicArticle |
| 32781 |
type |
Article |
| 32781 |
label |
Gauci, V. ; Dise, N. B. and Howell, G. (2006). Suppression of rice methane production
and emission by low dose sulfate application. In: American Geophysical Union, Fall
Meeting 2006, 11-15 Dec 2006, San Francisco, USA. |
| 32781 |
label |
Gauci, V. ; Dise, N. B. and Howell, G. (2006). Suppression of rice methane production
and emission by low dose sulfate application. In: American Geophysical Union, Fall
Meeting 2006, 11-15 Dec 2006, San Francisco, USA. |
| 32781 |
Title |
Suppression of rice methane production and emission by low dose sulfate application |
| 32781 |
in dataset |
oro |