간척지 논 토양 개량제로서 석고처리가 메탄 배출량 저감에 미치는 영향 = Effect of Gypsum Application on Reducing Methane (CH4) Emission in a Reclaimed Coastal Paddy Soil

다국어 초록 (Multilingual Abstract)

BACKGROUND: Gypsum(CaSO4·2H2O) is known as an ideal amendment to improve soil quality of the reclaimed coastal land. Since gypsum has very high concentration of electron acceptor like SO4(2-), its application might be effective on reducing CH4 emission during rice cultivation, but its effect has not been studied well. METHODS AND RESULTS: The effect of gypsum on CH4 emission and rice growth characteristics was studied by pot test, which was packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Chemical-grade gypsum was applied in two soils having EC 2.25 and 9.48 dS/m at rates of 0, 0.5, 1.0 and 2.0%(wt/wt). CH4 emission was characterized a week interval by closed chamber method during rice cultivation. CH4 emission rate was significantly decreased with increasing salt accumulation and gypsum application levels. With increasing gypsum application, dissolved SO4(2-) concentration in the leachate water was significantly increased, which might have suppressed CH4 production in soil. Total CH4 flux was dramatically decreased with increasing gypsum application. In contrast, rice yield was increased with increasing gypsum application and then achieved maximum productivity at 1.0% gypsum application in two soils. CONCLUSION(s): Gypsum is a very good soil amendment to suppress CH4 emission in reclaimed coastal paddy soils, and improve rice productivity and soil properties. The optimum application level of gypsum is assumed at ca. 1% to improve soil productivity with reducing effectively CH4 emission during rice cultivation.