Methane Emission among Rice Ecotypes in Korean Paddy Soil

논 토양에서 벼 기상생태형별 $CH_4$ 배출양상 및 배출량 추정

This study was conducted to investigate methane emission among rice ecotypes in paddy soil (Jeonbug series). The varieties of rice involved early maturing short-grain variety, Samcheonbyeo, middle maturing variety, Hawsungbyeo and late maturing variety, Dongjinbyeo. The seasonal change of methane flux was high from ear formation stage to heading stage. It was found that the methane flux was tended to be lower in early maturing variety than in the mid-to-late maturing variety. The plots without rice straw reduced methane emission as much as 46% relative to rice straw application. The methane emission rate through rice stem was highly correlated with temperature fluctuation. Methane emission on ecotypes by rice straw application was 0.394 g $m^{-2}day^{-1}$ in early maturing variety (Samcheonbyeo), 0.407 g $m^{-2}day^{-1}$ in mid maturing variety(Hawsungbyeo), 0.411 g $m^{-2}day^{-1}$ in late maturing variety(Dongjinbyeo).

유기물 시용 및 벼 기상 생태형별 $CH_4$ 발생양상을 구명하고 이를 근거로 논 토양에서 배출되는 $CH_4$ 배출량을 추정하기 위해 미사질 양토에서 시험한 결과를 요약하면 다음과 같다. 1. 시기별 $CH_4$ 배출은 조생종이 2번의 peak를 나타냈으며 중생종과 만생종은 3번의 peak를 나타냈으며 줄기를 통한 $CH_4$ 배출은 온도가 높을수록 많은 경향이었다. 2. $CH_4$배출량은 조생종에 비하여 중생종과 만생종이 높은 경향이었으며, 볏짚 시용구와 비교해볼 때 볏짚 무시용구에서 46%의 $CH_4$ 배출이 감소되었다. 3. $CH_4$ 배출 계수($gm^{-2}day^{-1}$)는 조생종이 0.394, 중생종이 0.407, 만생종이 0.411이었으며, 볏짚 무시용시 $CH_4$ 배출계수는 조생종이 0.198, 중생종이 0.269, 만생종이 0.273이었다.