Seasonal Change of Rice-mediated Methane Emission from a Rice Paddy under Different Water Management and Organic Amendments

Methane emission was measured in a rice paddy under different water management and organic amendments. Methane emission from planted chambers and unplanted chambers was monitored to evaluate the rice-mediated methane emission. In flooding methane emission from planted chambers with NPK, NPK(+P), was $0.174g\;CH_4\;m^{-2}\;d^{-1}$ while that from unplanted chambers with NPK, NPK(-P), was $0.046g\;CH_4\;m^{-2}\;d^{-1}$ Methane emission from planted chambers with rice straw compost amendment, RSC(+P), was $0.214g\;CH_4\;m^{-2}\;d^{-1}$, while that from unplanted chambers with rice straw compost amendment, RSC(-P), was $0.076g\;CH_4\;m^{-2}\;d^{-1}$. Methane emission from planted chambers with rice straw amendment in Fehruary, RS2(+P), was $0.328g\;CH_4\;m^{-2}\;d^{-1}$, while that from unplanted chambers with rice straw amendment in February, RS2(-P), was $0.1g\;CH_4\;m^{-2}\;d^{-1}$. Methane emission from planted chambers with rice straw amendment in May, RS5(+P), was $0.414g\;CH_4\;m^{-2}\;d^{-1}$, while that from unplanted chamhers with rice straw amendment in May, RS5(-P), was $0.187g\;CH_4\;m^{-2}\;d^{-1}$. In intermittent irrigation methane emission from NPK(+P) was $0.115g\;CH_4\;m^{-2}\;d^{-1}$, while that from NPK(-P) was $0.041g\;CH_4\;m^{-2}\;d^{-1}$. Methane emission from RSC(+P) was $0.137g\;CH_4\;m^{-2}\;d^{-1}$, while that from RSC(-P) was $0.06g\;CH_4\;m^{-2}\;d^{-1}$. Methane emission from RS2(+P) was $0.204g\;CH_4\;m^{-2}\;d^{-1}$, while that from RS2(-P) was $0.09g\;CH_4\;m^{-2}\;d^{-1}$. Methane emission from RS5(+P) was $0.273g\;CH_4\;m^{-2}\;d^{-1}$, while that from RS5(-P) was $0.13g\;CH_4\;m^{-2}\;d^{-1}$. Methane transport via rice plant under flooding for NPK plot, RSC plot, RS2 plot and RS5 plot was 73.6%, 64.5%, 69.5% and 54.8%, respectively, and mean was 65.6%. Methane transport via rice plants under intermittent irrigation for NPK plot, RSC plot, RS2 plot and RS5 plot was 64.3%, 59.2%, 55.9% and 52.4%, respectively, and mean was 58.0%.

물 관리와 유기물 시용이 다른 논에서 벼 식물체를 통한 메탄 배출의 계절변화

물관리와 유기물 시용이 다른 논에서 메탄 배출을 측정하였다. 벼 식물체를 통해 배출되는 메탄을 측정하기 위하여 벼를 심은 chamber와 심지 않은 chamber를 반복으로 포장에 설치하였다. 기체시료는 벼 재배기간중 주 1회 채취하였다. 상시담수에서는 벼를 심은 NPK구, NPK(+P),는 $0.174g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 심지 않은 NPK구, NPK(-P),는 $0.046g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. 벼를 심은 볏짚퇴비 시응구, RSC(+P), 는 $0.214g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 심지 않은 볏짚퇴비 시용구, RSC(-P),는 $0.076g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. 볏짚을 2월에 시용하고 벼를 심은 시험구, RS2(+P), 는 $0.328g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 볏짚을 2월에 시용하고 벼를 심지 않은 시험구, RS2(-P),는 $0.1g\;CH_4\;m^{-2}\;d^{-1}$의 배출을보였다. 볏짚을 5월에 시용하고 벼를 심은 시험구, RS5(+P). 는 $0.414g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 볏짚을 2월에 시용하고 벼를 심지 않은 시험구, RS5(-P),는 $0.187g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. 간단관개에서는 NPK(+P)는 $0.115g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 NPK(-P)는 $0.041g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. RSC(+P)는 $0.137g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 RSC(-P)는 $0.06g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. RS2(+P) 는 $0.204g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 RS2(-P)는 $0.09g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. RS2(+P)는 $0.273g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였으나 RS5(-P)는 $0.13g\;CH_4\;m^{-2}\;d^{-1}$의 배출을 보였다. 상시담수 처리에서 벼 식물체를 통한 메탄 수송은 NPK구, RSC구 (볏짚퇴비를 5월에 시용한 구), RS2구(볏짚을 2월에 시응한 구)와 RS5구 (볏짚을 5월에 시용한 구)에서 각기 73.6 %, 64.5%, 69.5%, 54.8%였었고 평균 65.6%였었다. 간단관개처리에서 벼 식물체를 통한 메탄 수송은 NPK구, RSC구, RS2구와 RS5구에서 각각 64.3, 59.2, 55.9, 52.4였다.