117-51 Effects of Irrigation Intervals for Paddy Rice Plants On Greenhouse Gas Fluxes (CO2, CH4 and N2O).



Monday, October 17, 2011
Henry Gonzalez Convention Center, Hall C, Street Level

Yusuke Kudo, Kosuke Noborio, Takashi Kato and Naoto Shimozono, Meiji University, Kawasaki, JAPAN
Effects of irrigation intervals for paddy rice plants on greenhouse gas fluxes (CO2, CH4 and N2O).

Yusuke Kudo* and Kosuke Noborio*

Graduate School of Agriculture, Meiji University*

Farmlands may be thought as emitting sources of greenhouse gases (GHGs) such as carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O). Especially, mitigating GHG emissions in rice paddy fields may have a large impact in monsoon Asia, because 90% of world rice paddy fields are located in Asia including in Japan. Previous studies showed that CH4 emission was reduced using intermittent irrigation alternatively repeating moistening and drying soil. However, transient drying soil by intermittent irrigation may emit more CO2 and N2O. In addition, each of three gases may be differently emitted by different irrigation interval scenarios. The purpose of this study was to investigate effects of irrigation intervals on GHG fluxes (CO2, CH4 and N2O) in rice paddy fields. Rice plants are transplanted in six lysimeters (2×2×2 m) in Meiji University in central Japan. Three water management practices are used: (1) two-day drainage after one-day flooding, (2) four-day drainage after one-day flooding, and (3) continuous flooding except during the midseason drainage as the control practice. We measure the gas fluxes of CO2, CH4 and N2O during growing season until harvest using the closed chamber method. Each gas concentration is analyzed with a GC equipped with FID and ECD. The accumulation of gas fluxes using global warming potential (GWP) for water management practice is compared and discussed.

See more from this Division: S01 Soil Physics
See more from this Session: General Soil Physics: II (Includes Graduate Student Competition)