Effect of water management on methane emission from a Japanese rice paddy field: Automated methane monitoring

Abstract

The effect of differing water management schemes on the emission of methane (CH4) from rice paddies to the atmosphere was studied in a Japanese paddy field. Using an automated sampling and analyzing system, the test site was divided into two plots: a continuously flooded plot which was maintained flooded by constant irrigation from May to August, and an intermittently drained plot in which short‐term draining practices were performed several times during the flooding period . The draining practice had a strong effect on CH4 emission. A large flush of CH4 emission was observed in the intermittently drained plot immediately after each drainage. It was followed by a rapid decrease in CH4 flux in most of the cases. A large flush of CH4 was observed after the final drainage at the end of August in the continuously flooded plot, accounting for about 7% of the total CH4 emitted in the plot. Total emission rates of CH4 during the cultivation period were 14.8 and 8.63 g m−2 for 1991 and 9.49 and 5.18 g m−2 for 1993 in the continuously flooded and intermittently drained plots, respectively. Companion N2O flux measurements showed that almost no N2O was emitted from either plot until the final drainage. These results indicate that short‐term draining practices strongly reduce CH4 emission from rice paddy fields, and that improvement in water management can be one of the most important mitigation strategies for CH4 emission from rice paddy fields.

Effects of dicyandiamide and acetylene on N2O emissions and ammonia oxidizers in a fluvo-aquic soil applied with urea

“…N 2 O concentration was determined with a gas chromatograph (Agilent 7890A). N 2 O emissions were calculated as the difference between 0 and 12 h based on the equation reported by Yagi et al (1996). Three bottles per treatment were destructively sampled at days 3, 7, 15, and 28 for soil samples.…”

Effect of Water and Straw Management Practices on Methane Emissions from Rice Fields: A Review Through a Meta-Analysis

“…In fact, water regime (irrigation and drainage) affects directly soil characteristics, preventing or promoting the development of reductive conditions. The presence of standing surface water is essential for the development of the anaerobic conditions in paddy soil by limiting the transport of atmospheric oxygen into soil, which is favorable for CH4 production (Yagi et al, 1996;Bharati et al, 2001;Singh et al, 2009). Consequently, CH4 mitigation strategies from rice fields must consider rice agricultural practices and water regimes which reduce or limit the flooded period.…”

Managing Water and Soils to Achieve Adaptation and Reduce Methane Emissions and Arsenic Contamination in Asian Rice Production

“…The authors suggest that the latter program of eleven intermittent drainage events reflects conventional Japanese rice cultivation in the region. There were no significant differences in nitrous oxide emissions or rice yields on the continuously flooded and intermittently drained plots in either year [181]. The authors conclude that water management can be an important methane mitigation measure, provided that rainfall is not excessive and farmers have adequate control of irrigation water deliveries.…”

“…Yagi et al [181] observed reductions in methane emissions of 42% and 45% in 1991 and 1993, respectively, on experimental plots in Kanto Province, Japan, that were drained at least two times during the season. Intermittent drainage was applied twice in 1991 and eleven times in 1993.…”