Understanding the nature of methane emission from rice ecosystems as basis of mitigation strategies

Conference · Tue Dec 31 04:00:00 EST 1996

DOI:https://doi.org/10.1016/S0306-2619(97)00022-6· OSTI ID:484395

Buendia, L V; Neue, H U; Wassmann, R ^[1]

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1. International Rice Research Institute, Laguna (Philippines); and others

Methane is considered as an important Greenhouse gas and rice fields are one of the major atmospheric methane sources. The paper aims to develop sampling strategies and formulate mitigation options based on diel (day and night) and seasonal pattern of methane emission. The study was conducted in 4 countries to measure methane flux using an automatic closed chamber system. A 24-hour bihourly methane emissions were continuously obtained during the whole growing season. Daily and seasonal pattern of methane fluxes from different rice ecosystems were evaluated. Diel pattern of methane emission from irrigated rice fields, in all sites, displayed similar pattern from planting to flowering. Fluxes at 0600, 1200, and 1800 h were important components of the total diel flux. A proposed sampling frequency to accurately estimate methane emission within the growing season was designed based on the magnitude of daily flux variation. Total methane emission from different ecosystems follow the order: deepwater rice > irrigated rice > rainfed rice. Application of pig manure increased total emission by 10 times of that without manure. Green manure application increased emission by 49% of that applied only with inorganic fertilizer. Removal of floodwater at 10 DAP and 35 DAP, within a period of 4 days, inhibited production and emission of methane. The level of variation in daily methane emission and seasonal emission pattern provides useful information for accurate determination of methane fluxes. Characterization of seasonal emission pattern as to ecologies, fertilizer amendments, and water management gives an idea of where to focus mitigation strategies for sustainable rice production.

• Research Organization: Lawrence Berkeley National Lab., CA (United States)
• OSTI ID: 484395
• Report Number(s): LBNL--39686; CONF-9611151--; ON: DE97003750
• Country of Publication: United States
• Language: English

Related Subjects

29 ENERGY PLANNING, POLICY, AND ECONOMY
54 ENVIRONMENTAL SCIENCES
CLIMATIC CHANGE
CULTIVATION
EMISSION
METHANE
MITIGATION
RICE