Eddy correlation measurements of methane fluxes from Italian rice-paddy fields

1999 ◽  
Author(s):  
Peter W. Werle
Keyword(s):  
Rice Paddy ◽  
Eddy Correlation ◽  
Paddy Fields ◽  
Methane Fluxes ◽  
Rice Paddy Fields

scholarly journals Comparison of Closed Chamber and Eddy Covariance Methods to Improve the Understanding of Methane Fluxes from Rice Paddy Fields in Japan

Atmosphere ◽  
2018 ◽  
Vol 9 (9) ◽  
pp. 356 ◽  
Author(s):  
Nongpat Chaichana ◽  
Sonoko Bellingrath-Kimura ◽  
Shujiro Komiya ◽  
Yoshiharu Fujii ◽  
Kosuke Noborio ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Rice Paddy ◽  
Paddy Fields ◽  
Closed Chamber ◽  
Cropping Season ◽  
Greenhouse Gas Flux ◽  
Land Use Types ◽  
Methane Fluxes ◽  
Footprint Analysis ◽  
Rice Paddy Fields

Greenhouse gas flux monitoring in ecosystems is mostly conducted by closed chamber and eddy covariance techniques. To determine the relevance of the two methods in rice paddy fields at different growing stages, closed chamber (CC) and eddy covariance (EC) methods were used to measure the methane (CH4) fluxes in a flooded rice paddy field. Intensive monitoring using the CC method was conducted at 30, 60 and 90 days after transplanting (DAT) and after harvest (AHV). An EC tower was installed at the centre of the experimental site to provide continuous measurements during the rice cropping season. The CC method resulted in CH4 flux averages that were 58%, 81%, 94% and 57% higher than those measured by the EC method at 30, 60 and 90 DAT and after harvest (AHV), respectively. A footprint analysis showed that the area covered by the EC method in this study included non-homogeneous land use types. The different strengths and weaknesses of the CC and EC methods can complement each other, and the use of both methods together leads to a better understanding of CH4 emissions from paddy fields.

scholarly journals Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy

2011 ◽  
Vol 8 (12) ◽  
pp. 3809-3821 ◽  
Author(s):  
A. Meijide ◽  
G. Manca ◽  
I. Goded ◽  
V. Magliulo ◽  
P. di Tommasi ◽  
...  
Keyword(s):  
Paddy Field ◽  
Rice Paddy ◽  
Northern Italy ◽  
Paddy Fields ◽  
Anthropogenic Sources ◽  
Vegetative Period ◽  
Rice Paddy Field ◽  
Ch4 Emissions ◽  
Methane Fluxes ◽  
Rice Paddy Fields

Abstract. Rice paddy fields are one of the greatest anthropogenic sources of methane (CH4), the third most important greenhouse gas after water vapour and carbon dioxide. In agricultural fields, CH4 is usually measured with the closed chamber technique, resulting in discontinuous series of measurements performed over a limited area, that generally do not provide sufficient information on the short-term variation of the fluxes. On the contrary, aerodynamic techniques have been rarely applied for the measurement of CH4 fluxes in rice paddy fields. The eddy covariance (EC) technique provides integrated continuous measurements over a large area and may increase our understanding of the underlying processes and diurnal and seasonal pattern of CH4 emissions in this ecosystem. For this purpose a Fast Methane Analyzer (Los Gatos Research Ltd.) was installed in a rice paddy field in the Po Valley (Northern Italy). Methane fluxes were measured during the rice growing season with both EC and manually operated closed chambers. Methane fluxes were strongly influenced by the height of the water table, with emissions peaking when it was above 10–12 cm. Soil temperature and the developmental stage of rice plants were also responsible of the seasonal variation on the fluxes. The measured EC fluxes showed a diurnal cycle in the emissions, which was more relevant during the vegetative period, and with CH4 emissions being higher in the late evening, possibly associated with higher water temperature. The comparison between the two measurement techniques shows that greater fluxes are measured with the chambers, especially when higher fluxes are being produced, resulting in 30 % higher seasonal estimations with the chambers than with the EC (41.1 and 31.7 g CH4 m−2 measured with chambers and EC respectively) and even greater differences are found if shorter periods with high chamber sampling frequency are compared. The differences may be a result of the combined effect of overestimation with the chambers and of the possible underestimation by the EC technique.

scholarly journals Seasonal trends and environmental controls of methane emissions in a rice paddy field in Northern Italy

2011 ◽  
Vol 8 (5) ◽  
pp. 8999-9032 ◽  
Author(s):  
A. Meijide ◽  
G. Manca ◽  
I. Goded ◽  
V. Magliulo ◽  
P. di Tommasi ◽  
...  
Keyword(s):  
Eddy Covariance ◽  
Water Table ◽  
Paddy Field ◽  
Rice Paddy ◽  
Northern Italy ◽  
Paddy Fields ◽  
Rice Paddy Field ◽  
Ch4 Emissions ◽  
Methane Fluxes ◽  
Rice Paddy Fields

Abstract. Rice paddy fields are one of the greatest anthropogenic sources of methane (CH4), the third most important greenhouse gas after water vapour and carbon dioxide. In agricultural fields, CH4 is usually measured with the closed chamber technique, resulting in discontinuous series of measurements performed over a limited area, that generally do not provide sufficient information on the short-term variation of the fluxes. On the contrary, aerodynamic techniques have been rarely applied for the measurement of CH4 fluxes in rice paddy fields. The eddy covariance (EC) technique provides integrated continuous measurements over a large area and may increase our understanding of the underlying processes and diurnal and seasonal pattern of CH4 emissions in this ecosystem. For this purpose a Fast Methane Analyzer (Los Gatos Research Ltd.) was installed in an eddy-covariance field set-up in a rice paddy field in the Po Valley (Northern Italy). Methane fluxes were measured during the rice growing season, both with EC and with manually operated closed chambers. Methane fluxes were strongly influenced by the presence of the water table, with emissions peaking when it was above 10–12 cm. Further studies are required to evaluate if water table management could decrease CH4 emissions. The development of rice plants and soil temperature were also responsible of the seasonal variation on the fluxes. The EC measured showed a diurnal cycle in the emissions, which was more relevant during the vegetative period, and with CH4 emissions being higher in the late evening, possibly associated with higher water temperature. The comparison between both measurement techniques shows that greater fluxes are measured with the chambers, especially when higher fluxes are being produced, resulting in 30 % higher seasonal estimations with the chambers than with the EC (41.1 and 31.8 g CH4 m−2 measured with chambers and EC respectively). The differences may be a result of the combined effect of overestimation with the chambers, the possible underestimation by the EC technique and of not having considered the daily course of the fluxes for the calculation of seasonal emissions from chambers.

scholarly journals Dry matter accumulation and plant type of the high yielding soybean grown under converted rice paddy fields.

1984 ◽  
Vol 53 (4) ◽  
pp. 510-518 ◽  
Author(s):  
Kimio NAKASEKO ◽  
Humio NOMURA ◽  
Kanji GOTOH ◽  
Takeshi OHNUMA ◽  
Yoshikatsu ABE ◽  
...  
Keyword(s):  
Dry Matter ◽  
Rice Paddy ◽  
Paddy Fields ◽  
Dry Matter Accumulation ◽  
Plant Type ◽  
Rice Paddy Fields
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