Seasonal variation of carbon dioxide exchange in rice paddy field in Japan

A micro paddy lysimeter (MPL) was employed to monitor the behavior of nursery-box-applied imidacloprid granules in the rice paddy environment using two treatment methods, i.e. before transplanting (BT) and at sowing (AS). Tested application rates were three-fold the recommended rate. Under a water management scenario in an actual eld, the behavior of nursery-box-applied imidacloprid granules in paddy water and paddy soil in MPL was comparable with eld monitoring data in the literature. Imidacloprid concentration in water peaked at 189±36 μg/L and 13.1±1.4 μg/L at 1 day a er transplanting (DAT), and the halflives (DT 50 ) were 2.5 days, and 4.7 days for BT and AS treatments, respectively. In the soil pro le, the maximum concentration of imidacloprid at 21 DAT was 65.6±0.4 μg/kg and 39.7±4.9 μg/kg in the 0-2.5 cm layer in the inter-row zone for BT and AS treatments, respectively. Imidacloprid was found in the 12.5-15.0 cm layer at 3.2±0.7 μg/kg for BT treatment and 13.7±3.8 μg/kg for AS treatment, in the inter-row zone. In AS treatment, imidacloprid mainly stayed in the root zone (0-5 cm surface soil layer), and its concentration was 895±4 μg/kg at 21 DAT. MPL presented as a convenient and alternative tool to monitor the behavior of nursery-box-applied pesticide in the rice paddy environment.

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“…is temperature range was comparable with the typical temperature regime in a Japanese paddy eld during rice cultivation. 5,16) …”

Section: ) C)mentioning

confidence: 99%

Behavior of nursery-box-applied imidacloprid in micro paddy lysimeter

et al. 2012

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“…Nighttime NEE represents nighttime respiration (autotrophic and heterotrophic) because plants do not photosynthesize at night. The following model (Marshall and Biscoe, 1980;Falge et al, 2002;Saito et al, 2005) was used to describe the effects of temperature on night-time NEE:…”

Section: Ec Flux Datamentioning

confidence: 99%

Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes

Yuan

Liu

Zhou

et al. 2007

Agricultural and Forest Meteorology

580

425

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“…These observation sites are mostly located in forest ecosystems because they are believed to be the most influential terrestrial ecosystems in the global CO2 budget (Saigusa et al, 2002;Carrara et al, 2003). On the other hand, non-forest ecosystems, such as grasslands, wetlands and agricultural fields have also been observed because they contribute to regional and global CO2 budgets (Saito et al, 2005;Tsai et al, 2006). Rice is the major crop in Asia, and according to the Food and Agricultural Organization of the United Nations (FAO), the area of rice paddies in this region is about 87% of the world's total rice cultivation area (FAO, 2004).…”

Section: Introductionmentioning

confidence: 99%

CO2 and H2O Fluxes Ratio in Paddy Fields of Thailand and Japan

Pakoktom

Aoki

Kasemsap

et al. 2009

Hydrological Research Letters

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Abstract:Measurements of CO2 flux (FCO2 ) and H2 O flux (FH2O) were carried out on paddy fields of Thailand and Japan during the 2004, 2005 and 2006 growing seasons using the Bowen ratio technique. The objective was to determine the water resource requirement to achieve a certain amount of CO2 assimilation per land area and analyze the ratio between FCO2 and FH2 O (CWFR = FCO2/FH2O). The relationship between FCO2 and FH2O was investigated using regression analysis in 4 growing stages. Relatively high correlations (r 2 = 0.56 0.96, p < 0.01) between FCO2 and FH2O were found when data were grouped by growing stage. Using daytime average data, there was high correlation (r 2 = 0.61 0.94, p < 0.01) between daytime average CWFR (CWFRd) and daytime average vapor pressure deficit (VPDd) in paddy fields of Japan and Thailand for each growing stage. Pooled data from Thailand and Japan showed high correlations (r 2 = 0.61 0.94, p < 0.01) between CWFRd and VPDd for each growing stage. The developed regression equation was tested using an independent published dataset, and it was found that the estimation error was only 2.7%. The regression equations will be useful for estimating CWFRd by only VPDd and accordingly for assessing the water resource requirement. KEYWORDS carbon dioxide flux; carbon dioxide flux and water vapour flux ratio; paddy rice field; vapour pressure deficit; water vapour flux.

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Seasonal variation of carbon dioxide exchange in rice paddy field in Japan

Cited by 175 publications

References 35 publications

Behavior of nursery-box-applied imidacloprid in micro paddy lysimeter

Behavior of nursery-box-applied imidacloprid in micro paddy lysimeter

Deriving a light use efficiency model from eddy covariance flux data for predicting daily gross primary production across biomes

CO2 and H2O Fluxes Ratio in Paddy Fields of Thailand and Japan

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