Comparison of the Evapotranspirations among a Paddy Field, Cassava Plantation and Teak Plantation in Thailand

Attarod, Pedram; Komori, Daisuke; Hayashi, Kanako; Aoki, Marcelo Saldanha; Ishida, Tomoyasu; Fukumura, Kazunari; Boonyawat, Samakkee; Polsan, Panya; Tongdeenok, Piyapong; Somboon, Promsen; Punkngum, Somnimitr

doi:10.2480/agrmet.789

Cited by 13 publications

(11 citation statements)

References 3 publications

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“…In artificial ecosystems including agricultural lands, it is essential to evaluate evapotranspiration for developing more efficient and sustainable water management techniques (Attarod et al, 2005). The difficulties in measuring evapotranspiration directly have led to the development of numerous empirical and theoretical models, which have been presented in recent decades for prediction of evapotranspiration from crop fields (Casa et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Estimation of Crop Coefficients and Evapotranspiration by Meteorological Parameters in a Rain-fed Paddy Rice Field, Cassava and Teak Plantations in Thailand

ペデラーム¹,

正敏²,

大輔³

et al. 2006

J. Agric. Meteorol.

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In the present study, an attempt has been made to present empirical equations including easily available meteorological parameters for estimating crop coefficients (Kc) and actual evapotranspiration (AET).The Bowen ratio method (BREB) was used to measure AET, and the Penman-Monteith (PM) equation was employed to compute reference evapotranspiration (ET0). Kc was calculated by the ratio of AET to ET0. Measurements were carried out in three popular vegetations in Thailand, a rain-fed paddy rice field, cassava and teak plantations.We investigated the correlations between Kc and individuals as well as combinations of the meteorological parameters of solar radiation (Rs), air temperature (Ta), wind speed (WS), vapor pressure deficit (VPD), and soil water content (SWC) in each site. Moreover, the above-mentioned correlations were examined using pooled data of the paddy and cassava as well as combined data of all sites.The highest correlation coefficients were found between Kc and combinations of the five mentioned parameters for the three sites. We found that the correlation coefficients between Kc and four easily available parameters excluding SWC were nearly the same as those of the five parameters. Since SWC data are sometimes unavailable, the authors presented the equations including only the easily available parameters to obtain the optimum estimation of Kc.One equation was obtained from the pooled data of paddy and cassava. Root mean square error (RMSE) of the estimating AET using this equation was 0.84 mmday 1 on a 1-day scale. The authors finally proposed another equation for the three sites. RMSE of the final equation on a 1-day scale was found to be 0.72 mmday 1 that corresponds to 19% error. Accordingly, errors of the estimated AET by the final equation at 5, 10, 15 and 20-days of averaging time scales were 15, 12, 11 and 10%, respectively. Therefore, we concluded that averaging over more than 10 days might be more suitable for estimating AET by the final equation.

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Section: Introductionmentioning

confidence: 99%

Estimation of Crop Coefficients and Evapotranspiration by Meteorological Parameters in a Rain-fed Paddy Rice Field, Cassava and Teak Plantations in Thailand

ペデラーム¹,

正敏²,

大輔³

et al. 2006

J. Agric. Meteorol.

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“…Water consumption in paddy fields is mostly due to evapotranspiration which is equal to H2 O flux (FH2 O), and CO2 assimilation is mainly CO2 flux (FCO2) because soil respiration in paddy rice field is small if the surface is submerged. Both FH2O and FCO2 are closely related to rice production (Attarod et al, 2005). The Bowen ratio technique is a micrometeorological method to quantify crop water use (Mo and Liu, 2001;Shen et al, 2004;Attarod et al, 2006) and it is relatively inexpensive compared with other micrometeorological techniques (Casa, 2000).…”

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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“…Then daytime AET was calculated from daytime latent heat flux as AET = LE/λ, in which λ is the latent heat of vapori- zation of water (MJ/kg). The average contribution of the latent heat flux to net radiation (LE/R n ) was calculated to understand the energy allocated to the evapotranspiration process (Attarod et al 2005).…”

Section: Methodsmentioning

confidence: 99%

“…The main goal of irrigation is to supply plant with water as needed to obtain optimum yield and quality of a desired plant constituent. This is why in agricultural lands, AET measurement is needful for developing more efficient and sustainable water management techniques as well as for irrigation scheduling of crops (Attarod et al 2005). To better predict actual or potential crop production, it is quite necessary to evaluate AET.…”

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confidence: 99%

Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

Attarod¹,

Aoki²,

Bayramzadeh³

2009

PLANT SOIL ENVIRON

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The main goal was to understand the trends of actual evapotranspiration (AET) and crop coefficient (K c ) in summer and winter seasons crops in Japan, maize, soybean, wheat and Italian rye-grass. Bowen ratio energy balance technique (BREB) was applied to measure the AET and heat flux between ground surface and atmosphere. Measurements were carried out using an automatic weather station (AWS) installed seasonally in the experimental farm of Tokyo University of Agriculture and Technology (TUAT). Penman-Monteith equation recommended by FAO was used to calculate reference crop evapotranspiration (ET 0 ) and K c was obtained from the ratio of AET to ET 0 . The results indicated that the average amount of daytime AET in the winter and summer seasons crops were approximately 2.5 and 3.5 mm, respectively. Monthly daytime AET varied between 1.3 and 5.7 mm in winter season crops and between 1.4 and 6.5 mm in summer season crops. No significant differences between daily average values of AET for winter season as well as for summer season crops were found at 5% level of confidence (t = 0.9278, wheat and Italian rye-grass and t = 0.6781, soybean and maize). Average K c values of summer season crops were found to be slightly higher than those of winter seasons crops. For planning the irrigation scheduling, it is quite necessary to understand the behaviors of AET and K c during the growing season.

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Comparison of the Evapotranspirations among a Paddy Field, Cassava Plantation and Teak Plantation in Thailand

Cited by 13 publications

References 3 publications

Estimation of Crop Coefficients and Evapotranspiration by Meteorological Parameters in a Rain-fed Paddy Rice Field, Cassava and Teak Plantations in Thailand

Estimation of Crop Coefficients and Evapotranspiration by Meteorological Parameters in a Rain-fed Paddy Rice Field, Cassava and Teak Plantations in Thailand

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

Measurements of the actual evapotranspiration and crop coefficients of summer and winter seasons crops in Japan

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