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International Agrophysics
publisher:Institute of Agrophysics
Polish Academy of Sciences
Lublin, Poland
ISSN: 0236-8722

vol. 19, nr. 2 (2005)

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Comparison between experimental and estimated crop evapotranspiration in Romania
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Cr. Paltineanu
Research Institute for Fruit Growing, 0312 Pitesti-Maracineni, Romania

vol. 19 (2005), nr. 2, pp. 159-164
abstract The purpose of this paper is to compare experimental crop evapotranspiration (ETc-exp) obtained under irrigation conditions in fields versus estimated values of crop evapotranspiration (ETc-est) based on the Penman-Monteith reference evapotranspiration (PM-ETo) and using the method developed by Allen et al. (1998), for various crops as well as for different soil and climate conditions in Romania. Crop coefficients (Kc) for some representative crops like: barley, wheat, maize, sunflower, sugarbeet, soybean, tomato, potato, alfalfa, peach, apricot, table grapes were calculated for the same period of time. ETc was calculated using the above Kc multiplied by the mean values of PM-ETo for the experimental period. The ETc-exp data were taken from the Romanian literature reported in Romania. The locations where the experiments took place were widely spread, covering large areas within the lowlands of this country (southern, eastern and western parts). Then, ETc-est data were correlated and compared with ETc-exp data for the above crops using common statistical procedures. A highly significant correlation between the estimated ETc and experimental ETc data was obtained for most of the crops. However, ETc estimated by Allen’s method was slightly lower than real ETc for previously reported crops tested in this area. This could be attributed to inaccurate measurements of deep drainage and runoff in some of the experiments rather than to the deficiency of Allen’s method. This paper confirms in Romania, with fairly good results, the method developed by Allen et al. (1998), in estimating Kc, and implicitly ETc, for any region or watershed. The findings of this paper could also contribute to better water management in regions similar in climate with the Romanian territories discussed in this paper with many high water consumers.
keywords reference evapotranspiration, crop coefficients, irrigation application