COMPARISON OF REFERENCE EVAPOTRANSPIRATION IN SEMI ARID REGION

K. ARUNADEVI¹*, J. RAMACHANDRAN², S. VIGNESH³, S. VISUVANATHAKUMAR⁴, S. ANUPRIYANKA^5
1Department of Soil and Water Conservation Engineering and Agricultural Structures, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Kumulur, Trichy 621712
²Department of Soil and Water Conservation Engineering and Agricultural Structures, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Kumulur, Trichy 621712
³Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Kumulur, Trichy 621712
⁴Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Kumulur, Trichy 621712
⁵Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Kumulur, Trichy 621712
* Corresponding Author : aruna_swce@yahoo.com

Received : 30-10-2017     Accepted : 16-11-2017     Published : 30-11-2017
Volume : 9     Issue : 52       Pages : 4886 - 4888
Int J Agr Sci 9.52 (2017):4886-4888

Keywords : Reference Evapotranspiration, FAO Penman Montieth Method, Crop Wat, Pan Evaporation Method
Academic Editor : Vanitha Subramani, Dr Amit Kesarwani
Conflict of Interest : None declared
Acknowledgements/Funding : The author kindly acknowledges the meteorological observatory, Agricultural Engineering College and Research Institute, Tamil Nadu Agricultural University, Kumulur, Trichy 621712 for providing the weather data
Author Contribution : All author equally contributed

The reference evapotranspiration calculation is important to find out the evaporative demand of the atmosphere. It is not dependent on crop types, development and management practices. Various methods are available to estimate reference evapotranspiration (ETâ‚€) from standard meteorological observations. The Penman-Monteith method is considered to be the most physical and reliable method and is often used as a standard to verify other empirical methods[1].In this study, the values of Reference Evapotranspiration ETo by FAO Penman-Montieth equation, CROPWAT 8.0 software, and Pan evaporimeter data for the period of June 2015 to May 2016 Agricultural Engineering College and Research Institute, Kumulur, Trichy was compared. The calculation of ET0 with FAO Penmann Monteith method was done in Excel and the values of ET0 varied from 4.5mm/day to 6.21 mm/day. The ETo value was 3.93mm/day to 6.16 mm/day when calculated through CROPWAT 8.0 software. The ETo value for using the Pan Evaporimeter data varied from 2.2mm/day to 6.7 mm/day. ETo values calculated from the three methods were compared and shown in graphical format.

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