Reference evapotranspiration estimation by different methods for the sucroenergy sector of Colombia

Andrés J Peña Q,Christian J Mendoza C

doi:10.1590/1807-1929/agriambi.v25n9p583-590

Abstract

ABSTRACT In the Colombian Sugarcane Research Center CENICAÑA, efficient use of water is always performed based on estimating reference evapotranspiration. In this method, class A pans have been used to estimate the reference evapotranspiration, which provides a more precise estimate of this important variable for water resource management. The objective of this study was to evaluate different reference evapotranspiration methods for the region of influence of the climatological station of the CENICAÑA experimental station. The class A pan method traditionally used in CENICAÑA was compared with and the Penman-Monteith FAO 56 standard method. The historical series used was from January 1, 1994, to December 31, 2014. The climatic variables were the maximum, mean, and minimum temperatures, the mean relative air humidity, solar radiation, and wind speed at 10 m. Willmott’s coefficients, the confidence index (c), and the root mean squared error were used in the performance evaluation. In the comparison with the Penman-Monteith FAO 56 method, all methods presented performance below the minimum requirement of (c) = 0.400. When all methods were compared with the method used in CENICAÑA (Class A pan), only the Penman-Monteith FAO 56 method showed performance classified as good (c = 0.689).

Highlights

Water management and efficient water resource use are two challenges in the sustainable management of any crop
The ET0 values calculated using the class A pan method are positively associated with the ET0 values generated using the Penman-Monteith standard method
When the correlation coefficient was evaluated, the method that had the best adjustment was the Penman-Monteith standard method with r = 0.92 (Table 4). This method was the only one that had good performance (Table 1). These results confirmed the findings reported by Montero et al (2018), who carried out an analysis to compare ET0 data from a satellite image and data estimated from CENICAÑA’s weather data

Summary

Introduction

Water management and efficient water resource use are two challenges in the sustainable management of any crop. The determination of water requirements is capital for achieving high water-use efficiency. Insufficient or excess water application result in losses and damages to the crops, soil, and nutrients, decreasing irrigation efficiency (Fietz et al, 2005; Bernardo et al, 2006). The reference evapotranspiration (ET0) is used to determine the atmospheric power to remove water from a crop surface with no soil-water deficit. ET0 could be indirectly measured with a class A pan (ECA) or computed using weather data. The Penman-Monteith (FAO-PM) method for ET0 estimation is based on weather data. This method has been parameterized and recommended as standard by the Food Agriculture Organization (FAO). In some conditions, more straightforward approaches are necessary to estimate ET0 (Landeras et al, 2008; Martí et al, 2015)

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Methods

Results

Conclusion