POLISH JOURNAL OF ENVIRONMENTAL STUDIES, vol.28, no.1, pp.165-175, 2019 (SCI-Expanded)
In this study, the energy balance approach was used to estimate evapotranspiration (ET) of red pepper plots managed with four different irrigation strategies (100, 70, and 40% of ET, and rainfed) with drip irrigation systems in the sub-humid Bafra Plains located in northern Turkey. In order to calculate components of energy balance, hyper-spectral reflectance, infrared surface temperature, and net radiation data were measured using nadir-looking hand-held proximal sensing devices over the experimental plots. Additionally, soil moisture levels were monitored frequently with a well-calibrated neutron moisture meter and a soil water budget approach was used to calculate actual ET values. Current findings revealed that the response of red pepper crops to water stress offered a significant opportunity to detect different levels of spectral reflectance, surface temperature, and net radiation. Furthermore, statistical comparisons revealed significant relationships between measured and estimated daily ET (r = 0.92 and RMSE = 0.83) and cumulative ET (r = 0.99 and RMSE = 43.98) values. Estimation errors for daily and cumulative ET using the energy balance algorithm were 27% and 14%, respectively. Overall, present results indicated that the energy balance algorithm with field level remotely sensed data had a great potential to estimate ET of red peppers at plot scale.