Evapotranspiration, crop coefficient and water consumption of pulse-irrigated bell peppers at different growing seasons

Abstract Pulse irrigation is among the techniques used to improve the efficiency of water management, consisting of the fractional application of the actual irrigation needed. Seeking to maximize the use of water in agricultural production, the objective was to determine the water consumption of bell peppers through the crop coefficient, crop evapotranspiration and pulse-irrigated reference evapotranspiration, at different growing seasons. The experiments were carried out from January to March, May to July and August to October, with the installation of 25 drainage lysimeters, distributed along five planting rows. The crop coefficient obtained for each irrigation pulse was determined through the ratio between the crop evapotranspiration and the reference evapotranspiration. Crop evapotranspiration was obtained daily for each irrigation pulse, determined by the difference between an applied and a drained depth. The reference evapotranspiration was estimated using the Penman-Monteith, Hargreaves-Samani, Solar Radiation, Blaney-Criddle and Priestley-Taylor methods. The Penman-Monteith method showed higher reference evapotranspiration when compared to the other estimation methods. Crop evapotranspiration was lower in the continuous pulse, due to the availability of water for the plant to be applied in the total irrigation time. Thus, the lowest water consumption obtained in pulse 1 and the higher obtained in pulse 5, in all seasons. Evidencing that the addition of irrigation pulses provided the best use of water by the crop. This study demonstrates the importance of optimizind the use of water in irrigated agriculture, helping technicians and producers in decision making.