Irrigation Scheduling Based on Evapotranspiration of Tomato (Solanumm Lycopersicum) Using Atmometer in The Upland Rolling Production Area

Abstract

Objective : The goal is to provide the right amount of water to the crop, at the right time, to meet the crop's needs. It was conducted to estimate evapotranspiration using atmometers for irrigation scheduling that may be highly beneficial in soil water balance, water allocation and budgeting, irrigation management, and improving crop yield and production for greater income. Methods: This study was conducted at the Organic Agricultural Research and Development Innovation Center at the Bataan Peninsula State University – Abucay Campus, Bangkal, Abucay, Bataan, Philippines (North 14°44'28” East 120°27'04”). The effects of using different evapotranspiration estimation methods on the timing and amounts of water application were then evaluated by using a computed irrigation scheduling model. Findings: The atmometer ( and Penman-Monteith ( values were statistically analyzed using linear regression (y=0.8573x + 1.586), coefficients of determination (R² = 0.7236), root mean – squared error (RMSD = 0.73), mean bias error (MBE = 0.03), and the t-statistics (significant at 5% level). The study revealed that the ETo-A data strongly correlated with the ETo-PM data. Using an atmometer for scheduling irrigation on tomatoes would have resulted in an equally similar distribution of irrigation events, more water would have been provided throughout the season compared to using ETo-PM data. Novelty : The calibrated evapotranspiration data from the atmometer may guide appropriate irrigation depth and schedule for tomatoes. By aligning irrigation intervals with other crops’ water requirements, farmers can optimize water usage, minimize water stress, and achieve higher crop yields. Keywords: Atmometer, Bataan Philippines, Evapotranspiration, Tomato, Penman-­Montheith Equation