Vol. 9, Issue 3, Part I (2025)

A two-year research study (2020-2022) titled "Formulating Empirical Models to Optimize Mustard Irrigation Levels Using Energy Balance Residual and Benefit-Cost Analysis" was conducted at the IRS Farm of Sam Higginbottom University of Agriculture, Technology and Science, Prayagraj, Uttar Pradesh, India. The study focused on irrigation scheduling based on the Energy Balance Residual for the mustard crop, specifically the Varuna (T-59) variety. The experiment followed a randomized block design (RBD) with five irrigation treatments: I₁: λET = 1.75, total irrigation depth = 180 mm, I₂: λET = 1.5, total irrigation depth = 240 mm, I₃: λET = 1.0, total irrigation depth = 300 mm, I₄: λET = 0.755, total irrigation depth = 360 mm, I₅: λET = 0.5, total irrigation depth = 420 mm. Among these treatments, the highest yield (2.23 t/ha), 1000-seed weight (5.4 g), and harvest index (24.3%) were observed when irrigation was scheduled at λET = 1.5 with a total water depth of 240 mm (Treatment I₂). Additionally, the maximum benefit-cost ratio (BCR) of 3.43 was recorded under this treatment. Furthermore, the residual method of energy balance demonstrated a satisfactory correlation between the benefit-cost ratio and irrigation depth, with a coefficient of determination (R² = 0.6808).