Study on Soil Moisture Depletion Pattern of Wheat Under Different IW/CPE Ratio

Wheat is one of the most important cereal crops and staple food of nearly 35 percent of the world population. In climatologically approaches, irrigation is scheduled on IW/CPE ratio. In IW/CPE approach, known amount of irrigation water is applied when cumulative pan evaporation reaches predetermined level. The experiment was conducted in randomized block design with irrigation scheduling on climatological approach i.e. on IW/CPE ratios of IW/CPE=0.6, IW/CPE=0.8, IW/CPE=1.0, IW/CPE=1.2 and control treatment with six irrigations at critical growth stages of wheat. Seasonal water requirement of wheat was found to be highest (570 mm) under irrigation scheduling at control treatment (I 4). Favorable soil moisture was maintained in the irrigation scheduling treatment of IW/CPE=1.2 (I 4) throughout the growing period and it was always maintained in allowable depletion regime. However, soil moisture was inadequate in irrigation scheduling at IW/CPE=0.6 (I 1). Highest water use efficiency was recorded in treatment I2 which may due to lowest water use, followed by I 3, I 4, I 1 and I 5.