Evaluation of economical water productivity index of single irrigation management for two rainfed wheat varieties (Case of study: Maragheh)

The effects of planting date and single irrigation (SI) allocation scenarios on increasing and stability of yield were investigated to determine the total water productivity and economical water productivity (WPe), for rainfed wheat at Dryland Agricultural Research Institute in Maragheh, Iran, during 2000-2004. The treatments included three sowing dates (early, normal and late), four allocation scenarios of single irrigation (Rainfed, 50, 75 and 100 mm SI at planting time) and two wheat varieties. The partial budgeting method, marginal benefit – cost ratio, different states of water and irrigation prices, were used for evaluation of combined treatments. Single irrigation at planting time is an economical option at this region. Maximum total water productivity (5.3 kg.mm-1.ha-1), maximum net benefit (4191038 Rials.ha-1), maximum net benefit per irrigation water use, economical water productivity (13970 Rials.mm-1) and maximum benefic - cost ratio (2.28) obtained at this single irrigation allocation scenario.