Estimating Water Productivity in Vineyards under Surface and Drip Irrigation Systems

In this study, water productivity in six vineyards under surface and six under drip irrigation systems was measured in Zanjan Province, then, the effect of modified irrigation schedule to improve water productivity was investigated in two selected vineyards. The average volume of applied irrigation water in vineyards with surface and drip irrigation systems was 6929 and 5418 m3.ha-1, respectively. Also, the average of water productivity indices, Gross Benefit, and Net Benefit were obtained as 2.9 kg.m-3, 91.5, and 55.4 thousand Rials.m-3 in vineyards with surface system and 3.6 kg.m-3, 112.4, and 59 thousand Rials.m-3 in vineyards with drip system. In terms of water productivity index, drip irrigation was relatively superior to the surface method. In most of the monitored vineyards, the applied irrigation schedule was not in accordance with the net irrigation requirement. The results of the modified irrigation schedule indicated that water productivity could be improved by 24.7%.