A comparative study on energy and water use indicators for soybean production under different irrigation systems in Iran

In this study source wise and operation wise energy consumption for soybean production under canal and pump irrigation system conditions were investigated. Also energy and water indicators were analyzed to better understand the main effects from utilization of different irrigation systems on water and energy use. For these purposes data were collected from 94 soybean producers in Golestan province of Iran, using a face to face questionnaire method. The results revealed that under pump and canal irrigation conditions the total energy input was 38266.71 and 17255.96 MJ ha⁻¹, and energy use efficiency was 2.14 and 4.62, respectively. The three major energy consumer inputs under pump irrigation system were electricity, fertilizers and diesel fuel; while in canal irrigation conditions they were fertilizers, diesel fuel and indirect energy of irrigation, respectively. On the other hand, water energy use efficiency was calculated as 3.68 and 29.94 for pump and canal irrigation conditions, respectively. Water energy ratio under canal irrigation was found to be 58.23%, from which the shares of direct and indirect energies of irrigation were 49.08% and 9.15%, respectively; while under canal irrigation conditions it was found to be 15.42% and the contribution of direct energy compared to indirect energy for irrigation was relatively low. In order to reduce energy consumption and improve energy use efficiency and water productivity, it is suggested to use canal irrigation systems, design suitable schemes for high irrigation efficiency and to improve the energy use efficiency for of water pumping systems.