Document Type : Research Paper
Water Science and Engineering Department, Faculty of Agriculture, University of Zanjan, Zanjan, Iran.
National Planning Expert, Management and Planning Organization, Zanjan, Iran.
Department of Water Science and Engineering, Faculty of Agriculture and Natural Resources, Imam Khomeini International University, Qazvin, Iran.
Agricultural Extension and Rural Development, Agricultural Extension and Education Department, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran.
The present study was conducted to survey water use efficiency in onion production and field evaluation of its improvement strategies. In the first phase, 12 onion farms located in Zanjan plain were selected and studied. The factors related to productivity such as inflow discharge, water consumption, irrigation program, soil nutrition, crop yield, production costs and revenue were determined and then the physical and economic indicators of water productivity were calculated. In the second phase, irrigation management was implemented as a practical solution to improve water use efficiency in the control treatments and compared with the results from actual conditions. Based on the results of field monitoring, the average volume of water consumption in onion farms was obtained about 19626 m3/ha and the average water productivity indices CPD, BPD, and NBPD were calculated 3.14 kg/m3, 68 and 40 thousand Rials/m3, respectively. On average, implementation of proper irrigation program led to a reduction of 58 percent of water consumption and, consequently, an increase of 147 percent of the water use efficiency index in experimental farms. Using the wrong pattern in irrigation programming and lack of control and supervision over the exploitation of water resources were identified as the main reasons for excessive water consumption in onion farms. The results showed that only by correcting the irrigation time, the volume of water consumption can be reduced significantly and the water use efficiency can be improved.