Investigation of Irrigation Water Productivity in Sprinkler and Surface Irrigation Systems (Case study: Qazvin Plain)

Due to the quantity and quality limitations of available water resources, the measurement and analysis of water and economic productivity indices in various irrigation systems (including surface and pressurized systems) has a great importance. The objective of this study was to compare water and economic productivity of pressurized and surface irrigation systems. For this purpose, the data of irrigation systems as well as crop yield in Qazvin Plain in 2011 were used. The required data were collected using the survey in the studied fields, questionnaires, the design report of irrigation systems and Qazvin Agriculture Organization. The results showed that the irrigation water productivity for barley, alfalfa, maize and wheat was 0.75 to 2.5, 0.2 to 1.76, 0.3 to 2.78 and 0.61 to 2.2 kg/m3, respectively, in sprinkler irrigation systems. In surface irrigation system, the water productivity for barley, alfalfa, maize and wheat was 0.43 to 1.42, 0.12 to 1.64, 0.22 to 1.58 and 0.43 to 1.25 kg/m3, respectively. The minimum and maximum amounts of economic productivity of surface irrigation systems in Rials/m3 were 1387 and 4617 for barely, 382 and 5050 for alfalfa, 905 and 6474 for maize and 1447 and 4159 for wheat. The minimum and maximum values of economic productivity of sprinkler irrigation systems in Rial/m3 were 2442 and 8126 for barley, 673 and 5420 for alfalfa, 1283 and 11395 for maize and 2016 and 7319 for wheat.