Problems and Measures of Improving Water Use Efficiency at Fields in Iran

Development of agriculture and sustainable crop production in the arid and semi-arid regions depends mainly on improving water productivity (WP) at the field scale¡ which is referred to as water use efficiency (WUE). The WUE index is indicative of the amount of crop produced per unit amount of water consumed at the field level. This index increases with the increase in crop yield¡ reduction in water used¡ and both of the effects of these two factors together. The issues and sources of inefficiencies leading to the low values of WUE at the field scale could be various. The field scale is the domain which all of the agronomic practices¡ including land preparation¡ cultivation¡ crop treatments¡ and crop harvest occur in this environment. Moreover¡ the field is the place which all of the water management activities¡ from the source of water to the location of consumption¡ are all for this place. Therefore¡ the problems and issues of this water management scale directly and significantly affect on the extents of water use and the yield¡ which is the final goal of the producers. Considering interrelation and linkage of different scales¡ the issues of the field scale¡ causes higher scale problems¡ e.g.¡ environmental pollution¡ over exploitation of water resources¡ and socio-economic problems.Through facilitated brain storming meetings and harvest of the ideas of experts¡ resource persons¡ and the stakeholders from water management sector in general and the agricultural water in specific¡ the issues¡ problems¡ and challenges regarding improvement of WUE in the field scale in Iran were systematically and in a participatory way was identified. The experts were gathered and participated in the different brain storming meetings to identify the relevant problems¡ issues¡ and the challenges. The research outputs were mainly in the form of problem-tree. However some related measures and strategic executive and research pivots and objectives were also developed.Based on the results¡ the main sources of inefficiencies in field-scale WP (WUE) could be summarized in six main category as: 1) Low irrigation efficiencies¡ 2) Inadequate sources of reliable irrigation water resources¡ 3) Low quality of soil and water resources¡ 4) Low values of mechanization indices¡ 5) Problems associated with the irrigation systems¡ 6) Low levels of farmer’s knowledge and skills. From quantitative aspects¡ the number of problems in each of the six categories included 10.9¡ 9.3¡ 13.9¡ 39.5¡ 17.1¡ and 9.3 percent of the total problems respectively. From the strategic view points¡ the results of this research indicated that the issues and measures of improving WUE should not only followed in the water management sector but the agronomic issues and measures¡ especially agricultural mechanization¡ also play and important role in this aspect.