Desalination and Water Treatment www.deswater.com doi: 10.5004/dwt.2020.25517 Presented at the 13th Gulf Water Conference – Water in the GCC: Challenges and Innovative Solutions. 12–14 March 2019, Kuwait 1944-3994/1944-3986 © 2020 Desalination Publications. All rights reserved. Improvement of water and energy use in sprinkler irrigation under semi-arid conditions Samir Yacoubi a , Adel Slatni a , Ali Chebil a , Khemaies Zayani b a National Research Institute for Rural Engineering, Water and Forestry, INRGREF, BP 10 Ariana 2080, Tunisia b Ministry of Agriculture, Water Resources and Fisheries/National Agronomic Institute of Tunisia (INAT), Tunisia abstract This study aims to assess the impact of sprinkler irrigation performance on the energy requirements of solid-set sprinkler irrigation systems. For this purpose, a methodology to evaluate the energy requirements for solid-set sprinkler systems was proposed. Experimental and simulated irrigation data were used to analyze the impact of water application efficiency on the energy required to distrib- ute water on soil surface. Results show that the decrease in the water application efficiency from 81% to 69% due to deep percolation losses over the potato irrigation season greatly increases the water distribution energy (34.4%) with an increase in the energy cost (kWh per ton) of 22.4% as well as a reduction of 18% in the water use efficiency. Results indicate also that improvement of water appli- cation efficiency of irrigated tomato from 74.1% (day irrigation) to 86.8% (night irrigation) induced a reduction in the energy cost (kWh per ton) of 22.8% although the net seasonal irrigation depth for night time was larger than that for day time due to the decrease in wind drift and evaporation losses. Keywords: Sprinkler irrigation; Energy; Application efficiency; Water distribution 1. Introduction For the majority of the Mediterranean countries, scarcity of water resources, the ever-growing water demand and the increase in irrigation acreages make of rational water use a major concern. This objective may be achieved using pres- surized irrigation systems (sprinkler and drip irrigation). Playán and Mateos (2006) indicated that improvement of the irrigation performance depends on the appropriate choice of the equipment according to the soil and climate characteristics, water availability and socio-economic con- ditions. According to Keller and Bliesner (1990), distribu- tion uniformity, wind drift and evaporation losses (WDEL) as well as application efficiency are the prominent perfor- mance factors in the design and management of sprinkler irrigation systems. Clemmens and Dedrick (1994) indicated that when appropriately designed and managed, sprinkler irrigation systems can reach irrigation efficiency greater than 80%. Burt et al. (1997) reported that sprinkler irriga- tion performances are affected by climatic and technical factors such as wind speed, operating pressure, sprinkler characteristics and sprinkler spacing. Under sprinkler irri- gation, the farmer is often faced to an economic dilemma. Indeed, under-irrigated areas results on a reduction of crop yield and inputs (fertilizers, phytosanitary products, etc.). Conversely, over-irrigation increases the cost of water pumping and can lead to yield losses by asphyxiation, leach- ing of nutrients, and may even lead to contamination of groundwater. It is worthy to say that switching from surface to pres- surized networks results in additional costs of investment, pumping and maintenance. Regarding the implication of sprinkler irrigation uniformity on water productivity, eco- nomic analysis results of Berman (2008) indicates that there are clear incentives for adopting more water-efficient sys- tems despite the higher capital cost, because of the depress- ing effect of overwatering on crop yield. Under irrigation modernization process in Spain, Corominas (2010) reported that for the period 1970–2007, water consumption per hect- are was reduced by 21%, while energy demand increased by 657%. Because of scarcity of water resources, Tunisian authorities have adopted a national program for water