Abstract
Water is one of the most essential parameters for crop production. There is a direct relation between crop yield and water use in plants. Agriculture in arid regions has special aspects. In these areas, agriculture is limited by water and irrigation. Therefore, agricultural practices are organized for optimum water use and maximum yield per unit volume of water which is used. Sprinkler irrigation is one of the methods which has important role in suitable use of water and increasing water use efficiency (WUE). In this research, water use efficiency and yield (quantity and quality) of sugar beet in sprinkler and furrow irrigation was studied in Mashhad, Karaj and Esfahan. In the first year, experiments were done in three locations based on T student test without replications. In the second year, experiments were done in three replicates with randomized block arrangement in Mashhad and Karaj. Irrigation treatments were sprinkler, conventional and cut back furrow irrigation. Water requirement in sprinkler irrigation treatment was calculated based on Penman-Monteith method. Ordinary furrow irrigation treatment applied according farmers' conventional methods. Also, cut back irrigation treatment was applied based on reducing irrigation discharge to 0.6-0.7 after delivering of water to the end of furrows. Results showed that there were significant different in root yield, net and gross sugar yield, water use efficiency and sugar content between experimental regions. However, there was significant difference in root yield and water use efficiency between irrigation treatments. The sprinkler irrigation treatment produced the highest root yield (56.5 ton/ha). The cut back and conventional furrow irrigation treatments produced root yield of 48 and 43.6 ton/ha, respectively and were place in the same statistical level. Root and gross sugar water use efficiency in sprinkler irrigation treatment were 5.55 and 0.86 kg/mЗ, respectively. This treatment was better and has significance difference with two other irrigation treatments. Although, cut beck irrigation had better performance compared to conventional furrow irrigation but in overall, sprinkler irrigation treatment had better performance in used water, irrigation efficiency, root yield, sugar yield and WUE with respect to furrow irrigations. According to obtained results, it is recommended that in regions with limited water resources, sprinkler irrigation has been applied for increasing yield and WUE. However, in region with limitation in application of sprinkler irrigation methods (such as high speed winds, heavy soils, etc.), it is recommended that modified furrow irrigation method such as cut back method has been applied for increasing irrigation efficiency and WUE.
Keywords: Sprinkler irrigation, Furrow irrigation, Water productivity, Sugar beet |
