Irrigation Efficiency, Water Requirement and Water Productivity in Surface Irrigation Method in Apricot and Grape Gardens

Increasing irrigation efficiency and reducing water losses in gardens is necessary due to the severe shortage of water resources in the country. In order to increase the irrigation systems efficiency it is necessary to evaluate them. For this purpose, 6 gardens with basin irrigation system were selected. The amount of irrigation water volume, depth of root development, yield, application efficiency (early, mid and late of the growing season) and water productivity were determined. Also, the water requirement was calculated by the Penman Monteith method using meteorological data (recent ten years) and compared with the values provided in the National Water Document. In apricot orchards, the average application efficiency varied from 43.3 to 58.4 percent (average of 49.7 percent) and in vineyards from 41.7 to 61.9 percent (51.4 percent on average). Deep percolation was the major portion of irrigation water losses in apricot and grape gardens by 49.7 and 51.4%, respectively. The average water productivity of these products was 0.78 and 5.2 kg.m3 respectively. The results showed that in gardens where land leveling and water supply of the trees were well done, irrigation efficiency and water productivity were significantly increased. Comparing the computational water requirement with the volume of irrigation water shows the imposition of deficit irrigation in these gardens. The results also showed that the computational water requirement was much higher than the values mentioned in the National Water Document, which highlights the need to update the National Water Document.