Evaluation of the scheduling of an existing drip irrigation network: Fadak Farm, Karbala, Iraq

Abstract

Abstract Iraq has a subtropical semi-arid climate; it was previously considered to be rich in water, but for several reasons, including climate change and dam construction by neighbouring countries, a shortage of water resources has developed in recent years. Using the drip irrigation method is one of the most efficient ways to rationalise water consumption and avoid losses. This study was conducted in order to assess the scheduling of the drip irrigation system used on the Fadak farm in the holy city of Karbala in Iraq, in order to investigate irrigation scheduling there and to compare this with established irrigation scheduling parameters. This required the study of the physical properties of the soil and water consumption calculations for the palm trees being irrigated using the CROPWAT 8.0 simulation program. The results indicated that the volume of water actually supplied to each plot of around dunum( 2,500 m2) is 1,533.5 m3 annually, while the volume of water that should be supplied to the farm is 1,388 m3, suggesting that there is wastage of 145.5 m3, or 10.7%, annually. The monthly losses show that the irrigation scheduling system currently used on the farm exposes the plants to excess irrigation over many months, resulting in a loss of water, while causing plants to be exposed to a decrease in irrigation water, which causes stress, in other months. Using surface irrigation, the volume of water needed per dunum is 12,617 m3, however, causing water waste to the volume 11,229 m3. This study thus confirms the general efficiency of the drip irrigation system, as well as highlighting that the CROPWAT 8.0 program is useful for calculating water consumption.