Date Palm Production and Water Productivity Under Subsurface Drip Irrigation System

Abstract

The majority of date palm cultivation in Oman is irrigated using flood irrigation method and just limited area irrigated by Bubbler Irrigation (BI) system. Subsurface Drip Irrigation (SDI) has been proved as a water saving method that increase both crop production and Water-Use efficiency (WUE). However, it is being not tested for date palm irrigation. An experiment at Al-Kamil Research Station in Al-Sharqiyah North governorate was conducted from 2013 to 2016 to evaluate subsurface drip irrigation system in terms of date palm production and Water Productivity (WP) for date palm irrigation and compared with bubbler irrigation system which is recommended for date palms irrigation. Four irrigation treatments were 100% ETc using bubbler irrigation, 60%, 40% and 20% ETc Subsurface irrigation system. Irrigation scheduling was developed based on crop evapotranspiration (ETc= ETo x Kc), ETo was calculated by Penman-Monteith equation on CROPWAT program using climatic data from nearby weather station. Crop coefficient was taken to be 0.90 (FAO, 1991). The results show no significant differences in fruit production between date palm trees irrigated by 100% ETc using bubbler system and those irrigated with 60% of the water requirement under sub-surface drip irrigation system. Fruit production was significantly reduced under the irrigation with 40% and 20% of ETc under sub-surface drip irrigation system as compared to that irrigated with 60% ETc. The highest WP of 4.7 kg/m3 was obtained at the rate of 20% of the water requirements under sub-surface drip irrigation system. All the results proved that sub-surface drip irrigation system contributes to 40% water saving without reduction in fruit production of date palm trees.