Water saving in arid regions: a comparison of surface and subsurface drip irrigation systems for irrigation of date palms

Abstract

Surface and subsurface drip irrigation methods can play a significant role in overcoming the scarcity of water mostly in water shortage areas. A field study was conducted to investigate the effectiveness of surface and subsurface drip irrigation systems, in terms of both water use requirement and yield of date palms at Al-Hassa, Saudi Arabia. Mature palm trees of Khalas variety with 8 m spacing for both row to row and tree to tree were selected. Irrigation scheduling was done through evapotranspiration (ET)-based sensors as well as crop water requirement guidelines for Kingdom of Saudi Arabia to ensure enough soil water levels in the soil. Statistical testing indicated that methods of irrigation had not noticeable effect on agronomic traits of date palm trees in response to water applied, where decreasing water supply from 100% of crop evapotranspiration (surface drip) to 70% of crop evapotranspiration (subsurface drip) did not show any significant differences in yield, fruit weight, fruit length and fruit diameter. The water use efficiency was significantly increased by 27% more in case of subsurface drip (1.32 kg m-3) compared to surface drip irrigation system (0.96 kg m-3). Subsurface drip irrigation system was additionally found to be the favorable in respect of economic analysis to save 30% of the applied irrigation water at the time in which produced almost the same net profit.