English

Mohammed Al Ghobari Hussein,Said Abdalla El Marazky Mohamed

doi:10.5897/ajar11.2194

Abstract

This study evaluated the wetting patterns around drip and subsurface irrigation systems (DI and SI), respectively with three irrigation scheduling techniques. The drip and subsurface irrigation systems were used to irrigate a tomato crop. The wetting patterns for each irrigation system and each irrigation scheduling technique was evaluated below the soil surface at different distances and depths from the emitter 24 and 48 h after irrigation. The soil moisture distribution patterns showed that the vertical movement of soil moisture was higher than the horizontal movement under both DI and SI systems. The overall wetted area, delimited by the wetting front was largest for the manually controlled irrigation scheduling with both DI and SI, and smallest for the Smart controller irrigation scheduling under both DI and SI systems. The effect of irrigation scheduling techniques on the water distribution pattern varied at different soil depths. Average coefficients of uniformity values for the DI and SI systems were 84.32 and 88.72%, respectively. The coefficients of uniformity for SI were higher by approximately 4.40% than for DI for all irrigation scheduling techniques, although there was variation in Cus values between the DI and SI systems with all three techniques. It can be concluded that a parameter related to the soil water content is an important consideration in estimation of soil wetting patterns with both DI and SI systems. The results of this research can be used in the design, operation, and management of DI and SI systems. Key words: Drip irrigation; subsurface irrigation; Soil water; Wetting pattern; coefficient of uniformity, Irrigation scheduling techniques.

Highlights

Water is one of the most precious and heavily scrutinized natural resources worldwide, in arid regions, and improving agricultural water use efficiency is vitally important in parts of the world that have limited water resources
The soil water distribution pattern showed the highest water content near the drip line under the subsurface irrigation (SI) system for all scheduling techniques, with the water content increasing with distance and depth in both lateral and perpendicular directions 24 h after irrigation
With the SI system, variations in soil moisture occurred in terms of lateral and perpendicular movement above and below the drip emitters and at different radial distances from the drip emitters in the root zone (10 to 50 cm depth and 20 cm around the plant root) for both 24 and 48 h after irrigation for the different irrigation scheduling techniques

Summary

Introduction

Water is one of the most precious and heavily scrutinized natural resources worldwide, in arid regions, and improving agricultural water use efficiency is vitally important in parts of the world that have limited water resources. Innovative irrigation solutions must address the water scarcity problems affecting arid countries. The type of irrigation system is important and the availability of suitable irrigation systems barely meets the needs of agricultural expansion. Irrigation water is rapidly becoming the primary limiting factor for crop production. Goldberg et al (1976) described how measuring the consumptive water use of crops grown under protected conditions is a good approach to improve water management and achieve optimum water use efficiency. Drip irrigation (DI) and subsurface irrigation (SI) systems were proven to increase water productivity (Mailhol et al, 2011)

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