الملخص الإنجليزي
Finding new irrigating technologies that conserve water and prevent high evaporation rates is vital for home gardening in arid countries like Oman. Knowing the attitudinal and socio-demographic variables of the gardeners is necessary prior designing and applying such technologies. Objectives of this study were to: (i) identify home gardening characteristics, practices and evaluating gardener's perceptions about soil and water management, (ii) design and assess the effectiveness of Smart Capillary Barrier-Wick Irrigation system (SCB-W), a composite consisting of silt loam blocks surrounded by sand proppant, to conserve water, and (iii) model moisture dynamics, evaporation, and root water uptake (RWU) of the SCB-W system numerically using HYDRUS-3D. A sociological study using a questionnaire was conducted in 125 houses in A'Seeb area, Muscat Governorate, Oman. A pot experiment was carried out at the Agricultural Experimental Station, Sultan Qaboos University, Oman, to study the ability of SCB-W in conserving water compared to wick irrigation with homogenous soil (HW). The effect of the diameter of the wick cylinder and placing a mulched sandy layer on top of the soil composites were also investigated. HYDRUS3D was used to numerically simulate the effect of type of soil composite, i.e. SCB-W vs. HW, diameter of the wick cylinder on water dynamic and water conservation; and RWU of tomato and lettuce grown. Our study indicated that many home gardens owners are practising poor irrigation water managements, having a vague perception about crop water requirement, do not use any water-saving technologies, and hiring low-paid and not-qualified gardeners. Many gardeners highlighted the need for new technologies that save water and reduce their water bills. Based on the field experiments and numerical modelling, SCB-W stored 20% to 46% more soil water than HW. Application of SCB-W to A'Seeb area may save up to 2.6 million my of water annually that is equivalent to 1.3 million OMR. Modelling of RWU showed that plants grown in SCB-W experience less stress to water shortage. Depending on the type of plant, irrigation frequency in SCB-W can be reduced as compared with HW. Future work will include raising awareness among the gardeners and homeowners about the proper soil and water management, testing water use efficiency of the SCB-W system under field crop conditions, and improving the SCB-W design and evaluating its feasibility for home garden applications.
Keywords: Wick irrigation system; HYDRUS-3D; Irrigation efficiency; Water scarcity; Urban gardening.
