Soil water distribution and dynamics across prescribed capillary barriers under evaporating surfaces. (February 2023)

• Record Type: Journal Article
• Authors: Al-Mayahi, Ahmed K.; Al-Ismaily, Said S.; Breitenstein, Daniel; Al-Busaidi, Hamed S.; Al-Maktoumi, Ali K.; Lehmann, Peter; Or, Dani; Kacimov, Anvar R.; Fahrni, Simon; Al-Shukaili, Afrah H.
• Is Part Of: Biosystems engineering. Volume 226(2023)
• Page Start: 55
• Page End: 70
• Publication Date: 2023-02
• Subjects: Evaporation -- Soil moisture -- Capillary barrier -- HYDRUS 2D/3D -- Capillary flow -- Column experiment; Bioengineering -- Periodicals; Agricultural engineering -- Periodicals; Biological systems -- Periodicals; Génie rural -- Périodiques; Systèmes biologiques -- Périodiques; 631
• DOI: 10.1016/j.biosystemseng.2022.12.010
• Languages: English
• ISSNs: 1537-5110

Abstract

Abstract : Engineering soil substrate using a porous composite constructed by a block-structured design (BSD), offers an innovative water-saving approach for high-cash crops in arid regions. We report modeling and experimental studies of the effects of two geometries: a single block (1L) and two stacked blocks (2L) BSD designs on evaporative losses and water distributions in laboratory column experiments involving wetting and evaporation cycles. A reasonable agreement between water content measurements and numerical simulations (HYDRUS 2D/3D code) is demonstrated (7.2E-2<RMSE<1.1E-1, -5.7E-1<NSE< 5.6E-1and 9.4E-1<d < 9.5E-1). The 2L-BSD showed three times slower evaporation rate than 1L-BSD during the drying phases. The presence of a horizontal sand layer at the middle of the 2L-BSD disrupted the hydraulic continuity to the surface, thus inhibiting evaporation from the bottom BSD in the 2L design. Our long term field experiment of 2L-BSD with date palm showed water savings of up to 13.3% to 52% than standard sand mulch soils. Our results illustrate the crucial role of porous media engineering in promoting infiltration after irrigation events or occasional rainfall and sheltering soil water smartly preserved in the root zone from evaporation that is of paramount importance for increasing water use efficiency in desert agriculture. Highlights: A novel water-saving engineered soil substrate is analyzed. Evaporation loss and water dynamics was quantified experimentally and numerically. Our agro-engineering substrate reduces evaporation and saves irrigation water. This capillary barrier-based porous composite is applicable to arid farming.