Micro-Sprinkler Irrigation Efficacy: A Meta-Analysis of Water Productivity and Salinity Mitigation for Date Palm Smallholders in the Draa Valley, Morocco

{ "background": "In arid regions such as the Draa Valley, date palm cultivation faces severe challenges from water scarcity and soil salinisation. Traditional flood irrigation methods are inefficient and exacerbate salinity, threatening smallholder livelihoods. Micro-sprinkler irrigation is promoted as a water-saving alternative, but its aggregated efficacy for this specific agro-ecological context lacks comprehensive synthesis.", "purpose and objectives": "This meta-analysis quantifies the effect of micro-sprinkler irrigation on water productivity (WP) and salinity mitigation in date palm systems for smallholders in the Draa Valley. It aims to provide a robust evidence base for irrigation policy and practice.", "methodology": "A systematic review identified relevant field studies. A random-effects meta-analysis model, $\\hat{\\theta} = \\sum wi yi / \\sum wi$, where $wi = 1/(v_i + \\hat{\\tau}^2)$, was used to pool standardised mean differences (Hedges' g) in WP and soil electrical conductivity (ECe). Heterogeneity was assessed using the I² statistic, with sensitivity analyses conducted to evaluate publication bias.", "findings": "Micro-sprinkler irrigation significantly increased water productivity by a pooled mean of 32% (95% CI: 24% to 40%) compared to traditional flood irrigation. A moderate reduction in root-zone salinity (ECe) was also observed (Hedges' g = -0.65, 95% CI: -0.92 to -0.38), though heterogeneity was high (I² = 67%).", "conclusion": "Micro-sprinkler systems are a technically effective intervention for enhancing water use efficiency and moderately mitigating salinity in date palm cultivation within the studied region. The high heterogeneity in salinity outcomes indicates important context-dependent factors.", "recommendations": "Policy should support targeted subsidies and training for smallholders to adopt micro-sprinkler technology. Further research must identify site-specific factors, particularly soil texture and groundwater