Evaluating the Impact of Irrigation Water Blending Practices and Quality Enhancement on the Productivity of Date Palm (Phoenix dactyliferous L.) in Wadan, Libya.

الملخص

This study aimed to evaluate the impact of mixing irrigation water from shallow and deep wells and improving its quality characteristics on the quantitative and qualitative productivity of date palms (Phoenix dactylifera L.) in Waddan, Libya. The study employed a descriptive-analytical approach and a cross-sectional design. Experimental procedures involved collecting representative water samples from 12 groundwater wells (comprising both deep and shallow wells) to analyse physicochemical properties, specifically electrical conductivity (EC), pH, and major dissolved ion concentrations and to calculate chemical indices related to permeability and salinity, such as the Sodium Adsorption Ratio (SAR), the adjusted SAR (SARadj), and Residual Sodium Carbonate (RSC). The field survey steps also included distributing a questionnaire to a simple random sample of 40 farmers to document irrigation methods employed (such as surface irrigation using modern systems), water-mixing practices, and field treatments such as the application of acids and soil amendments.

Hydrochemical results indicate that the water falls within the sodium-sulfate classification, revealing a distinct chemical discrepancy between conventional SAR and SARadj values: the latter exceeds 20 in several wells due to elevated bicarbonate concentrations, suggesting a deterioration in soil permeability and structure. Conversely, all samples recorded negative RSC values ​​(reaching -19.19 meq/L), confirming an abundance of calcium and magnesium, which act as natural soil conditioners. Field observations revealed that surface basin irrigation is the prevailing method and that 95% of farmers encounter clear signs of salinity. While 82.5% of farmers employ water mixing as a strategy to reduce salinity levels,