Deficit irrigation and water productivity of date palms in Al-Qassim oasis, Saudi Arabia
Аннотация
Date palm orchards in the Al-Qassim oasis face chronic water scarcity, rising pumping costs, and salinity risks from arid climate and groundwater dependence. This study evaluates regulated deficit irrigation to raise irrigation efficiency and water productivity without degrading fruit yield and quality. Using open climate and groundwater data and a two-season before-after panel of commercial orchards, we compare full irrigation at one hundred percent of crop evapotranspiration with seasonal deficits of twenty-five and forty percent delivered by drip systems. Measured outcomes are applied water per tree, midday stem water potential, fruit set, fresh yield, total soluble solids, irrigation water productivity, and leaching fraction. A water-smart performance index and cluster analysis benchmark treatment effects. Moderate deficit reduced withdrawals and preserved yield while increasing sugar content and water productivity, whereas severe deficit caused diminishing returns and salinity accumulation. Findings provide guidance for oasis agriculture that aligns conservation with profitability and resilience.