Abstract: Aims Sand cover conditions in arid zones significantly affect soil water status, which in turn affects the utilization of soil water by vegetation. However, little is known about the water uptake strategies of ZiZiphus jujuba under different sand cover conditions and its dynamic response to input water. Methods In this study, the water utilization strategies of Z. jujuba under different sand cover thicknesses and their responses to input water were investigated using the hydroxide stable isotope method combined with a Bayesian mixed model (MixSIAR) in May 2023. Important findings The peak of soil water content (SWC) appeared on the 2nd day after irrigation in the non-sand-covered sample plots, on the 4th day after irrigation in the 5 cm sand-covered sample plots, and on the 6th day after irrigation in the 10 and 15 cm sand-covered sample plots, and sand-covered significantly increased the SWC, and enhanced the water retention of the soil. The δ18O and δ2H were -5.4‰– -2.2‰ and -76.1‰– -61.0‰ in the non-sand-covered sample plots, and -5.6‰– -3.0‰ and -61.0‰– -75.7‰ in the sand-covered sample plots, respectively. After the occurrence of irrigation, the percentage of water utilisation by date palm in the 0–10 cm soil layer without sand cover (16.2%, 9.1%, 10.0%) was stable compared with that in the sand-covered sample plots (73.0%, 54.5%, 37.0%; 49.0%, 46.2%, 22.8%; 27.1%, 36.1%, 21.4%) and sand-covering measures increased the date palm's water utilization of the 0–10 cm soil water. The sand mulching measures increased the utilization of 0–10 cm soil water by date palm, i.e. there was a lag in the utilization of deep soil water by date palm. The above results show that sand mulching can effectively improve the water retention of soil and influence the water utilization strategy of plants, which is conducive to the adaptation of plants to local drought conditions and other environmental changes.

Key words: isotopes, sand cover thicknesses, Bayesian modeling, soil moisture, ZiZiphus jujuba, water utilization