Drought and water scarcity are currently the main problems facing dryland sustainable agriculture. Thus, this research aims to assess the impact of three forms of mulching [transparent plastic mulch (TPM), wheat straw mulch (WSM), and bare soil (BS)] and three different application rates of polyacrylamides (PAMs at 0, 10, and 20 kgha-1) under three levels of deficit drip irrigation (DI at 60, 80, and 100% of crop water requirement) on the productivity of squash plants, water use efficiency (WUE), and soil properties. Using a split-split plot design with three replications, the experiment was carried out in Hada Al Sham, Jeddah, Saudi Arabia, during the planting seasons of 2023-24 and 2024-25. The results of the study demonstrated that combined and independent treatments of PAMs and mulching under deficit drip irrigation contributed significantly to increasing the yield and WUE of squash while enhancing soil properties in both seasons. Compared with the control (without PAMs), the number of fruits per plant increased significantly by 12.19% and 22.72%, respectively, in the 2023-24 and 2024-25 seasons when PAMs were applied at a rate of 20 kgha-1. When compared with the control (BS), TPM and WSM significantly increased fruit yield by 61.32% and 24.44%, respectively, compared with control in the 2023-24 season. Similarly, compared with the control, PAMs at 20 and 10 kgha-1 increased fruit yield by 16.11% and 8.78%, respectively. However, compared with 100% and 60% DI in the 2023-24 season, 80% of DI helped to raise WUE by 12.82% and 25.71%, respectively. In comparison with BS, WSM increased the amount of organic matter in the soil by 50.0% and 28.57% in the 2023-24 and 2024-25 seasons, respectively. In the squash field, mulching and PAMs resulted in substantial increases in N, P, K, S, Zn, Mg, and B in the experimental soil. In drylands, combining PAMs and mulching improves soil quality and increases squash plant productivity.