Recently, using superabsorbent polymers (SAPs) are considered as a solution for reducing the water consumption particularly in agricultural applications. Presented here is the synthesis of a novel biocompatible SAP, utilizing for reducing the water consumption particularly in agricultural applications via graft copolymerization of hydroxypropyl distarch phosphate (HDP) based on tapioca starch with acrylic acid (AA), loading with clinoptilolite zeolites. A two‐level factorial design of experiments, investigating the effect of the SAP composition on the water absorbency exhibited that the optimum SAP has the maximum water absorbencies of 1075 and 67 g g−1 in distilled water and 0.9 wt % NaCl solution, respectively. The chemical structure of the best superabsorbent was characterized using Fourier transform infrared, X‐ray diffraction, thermogravimetric analysis, and scanning electron microscopy analyses. The results revealed that AA was successfully grafted onto HDP and surface morphology of the superabsorbent was improved with incorporated clinoptilolite zeolites. In addition, the results of water absorption in different soil textures showed that within a first week after irrigation, the soil texture with 100% sand has the maximum water retention (69.6 g more than its control sample), as well as that with 50% sand, loses the absorbed moisture 49 days later than its control sample. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47365.