A copolymer hydrogel consisting of Polyacrylic Acid (PAAc) combined with an irradiated solution of carboxymethyl cellulose (CMC, 1 wt%) was prepared. The focus was on controlling the radiation degradation of CMC by exposing it to different six doses of γ‐irradiation from 0 up to 3 kGy. After the irradiation process, the six CMC solution samples were mixed with 10 vol% of Acrylic Acid (AAc) monomer and re‐irradiated at a dose of 25 kGy to begin the polymerization process. A scanning electron microscope (SEM) was used to image the macroporous structure of the obtained (CMC/PAAc) hydrogel. Moreover, the SEM image confirmed the interpenetrating and semi‐interpenetrating polymer network structure based on the irradiation process. The controlled release of urea is achieved due to the binding between urea and the functional groups of the investigated hydrogel by hydrogen bonds. The growth of common bean plant (Phaseolus vulgaris L.) and chlorophyll contents were increased when soils were treated with (CMC/PAAc) compared with soils with free hydrogel in water‐stress conditions.