Polyacrylamide/poly(ethylene oxide) (PAAm/ PEO) crosslinked hydrogels were designed for controlled delivery of an herbicide, Atrazine, which is used in the agricultural field. Atrazine was incorporated into a PAAm/PEO matrix during an electron beam irradiation process. The Atrazine release rate from matrices prepared under different conditions was studied to determine which factors have the most affect and control over the PAAm/PEO matrix release property. The copolymer blend composition, copolymer gel content, and irradiation dose greatly affected the Atrazine release rate. In addition, its release rate was influenced by the pH and temperature of the matrix-surrounding medium. The Atrazine release rate decreased as the pH increased, but it increased as the temperature increased. The properties of the prepared crosslinked hydrogels may make them acceptable for practical use as bioactive controlled release matrices. (c) 2005 Wiley Periodicals, Inc.