MEMBRANE-ENCAPSULATED CONTROLLED-RELEASE UREA FERTILIZERS BASED ON ACRYLAMIDE COPOLYMERS

About 40-70% of the applied urea fertilizer is lost to the environment , causing serious pollution. Controlled-release technology is useful i n increasing the efficiency of fertilizer urea as well as in checking environment pollution. Four laboratory-level controlled-release urea f ertilizers were formulated based on polymers which are soil conditione rs and then evaluated for their slow-release property. Urea was coated with the copolymer of acrylamide and ne/N,N'-methylenebisacrylamide/t etraethyleneglycol diacrylate or pentaerythritol triacrylate and seala nt materials (wax and polystyrene). Urea coated with copolymer of acry lamide-tetraethyleneglycol diacrylate was found to be having a better slow-release property among the systems prepared. (C) 1996 John Wiley & Sons, Inc.