TECHNOLOGY FOCUS - AGRICULTURE - Preferred Components: The base material comprises one or more of lignins, polysaccharides, natural polymers having glycosidic bonds, proteins, polypeptides and polynucleotides; and includes (II). The functional groups are pyridine, acrylamide, guanidine, triazole, urea, imine, carbamate, urethane, carboxy and/or sulfo groups; and may be present on a film or coating component as well as the base material. (I) is in the form of one or more of loose powder, foam, foamed natural polymers or natural/synthetic polymer mixtures, compacted pellets, gels, granules, injection moldings, extrudates, textile structures and/or other geometric structures.Preferred Composition: (I) optionally further contains one or more of: (A) (in)organic materials providing active agent-containing decomposition products and/or storing active agents, specifically (i) fibrous structures, plant components (or derivatives) and/or inorganic materials such as clays, clay minerals, layered silicates, stone, slag, ground rock, metals and/or minerals and/or (ii) ion binding capacity increasing fillers (specifically sparingly soluble salt forming agents), inclusion complex formers (e.g. cyclodextrin) and/or further ion immobilizing agents; (B) biodegradable microspheres containing bacteria (specifically nitrogen fixing bacteria), fungi, fungal spores, sterilizing agents, plant hormones, vitamins, aminoacids, insecticides, fungicides, pesticides and/or nematocides); and (C) release and/or biodegradation controlling components (specifically films or coatings).Preferred Process: (II) Is produced by radiochemical treatment (specifically using electromagnetic radiation, especially gamma-radiation) in presence of monomeric and/or short-chain compounds. ACTIVITY - Fertilizer.    MECHANISM OF ACTION - Controlled release fertilizing ion source.    EXAMPLE - Lignin powder was impregnated with a quaternized methacrylate monomer, radiochemically functionalized and contacted with a liquid to absorb ins. The anion uptake capacity was dependent on the amount of functionalized monomer used.