Abstract: Bioactive substances are imbedded or mixed into functionalized matrices to form homogenous water-insoluble solid complexes with desirable field properties such as reduced leaching in soil, improved leaf retention (rainfastness), selective unloading to roots and convenient packaging and application. Bioactive substances that may be so complexed include pharmaceutical agents and pesticides including herbicides, insecticides, bacteriocides, rodenticides, nematicide and fungicides. The matrices comprise either a monomeric-, oligomeric- or (co)polymeric backbone which may be derivatized with chemical groups that exhibit ionic (amines, carboxyls), hydrophobic, and ligand-binding interactions to form the matrix of the formulation. The various matrices may be mixed with additives or modifiers, grafted, or fused to obtain optimal properties. The matrix/pesticide formulations may be applied as granules, as suspensions, emulsions in sprays, as foams, or as coats for seeds and fertilizers.