a method for controlling the growth of destructive insects and microorganisms in ground soil , includes the step of adding chitin to ground soil for inducing bacteria in the ground soil to synthesize chitinase for controlling the spread of destructive insects and microorganisms therein . the chitin may be added to the ground soil by distributing it on the upper surface of the soil or , preferably , by incorporating into the soil . in a preferred embodiment , the step of deacetylating the carbohydrate chains of the chitin for is carried out before adding to the ground soil for increasing the aqueous solubility of the chitin by producing smaller polymeric units or by increasing the availability of polar hydroxyl groups on glucosyl moieties thereof . various bacterial cultures may also be added to the chitin prior to its distribution on , or incorporation in , the ground soil . a method for using dried shrimp shells for the production of an economically - viable non - genetically - modified organism - based chitinase lawn and garden fermentation broth , for eventual addition to ground soil for controlling the growth of destructive insects and microorganisms in ground soil , is also provided .