Abstract: Soybean meal and urea compositions have been found to exhibit enhanced and commercially useful nematistatic and nematicidal activity in soils. Chitin-containing materials, e.g., crab shells, shrimp shells, fungal mycella, etc., have also been found to exhibit enhanced and commercially useful nematistatic and nematicidal activity in soils when admixed with other organic nitrogen-containing materials such as ammonium phosphates, a source of urea, and plant, fish or animal meal. Also, compositions formulated of two different chitin source materials can be used. The soybean-urea compositions as well as the blended chitin-containing formulations are non-phytotoxic and simultaneously provide cost-effective biological suppression of plant pathogenic nematode populations and excellent plant nutrition.