Increased organic matter concentration and decomposition boost nitrogen and phosphorus levels. Because some nematodes prey on other animals, they can be useful for control of pest insects. Nematodes are also being investigated for their potential as biological controls for noxious weeds. Nematodes aren't all good guys. Nematode infestations can be identified by yellowing, stunted plants that grow in sparse stands.
Research is underway to develop plants that can resist nematode predation.
Freckman, Diana W., ed. Nematodes in Soil Ecosystems. University of Texas Press. 206 p. Freckman, Diana W. 1988. Bacterivorous nematodes and organic-matter decomposition.