Soil nematode control techniques are established, the technique comprising diffusing uniformly 16-membered ring macrolide compounds which affect various organisms including nematodes at low concentrations, are hardly dissolved in water, and have a high soil adsorption within a treatment area, which technique is easy to use and eliminates the effect against organisms in the surroundings. By spraying an emulsion of the 16-membered ring macrolide compound with a water-soluble solvent to the soil surface and then mixing the emulsion with the soil or by mixing a granule adhering such the emulsion to a mineral carrier with the soil, soil nematodes parasitized crops are controlled as preventing seepage of the agent to an area outside of the treatment area.
