Provided is a method for reducing damage by harmful organisms in corn cultivation. Damage by harmful organisms in corn cultivation can be reduced by carrying out the steps of A) ditching a cultivated land B) seeding with corn a furrow formed in the foregoing step C) applying to the furrow an aqueous dispersion or aqueous solution of one or more selected from the below-mentioned compound group (I) and D) closing the furrow. Compound group (I): clothianidin, thiamethoxam, imidacloprid or thiacloprid.
