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) making a furrow in a cultivated land; B) seeding the furrow formed in the foregoing step with corn; C) applying to the furrow one or more selected from Compound Group (II), or C′) applying to the furrow one or more selected from Compound Group (I) and one or more selected from Compound Group (II); and D) closing the furrow. Compound Group (I): clothianidin, thiamethoxam, imidacloprid and thiacloprid; Compound Group (II): bifenthrin, bioresmethrin, deltamethrin, bioallethrin, ethofenprox, fenpropathrin, cypermethrin, alpha-cypermethrin, zeta-cypermethrin, fenvalerate, esfenvalerate, cyfluthrin, beta-cyfluthrin, alpha-cypermethrin, tralomethrin, fluvalinate, permethrin, lambda-cyhalothrin, flucythrinate and tefluthrin.