Exposing soybean seedlings to wind or to wind plus sand at a windspeed of 13.4 m/sec for up to 40 minutes decreased nitrate reducíase activity and increased nitrate content immediately after exposure. Enzyme activity immediately after exposure was lower in damaged seedlings than in the untreated check, but after 24 hours the check had the lower activity. The enzyme activity and nitrate concentration remained higher in damaged seedlings than in the check for up to 40 days after exposure.