Where a lot on which is located an industrial use abuts or adjoins any residential district, a landscaped buffer strip shall be provided, located on the industrial lot for the full length of the district boundary line. It shall be at least 15 feet in width, devoted to screen planting, and at least six feet in height except where the buffer strip adjoins the front lot line. It shall not be used for parking, loading or unloading, and shall not be included in the measurement of any minimum yard.