A cultivation air seeder has an ornamental facing around three sides of its large, metallic bulk seed hopper to enhance the appearance of the hopper and provide environmental protection for sensitive mechanical, electronic and hydraulic components. A front section of one facing panel on each side of the machine is hinged about a generally upright axis to allow the panel section to be opened and closed like a door for operator access to the components behind it. The facing can be stylishly molded from a synthetic resinous material or other non-metallic substance to facilitate manufacture and is disposed to conceal unsightly weld lines and other imperfections on the exterior surface of the hopper.