The Secretary of Agriculture is authorized and directed, in cooperation with the land grant colleges and universities of the various States or, in his discretion, with other suitable State agencies, to aid farmers through advice, education, demonstrations, and other similar means in establishing, renewing, protecting, and managing wood lots, shelter belts, windbreaks, and other valuable forest growth, and in harvesting, utilizing, and marketing the products thereof. Except for preliminary investigations, the amount expended by the Federal Government under this section in cooperation with any State or other cooperating agency during any fiscal year shall not exceed the amount expended by the State or other cooperating agency for the same purpose during the same fiscal year, and the Secretary of Agriculture is authorized to make expenditures on the certificate of the appropriate State official that the State expenditures, as provided for in this section, have been made. There is authorized to be appropriated annually out of any money in the Treasury not otherwise appropriated, not more than $500,000 to enable the Secretary of Agriculture to carry out the provisions of this section.