There is allocated to the Secretary of Commerce for each fiscal year, beginning with the fiscal year beginning July 1, 1938, out of funds appropriated for such fiscal year pursuant to section
1391 of this title, or section
590o of title
16 the sum of $1,000,000 to be expended for the promotion of the sale of farm commodities and products thereof in such manner as he shall direct. Of the sum allocated under this subsection to the Secretary of Commerce for the fiscal year beginning July 1, 1938, $100,000 shall be devoted to making a survey and investigation of the cause or causes of the reduction in exports of agricultural commodities from the United States, in order to ascertain methods by which the sales in foreign countries of basic agricultural commodities produced in the United States may be increased.