During any year in which no set-aside or diversion of acreage is in effect under the Agricultural Act of 1949 [
7 U.S.C. 1421 et seq.], the Secretary of Agriculture may formulate and administer a program for the production, subject to such terms and conditions as he may prescribe, of commodities for conversion into alcohol or hydrocarbons for use as motor fuel or other fuel. Under such program, producers of wheat, feed grains, upland cotton, and rice shall be paid incentive payments to devote a portion of their acreage to such production.