7 U.S.C. § 1339c

Effective with the 1964 crop, during any year in which an acreage diversion program is in effect for feed grains, the Secretary shall, notwithstanding any other provision of law, permit producers of feed grains to have acreage devoted to the production of feed grains considered as devoted to the production of wheat and producers of wheat to have acreage devoted to the production of wheat considered as devoted to the production of feed grains to such extent and subject to such terms and conditions as the Secretary determines will not impair the effective operation of the program for feed grains or wheat. In establishing terms and conditions for permitting wheat to be planted in lieu of oats and rye, the Secretary may take into account the number of feed units per acre of wheat in relation to the number of feed units per acre of oats and rye.