((a)) Notwithstanding any other provision of this Act, price support at a level in excess of the maximum level of price support otherwise prescribed in this Act may be made available for any agricultural commodity if the Secretary determines, after a public hearing of which reasonable notice has been given, that price support at such increased level is necessary in order to prevent or alleviate a shortage in the supply of any agricultural commodity essential to the national welfare or in order to increase or maintain the production of any agricultural commodity in the interest of national security. The Secretary’s determination and the record of the hearing shall be available to the public.

((b)) Effective only for the 1991 through 1995 crops of wheat, feed grains, cotton, and rice, the Secretary of Agriculture may provide for annual adjustments in the established prices for such program crops to reflect any change during the last calendar year ending before the beginning of each such crop year in the index of prices paid by farmers for production items, interest, taxes, and wage rates in such calendar year.