An act to adjust target prices for the 1980 and 1981 crops of wheat and feed grains; to extend the disaster payment programs for the 1980 crops of wheat, feed grains, upland cotton, and rice; and to authorize the Secretary of Agriculture to require that producers of wheat, feed grains, upland cotton, and rice not exceed the normal crop acreage for the 1980 and 1981 crops.

Agricultural Adjustment Act of 1980 - Amends the Agricultural Act of 1949 to set the established per bushel price for 1980 crops at $2.35 for corn and $3.63 for wheat. Requires that the 1981 price crop established prices for corn and wheat not be less than the 1980 established prices, adjusted upward to reflect such changes in the costs of production as the Secretary of Agriculture finds necessary and appropriate for the purpose of establishing and maintaining a fair and equitable relationship between loan rates, established prices, and production costs for corn and wheat and competing commodities.

Extends disaster payment programs to cover the 1980 crops of rice, upland cottons, feed grains, and wheat.

Amends the Food and Agriculture Act of 1977 to limit to $100,000 the total amount of disaster payments which a person is entitled to receive under one or more of specified annual programs for each of the 1980 and 1981 crops of wheat, feed grains, upland cotton, and rice.

Amends the Food and Agriculture Act of 1977 to authorize the Secretary to require, as a condition of eligibility for price support loans, purchases, and payments under the Agricultural Act of 1949 for the 1980 and 1981 crops of wheat, feed grains, upland cotton, and rice, that producers not exceed the acreage on the farm normally planted to crops designated by the Secretary, adjusted as deemed necessary by the Secretary to be fair and equitable among producers. Requires that the acreage for any farm normally planted to crops designated by the Secretary be reduced by any set-aside or diverted acreage. Authorizes the Secretary to increase the established price for any such commodity by the amount the Secretary determines appropriate to compensate producers for participation in the program for such commodity and any required set-aside with respect to such commodity, whenever the Secretary requires such compliance with the normal crop acreage. Requires the Secretary, in determining such increases, to take into account changes in the cost of production resulting from such program participation and required set-aside. Authorizes the Secretary to increase the established price for any other commodity as determined necessary for effective program operation, if the established price for any such commodity is increased. Requires the Secretary to adjust any such increases to reflect any land diversion payments for the commodity for which an increase is determined.

Allows producers of the 1980 crop of any commodity, who exceed the acreage on the farm normally planted to crops designated by the Secretary, to receive loans and purchases and payments based on the established price for a commodity as determined under the applicable provisions of the Agricultural Act of 1949 in effect on the data preceding the date of enactment of this Act.