Everett G. (Bud) Rank Jr., on leave from his California farm to work in the Reagan administration, will receive about $214,000 worth of free cotton from the federal payment-in-kind (PIK) program that he administers in the Agriculture Department, according to government records.

Rank is one of five partners in Cinco Farms, a Fresno County farming operation that is scheduled to receive 1,338,820 pounds of free surplus cotton through PIK. His share would be 267,764 pounds of cotton, which could be sold at today's prices for about 80 cents a pound, according to cotton handlers in Fresno, the center of San Joaquin Valley agriculture.

Rank said in an interview that he did not learn until last week that his farm had been enrolled in the PIK program and that he saw no conflict between that and his role as chief administrator of the PIK program.

But David Scott, chief counsel of the Office of Government Ethics at the Office of Personnel Management, said yesterday, "There clearly is a problem here. We will want to take a look into it, and will begin by contacting ethics people at USDA to take a look at this."

William J. Riley Jr., the Agriculture Department's director of personnel, said that he was not aware that Rank's farm was enrolled in PIK.

"Yes, of course, we will take a look at it," he said. "But I don't know if we would come to a different conclusion than Mr. Rank has."

Secretary of Agriculture John R. Block said that he also was unaware of Rank's enrollment in PIK, but he added that Rank had met federal requirements by giving up a directorship of the operation.

In contrast to Rank, Block has pledged that his own large farm operations in Illinois would not take part in federal farm aid programs, thus avoiding any real or apparent conflicts.

Block appointed Rank, a Republican, as national administrator of the Agriculture Department's Stabilization and Conservation Service shortly after the Reagan administration took office in 1981. Rank became chief of the PIK program when it was set up early this year to prop up farm prices and reduce crop surpluses.

Rank said that, to avoid conflicts of interest, he gave up his directorship of Cinco Farms when he came to Washington. He said that he was unable to sell his stock in the partnership when he came here and continues to receive rent from the farming operation in the huge Westlands Water District of the San Joaquin Valley.

Cinco Farms is headed by William McFarlane, a Fresno County grower who was president of a coalition of agribusiness interests that lobbied Congress heavily in 1981 and 1982 to retain federal irrigation subsidies in Westlands and in other western states.

Government records indicate that Cinco Farms enrolled its entire eligible base acreage of 2,163 acres in the PIK cotton program. Under terms of the federal surplus-reduction scheme, Cinco Farms is leaving that land idle this year and will receive 1.3 million pounds of surplus cotton for resale in the fall.