Secretary of State George P. Shultz will remain on the job in President Reagan's second term, but two more top Agriculture Department appointees resigned yesterday in the latest round of Washington's quadrennial game of musical jobs.

Agriculture Secretary John R. Block also reportedly told a corn growers' group that he, too, will remain at his post in Reagan's second term -- apparently joining at least five other incumbent Cabinet officers who have indicated that they will stay where they are in 1985.

But speculation grew about two other Cabinet positions: Education and Labor. Education Secretary T.H. Bell has announced that he is returning home to Utah; Labor Secretary Raymond J. Donovan remains on leave, awaiting trial on charges of fraud and grand larceny in connection with a New York City subway project that his construction company began in 1978.

One boomlet already has started for the Education job, promoting former Minnesota congressman and governor Albert Quie, a moderate Republican who played an active part in education affairs during his term in the House.

And another boomlet was promoting conservative Rep. John N. Erlenborn (R-Ill.), who did not seek reelection, for the Labor job, should Donovan quit. Erlenborn has been ranking minority member of the Education and Labor Committee, which oversees the Labor Department.

Erlenborn, who will enter private law practice here in January, said he "would be less than honest" to deny his interest in the Labor position. But he added, "the job is not open . . . and I hope I don't have to face the choice."

State Department spokesman John Hughes said yesterday that Shultz had been asked to stay on the job and that Shultz "is honored to continue as the president has requested him." Hughes declined to say when Reagan had asked Shultz to stay.

Block was not available for comment, but an official of the National Corn Growers Association said the Agriculture secretary had told the group's board of directors that he will remain for a second term. "He told us he wanted to lay the rumors to rest and he will stay for a second term," said Michael Hall, executive vice president.

At Agriculture, however, Block will face the task of replacing three of his top assistants at a time when the department is gearing up for debate over a new farm bill.

One of the key figures, Deputy Secretary Richard E. Lyng, 66, submitted his resignation earlier this month. Yesterday, another major player in the farm policy debate, Assistant Secretary for Economics William G. Lesher, 38, unexpectedly announced plans to leave in January, although he told Reagan in his resignation letter that he would remain beyond then if needed "to help in the transition for a short while."

Lesher's name had surfaced as a leading candidate to replace Lyng. But he said yesterday that "four years is enough in any job . . . . Others need to come in." Lesher said he does not know yet what he will do after leaving the department.

The other USDA resignation came from John B. Crowell Jr., 54, assistant secretary for natural resources and environment, a controversial former chief general counsel for the Louisiana-Pacific Corp. Environmentalists and Senate Democrats temporarily blocked his confirmation in 1981 until he promised to recuse, or disqualify, himself from any Forest Service decisions affecting his former employer. Crowell indicated that he will return home to Portland, Ore.