The Senate Foreign Relations committee decided yesterday to begin 20 days of hearings on the strategic arms limitation treaty (SALT II) on July 9, and to prepare for a floor debate on the controversial treaty that could begin Oct. 1.

In a preliminary meeting on procedures for handling SALT, the committee rejected a staff proposal to invite former president Gerald R. Ford to testify, deciding instead that "former presidents could not tell us a great deal about what was in the treaty," according to committee Chairman Frank Church (D-Idaho).

This decision avoided any question of possibly also inviting Richard M. Nixon, who negotiated the first SALT pact.

Church said the committee was favorably disposed to the idea of televising the floor debate on SALT II, but noted that it had no direct jurisdiction over this matter. Majority Leader Robert C. Byrd (D-W.Va.) has indicated opposition to the idea of televising the floor debate, something that has never been done in the Senate.

Church said television cameras would be welcome in the Foreign Relations Committee's hearings.

Church, Byrd and John C. Stennis (D-Miss), chairman of the Armed Services Committee, agreed yesterday that Armed Services will begin its separate hearings on SALT II on July 23. This will give Foreign Relations two weeks when it alone will be considering the new treaty. Church said he was pleased with this arrangement.

The Foreign Relations Committee tentatively plans to devote six days to hearing from administration officials and five days to outside experts, including former officials.

One former official expected to testify and to influence the debate is Henry A. Kissinger, who spent four years unsuccessfully trying to negotiate a SALT II agreement before leaving the government.

The committee will end four weeks of hearings in early August in time for the Senate's summer vacation, but will resume hearings in September and complete marking up the treaty by late that month, according to the schedule approved yesterday.

Some members of the committee, assistants to members and Carter administration officials have expressed concern in recent days that the committee is not yet prepared to conduct smooth, orderly hearings on SALT II. A preliminary draft of a staff plan for hearings circulated last week was criticized by some who saw it as too vague.

Sen. George McGovern (D-S.D.) urged Church to establish a broad political context for the hearings so they would not bog down in arcane pro and con arguments about the details of the treaty.

Church agreed, and a revised plan for hearings, prepared for yesterday's meeting, does call for consideration of broad political issues as well as the treaty document.

William Bader, the new staff director of the committee, has hired a panel of consultants as well as several new full-time staff members to deal with SALT. The one full-time staff member who handled SALT for the committee before this year left recently to take a job in the Carter administration.