Isidoro Rodriguez, the Department of Agriculture's minority-affairs director, was placed on 10-day leave yesterday while officials began a review of his controversial memo proposing a sweeping reversal of civil rights enforcement policies.

Rodriguez' memo, addressed to Secretary John R. Block but sidetracked by aides before it could reach him, urged changes at USDA--such as dropping minority hiring goals and quotas--that would then become "a benchmark" for the entire administration.

Rodriguez, a political appointee who joined USDA about a year ago, wrote that the Justice Department was playing a key role in orchestrating the changes he proposed that Block put in place. At his televised news conference Wednesday, President Reagan said he was unaware of the Rodriguez memo but that he would "look into it." USDA officials, however, said yesterday that they had had no further instructions from the White House.

On another front, Assistant Attorney General William Bradford Reynolds, chief civil rights enforcer at the Justice Department, denied that he had had any contact with Rodriguez and said he was unaware of a plan described by Rodriguez to make USDA the administration's lead agency in watering down rights enforcement.

"To the extent that Mr. Rodriguez suggests there needs to be a review of federal regulations to modify quota requirements based on race, I would agree with that," Reynolds said. "As to the rest of the memo, we have not had any conversations nor was I aware of any plan to use Department of Agriculture regulations as the vehicle for widespread regulatory reform."

Block was in Mexico yesterday, but in his absence Deputy Secretary Richard E. Lyng approved an order putting Rodriguez on leave while an investigation is conducted into the background of the controversy. Rodriguez could not be reached for comment.

Departmental sources indicated that the investigation very likely also would deal with allegations by USDA employes that Rodriguez has "bullied" and run roughshod over bureaucrats in his Office of Minority Affairs and systematically reduced minority protection actions. Acting Assistant Secretary John Franke, who earlier stopped the memo from going to Block, said this week that he had taken up some of the allegations with Rodriguez and that he expected improvements in management of the office.

Other officials indicated that USDA also will take a new look at another controversy involving Rodriguez--his collection of unemployment benefits from the District of Columbia in 1980 when he actually was employed.

After an investigation, the district's Department of Employment Services (DES) recovered $1,267 it had paid to Rodriguez when he was working for the D.C. government. Later unemployed again, he collected more benefits in 1980 and 1981 but was cut off in mid-1981 and disqualified from further aid for two years.

Rodriguez appealed the disqualification, but was overruled last year by the D.C. Court of Appeals, which held that "there is substantial record evidence to support a finding that petitioner Rodriguez committed fraud."

He now is seeking a reversal of that at the U.S. Supreme Court, which has not acted on his petition. Grace Rosner, general counsel for DES, said the district is challenging Rodriguez' new move. "We have filed a motion before the court and I am confident that our position will be vindicated," she said.