The Agriculture Department has started a system of political loyalty checks on some scientists, apparently the first time such checks have been imposed on government peer review panels since the 1950s.

Scientists must routinely pass political checks as well as FBI security checks before holding policy-making jobs in Agriculture, but a bitter controversy broke out when the department extended those political loyalty checks early this year to university scientists who make no policy decisions but only provide expert advice on the scientific quality of grant applications.

"In my opinion, scientists should be checked for philosophical compatibility" with the administration's views, said James Handley, special assistant to Agriculture Secretary John R. Block.

"We like to believe we have a more conservative philosophy than the last administration. . . . We would like to appoint people who share our political views," Handley said.

Two former directors of the research program in question, called the Competitive Grants Program, have condemned the political loyalty checks as "absurd" and said they may "utterly destroy" the grant program when scientists discover that politics is being mixed with science.

Dr. Larry Schrader of the University of Wisconsin, who ran the Competitive Grants Program last year, said that no such political checks were run until this year. When he found out about the checks this year, he said, "I was mad as a wet hen. Many people have worked their butts off to keep this program credible. . . ."

The program will disburse about $16 million in agricultural research grants. There are about 800 applicants for the money, and the applications are reviewed by about 80 university scientists chosen for their specialized knowledge in different branches of agricultural research.

Similar panels exist at the National Science Foundation and the National Institutes of Health. Officials at both those agencies expressed surprise and dismay at the political checks carried out at Agriculture.

They said no such political checks exist in their agencies. Security checks are done, the officials said, but appointments are not held up while they are conducted, nor are most officials even aware that they take place.

At USDA, the names of scientists nominated for review panels are passed to the FBI for security checks, and to Block's office for political checks. The checks this year delayed by some months the start of grant application reviews.

Special assistant Handley said he did not know if anyone had been prevented from sitting on a review panel because of the checks, but officials closer to the review panels said that probably no one was excluded for political or security reasons.

Handley said he believes that the FBI check for "security and background" is required by the Federal Advisory Commission Act. Officials in NSF and NIH said that that is not necessarily the case; the act itself does not explicitly call for such investigations.

Handley said USDA picks peer reviewers "first and foremost" by their scientific credentials. But he said it is possible that many of the reviewers are picked because they are part of a "good old boy network" in science, and many others, including Agriculture's own scientists, could do the job of reviewing grants for scientific merit.

Where two scientists might have equal credentials, he said, "and you find one of those people shares your philosophical viewpoint, and one is very much opposed to you . . . our job is to appoint those people with our" political views.

Former director Schrader said that if the checks were established as policy, it would "utterly destroy" the credibility of the program among scientists, and scientists would soon refuse to be part of it.

Dr. Joe Key, who headed the program in its first two years and now is at the University of Georgia, said such political checks are "absurd" and either naive on the part of department officials or a conscious attempt to undermine the program.

Everett Mendelsohn, historian of science at Harvard University, said that political loyalty checks have not been used on science panels since the 1950s. Both NIH and NSF had them then, he said, not to check for loyalty to a party or ideal but to check for evidence of communist sympathy.

Without complete freedom from politics in science, "we don't get reliable knowledge, we obtain knowledge that is biased and faulty from the beginning," Mendelsohn said.