No Lysenkos for America

Secretary of Agriculture John Block ended a departmental procedure of political loyalty checks yesterday, the same day they had made headlines. It was a happy ending to a potentially sad story.

American agricultural research was already in decline, according to a congressional study, when a development surfaced that would hardly have helped matters. The Department of Agriculture was reported to have instituted political loyalty checks on university scientists who review research grant applications. A department official was quoted to the effect that the administration would like to appoint scientists of ''philosophical compatibility'' who share its conservative views.

Checks for political conformity would have been no news in the appointment of policymakers. But enlarging the net to scientists on an expert review panel was at least ''absurd,'' as two former directors of the research program reportedly called it. It could be ominous if politics were allowed to inhibit the scientific judgment needed to foster the quality of research that has made American agriculture an example to the world. The congressional Office of Technology Assessment found that funding has not kept up with the need for improved farm technology. The funds that are available must not be wasted through ideological intrusion.

The now terminated political checks had not resulted in any party-line relationship to appointments, according to an Agriculture Department spokesman. He said Secretary Block asked a simple question. If the checks have no bearing, why continue them? Silence from the staff. Decision to stop by the secretary. All credit to Mr. Block for keeping the story from getting worse. But how to prevent something similar arising in the future?

There ought to be a safeguard in President Reagan's alertness to the bad examples of the Soviet Union. Soviet agriculture was set back severely when ideology became confused with science. Collective farms were not allowed to plant hybrid corn, for instance, when Stalin promoted the discredited biological theories of politically compatible Trofim Lysenko. A breed of American Lysenkos would indeed be absurd.