Into the annual housing bill he sent to Congress this year Housing and Urban Development Secretary Samuel R. Pierce Jr. tucked a small civil rights section. Its most important provision would authorize the distribution of $4 million to private fair housing groups across the country to set up "testing" programs. In testing, if a black person has been told a house or an apartment is not available, a white person with similar credentials may be sent to apply. If the white person is not told the same story, the testing group has evidence of bias that can be used in court. The practice was upheld by the Supreme Court in 1982. Supporters say it is the best and sometimes only way to establish discrimination.

The $4 million testing program would represent the first use of federal funds for such efforts, and it is a modest effort. But members of both parties on the House subcommittee on housing and community development are balking at it. They are being encouraged in this by the National Association of Realtors, which describes testing as a kind of entrapment or "witch hunt" in which the government should have no part.

The administration's proposal has not been helped, either, by the strained relations between the subcommittee's controlling Democrats and Secretary Pierce, with whom they have had sharp words on a num- ber of issues over the years, civil rights included. We think that the congressmen should step back from these considerations and vote aye. To combat discrmination in such fields as education and employment, the government has created fairly elaborate enforcement mechanisms over the years. The effort to end housing discrimination has been an orphan. For the last several years there has been inconclusive debate over a major housing enforcement bill. Civil rights groups have backed one meastration another. The debate is likely to continue. The Pierce proposal would be a useful step in the interim.

It is a step that groups such as the National Committee Against Discrimination in Housing, Inc., have advocated for years. That group performed "testing" for HUD in 40 metropolitan areas in 1977 and 1978. It found discrimination against blacks 72 percent of the time in rental cases and 48 percent in buying homes. That figure on sales did not include cases involving "steering" -- directing blacks only to homes in black neighborhoods -- which is also discriminatory. A spokesman for the group says that housing discrimination is as bad or worse now.

Supporters say that, under the Pierce proposal, funds would go only to trustworthy private groups, mainly to defray legal expenses in discrimination cases. No other new enforcement effort is in sight. Why not try this one?