A United States plan to hide landbased missiles in a filed of missile silos could force the Soviets to give up trying to target them all and to negotiate a ceiling on warheads, the new chief of the Air Force said yesterday.

Gen. Lew Allen Jr., who took over as Air Forces chief of staff this month, made that point in discussing with reporters the newest idea for decreasing the risk of U.S. land missiles being knocked out in a surprise attack.

Called MAP, for Multiple Aim Point, the proposed system envisions digging 20 different underground holes, called silos, for a single missile. The missile would be trucked covertly from one hold to another so that the Soviets would not know which hole held it.

Allen, formerly director of the National Security Agency, which helps keep track of Soviet weaponry, said that "as a United States technician, I have no trouble describing a satisfactory verification scheme," for assuring the Soviets that a field of 20 holes held only one missile.

The Soviets, he said, could be allowed to pick a field of holes to inspect, either by their technicians on the ground or by spy satellites. The United States could slide back the lids over the missile holes during that inspection period to show that all but one were empty.

Studies have compelled the Air Force to conclude that "we really can't make our silos hard enough" to stand up against increasingly accurate Soviet missiles, he said. Soviet accuracy has progressed further than U.S. intelligence specialists had predicted, he added.

The best way to combat the thousands of Soviet warheads is to deploy "a great sponge to absorb" them, Allen said in giving the rationale for going to the MAP system.

By the mid-1980s, he said, the Soviets will have an "awesome" force of 6,000 "accurate reentry vehicles," the Pentagon term for nuclear warheads launched by missiles. By deploying 300 missiles, each in a filed of 20 holes, backers of the Multiple Aim Point system contend the 6,000 Soviet warheads would be drawn off the Russian nuclear offense.

Allen said it would "probably be less expensive" for the United States to dig more missile holes than it would be for the Soviets to add warheads to cover them. This competition, the general added, might improve the prospect for a U.S. Soviet agreement to limit the number of nuclear warheads on each side.

Pentagon sources estimate that the MAP plan consisting of 300 missiles and 6,000 holes could be built for about half the $40 billion price tag for another plan that would put big missiles in underground tunnels where they would be moved back and forth to make them hard to hit.

If Soviets leaders are presented "with a no-win situation" by such a system as the MAP deployment, they would be deterred from pushing the nuclear button in the first place, Allen argued.