Occidental Petroleum Chairman Armand Hammer said yesterday that, based on talks last week with Soviet President Leonid Brezhnev, he expects the Afghansistan crisis to end soon and trade with Soviets to return to normal.

Hammer also said he concluded from his talks with Brezhnev and other top Soviet officials that the Russians will honor their commitment to ship ammonia to the U.S. despite the embargo on phosphate shipments to the Russians ordered last week by President Carter.

Hammer met with the Russians to discuss Occidental's $20 billion contract to supply the Soviets with phosphate products in return for ammonia used to make fertilizer. Besides the embargo place on exports, Carter in January placed a one-million-ton quota on the import of ammonia from the Soviet union.

"After recent talks with Brezhnev, I'm convinced this trouble in Afghanistan can be settled, it will be settled and we can return to trading with the Soviets as usual," Hammer testified before the International Trade Commission which is considering whether to continue the ammonia import embargo. The crisis "is just a temporary condition. I hope the Russians will go along, meet their payments with the Export-Import Bank and private banks and continue trading with the United States."

Hammer, whose company has a large 20-year, $20 billion contract dependent on the outcome of the Afghanistan situation, said that he suggested to Brezhnev that Foreign Minister Andrei Gromyko meet with Secretary Of State Cyrus R. Vance, probably following the funeral of ailing Yugoslav President Tito, to discuss a resolution of the crisis.

Hammer said Brezhnev told him the idea sounded good to him. But the State Department last week said Vance and Soviet Ambassador Anatoly F. Dobrynin discussed the issue and not Gromyko.

Hammer said he also "though that countries like France could play a mediating role in bringing the two countries together."

The commission hearing yesterday was to determine whether to toughen or soften the ammonia imports quotas. The commission recommended the one-million-ton quoto last October, but President Carter rejected it.

But in January, Carter changed his mind and instituted the quota and requested that the commission reinvestigate the matter, saying that "recent events have altered the international economic conditions under which I made my determination that it was not inthe national interest to impose import relief . . ."

Representatives of the domestic ammonia industry, who favor the quota, yesterday said that they are injured by "rapidly increasing imports of ammonia from the U.S.S.R." because the imports burden them with the cost of maintaining idle capacity, force them to lay off workers and accrue them below-normal profits.

Hammer said that Occidental's agreement with the Russians would benefit farmers through lower fertilizer prices, and consequently aid consumers throuhgh lower food costs and help international relations by keeping communication open between the two countries.

He added later, under questioning, that yes, Occidental would profit from the agreement, too.

Hammer said the Soviets could sell their ammonia elsewhere but they haven't. "It is my belief that the Soviets intend to continue their shipments of ammonia to the United States and it is my long-held belief that the Soviets are reliable and depe ndable trading partners.

"It is our hope that this important and beneficial trade agreement can be preserved -- that we will be able to continue importing ammonia until improvement in U.S. -- Soviet relations permits a resumption of phosphate exports," Hammer said.

"The survival of the agreement now depends on the outcome of this proceeding," Hammer continued "If ammonia imports are subjected to a more severe limitation than the quota ordered by the President, the Russians could well regard this as an indication that the U.S. will not live up to its commitments, and I believe that could be the final blow which would end the agreement and cut off all ammonia imports."