Soviet Premier Nikolai Tikhonov called on the United States today to set aside political differences and move toward improved trade relations, saying the Soviet Union is prepared to move in that direction because that would help meet its needs "for equipment, technology and the demand for consumer goods."

A senior Kremlin spokesman later amplified the premier's remarks by saying that "we are interested in trading with the United States" and specifically mentioned readiness to open negotiations to renew the five-year grain agreement that expires this fall.

Lenoid Zamyatin, the spokesman, brushed aside claims that the U.S. grain embargo has exacerbated deepening Soviet food supply problems, but added: "We may conduct talks on grain and other matters. If the United States wants to discuss grain separately, we are prepared."

Zamyatin, chief of the Central Committee's international information department, said the Carter administration's embargo of 17 million tons of feed grain last year in retaliation for the Afghanistan invasion had no effect on the country's food stocks. "They talk too much in the West that we are hungry in the Soviet Union," he declared. "We can never be blockaded."

Tikhonov said in his speech that the Soviet Union "is prepared to develop economic relations with the United States on the basis of equality and mutual benefit."

While criticizing what he called Washington's use of trade for "unseemly political ends," the 75-year-old premier told the Communist Party congress here that such trade was important to "help meet the needs of the national economy for equipment, technology and the demand for consumer goods."

Tikhonov's speech echoed the main points outlined by President Leonid Brezhnev in his keynote speech on Monday, but it also provided an outline of major economic difficulties ranging from low productivity to restricted manpower resources. Brezhnev had specifically mentioned that "difficulties in supplying the population with food still exist" and that the "main difficulty is the shortage of feed" restricting meat supply increases.

President Reagan is studying whether fo fulfill a campaign pledge to lift the embargo, a move favored by Midwest farmers who supported him.

Zamyatin's statement today echoes other initiatives heard at the congress for resumption of a dialogue with Washington to rescue bilateral relations from the post-invasion deep freeze.

Tikhonov, who succeeded the late Alexei Kosygin last fall, also announced a major shift in priorities for the next five years with a plan that calls for greater growth in the consumer goods sector than in basic industrial output.

The Polish crisis, which began last summer with strikes over food shortages and is now Moscow's most threatening East Bloc problem, presumably has made the government uneasy about its own citizens' discontent.

Tikhonov set consumer goods production to rise 29 percent by 1985, while heavy industry will grow 1 percent less. agricultural output, which barely averaged 2 percent a year from 1976 to 1980 despite continuing massive investment, is to rise 14 precent by 1985. Meanwhile, capital investment in new factories is to be cut in half, from a 29 percent increase in 1976-80 to not more than 3 percent a year through 1985.

Because of the investment cutback and a shrinking pool of new labor, the result of low birthrates in most of Rusia, Tikhonov said that virtually all economic expansion must come from greatly increased worker productivity -- what he called "the switchover to efficient socialist production."

Higher efficiency in factory and workplace would bring less waste of raw materials, energy, and time, he said. But in human terms, in the view of Western specialists, the goals are too high. The most recent studies show, for example, that compared with West European standards, it takes the Soviets four times as much resources in energy and materials to produce the same manufactured item.

The need for economizing, Tikhonov made clear, has never been greater. "In the coming period, it will become particularly important to reduce consumption of materials, make economical use of raw materials, fuel, energy, metal, cement, fertilizers."

Energy savings are crucial if the Soviet Union is to continue its highly profitable oil exports. Now the world's largest producer, petroleum output is to grow only fractionally while outside and internal demand continue to zoom. Natural gas production is to increase 50 percent, but a $12 billion pipeline project from West Siberia to West Europe is still in the negotiating stage and would be delayed for three years if Moscow intervenes in Poland.