Argentina said today that it would not "take commercial advantage of the circumstances" created by a U.S. grain embargo of the Soviet Union but would not participate in a boycott or directly limit the amount of grain the Soviets buy here.

The Foreign Ministry statement followed a three-hour meeting this afternoon between Lt. Gen. Andrew J. Goodpaster acting as special emissary for the Carter administration, and President Jorge Videla.

It left unclear the extent to which Argentina would offset the 17 million metric tons of grain and soybeans denied the Russians by the United States in repisal for the Soviet invasion of Afghanistan.

Goodpaster arrived here Wednesday on a hastily arranged visit after Wshington belatedly recognized that Argentina's refusal to participate in the boycott -- announced by Carter on Jan. 4 -- could make it largely ineffective.

The former NATO commander and current head of West Point, who left here today for Brazil, described his talks as "very constructive, very positive and very agreeable." Videla, a retired general, led to coup that brought the military to power here in 1976.

Since Goodpaster's unannounced arrival, it has been clear that both Argentina and the United States are hoping to find a way to improve relations, which have deteriorated badly since the Carter administration in early 1977 pinpointed the military government as one of the world's chief violators of human rights.

The government here has rejected the continuing criticism as unfair, saying Washington failed to take into account the serious urban terrorist movement extant when the military overthrew Isabel Peron's government.

The Montonero left-wing guerrillas were responsible for hundreds of kidnapings of wealthy businessmen, both Argentine and foreign, before and after 1976.

Since the military takeover, between 8,000 and 10,000 people have "disappeared" as part of the antiterrorist campaign while thousands more have been jailed, tortured or forced to flee the country.

In 1977 the government chose to end its traditional military relationship with the United States and buy arms from other countries, including France, Israel and Czechoslovakia, rather than submit to the State Department review of the human rights situation here required by Congress for all countries receiving U.S. military credits or assistance.