The Soviet Union managed to import twice as much grain this year as last, despite the embargo imposed at President Carter's request in January by the Western allies, according to confidential reports repared by the Executive Commission of the ninenation European Community.

The extra grain came from Canada, Australia, Argentina and the United States itself, community sources with access to the reports said.

The numbers make the community, which was the only major Western grain exporter to respect the embargo by not trying to fill the gap created by the U.S. suspension of exports, now look "ridiculous," the sources said. Sentiment among the member states' ambassadors to the community headquarters in Brussels is turning against continuing the embargo, but nothing is likely to be done until after the U.S. presidential elections, a knowledgeable source said.

U.S. Agriculture Department sources in Europe confirm the accuracy of the community's statistics on U.S. grain exports to the Soviet Union, but they in effect accused European analysts of being the ones who are guilty of playing games with the numbers. Community officials have been privately accusing the Americans of using bookkeeping tricks and indirect sales through the West German port of Hamburg to cover up the real volume of U.S. sales to the Soviets.

French officials said that the community reports on the situation were the direct result of French insistence that the Executive Commission carry out the mandate it received when the embargo went into effect in early January to monitor the activities of other grain exporters. In response to that pressure, the commission delivered a first, oral report to the nine ambassadors in Brussels last Thursday and was scheduled to give a written follow-up report at the next weekly meeting this Thursday, community sources said.

France produces two-thirds of the community's grain and is the only member with surpluses for exports.

Statistics collected by the community show that the Soviet Union imported 28.2 million metric tons of wheat and other grain cereals during the 1979-1980 export season, compared to 14.9 million tons the previous year.

U.S. exports totaled 15.3 million metric tons, compared to 11.2 million tons in 1978-1979, Canada went from 2.1 million tons last year to 3.5 million tons this year, Australia from 0.1 million tons to 3.9 million, and Argentina from 1.4 million to 5.5.

[According to figures leased by the Argentine government, exports to the Soviet Union totaled approximately 5 million tons in 1979 abd 6.6 million tons between Jan. 1 and Spet. 30 of this year.]

Community sources say they have no reproach for Argentina, which never engaged in the "hypocrisy" of saying it would respect the embargo. But the sources condemn Canada and Australia for having simply violated the export ban. As for the United States, some sources backed off their previous harsh criticisms when they were confronted with the U.S. official explanations of the statistics.

U.S. sources noted that the Soviet-American five-year contract provides for 8 million tons a year during a relatively arbitrarily defined "agreement year" that runs from October of one year through September of the next. President Carter had pledged that Washington would honor that contractual commitment but would not deliver any extra amounts sought by Moscow.

U.S. Agriculture Department sources say that a final total of 15.3 million tons for the year can be reached by the Europeans by ignoring the peculiar calendar of the Soviet-American grain agreement. When figuring the year diffierently, they said, 6 million tons that were negotiated earlier this year but could not be delivered until after this Oct. 1 and 1.3 million tons added in from last year did indeed make a grand total of 15.3 million tons.

Nevertheless, French officials take the view that "if the United States is not respecting the embargo, there is no reason for us to do it," France and the rest of the community went beyond Carter's demands by also applying an embargo on "transformed grain" in the form of meat and butter, the officials said.

While Carter continues to defend the embargo, Republican presidential candidate Ronald Reagan is opposed ot it. His message to U.S. farmers reiterated in a recent speech in Nevada, Iowa, asserted that Carter had all but wrecked the family farm with an embargo that was "grandstanding for the American people at your expense."

The United States continued to sell the Soviet Union "massive" qualtities of soya beans as livestock feed, said a community source who conceded that this was no violation of the letter of the embargo but did contradict its spirit.

The embargo turned out to be "a bad joke," said a French official. "The Europeans were the only ones who respected it."

France had a very good gain harvest this year, and is expected to sell its usual 6 to 8 million tons to the other, grain-short members of the community. But French granaries would still be overflowing, and French agricultural officials say that the country must sell 3 million more tons of the current harvest outside the Common Market.

A Brussels official noted that France could sell its surplus to China, which has just given notice that it is in the market for 7 million tons. But, he noted, because of high transportation costs "it makes much more sense to sell it to the Russians."

With reports from Moscow indicating the Soviet harvest would be about 50 million tons short this year, a sale by Paris to Moscow would presumably present no problems, provided the community drops the embargo.

From the start, France has said that it did not think economic sanctions against the Soviet Union were wise or helpful. But the French government had decided to accept the U.S. pleas not to take advantage of any slack created by American application of economic sanctions. The French maintain they strictly adhered to this policy, even though Washington formally protested French participation in the construction for the Soviets of a $300 million steel-production complex abandoned by the American interests under the U.S. president's embargo program.