The depth of Poland's economic crisis was underlined today by a government announcement extending rationing to cover a wide range of foodstuffs including butter, flour, and rice.

[Reuter news agency reported early Wednesday morning that the official state news agency editor on duty said in a telephone interview that the announcement was being withdrawn. But there was no official retraction and he could give no reason for the change.]

The new restrictions, which come into force at the beginning of next month, mean that Poland is just a step away from total rationing of all food products. It is already extremely difficult to buy basic items such as bread, milk and cooking oil.

After eight months of labor unrest, Poland is entering the critical preharvest period when foodstuffs are the most scarce. In addition, because of lack of foreign exchange, there are some doubts whether the country can afford to pay for discount food aid offered by some Western countries.

The shortage of food, rather than the possibility of foreign intervention, is the number one subject of conversation here. The almost commonly heard opinion is that there is less to buy on the market than at any time in the last 30 years.

The food situation has provided a powerful stimulus to settle the long-running controversy over private farmers' demands for an independent union. Permission to form the union, although strongly opposed by party leaders, seems inevitable if production is to be increased.

Representatives of government and farmers, who are occupying official buildings in the northern town of Bydgoszcz, were postponed today until after Easter. The talks will reconvene in Warsaw, when, according to present indications, an independent farmers' union in one form or another will be legalized.

The extension of rationing was foreshadowed in a speech to parliament last week by the prime minister, Gen. Wojciech Jaruzelski, who described everyday shopping as "a torture" for the housewife. Rationing of meat and sugar is already in force.

Under the new regulations, Poles will be entitled to an average of 1.1 pounds of butter and 2.2 pounds of flour a month. Every three months, they may also buy 4.4 pounds of cereals and 1.1 pounds of rice.

Raising agricultural production has become the most important priority for the government in its efforts to extricate the country from its grave economic crisis.

Part of the reason for the food shortages lies in last year's crippling harvest, which caused a 10 percent drop in agricultural production.But the deeper cause lies in the chronic inefficiency of Polish agriculture, with private farmers complaining of low prices and shortage of essential supplies such as grains and fertilizers.

[The Soviet military newspaper Krasnaya Zvezda today said the Polish Army is ready to defend "the socialist homeland" with Soviet allies, Washington Post correspondent Kevin Klose reported from Moscow.]

[It said many Polish Army Communists had only recently realized "there is now a real threat" to the country from "antisocialist forces (that) shamelessly speculate on workers' discontent and economic short-comings."]