WASHINGTON - Under pressure from farmers, livestock producers and soaring food prices, the Department of Agriculture is weighing a proposal that could lead to the plowing of millions of acres of land that had been set aside for conservation.

At issue is the Conservation Reserve Program (CRP), under which the government has paid farmers to stop growing row crops, such as corn and soybeans, on 34 million acres across the country. Designed in the mid-1980s to hold down production and bolster commodity prices, the $1.8 billion-a-year program has turned into a major boon for conservation, with much of the acreage planted with perennial grasses or trees, or restored to wetlands.

But the ethanol boom, widespread flooding and high prices for feed crops have changed the equation. Livestock producers have been howling about the high price of animal feed. Pork producers say they are losing $30 per pig.

"We need more corn. That's all there is to it," said Dave Warner, spokesman for the National Pork Producers Council, one of many agricultural trade groups pressuring Agriculture Secretary Ed Schafer to change the rules of the conservation program to release land into production.

Schafer is expected to announce his decision imminently. Whatever he decides is certain to be controversial. Environmentalists are decrying the idea, saying that the program represents a huge taxpayer investment in conservation and that expanded cultivation might exacerbate future flooding.

"He's got to choose between agriculturalists and environmentalists, and I'm not sure he wants to make that choice," Sen. Charles Grassley, R-Iowa, said. Grassley has met with Schafer and urged him to let farmers out of their CRP contracts without paying a penalty.

This week, Schafer issued an order allowing livestock to graze on millions of acres of recently flooded CRP land.