DES MOINES, IA - A new study shows that federal farm subsidies are going to larger farm operations, which enables them to grow even larger while small operators struggle to make a living.

A new government study said half of all federal crop subsidies in 2003 went to farms with household incomes of more than $75,772, up from $55,607 in 1997 and $47,121 in 1991, after adjusting for inflation.

The figures, released by the U.S. Department of Agriculture, were obtained by the Des Moines Register's Washington bureau.

In Iowa, half of the subsidies in 2003 went to households with incomes of more than $65,124, while one-fourth went to families making more than $137,625. Farm households in Iowa making at least $250,000 claimed 10 percent of the payments. Figures for previous years were not available.

"More and more production is starting to shift into some very large operations," said James MacDonald, who led the study.

Bob Gunzenhauser, a fifth-generation farmer with about 940 acres of corn, soybeans, oats and wheat in the Humeston area, said he and his wife make about $30,000 a year. By comparison, the median U.S. household income in 2003 was $43,318.

The Gunzenhausers' income includes profits from the farm, money from her part-time librarian job and his earnings from side jobs selling seed and doing business consulting.

"At 940 acres ... we're barely getting by," he said. "I could see a farm two to three times larger than us could be making that $75,000 income per year and be at a point where they're living comfortably, as comfortably as their neighbors in the city."

Much of that income comes from government subsidies, he said.

A national debate is growing over the impact of subsidies on farmers and land ownership.

Farm program critics say the payments make it possible for big farms to acquire even more land.

Some critics also say the subsidies stimulate overproduction of crops that drives down world commodity prices, making it harder for farmers in places like Africa to make a living.

The Bush administration has proposed to cap at $250,000 a year the amount of subsidies a farm can receive. Under current rules, subsidies for corn, soybeans, cotton and other crops are essentially unlimited.

The U.S. Senate last year rejected the proposed cap, but lobbyists for agricultural groups that oppose the limit concede that it's likely to be a big issue when lawmakers write a new farm bill next year. Farm groups argued successfully last year that Congress shouldn't alter payment rules in between farm bills.

"The story changes significantly in 2007," said Mary Kay Thatcher of the American Farm Bureau Federation.

Chuck Hassebrook of the Center for Rural Affairs, a Lyons, Neb.-based advocacy group that supports new payment limits, said it is becoming more important to farmers in the Midwest.

"They don't think the government should be subsidizing the biggest farmers in their county to drive everyone else out of business," he said.

Iowa received $1.3 billion in subsidies in 2004, 10 percent of the total payments nationwide, according to data compiled by the Environmental Working Group.