Hundreds of hard-pressed midwestern farmers came to this historic city of the sodbusters today to tell a House Budget Committee hearing that President Reagan's proposal to chop farm subsidies will aggravate what one witness called "a crisis in agriculture."

The five-hour hearing was the third of several scheduled by the Democratic-dominated committee around the nation.

Careworn men and women, many of whom said they were experiencing severe financial crises, applauded repeatedly as witnesses declared that Reagan's proposed 1986 budget goes too far too soon in slashing aid to farmers.

The administration wants to cut several billion dollars from the $15 billion federal farm-assistance bill.

Dozens of those present face large debts, huge harvest surpluses and collapsing foreign markets. Thousands of farmers who bought expensive land on borrowed money during the 1970s boom years face liquidation because land and crop prices have plummeted.

Bankruptcies and foreclosures are common, and dozens of banks have closed because of uncollectible farm loans.

While numerous witnesses said they accepted the need for farm-policy reform, they insisted that this is not the time for it.

"Gentlemen, we have a crisis in agriculture," State Sen. Jim Allen, a farmer, declared to thunderous applause.

Democratic Gov. John W. Carlin was cheered when he said proposed farm-aid reductions are "like asking a woman who's been raped to pay for the defense counsel."

Maybe [Agriculture Secretary] John Block hasn't gotten the message, but the message is getting louder," Carlin said.

More than 500 farmers and family members joined economists, bankers and state leaders in a crowded room of American Legion Post No. 6 on the main street of this northeastern Kansas city.

Founded in 1854 by proslavery men, Atchison was a starting point of the Pony Express in the 1860s and later of the Atchison, Topeka and Santa Fe Railroad. In its early days, ranchers derisively referred to farmers, who plowed the turf and made homes of it, as "sodbusters."

Today, economic woes buffet the 11,400 residents; numerous downtown stores sit empty, and residents say jobs are scarce.

No Republican panel members attended the hearing, chaired by Rep. Howard E. Wolpe (D-Mich.), who was joined by Reps. Chester G. Atkins (Mass.), Martin Frost (Tex.) and James C. Slattery (D-Kan.), whose district includes Atchison. Members said Agriculture Department representatives had been invited but did not come, and the panel's makeup reflected the intensely partisan reaction to budget-cut proposals.

"Suicide rates in rural areas are much higher than other areas, which is proof that the problem is very real," Wolpe said.

Eugene Milne, Edwin Bauman Jr. and Terry Oberding, members of a farm family near Sabetha, a plains community northwest of here, told of increasing debt despite what they described as careful investment and lavish attention to their land.

Unlike many farmers, they said, they did not expand their debt in the 1970s boom by borrowing heavily against rising land prices that have since plunged, dragging thousands into bankruptcy. Rather, their plight more closely resembles what Slattery described as a "profit crisis," not a debt crisis.

Like many farmers present, the three said they favor the general direction of the administration drive to cut back the complex, costly web of farm subsidies.

Milne, 67, said he has been "on a farm since birth, except four years I helped Uncle Sam" during World War II. He said he raises wheat, corn, milo and soybeans on 750 acres.

Despite little debt for new machinery or land, he said, harvest prices were so low last year that "I just had my income figured, and I've got a $14,000 loss for the year. That's the first time in my life I didn't pay income [tax]. I got more for grain in 1947 than now."

Bauman, 57, Milne's nephew, raises similar crops on 330 acres, and his newest farm implement is a nine-year old combine. "I've made some money in farming," Bauman said. "Why, the missus and I made a trip to Hawaii. But for the past three, four years, I've had no profit. Last year, it became a loss."

Oberding, 40, is Milne's son-in-law. He said he left a well-paying job as a mechanic to join Milne in farming a few years ago. "He's going to retire and, when I joined him, I thought it was a good thing. But it's been going downhill every year ever since," he said.

Dr. Barry L. Flinchbaugh, an agricultural economist at Kansas State University, denounced the Reagan budget and said administration calls for a return to free-market farm economics are "a figment of the imagination . . . pure hocus-pocus. How can you ask one industry to operate in a free market when everybody else isn't doing it?"

Flinchbaugh said a major overhaul of and freeze on U.S. spending is needed. "The deficit is the root of agriculture's financial crisis," he said. "Uncle Sam's insatiable appetite for borrowed funds is the reason real interest rates are high."

Now is not the time, he said, for major surgery on farm programs. "We can't tolerate it," Flinchbaugh said of Reagan's proposed 37 percent decrease in farm expenditures.

"The crisis is so serious that we really don't have an environment in which to objectively write a new farm bill. The time to do that is when we have a healthy agricultural economy, not now. You don't make major changes, completely overhaul a program we've been living with since 1933, in the midst of our worst financial crisis," he said.