Parts of the government's Beltsville Agricultural Research Center (BARC), regarded by many as the leading institution of its kind in the world, are decaying and collapsing under the weight of age and official inattention.

"It's an embarrassment to the United States," said Waldemar Classen, director of the sprawling suburban complex that draws thousands of foreign visitors each year to observe laboratory work and trade ideas with some of this country's top scientists.

Crowded working conditions, leaking and unsealed greenhouses, broken heat lines, antique animal-holding facilities -- in contrast to other federal science centers in the Washington area -- have forced some Beltsville scientists to forgo or transfer research that otherwise would be done there.

The working farm and laboratories, many of which date to the 1930s and earlier, are home to about 2,500 Agriculture Department employees, including about 400 Ph.D. scientists. The complex occupies more than 7,000 acres on either side of U.S. 1, just outside the Capital Beltway in Maryland.

Despite its longstanding problems, the facility was bypassed by the 1988 continuing budget resolution, which diverted federal funds to research programs in powerful lawmakers' home districts.

As Classen and others at Beltsville scratched for money to make token repairs on their crumbling plant, Congress approved the distribution of more than $57 million around the country for new agricultural research facilities at favored universities and outposts of the Agriculture Department (USDA).

Most of these projects, assigned to the USDA Agricultural Research Service that manages Beltsville, went to states represented by senior senators and representatives with key seats on congressional appropriations committees. Maryland has two members on the committees -- Sen. Barbara A. Mikulski (D) and Rep. Steny H. Hoyer (D) -- but neither is on an agriculture subcommittee.

A few examples:

Senate Appropriations ranking minority member Mark O. Hatfield (R-Ore.) pushed through $10 million for a new Oregon State University research facility and $6 million for a wheat marketing center at ortland.

House Appropriations Committee Chairman Jamie L. Whitten (D-Miss.) obtained $50,000 seed money to start a natural products development center at the University of Mississippi.

Hawaii, through Sen. Daniel K. Inouye (D), reeled in $6.4 million for an aquaculture center.

Sen. Dennis DeConcini (D-Ariz.) landed $4.6 million for construction of a biotechnology center at the University of Arizona.

Iowa Sens. Tom Harkin (D) and Charles E. Grassley (R) got $6.4 million for a food product development center at Iowa State University.

Sen. Patrick J. Leahy (D-Vt.) got $2.2 million for a microbiology center in Vermont.

Last month's grappling for home-state money in the continuing resolution was not new, however. Between 1965 and 1985, according to USDA data, Congress appropriated $242 million for ARS facilities nationwide, while Beltsville, with about one-fifth of the agency's employees, received $8 million of that. ARS, in large part due to congressional priority setting, now conducts research at 127 locations in the United States.

In an interview, Agriculture Secretary Richard E. Lyng complained about "crazy" spending patterns that force his department to build science facilities for which there is no staffing budget. "We don't have the money to hire people to put in these buildings," he said.

But Congress ignored BARC in the new spending bill. It earmarked nearly $7 million for early work on Renaissance '93, a long-term renovation and rehabilitation plan that envisions spending $162 million by 1993. Classen said about $4 million from other ARS and BARC budget accounts also would be available this year.

Despite high-level statements of departmental support for BARC, the future of the Renaissance '93 plan is not clear. After the White House Office of Management and Budget and the department's budget office raised questions, Classen said he agreed to their suggestion last year that an outside consultant be hired to study the plan.

Adding an outside review, he said, could further delay the renovation program.

"There are things we should do {at Beltsville} and things that need to be improved right now," said Orville L. Bentley, assistant secretary for science and education at USDA.

State and local officials, as well as BARC employees, have been nervous about the center's future since 1982, when then-OMB Director David A. Stockman proposed that the massive complex be sold to developers and that research be carried out elsewhere. That idea was short-lived, and Renaissance '93 was drawn up in response to a congressional directive.

Meanwhile, as small-scale repair and renovation begins in some of the buildings, scientists in many of Beltsville's most important laboratories grouse about the ARS policy that takes "rent" and "overhead" costs from their project budgets to help pay for remodeling their often primitive facilities.

The most visible problem is a broken underground steam heat line that spews a constant geyser of vapor around the sides of the laboratory and greenhouse where BARC scientists conduct potato research. Before the steam was vented outside with a jury-rigged bypass, it collapsed a ceiling and covered lab walls with mold that reached a critical tissue-culture storage room.

"Old Faithful, we call it," one scientist said. "It has inhibited our work because the molds go all over the place . . . . If the line breaks again, we lose our greenhouse heat and our sterilizers."

In a nearby 1934-vintage greenhouse, where strawberry breeder Gene Galletta was tending tiny plants that could become new commercial "super" varieties around the turn of the century, conditions were only a little better.

"We can only grow plants in this greenhouse from November to March, which is limiting," he said. "We can't go beyond March because it gets too hot in here. We need air conditioning to make it cooler, but the center can't afford it."

In Greenhouse No. 8, plant scientist James Locke is in the midst of breakthrough research that has found a way to set beneficial soil fungi against other fungi that damage the roots of valuable flower plants.

Before he had left the previous night, Locke set the thermostat at about 70 degrees. A maximum-minimum thermometer showed that the temperature had fallen to 51 overnight. "I would have liked it to stay around 60," Locke said, "but we just can't maintain temperatures on cold nights. We're really in trouble on windy cold nights."

The heating system was running in fits and starts, and chilly air filtered in through an inch-high fissure along one side of the greenhouse. Ridge vents, vital for ventilation, had been nailed shut to avoid wind damage. Galvanized poles, brought in by Locke, were propping up the greenhouse roof to prevent further sagging and breakage of glass panes.

"This is a research house, and I'm being charged $7.50 a square foot to use it. Commercial greenhouse operators come in here, and they can't believe it," he said.

Not far away in the potato complex, Stephen L. Sinden's laboratory is a focus of worldwide attention: He has discovered how to breed resistance to the Colorado potato beetle into plants. The ravenous beetle, unfazed by pesticides, causes millions of dollars of damage in the East every year and is eating its way across the West.

Walls of the walk-in cooler essential to Sinden's research on enzymes and DNA are crumbling from uncontrollable humidity, even though the cooler was renovated 25 years ago. "We have to pay $18 per square foot here, which means we can't buy certain supplies we need . . . ," Sinden said.

"It's depressing when you go around to visit other institutions and universities and see the facilities they have. You come back and say, 'My God, how can we compete? How can we contribute?' "

What do visitors to Sinden's renowned laboratory think?

"If they are from high-tech institutions, they look around and they are flabbergasted," he said. "If they are from an underdeveloped country, they understand."