By almost any measure -- except the one that counts -- Henry Heidelberger had a good year on the 1,026 acres he farms about eight miles west of the Mississippi River here in Phillips County.

He had a bountiful rice and soybean harvest last fall. The wheat crop he harvested last spring was good, too. His fields already are verdant with the sprouts that will be next June's wheat crop.

But Heidelberger -- 48, and nine years a farmer -- lost money in this "good" year. He still owes his bank $5,000 of the $140,000 he borrowed to produce the 1982 crop, and he has payments coming due during the next few months on money he has borrowed to purchase land, improve a portion of his acreage for rice production, and buy a tractor and a car.

By next spring, when Heidelberger must borrow to finance his 1983 crops, he will be in arrears to his creditors by more than $54,000. He will have to carry that over and make it part of his 1983 crop production financing.

Increasingly, the plight of farmers like Heidelberger is being felt by rural banks, which are forced to carry borrowers who can't pay off their loans from the proceeds of their crop sales.

Although the nation's rural banks have shed many of their poorer credit risks, their agriculture portfolio is in little better shape than the international loan portfolio of the big multinational banks.

And the rural bankers are afraid that if they foreclose on too many of their borrowers, forcing them to sell their property, land values would plummet so fast that other well-collateralized loans in the banks' portfolios would become questionable.

"This year there's a good bunch of farmers who are going to have carryovers and one or two will have problems getting refinanced," says Heidelberger's banker, E. F. Kalb Jr., vice president of Merchants & Farmers Bank here.

Nationwide, according to an American Bankers Association survey, 4 1/2 percent of the farmers who borrow from banks will be turned away next year, and half of those will find no alternate lender. They likely will have to sell off their farms.

"In the old days in eastern Arkansas , the production loan was paid out of the rice crop. If there was any carryover, beans paid for that and the equipment and land, and the farmer had a little left over to live on," explains Ray Hambrick, executive vice president of First National Bank of DeWitt, a $47 million institution about 60 miles southwest of West Helena in Arkansas County.

But three years of bountiful crops have produced a huge and growing surplus that has driven farm prices down sharply, from the cornfields of Illinois to the wheat fields of Kansas and the cotton fields of West Texas.

Agriculture was among the more prosperous sectors of the economy in 1979, when net farm income was a record $27 billion. In each of the last two years, that figure has dropped to about $19 billion.

At the same time, the costs of production -- from fertilizers to pesticides to equipment -- has continued to rise, and high interest rates have pinched the farmer hard.

During the same period, farm borrowing has grown sharply. In 1979, the nation's farmers owed $117.7 billion, about $40 billion of that to banks. In 1982, they owed $164 billion, of which more than $45 billion was due to banks. Bankers are the biggest lenders to farmers for crop production. The government and life insurance companies play a larger role in financing land purchases.

Like Heidelberger, nearly all farmers must borrow in the spring to work and live until fall, when the crops come in. Growing numbers of them are finding that the cash they collect in the fall is insufficient to pay for the direct costs of producing their crop, let alone their "capital costs" of equipment and land.

"It's almost like starting over," Heidelberger said.

Almost, but not quite. When he started farming nine years ago, he made money -- enough not only to make all his debt payments, but also to record some profits. "In 1974 the same horsepower tractor I have now cost $12,700. Today it costs $37,000. But the beans I sold for $7 then go for $5.50 today," he says.

Even though he is losing money, Heidelberger is still a good credit risk. According to Kalb, his banker, Heidelberger owes about $460,000 on land that is worth more than $1 million. Like a homeowner taking out a second mortgage, he will have to trade some of the equity he has built in his land to secure his crop production loan for 1983.

Because his land is worth so much more than he owes on it, Heidelberger won't have problems financing his next crop year. He can use that equity as collateral for his 1983 loan. But not all farmers have as much equity. According to Mike Fitch, vice president of San Francisco's giant Wells Fargo Bank, farmers who are just starting out, or who expanded sharply during the prosperous 1970s, are saddled with high-cost equipment and land financed at sky-high interest rates, and have no cushion. They are the first casualties of the farm depression of the 1980s.

Hambrick expects 50 percent of the 130 farmers who have borrowed from First National of DeWitt will not be able to pay back their loans in full. "If the situation continues like it is, it'll be 70 to 80 percent next year," he added.

Hambrick said 90 percent of his bank's loan portolio is farm-related. But the bank prospers today because only half of its assets are loans; like many others rural banks, it invests heavily in government securities and other stable assets.

As a result, rural banks have plenty of money to lend. But they have fewer farm customers they are willing to lend to.

Hambrick said he would like to stop making loans to about 18 of his current farmer customers, but sees no way the loans can be worked out without forcing the farmer to liquidate.

If, as some fear, a number of farmers are forced out of business this year and have to sell their properties, the one bulwark of the farm economy -- land values -- could crumble.

The thought of a precipitous fall in land prices is frightening to the banks. Land values are the linchpin of rural lending, since banks are no longer willing to secure a production loan with the crop being financed. Prices are too low and volatile.

Between February 1981 and April 1982 farm land prices declined 1 percent -- the first decline in nearly 30 years, the Agriculture Department reported. In Phillips County prices have fallen as much as 20 percent, according to William Brandon, president of the First National Bank of Phillips County, in nearby Helena. He said the best land that went for $1,500 an acre a few years ago now sells for $1,200.

Like steel companies and auto companies, farmers are hoping to hold out until the economy, and their markets, improve. They are repairing old equipment rather than buying new tractors and combines -- to the detriment of staggering companies like International Harvester and their dealers.

They also are laying off workers they used to keep on all year. Nan Milliken, who farms with her husband near DeWitt, said, "15 hired workers were turned loose last week" in the DeWitt area.

Kalb said Merchants & Farmers will carry Heidelberger until March, when it is time to negotiate the terms for his 1983 crop production loan. He'll not only have to borrow enough to cover the costs of producing 1983's crop, he'll have to add on the $54,000, plus interest, on his old loans.

But that won't make Heidelberger give up. He says he'll continue to farm even though next year promises to be no better than 1982.

"What else can you do? I can't sell out, I can't let the fields lay idle."