LELAND, Miss.  Catfish farmers across the South, unable to cope with the soaring cost of corn and soybean feed, are draining their ponds.

“It’s a dead business,” said John Dillard, who pioneered the commercial farming of catfish in the late 1960s. Last year Dillard & Company raised 11 million fish. Next year it will raise none. People can eat imported fish, Mr. Dillard said, just as they use imported oil.

As for his 55 employees? “Those jobs are gone.”

Corn and soybeans have nearly tripled in price in the last two years, for many reasons: harvest shortfalls, increasing demand by the Asian middle class, government mandates for corn to produce ethanol and, most recently, the flooding in the Midwest.

This is creating a bonanza for corn and soybean farmers but is wreaking havoc on consumers, who are seeing price spikes in the grocery store and in restaurants. Hog and chicken producers as well as cattle ranchers, all of whom depend on grain for feed, are being severely squeezed.