U.S. farm income is almost certain to throttle back in the coming years, as lower commodity prices and higher interest rates squeeze margins for most farmers. But the expected income decline won’t necessarily spark a farm income bust and land price collapse as it did in the 1980s, according to Mike Boehlje, of Purdue University’s Center for Food and Agricultural Business.

"I really envision more of a soft landing," Boehlje said last week at a conference to examine agricultural risk at the Federal Reserve Bank of Chicago. "We could see income declines of 20 to 25 percent, which is not insignificant, but I don’t necessarily see a bust like we had in the 1980s."

After studying historical trends in the U.S. agricultural economy, Boehlje and other economists...