They call farming a cyclical business, but few cycles have had the ups and downs of corn prices over the last few years.

Two years ago, corn and soybean farmer Carol Miller surveyed her 118 dry acres in Ankeny, Iowa, during the worst Midwest drought in a half century. "We probably are going to lose 20 to 40 percent," she said in August, 2012. Two years later, water isn't the problem. Miller now may have too much corn.

"I can never say too much," she said.

It does appear, however, that she has plenty, and so does everyone else. The USDA is expecting a record corn harvest. A separate survey last week indicated a dry July may bring down yields a bit, though not significantly.

Corn at Miller's local grain elevator is being sold for as little as $3.50 a bushel, less than half the peak of $8 back during the worst of the drought. Going into this season, Miller contracted some corn for more than $4 a bushel, and her husband wishes they'd pre-sold the whole thing.

"With the cost of production and everything, it's going to take all the corn that you can harvest to meet your bills," Miller said. She said some reports suggest that corn under $4 a bushel is below break even.

Low prices have farmers holding off purchases, even as many are flush with profits from a multi-year run up in corn. A tax break for buying equipment has also come to an end. Deere is laying off more 1,000 manufacturing employees, and Wells Fargo reports that "The farm equipment cycle peaked in 2013 and has entered a period of decline that we believe will persist for multiple years."

Goldman Sachs estimates the increase globally in corn acreage has left the world market with 300 million bushels of "net surplus" a year. "With crop prices near cost of production in many areas and farm incomes down 25 percent in 2014-2015, by our estimates, we expect significantly tighter farm spending over the next year." It has a "sell" rating on Deere and AGCO.

"I wouldn't call what's going on right now in the agricultural industry anything like a catastrophic downturn. It's a mild downturn," said Alistair McLelland, AGCO's vice president of marketing for North America. His company hopes to weather the storm in North America by gaining market share in the midrange tractor segment, and while he expects sales of tractors and other equipment to fall in here this year, he thinks it's due to psychological factors rather than financial.

"If you saw your income coming down because your salary had been reduced, you'd tend to be a little more reluctant to be spending your money," he said. However, "We are still going to have farm income levels well above the 10-year average."

Carol Miller said she and her husband would like to buy more equipment this year, but they have to wait and see how the harvest turns out. "We were talking to a dealer just the other day for a trade on a combine, but it would be for a used combine, it wouldn't be for a brand new one."

As a result of lower prices, many farmers who have invested in extra storage over the last few years are considering keeping some of their harvest. "They have more flexibility to hold out for better prices," writes Credit Suisse.

"Our bins are empty right now," Miller said. Will she fill them with corn she's holding back from the market? "We'll wait to see what the markets do."

Coloring her decision is the knowledge that some neighbors are still holding onto corn from last year. Hold back too much corn, and you may run out of space to store it. "You're either going to have to truck it to an elevator and pay storage," Miller said, "or you're going to have to think about selling it."

Of course, for grain farmers, there is crop insurance, and under the new farm bill there are new options for coverage as the government phases out direct payment subsidies. Carol Miller will be taking a class next week to learn about her subsidized crop insurance choices. In the meantime, she's hoping there are no last-minute thunderstorms or hail before she begins to harvest.

"We cannot count on every single report coming out, because things change," said Miller. "It looks like a good year, but then again, we won't know until we get the combine in the field and get going."

Article link: http://www.cnbc.com/id/101947544