CHICAGO, March 13 (Reuters) - U.S. grain prices have surged since the Iran war began, triggering a flurry of corn and soybean sales by farmers who squirreled away last year's harvests due to weak prices.

 Since the U.S. and Israel attacked Iran, farmers across the Midwest have capitalized on climbing prices by selling corn, soy and wheat from storage bins to ethanol producers and major traders including Archer-Daniels-Midland ( ADM ) and Bunge. 

Growers also raced to sign contracts to pre-sell crops they have not yet planted and expect to harvest this year.

The rally was a welcome surprise for farmers and allowed many to lock in modest profits to cover soaring fertilizer, chemical and seed bills, though they said the gains were not enough to end a downturn in the agricultural economy.

Dave Kestel, a farmer in Manhattan, Illinois, said he sold about 40% of the corn and soybeans he harvested last year and roughly 10% of what he expects to harvest in 2026. He had been paying daily charges to store last year's crops and was eager to unload them when prices jumped.

"I was doing the farmer happy dance," Kestel said.

Soybean futures touched a May 2024 high above $12 per bushel on the Chicago Board of Trade on Thursday. Corn futures reached the highest point since May 2025 this week, while wheat set the highest level since June 2024.

Last year, prices sagged due to ample supplies and as soy exports suffered due to President Donald Trump's trade war with China. The U.S. Department of Agriculture has started distributing $12 billion in aid to farmers hurt by Trump's trade policy.

QUICK TO SELL

Analysts said the aid strengthens balance sheets in the short term but does little to improve underlying profitability.

Farmers were quick to sell crops as they sought to stem losses and questioned how long the rally would last. Corn and soybean prices at times have each been up about 6% from their levels since before the war began.

"We are basically filling all of our grain elevators in North America and in South America as we speak," Julio Garros, Bunge's chief operating officer, said during an investor event on Tuesday.

A spike in oil prices because of the war lifted prices for crops used to make biofuels. Also boosting corn prices, the conflict disrupted crucial fertilizer shipments.

The gains were generally enough to allow farmers to make money, though break-even levels vary, said Angie Setzer, partner at advisory firm Consus Ag Consulting.

"When the market rallied big, it provided a lot of opportunities that they had been waiting for," said Setzer, whose customers sold corn, soybeans and wheat. 

Some farmers took chances on the size of their fall harvests. Keaton Lyons, who farms about 1,200 acres in Rensselaer, Indiana, agreed to sell about 100,000 bushels of corn he will soon plant.

"Pricewise, I feel really good," Lyons said. "The thing that I'm nervous about is we don't have a kernel in the ground and we're 65% sold."

FARMERS SEIZE OPPORTUNITY

Many farmers sold much of last year's soybean crop in late 2025, but a large share of corn remained unpriced, so the recent surge could really help corn-heavy operations, said Wesley Davis, partner at Meridian Agribusiness Advisors. 

As of December 1, growers were storing 14% more corn on farms than a year earlier and 2% more soybeans, U.S. Department of Agriculture data show.  

In Waseca, Minnesota, Richard Guse, who farms about 3,500 acres with his brother and son, said he made a small profit selling about a third of his 2025 corn crop to ethanol producer Guardian Energy for $4.25 per bushel this week.

"The prices have run up in a hurry," Guse said. "It goes down a lot faster than it comes up."