OMAHA (DTN) -- Farmers will likely see higher diesel prices as they move into planting season with the U.S. attacks on Iran and Tehran's retaliatory strikes across the Middle East.

Some early indications also suggest farmers who haven't locked in their nitrogen supplies could see higher prices.

President Donald Trump on Monday said air strikes against Iran that began early Saturday could last four or five weeks, "but we have the capability to go far longer than that."

Markets responded to the conflict with front-month futures declines for corn, soybeans and wheat, while oil and diesel prices surged on Monday.

Analysts began to quickly dissect the impacts, with shipping companies suspending operations through the Strait of Hormuz. The strait between Iran and the United Arab Emirates and Oman is a major shipping route for oil, natural gas and fertilizer from several countries.

GRAIN TRADE

Grain markets declined in the March and May contracts, hurting the cash trade for farmers with grain in the bins to sell. Corn futures fell 5 1/2 cents in March, while soybeans were down 7 1/4 cents.

DTN Lead Analyst Rhett Montgomery said the grain markets likely saw some profit-taking on Monday. The higher dollar value may have encouraged traders to sell grain commodities, as well. And yet, soybean oil was trading up 1.39% on the day. Normally, that would drive soybean prices higher, but that wasn't the case.

"For whatever reasons, soybeans are taking the brunt of it today, but that might also be some anxiety about how China reacts to all of this," Montgomery said.

Wheat trade also responded more negatively to the news, with contracts falling 16 1/2 cents for March and 14 1/4 cents down for May. Wheat contracts for later months were also down more than 10 cents each.

The steep wheat decline is also a surprise because wheat has been following crude oil lately, but that didn't hold on Monday.

"Over the last month, if crude oil was up, wheat was up just on the whole geopolitical thing, but we had an ugly day today in wheat," Montgomery said.

DIESEL/FUEL PRICES

The Strait of Hormuz moves about 20 million barrels of crude oil and other petroleum products each day -- roughly 20% of global demand.

In comparison, the U.S. exports about 10 million barrels of petroleum products daily.

ICE Brent crude for May delivery hit a 14-month high of $82.37 before settling at $77.74, up $4.87, or 6.7%.

Diesel futures on ICE rose to a two-year high on Monday as well. Diesel prices were trading at nearly $3 a gallon -- the highest since late 2023, according to the Wall Street Journal.

The current average U.S. diesel price is $3.77 a gallon, up about 12 cents from a year ago, according to AAA.

One analyst who shared details with DTN on background also said liquified natural gas (LNG) exports will also be affected by the trade disruption, which could push up prices for nitrogen as well. Like petroleum, the Strait of Hormuz accounts for roughly 20% of global LNG trade. Qatar halted production at the world's largest LNG export plant after an attack by Iran.

FERTILIZER IMPACTS

The ripple effects were felt in nitrogen prices for products sitting at port in New Orleans.

Urea prices for barges in New Orleans traded from $520-$550 a ton, according to CRU Group, up from an average of $475 a ton last week.

That suggests retailers could see more pressure on nitrogen fertilizer prices overall. DTN analysts saw reports of at least some fertilizer retailers either pulling prices for nitrogen fertilizer or farmers unable to get a commitment to lock in a price.

Qatar, Saudi Arabia, Oman, the United Arab Emirates and Iran are all major exporters of nitrogen products, especially urea. Qatar, Oman and Saudi Arabia are all among top exporters of urea to the U.S.

"In other words, close to one-quarter of globally traded nitrogen fertilizer -- and a meaningful share of total global nitrogen production -- moves through that single maritime chokepoint that is now threatened by war," Forbes wrote in its analysis of the situation.

The bombing attacks did cause some stocks to rise, even though the overall stock market declined. CF Industries saw its stock price jump more than 3% on Monday over speculation about the impacts on agricultural inputs. Other fertilizer companies, such as Nutrien and Mosaic, saw an initial stock bump early Monday, but then their shares declined as the day progressed.

Eyes will remain on the Strait of Hormuz in the coming days because the region is not only a major urea and anhydrous exporter, but also a dominant player in the phosphate market, said Josh Linville, vice president of fertilizer for StoneX.

"The phosphate market is already suffering because we don't have China, the world's largest -- historically speaking -- exporting either," Linville said in a StoneX recorded interview posted to social media. "This has made a very bad situation and probably about the worst time of year on the calendar."

Chris Clayton can be reached at Chris.Clayton@dtn.com

Follow him on social platform X @ChrisClaytonDTN

(c) Copyright 2026 DTN, LLC. All rights reserved.