Fertilizer tied to the Strait of Hormuz is getting harder to buy, and that is forcing Iowa farmer Steve Kuiper to warn that planting-season costs are climbing fast. Kuiper, a fourth-generation corn and soybean grower who manages 4,000 acres and serves as first vice president of the Iowa Corn Growers Association, said the uncertainty spreading from the Middle East is already rippling through the farm economy.

“About 30% of farmers were very concerned about 2026,” Kuiper said, adding that roughly 40% had not yet purchased their full fertility needs by the end of March. Products such as urea and anhydrous are now pushing near historic highs, and Kuiper said they have risen 40 to 80% since then. For growers who wait to buy, the hit can be immediate. “Some farmers typically just don’t purchase fertilizer in advance. They just buy it as needed. they’re getting hit very hard,” he said.

The strain is rooted in global shipping. Before the war, roughly a third of the world’s fertilizer ingredients moved through the Strait of Hormuz, and disruptions there have restricted supply. Kuiper said the route remains critical even if the conflict eases because oil and petroleum would likely be prioritized first. Fertilizer would still have to come through the strait, be offloaded, and then be hauled up the Mississippi River before it reaches Midwestern farms.

That logistics chain matters because farmers are making decisions now for crops that will not be sold until later. Kuiper said the industry is entering a period in which growers do not know their cost per acre, making it difficult to plan seed, fertilizer and sales. “You don’t know what your cost per acre is going to be. And so, it’s difficult to make that sales decision if you don’t know what your cost is going to be,” he said. A recent National Corn Growers Association study, he added, shows farmers are even more worried about their 2027 crop.

Kuiper said the uncertainty is already changing behavior. Some farmers may scale back and let insurance cover part of the shortfall, he said, while recent tariffs are also adding to the cost burden. “What does that do for supply and demand in the world,” he said, arguing that tight fertilizer markets can lift commodity prices but only if supply remains adequate to meet demand.

The pressure does not stop with input costs. Kuiper said ag lenders are likely to move quickly if working capital weakens, and that several farmers are already feeling that squeeze. “Two guys that I know who are really good farmers. Their bank told them if it doesn’t get better this coming year, we just can’t back you for 2027,” he said. “So, that’s in the back of a lot of people’s minds.”

For growers heading into another season of uncertainty, the problem is no longer just a higher fertilizer bill. It is the possibility that the money to plant, borrow and sell gets tighter at the same time the world’s supply chain does.