Farmers are used to managing uncertainty—weather, pests, shifting commodity prices. What they are not built for is a sudden shock to the very inputs that make modern yields possible. That is exactly what the Iran war and the effective bottlenecking of the Strait of Hormuz have created: a fertiliser crisis that is already forcing growers to rethink what they plant, how much they can afford to produce, and what food might cost by the time today’s crops are harvested.

The Chokepoint Below the Headlines

On a map, the Strait of Hormuz looks like a narrow blue thread stitched between Iran and the Arabian Peninsula. In reality, it is one of the most important seams in the global food system. The United Nations and international agencies estimate that roughly one‑third of the world’s seaborne fertiliser trade—about 16 million tonnes a year—moves through this single corridor, alongside a major share of oil and gas.

Since late February, that thread has frayed. Traffic has fallen from around 130 ships a day to single digits as attacks and missile strikes have made transit risky and insurance costs surge. The immediate headlines have focused on oil, but the same disruption is hitting the bulk carriers that haul nitrogen, ammonia, sulphur and other fertiliser ingredients out of Saudi Arabia, Qatar, Iran, the UAE and their neighbours.

For fertiliser, the concentration is extreme. UN and FAO experts note that:

• 30–35% of global urea supply originates from the Hormuz region.
• 20–30% of ammonia exports, a key nitrogen source, come from the same cluster of countries.
• Close to half of all globally traded sulphur—vital for phosphate fertilisers—passes through this corridor.

In other words, a regional conflict has collided directly with one of the world’s most fragile agricultural supply chains.

Why Farmers Feel the Shock So Quickly

Fertiliser is not a nice‑to‑have; it is the backbone of modern yields. Nitrogen fertilisers like urea, which are heavily sourced from the Middle East, must be applied every single growing season to keep crops like wheat, maize, rapeseed and many fruits and vegetables productive. FAO economists are blunt: you can skip a year of potash or phosphates in a pinch, but you “can’t skip a season of nitrogen” without paying in lost output later.

The timing of the Hormuz disruption is brutal. In the Northern Hemisphere, farmers are entering the critical spring window when fields are fertilised and planted. South of the equator, others are trying to bring in harvests before winter. Both cycles depend on predictable deliveries of fertiliser that are now delayed, rerouted or simply unavailable.

Global prices have reacted accordingly. UN and FAO briefings describe nitrogen fertiliser benchmarks like urea and ammonia jumping 20–50% in a matter of weeks, revisiting the peaks last seen during the 2022 Russia–Ukraine shock. For farmers who were already working on thin margins, that kind of spike turns spreadsheets upside down. Some will cut back on application rates; others will switch crops entirely, trading higher‑input staples like wheat or maize for less demanding rotations.

The consequences will not be immediate empty shelves. FAO points out that the world entered 2026 with relatively high stocks of basic grains—buffer inventory built up over previous seasons. But if nitrogen use falls now, yields will start to slip as the year wears on. A 5% hit to global output may sound small on paper; on supermarket shelves, it translates into higher prices and tighter availability.

Food Security in the Line of Fire

What worries agrifood specialists is not just the price of a single input, but how many systems are being stressed at once. The FAO’s analysis of the conflict highlights three overlapping pressures:

• Higher energy prices increase the cost of producing fertiliser, since natural gas is a core feedstock for nitrogen.
• Shipping disruptions in the Strait and nearby routes raise freight costs and lengthen delivery times.
• Export restrictions from other major suppliers, such as China, further tighten global availability.

Fertiliser is the common denominator. When supplies are constrained, the first places to feel it are not the richest grain belts, but the regions that already spend a disproportionate share of household income on food. FAO economists single out parts of East Africa, South Asia and other “emerging markets east of Suez” as especially vulnerable to any combination of higher prices and reduced deliveries.

Even countries with stronger fertiliser industries, like the United States, are not insulated. Industry data compiled by global agencies show that around a third of the nitrogen, phosphate and potash used in U.S. agriculture is imported, meaning American farmers are also exposed to price shocks and possible rationing. For them, the question is not whether fertiliser is available at all, but whether it is affordable enough to apply at optimal rates.

A New Kind of Fertility Calendar

In calmer years, a farmer’s calendar is anchored by seasons and soil. Now, shipping lanes and geopolitical briefings sit alongside weather apps and soil tests. NFU‑style organisations across multiple countries are already warning that if current trends hold, food prices will begin to reflect today’s fertiliser costs within months—not years—especially for greenhouse crops, vegetables and dairy that are sensitive to feed and input shifts.

Global agencies are urging three kinds of responses. In the short term, they highlight the need to:

• Keep trade routes as open as possible for critical inputs like fertiliser.
• Use buffer stocks strategically, rather than panic‑drawing them down.
• Provide targeted support to smallholders and import‑dependent countries most at risk.

Longer term, organisations from the UN to specialised fertiliser associations argue that the Hormuz crisis underlines a structural vulnerability: global food production is simply too dependent on a handful of chokepoints and fossil‑fuel‑derived nutrients. Diversifying supply, investing in more efficient use, and exploring biological and local alternatives will not happen overnight—but the cost of waiting is becoming hard to ignore.

For now, the reality on the ground, and in the spreadsheets of growers from Kent to Kansas, is stark. When a third of the world’s fertiliser is squeezed through a narrowing strait, the effects ripple far beyond energy markets. They show up in planting decisions, in supermarket receipts, and in the everyday question of how much it costs to put bread—and everything that grows alongside it—on the table.