When fighting flares around the Strait of Hormuz, the world first watches oil prices. A less visible but arguably more pervasive channel runs through fertilizers: urea, phosphate and potash. Because modern agriculture depends on a steady flow of these inputs, disruption to Iran’s exports or to shipping through Hormuz can ripple quickly from chemical plants to the fields and, ultimately, to supermarket shelves.
Iran sits at an awkwardly pivotal intersection of energy and agricultural commodity networks. It is a major global exporter of urea and the single largest sulfur exporter by trade volume; sulfur is an indispensable feedstock for producing phosphatic fertilizers. The country’s roughly 13 million tonnes of annual urea capacity is estimated to meet 10–15% of global urea demand, while more than 30% of seaborne sulfur trade is linked to Iran. A military confrontation that closes Hormuz, or tightens sanctions and logistics, would do more than lift crude oil prices: it would choke the upstream raw materials for fertilizers.
China’s fertilizer picture is mixed. On nitrogen and finished phosphatic fertilizers Beijing can claim genuine strength—domestic synthesis capacity for ammonia and phosphate products is large enough to meet and sometimes exceed national demand. But that self-sufficiency masks structural vulnerabilities: China imports more than half of its sulfur and remains heavily dependent on imported potash (chloride of potassium), with domestic potash meeting only about 40–50% of demand. Annual potash demand is roughly 14–16 million tonnes against domestic production of 6–7.6 million tonnes, leaving an import gap in excess of eight million tonnes.
Those shortfalls matter because fertilizer prices transmit quickly through the food chain. Rising costs for nitrogen, phosphate or potash raise producers’ break-even prices for field crops; higher corn and soybean feed prices in turn squeeze margins in pork, poultry and dairy production. In a livestock sector already subject to cyclical pressures, input shocks force producers to raise slaughter prices or cut production—both of which push retail meat and dairy prices higher.
The mechanics of disruption are straightforward. A blockade of Hormuz would strand export cargoes and deter commercial shipping; aerial strikes, power outages or wartime controls could halt chemical plants inside Iran; and the threat of secondary sanctions or insurance spikes could choke trading channels even where physical logistics remain open. The result could be a rapid swing from the current ‘overhang’ in some fertilizers to an acute shortfall, and price jumps of 30–50% are already being observed in some markets.
China has tools to dampen the immediate shock: strategic reserves, targeted subsidies, freight support, and prioritising local distribution from major producing provinces. Mainland producers such as Salt Lake Co. and Zangge Mining are expanding capacity and enjoy strong state backing, while overseas investments by Chinese firms in potash projects aim to reduce import reliance over time. But these are partial fixes against geological and geopolitical realities: global potash reserves are heavily concentrated in Canada, Russia and Belarus, and domestic Chinese deposits are limited, low-grade and costly to exploit.
The crisis illustrates a broader point about modern security: energy geopolitics extends beyond fuel. Fertilizer inputs—sulfur, ammonia feedstock, potash—are strategic commodities that sit at the intersection of resource geography, industrial policy and trade routes. For a country of China’s scale, food-price stability depends not just on domestic farming but on securing far-flung commodity chains and diversifying supply, storage and industrial capacity.
A short-term flare-up would likely be manageable through policy interventions and trade adjustments, but repeated or prolonged disruptions would recalibrate incentives. Expect Beijing to accelerate overseas mineral diplomacy, enlarge strategic chemical reserves, and press state-owned and private firms to lock in long-term supplies. The Iran crisis is a reminder that food security in a globalised economy is as much about shipping lanes and sulfur as it is about seeds and tractors.