The escalating war involving Iran, the United States and Israel is already hitting global agricultural supply chains. As of early March 2026, the conflict has disrupted China's imports of sulphur, a critical raw material used in fertilizer production, just as the country begins its vital spring planting season-a development that could ripple through global food and fertilizer markets.

China, the world's largest grain producer, relies heavily on imported sulphur to manufacture phosphate fertilizers and agricultural chemicals used across millions of hectares of crops. According to a report from Guosen Securities, the country imports about 47% of its sulphur supply, and more than half of those imports come from Persian Gulf nations whose exports move through the strategically critical Strait of Hormuz.

But the situation changed rapidly after Iran declared the waterway closed to commercial shipping amid the escalating conflict. The disruption has already sent shipping costs and sulphur prices sharply higher, as Chinese buyers scramble to secure supplies.

A Chinese trader based in Oman, a key regional export hub, said shipments of sulphur from the Gulf are currently struggling to leave the region.

"Freight costs have now risen to around 3,000 yuan (US$435) per container, and trade activity has almost stopped," the trader said, noting that many buyers depend on long-term supply contracts that are now stalled.

The tightening supply is beginning to be felt inside China. A fertilizer buyer in Guangxi province said sulphur is already becoming difficult to find.

"It is currently impossible to find sulphur at a reasonable price. Supply is tight everywhere," he said.

The stakes are high because sulphur is a core input for phosphate fertilizers, which are essential for producing grain, oilseeds and other staple crops. Any disruption to the supply chain during the planting season risks pushing fertilizer prices higher, potentially raising food production costs worldwide.

According to Allan Pickett, executive director for fertilizers research at S&P Global Energy, fertilizer prices delivered in mainland China averaged around US$520 per tonne during January and February, already climbing as farmers prepare fields for spring planting.

Pickett warned that continued shipping disruptions in the Strait of Hormuz could add further pressure.

"Domestic producers typically build inventories ahead of the spring application season," he explained. "But further increases in sulphur prices or shortages could affect fertilizer production and push Chinese domestic prices higher."

For now, analysts believe China's fertilizer industry has a short-term buffer. Producers generally maintain one to one-and-a-half months of raw material inventories, according to Liu Zhenpeng, an analyst at commodities research firm Sublime China Information.

However, Liu cautioned that the war could influence sulphur markets in additional ways beyond shipping disruptions.

Sulphur is largely produced as a by-product of oil refining and natural gas processing. If the conflict reduces oil and gas shipments from the Middle East, refinery activity in the region could slow, cutting sulphur production and tightening global supply even further.

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That risk is significant given China's dependence on the Gulf. Chinese customs data shows the country imported nearly 5.4 million tonnes of sulphur last year from six Gulf states-the United Arab Emirates, Oman, Saudi Arabia, Kuwait, Qatar and Iran-representing 55.7% of its total imports.

Recognizing the strategic importance of fertilizer supply, China's National Development and Reform Commission (NDRC) said in February that it would take steps to ensure stable fertilizer prices and sufficient supply during the planting season.

The government pledged to prioritize domestic sulphur supplies for fertilizer producers, while ports will give priority to ships carrying imported sulphur and other fertilizer inputs. Authorities also encouraged companies to increase imports and maintain larger inventories to stabilize the market.

For global agriculture, the situation highlights a growing reality: geopolitical conflicts are increasingly shaping food production and fertilizer supply chains. As tensions in the Middle East ripple through energy, shipping and chemical markets, the consequences could extend far beyond the region-potentially influencing crop costs, fertilizer prices and food inflation worldwide.