Surging fertilizer prices are raising concerns over food security across Asia as the same geopolitical shock rattling energy markets is squeezing supplies of crop nutrients.

The Middle East is a major fertilizer exporter, accounting for about 30 percent of the global fertilizer trade, as liquefied natural gas is a feedstock for making fertilizer.

Seaborne fertilizer travels through the Strait of Hormuz, but the critical waterway remains effectively closed as the United States-Israel attacks on Iran entered their fourth week.

The volatility in energy prices has spilled over into fertilizer prices. The Middle East granular urea was trading at $665 per metric ton on Friday, or nearly 40 percent more compared with $485 a ton late last month.

Urea, a nitrogen-rich fertilizer, is widely used in planting rice and wheat. The two food crops are staples across the Asia-Pacific.

"As fertilizer becomes more expensive, farmers may use less of it, which can lower crop yields," said Marie Annette Galvez-Dacul, executive director of the Center for Food and Agri Business at the University of Asia and the Pacific in Manila.

"This can lead to higher food prices and make food less affordable, even if supply is still available," she said.

In the Philippines, the world's biggest rice importer, the government assured that rice supply is stable thanks to existing stocks.

Agriculture Secretary Francisco Tiu Laurel Jr said at a briefing on Thursday that the country has sufficient supply of agricultural products for at least the next 90 days. The state-owned National Food Authority has about 400,000 tons of rice in its warehouses, he added.

Elyssa Kaur Ludher, visiting fellow at the ISEAS-Yusof Ishak Institute in Singapore, said key rice exporters in India, Vietnam and Thailand are dependent on imported fertilizers from the Gulf countries. If rice production in these countries decreases, it will also limit the supply of tradable rice, she said.

Rice is a thinly traded commodity, with only 10 percent of global production traded internationally.

"In the past, such shortages have triggered food-item export bans," Ludher said. "It is hoped that (exporting) countries will not resort to that as it destabilizes markets and further pushes up prices."

A rice export ban will also exacerbate global food insecurity, she added.

Unlike fuel prices, which immediately shoot up in line with global oil prices, the effect of fertilizer on food prices is delayed, she said.

"The price shock will take one to two months to alter planting decisions and three to nine months to fully manifest in grocery store prices," she said.

'Medium-term risk'

The International Rice Research Institute in the Philippines said higher fertilizer prices are the "bigger medium-term risk" for the global rice trade. In India alone, at least three local fertilizer manufacturing plants have cut down production because of the limited supply of liquefied natural gas, the institute said.

Paul Teng, a visiting senior fellow at the ISEAS-Yusof Ishak Institute, said it is fortunate that most of the current rice crop in Southeast Asia has already been planted and fertilizers were bought well before the conflict erupted.

"But if the choke point persists, then it is likely that both supply and prices of rice will be affected for Southeast Asian farmers," Teng said. He expects higher prices to push farmers into reducing fertilizer usage, which will translate to lower output not only of rice but also other crops, including vegetables, palm oil and cacao.

prime@chinadailyapac.com