Mosaic Co.’s pullbacks in fertilizer production haven’t been enough to alleviate the impact of surging input costs from the war in Iran.

Skyrocketing prices for the sulfur required for phosphate fertilizer production caused a swing to a net loss for the Tampa-based company’s second quarter, from a year-earlier profit. Mosaic is the US’s largest phosphate producer, and nearly half of the world’s sulfur trade is linked to countries exposed to disruptions in the Strait of Hormuz.

“The ongoing Strait of Hormuz closure and the more recent Kazakhstan blockade continue to impact the global flow of sulfur, and spot prices remain unsustainably high,” Chief Executive Officer Bruce Bodine said on a call with analysts. “We have curtailed production in the US and Brazil simply because phosphate industry economics cannot accommodate current sulfur prices.”

The company’s plant in Faustina, Louisiana, remains completely idled, while its Bartow, Florida, facility is running at 40% of its targeted annual operating rate, the company said. The producer earlier this year also took about a million tons of phosphate production offline in Brazil, and pulled back further in July.

Mosaic, along with other North American fertilizer producers, has faced headwinds as inflation-pressed farmers defer the use of key crop nutrients. But peers Nutrien Ltd. and CF Industries Holdings Inc. have fared better as they produce more nitrogen fertilizers, which do not require sulfur, and last quarter reported a windfall as prices spiked.

Those soaring fertilizer prices have prompted the Trump administration to ramp up antitrust scrutiny of the industry. The White House also in June suspended duties on Moroccan phosphate for eight months or until the declared emergency over fertilizer availability ends, in a bid to address affordability for farmers. Those levies had been issued about five years ago following a petition from Mosaic.

The suspension has not yet impacted US phosphate prices, and elevated prices elsewhere in the world create “little incentive for producers to send fertilizer to the US,” Bodine said. He added that the company is “confident” the duties should continue once the suspension ends.

Mosaic posted a $104 million operating loss in its phosphate segment. That compares to an $8 million loss a year earlier. Sulfur costs in the second quarter averaged $522 per long ton, up from $379 in the first quarter. Those prices are set to rise further, as Mosaic settled third-quarter contracts for the input at $705 per long ton.

New Orleans spot diammonium phosphate prices are at the highest levels in about a year, according to data from Bloomberg Green Markets as of July 31.

(By Ilena Peng)