Environment+Energy Leader on August 28 framed sulfur as the binding cost in the US phosphate chain after Hormuz disruption and China's sulfuric acid export halt.
Third-quarter molten sulfur contracts delivered to Tampa, Florida, settled at a record $705 per long ton, up from $655 in the second quarter. US Gulf spot export prices reached $1,100 to $1,150 per metric ton in July as buyers competed for material that would normally have come from the Middle East.
DTN retail averages in the third full week of August put diammonium phosphate at $916 per ton and monoammonium phosphate at $959 per ton, up 8% and 6% year on year respectively.
University of Illinois and Ohio State researchers warned the same week that sulfur's surge could push phosphate costs higher still, with spot prices exceeding $1,000 per ton, more than 130% above January 2026 and more than 300% above August 2025.
Mosaic reported in August that it had completely idled its Faustina, Louisiana, facility while Bartow, Florida operated near 40% of its targeted annual rate. Other Central Florida plants ran in the low-to-mid 70% range.
Mosaic says roughly 80% of the sulfur used by its US operations comes from Gulf Coast refineries. The company has estimated global phosphate production could fall as much as 30 million metric tons below last year's level if constraints persist.
Producing one ton of DAP requires roughly 1.5 to 2 tons of phosphate rock, 0.4 ton of sulfur, and 0.2 ton of ammonia per University of Illinois input ratios cited in the piece.
A several-hundred-dollar sulfur price increase is difficult for manufacturers to absorb without cutting run rates or raising finished fertilizer prices.
USGS data in the article put total domestic sulfur production at an estimated 8.1 million metric tons in 2025, down from 8.32 million in 2024, with Louisiana and Texas accounting for about 54% of output.
Domestic elemental sulfur supplied about 63% of US sulfur consumption in 2025, with imports supplying 34% and Canada representing 53% of those imports from 2021 through 2024.
China's elemental sulfur imports fell to about 2.26 million tons in the first half of 2026, down 57.7% from 5.34 million tons a year earlier, with June imports alone down 85% year on year per SMM data cited in the article.
US Gulf solids that leave for North Africa and East Africa leave less molten for Florida phosphate and more room for Canadian Pacific tonnes to hold swing-supplier status.
Tampa is the US phosphate molten contract. Vancouver is the Pacific export stem for Alberta forming plants. A record Tampa print with Gulf solids still higher is the two-hub North American market after the same Hormuz shock.
Desk read: Mosaic's Faustina idle and Bartow curtailment are the production-side confirmation of the farmdoc price correlation desk covered August 25. Retail DAP near $916 with Tampa molten at $705/lt shows the lag between contract sulfur and bagged phosphate still compressing.