Canadian Potash and US Tariffs: Every Measure Since 2025, Canada's Share of US Imports, and Nutrien and Mosaic's Exposure

How Canadian potash has fared under US tariffs matters well beyond Saskatchewan. The United States imports almost all the potash its farms use, and most of it comes from Canada. Below are the tariff measures that have touched Canadian potash since 2025, with dates, followed by what two listed producers with Saskatchewan mines, Nutrien and Mosaic, report about where their tonnes go. The status shown is as of the most recent sources we could check, dated September and October 2026.

How dependent the US is on Canadian potash

According to the U.S. Geological Survey, the US imported 5.6 million tons of potash (K2O equivalent) in 2025 and produced only about 500,000 tons. Net import reliance was 92% of apparent consumption. Canada supplied 79% of US imports over 2021–2024, ahead of Russia at 12% and Israel at 3% (USGS, Mineral Commodity Summaries 2026: Potash).

Canada is also the world's largest producer. The USGS estimates Canadian mine output at 15 million tons of K2O in 2025, out of a world total of 49 million, or about 31%. Canada's reserves of 1.1 billion tons are the second-largest the USGS quantifies, after Russia's 2.0 billion. In November 2025, potash was added to the final US critical minerals list.

The tariff timeline

March 2025: IEEPA duties. The first US duties on Canadian goods under the International Emergency Economic Powers Act took effect on March 4, 2025. Potash got special treatment. From March 7, 2025, Canadian potash that qualified under the USMCA (CUSMA in Canada) was exempt. Potash that did not qualify paid an additional 10% instead of the 25% general rate (U.S. Customs and Border Protection, CSMS #64336037, March 6, 2025).

February 2026: IEEPA tariffs end. On February 20, 2026, the US Supreme Court ruled 6–3 that IEEPA does not authorize tariffs. Collection stopped for goods entered on or after February 24, 2026 (Sandler, Travis & Rosenberg, IEEPA tariff tracker). Refunds are being processed through a CBP tool called CAPE.

The measures that followed in 2026 are set out in Export Development Canada's fact sheet, last updated September 20, 2026 (EDC, U.S. tariff measures concerning Canadian goods):

• Section 122 (Feb. 24 to July 24, 2026): a 10% global import surcharge. Goods that qualified for CUSMA treatment were exempt, and the surcharge was eliminated on July 24, 2026.
• Section 301 "forced labour" duties (from July 24, 2026): 10% on goods from Canada and 16 other markets. CUSMA-qualifying goods are exempt.
• Section 338 (from Aug. 22, 2026): a 50% tariff on listed Canadian goods, which applies even to CUSMA-qualifying goods. EDC lists potash among the "notable categories not covered", together with energy, fish and critical minerals.

In short, CUSMA-qualifying Canadian potash has been exempt from each of these broad measures, and potash is outside the new 50% list. The remaining exposure is non-qualifying potash under Section 301. We could not confirm from the sources available whether potash appears in that order's product exemptions.

Prices

The World Bank's benchmark for potassium chloride (granular, CFR Brazil) averaged $367.50 per tonne in September 2026. That compares with $347.50 for 2025 as a whole and $402.90 in the second quarter of 2026 (World Bank Pink Sheet, Oct. 2, 2026).

Nutrien: most tonnes go offshore

Nutrien, based in Saskatoon, reported second-quarter 2026 results on August 5, 2026 (Nutrien Q2 2026 news release, SEC Form 6-K):

• Its potash segment sold 7.45 million tonnes in the first half of 2026. Of that, 2.21 million went to North America (about 30%) and 5.25 million offshore.
• Net selling prices were $290 per tonne in North America and $255 offshore.
• Nutrien raised its full-year potash sales guidance to 14.2 to 14.8 million tonnes, citing "strong demand in key offshore markets".
• Its "North America" figure includes Canada, so its US share is smaller than 30%.

Mosaic: a US company whose potash is now all Canadian

Mosaic, based in Tampa, completed the sale of its Carlsbad, New Mexico potash mine in April 2026. Its 10-Q says its US potash location "was sold during 2026", leaving its Saskatchewan mines (Mosaic Q2 2026 Form 10-Q). Results reported on August 4, 2026 (Mosaic Q2 2026 release):

• Potash sales were 2.0 million tonnes at an average MOP price of $275 per tonne at the mine gate.
• Potash segment adjusted EBITDA was $278 million.
• The company expects about 9 million tonnes of potash production in 2026.
• Mosaic sells its Canadian potash outside the US and Canada through Canpotex, the producers' export association.

For both companies, any duty on non-qualifying Canadian potash would land on tonnes they ship into the US market. For more, see our potash hub, Canada articles and company profiles.

How we checked this: AI-drafted from the sources linked above and checked against them by our AI editor.