American farms run on Canadian potash. In November it was made a critical mineral.
The United States is 92 percent reliant on imported potash and Canada supplies 79 percent of those imports. Potash was added to the US critical minerals list on 7 November 2025. Two and a half months later a trade proclamation directed negotiations, and in February the trade representative asked the public how to enforce minimum prices at the border on minerals defined by exactly that list. Today the Treasury Secretary welcomed the first reference prices. Potash is not among them yet.
There is no substitute for potassium. That is not a figure of speech and it is not our phrasing. It is a sentence in a United States government publication.
“No substitutes exist for potassium as an essential plant nutrient and as an essential nutritional requirement for animals and humans.”
Confirmed US Geological Survey, Mineral Commodity Summaries, February 2026, potash chapter, prepared by Stephen M. Jasinski. A United States federal work and in the public domain.
Four documents published over the last nine months have moved potash from an unremarkable duty-free import into the middle of a trade negotiation. None of them is secret and none has been widely connected to the others.
First, the dependency, measured
| United States potash, USGS figures | Value |
|---|---|
| Net import reliance, 2025 estimate | 92 percent of apparent consumption |
| Import sources, 2021 to 2024 | Canada 79 percent, Russia 12, Israel 3, other 6 |
| US mine production, 2025 estimate | 500 thousand tons K2O equivalent |
| Canadian mine production, 2025 estimate | 15,000 thousand tons |
| World production, 2025 estimate | 49,000 thousand tons |
| Share of US potash sales going to the fertilizer industry | About 85 percent |
| US mine and mill employment | About 900 people |
| Recycling | None |
| Government stockpile | None |
Measured USGS Mineral Commodity Summaries, February 2026. Production in thousand metric tons of potassium oxide equivalent. Net import reliance is defined by USGS as imports minus exports as a percentage of apparent consumption.
Putting those two percentages together, and the arithmetic is ours. If Canada supplies 79 percent of the imports and imports account for 92 percent of what is consumed, then Canadian potash is roughly three quarters of all the potash used in the United States. Using the gross import figure rather than the net reliance figure gives about 75 percent.
The caveat, stated because it matters. The 79 percent is a four-year average covering 2021 to 2024. The consumption and import figures are 2025 estimates. Combining them mixes periods, and USGS does not publish the product of the two as a single number. We are showing the working rather than presenting it as their figure.
Canada produces thirty times what the United States produces, and about 31 percent of world output. American production comes from two companies in southeastern New Mexico and two more in Utah, employing around 900 people in total.
Second, the list
On 7 November 2025 the Final 2025 List of Critical Minerals was published in the Federal Register at 90 FR 50494. USGS records what changed from the 2022 list.
“The changes in the 2025 list from the prior list published in 2022 were the addition of copper, lead, potash, rhenium, silicon, and silver... Based on that input, boron, metallurgical coal, phosphate rock, and uranium were also added.”
Confirmed USGS Mineral Commodity Summaries, February 2026, potash chapter. Both halves of the fertiliser input story, potash and phosphate rock, were added in the same revision. Neither was on the 2022 list.
Third, the proclamation and the notice
On 14 January 2026 the President issued Proclamation 11001, adjusting imports of processed critical minerals and their derivative products. The trade representative's own account of it is that the President concurred with the Commerce Secretary's finding, under section 232 of the Trade Expansion Act of 1962, that processed critical minerals and their derivatives are being imported in such quantities and circumstances as to threaten to impair national security, and directed Commerce and the trade representative to negotiate agreements.
On 26 February 2026 the Office of the United States Trade Representative published a request for comments, 91 FR 9686, on the design of a plurilateral agreement on trade in critical minerals. Two passages in it do the work.
“USTR anticipates that such an agreement will include a commitment by all parties to implement minimum prices or other price mechanisms, with appropriate border measures, to ensure secure and fairly-priced markets among the parties to the agreement.”
“What are mechanisms by which the United States and other parties to a plurilateral agreement could enforce minimum prices for imports of critical minerals so as to promote production and investment for the parties to the agreement? These may include, but are not limited to, ad valorem, specific, or compound tariffs and quotas or tariff-rate quotas.”
Confirmed Office of the United States Trade Representative, 91 FR 9686, published 26 February 2026, docket USTR-2026-0034, signed by Deputy United States Trade Representative Jeffrey Goettman. Comments closed 19 March 2026. A United States federal work and in the public domain.
This is the join, and it is a citation rather than an inference. The notice states that critical minerals are “specified by the U.S. Geological Service at 90 FR 50494”, and asks what factors should be used in prioritising “certain critical minerals, as defined by the U.S. Geological Survey, to be included within the scope of a plurilateral agreement”.
90 FR 50494 is the list that added potash. The document defining the pool of minerals is the document that put potash in the pool, three and a half months earlier.
The notice also asks what measures parties could take to restrict imports from trading partners that are not party to the agreement, and how to evaluate the appropriate phase-in time for price-related measures for each critical mineral.
Unconfirmed Potash being in the pool is not the same as potash being in scope. The whole purpose of the first section of that notice is to ask which minerals should be prioritised. No agreement exists, no text has been published, no signatories have been named, and no mineral has been confirmed as in scope. Anyone telling you potash is covered is telling you something no published document says.
Fourth, today
On 7 August 2026 the Treasury Secretary issued a statement welcoming S&P Global's introduction of new reference prices for critical minerals. The benchmarks announced cover gallium, germanium, tungsten, antimony, and neodymium and praseodymium.
Potash is not among them.
The same statement describes the agreement being negotiated in terms the February notice did not use, saying it “seeks to establish phased-in, mineral-specific price floors adjusted at the border while advancing common standards among like-minded trading partners”, and that negotiations build on discussions among G7 finance and trade ministers as well as action plans developed with Japan, Mexico and the European Union.
Canada is not named. The three partners with action plans are Japan, Mexico and the European Union. Canada is a G7 member and supplies 79 percent of American potash imports, and it does not appear in that sentence.
We are not going to guess at what that means. A press release naming three partners is not a list of all partners, and no negotiating party list has been published. What we can report is which countries Treasury chose to name today and which it did not.
What potash costs, and what it costs to bring in
| Year | All products, dollars per ton K2O | Muriate of potash |
|---|---|---|
| 2021 | 1,120 | 650 |
| 2022 | 1,790 | 980 |
| 2023 | 1,250 | 620 |
| 2024 | 1,150 | 690 |
| 2025 estimate | 1,200 | 600 |
Measured USGS average price, free on board mine, dollars per metric ton of potassium oxide equivalent. Muriate of potash is the bulk agricultural product. Its 2025 estimate is lower than every year shown except 2023.
The duty position today is the other half of the picture, and it is short.
| Tariff item | Number | Normal trade relations rate |
|---|---|---|
| Potassium chloride, 62 percent K2O or less | 3104.20.0010 | Free |
| Potassium chloride, greater than 62 percent K2O | 3104.20.0050 | Free |
| Potassium sulfate | 3104.30.0000 | Free |
| Potassic fertilizers, other | 3104.90.0100 | Free |
| Potassium nitrate | 2834.21.0000 | Free |
Measured USGS Mineral Commodity Summaries, February 2026, stated as at 31 December 2025. These are normal trade relations rates only. Section 232 actions, emergency economic powers measures and other instruments can sit on top of a normal trade relations rate.
The precedent the notice asks about
Section H of the February notice asks whether any historical commodity agreement could serve as a reference for designing the pricing mechanism. It names one.
“Would the features and the impact of the International Tin Agreement (1956), which remained in force for 29 years, or other relevant commodity agreements, serve as a useful reference for designing a plurilateral agreement on trade in critical minerals?”
Confirmed 91 FR 9686, section I.H.2. The question is quoted in full and the parenthetical and the duration are the notice's own.
The notice describes how long that agreement lasted. It does not describe how it ended. We are recording the omission and not filling it. A reader who wants to evaluate the precedent the trade representative raised has to go and look it up, and that is worth knowing before the agreement is designed rather than after.
What this does to a household
The chain is short and it is real, and no part of it has moved yet. About 85 percent of American potash goes to fertilizer. There is no substitute for potassium. A price floor enforced at the border on a product that is 92 percent imported, and three quarters Canadian, would reach a grocery bill through the cost of growing food. That is the mechanism. Whether it operates depends on decisions nobody has taken and documents nobody has published.
For a Canadian reader the exposure runs the other way as well. Canadian potash production is roughly 31 percent of world output and its largest customer is 92 percent import-reliant. Whatever is decided in that negotiation is decided about a Canadian export industry, and Canada was not named among the partners in today's statement.
Sources and verification
Addresses below are printed in full so you can copy one and check us. We do not link out.
Every potash figure: import reliance, import sources, production, reserves, prices, tariff lines, employment, the fertilizer share, the substitutes sentence, and the account of what the 2025 critical minerals list added. US Geological Survey, Mineral Commodity Summaries, February 2026, potash chapter, prepared by Stephen M. Jasinski. A United States federal work, in the public domain. Read in full 7 August 2026. Measured https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-potash.pdf
The price floor language, the border enforcement mechanisms, the tariff-rate quota reference, the definition of scope by reference to 90 FR 50494, the restriction of imports from non-parties, the section 232 background, and the International Tin Agreement question. Office of the United States Trade Representative, “Request for Comments on the Design of a Plurilateral Agreement on Trade in Critical Minerals and Policy Actions To Strengthen the Resilience of Critical Mineral Supply Chains,” 91 FR 9686, published 26 February 2026, document 2026-03868, docket USTR-2026-0034. A United States federal work, in the public domain. Read in full 7 August 2026. Confirmed https://www.federalregister.gov/documents/2026/02/26/2026-03868/request-for-comments-on-the-design-of-a-plurilateral-agreement-on-trade-in-critical-minerals-and
The five reference prices, the phased-in mineral-specific price floors adjusted at the border, the naming of Japan, Mexico and the European Union, and the count of nearly 2,500 comments. US Department of the Treasury, “Secretary Bessent Issues Statement Welcoming S&P Global Release of Critical Mineral Reference Prices,” 7 August 2026. A United States federal work, in the public domain. Confirmed https://home.treasury.gov/news/press-releases/sb0600
The Final 2025 List of Critical Minerals, as cited by the USGS chapter above. Federal Register, 7 November 2025, 90 FR 50494. Printed in full so a reader can check the list directly. Unconfirmed https://www.federalregister.gov/documents/2025/11/07/2025-19813/final-2025-list-of-critical-minerals