WASHINGTON—The Iran war has significantly constrained the global fertilizer trade through the closure of the Strait of Hormuz. It has limited supply, driving up agricultural input prices and affecting planting decisions and crop yields worldwide, ultimately hurting consumers. In particular, the closure has affected nitrogen fertilizer, for which more than 30 percent of global trade passed through the strait before the war. But crops require phosphate and potassium fertilizers, as well. While the strait is not a major chokepoint for these fertilizer types, the global fertilizer market is nonetheless affected, with diammonium phosphate prices up by 10 percent in April, and the price of muriate of potash—a potassium fertilizer—up nearly 20 percent in the first quarter of 2026 compared with a year earlier.
In the United States, nitrogen fertilizer production nearly doubled between 2010 and 2020, and the country is a major global producer of phosphate rock, used to make phosphate fertilizer. For potassium fertilizer, however, the United States is mostly dependent on imports, and its production in the United States has remained stubbornly steady, leading to an increase in imports over time. To ensure US farmers have enough of this important fertilizer for their crops going forward, Washington should advance an internationally minded policy approach toward mined nutrients, paying special attention to a main source of potassium fertilizer—potash.
A critical mineral with Canadian citizenship
Potash is a potassium-containing salt found primarily in underground deposits. Globally, potash production is highly concentrated in four countries: Canada, Russia, Belarus, and China, with Canada producing nearly a third of global annual output. US mines produce roughly 500,000 metric tons of potash per year, only about 8 percent of the 5.9 million metric tons of apparent annual US consumption. The remaining demand is met through imports, producing a net import reliance of about 92 percent. Reflecting the high concentration of global potash production, most of that supply comes from Canada (79 percent), with smaller volumes from Russia (12 percent) and other producers (9 percent) including Israel.
In the past few years, the United States has experienced several disruptions to its potash imports. In 2022, for example, both the United States and Canada issued cross-border vaccination mandates for truckers; that same year, Canadian Pacific Railway halted operations due to a Teamsters Canada union strike, interrupting the movement of potash between the two countries. The pressure on Canada to deliver potash to the United States also increased significantly with Western sanctions on Russia and Belarus in 2021. The United States still imports 12 percent of its potash from Russia despite maintaining its oil and gas sanctions against the country for its invasion of Ukraine. In December 2025, the United States broke from the European Union and lifted potash sanctions on Belarus as part of a prisoner-release deal, which was also likely in part an attempt to diversify imports and drive down the price of the mineral. Despite this, the United States remains dependent on Canada for its potash supply, making prices extra sensitive to geopolitical shocks.
Challenges of domestic potash development
The Trump administration has taken several notable steps to address this issue. In 2025, the US Department of the Interior added potash to its revised critical minerals list, expanding the scope of the administration’s critical minerals strategy. In March of that year, President Donald Trump issued an executive order intended to jump start US mineral production, and in February 2026, Vice President JD Vance proposed a critical minerals trading bloc among the Group of Seven (G7) partners. The plans for the trading bloc received mixed reactions from the European Union and the US mining industry. But these efforts underscore that the administration’s plan is centered on streamlining permitting and financing of mining operations to reduce US reliance on imports and non-allies—and that plan includes potash.
Mining more potash domestically is an obvious approach to correct the overreliance on Canadian imports, but this requires addressing market barriers. At present, US potash production is small-scale and not cost-competitive compared to Canada’s shallow, high-grade deposits. The United States has an estimated seven billion tons of domestic potash resources, concentrated mainly in New Mexico and Utah, but these resources are deep and expensive to develop and face permitting obstacles and uncertain timelines. This reduces estimated recoverable US potash reserves to roughly 970 million tons, a number low enough to deter private sector investment, especially when compared to Canada’s estimated 4.5 billion tons of recoverable reserves.
Despite the administration’s efforts to streamline permitting and facilitate the development of potash projects, domestic mining cannot realistically displace imports without sustained financing support. However, even with support in the form of government loans or offtake commitments, the expected return on investment for creating a domestic potash supply chain remains challenging.
Immediate priorities for a US potash resilience strategy
Establishing relations with existing producers can help diversify US potash imports, but ultimately, diversifying supply will require expanding exploration in countries that are not already major producers. The formation of potash is not random, and the potential for new mining locations can be well estimated. During exploration, however, the discovery of unconformities in layers, high impurity, and other structural issues can add up to high technical barriers to mining that can doom investments.
Nonetheless, as potassium is an essential plant nutrient that is not currently replaceable, and potash is the main source of it, the United States should seek to develop long-term partnerships with other interested parties to reduce the cost burden of exploration and technology development. The United States is already actively coordinating with foreign governments, multilateral development banks, and offtakers to secure critical minerals supply through initiatives such as the Forum on Resource Geostrategic Engagement (FORGE) and US Trade and Development Agency–led feasibility studies, and it should continue to do so with an increased focus on potash.
A complementary approach to buffering US potash supply from market and geopolitical shocks is to build a strategic stockpile. The US maintains stockpiles of strategic commodities, such as medical supplies and equipment and oil, to mitigate supply disruptions and stabilize markets in times of need. There is, however, no stockpile of potash or other fertilizer inputs. In February 2026, with the establishment of a stockpile led by the US Export-Import Bank called Project Vault, the US government signaled a commitment to invest in a backstock for critical commodity supply chains through public-private partnerships.
Potash’s new status as a critical mineral means that it is covered under this mechanism, which would help smooth short-term disruptions during critical planting seasons, buying time for markets to adjust without jeopardizing crop yields. Though a potash stockpile could prove useful in the long term, it requires careful design: excessive stockpiling can cause market distortions, and government-led programs are vulnerable to shifting political pressures.
Perhaps the most compelling, long-term approach to securing the US potassium supply is to look beyond potash and focus on recovery and circular fertilizer systems that capture nutrients from domestic waste streams and convert them into local fertilizers. These systems can recover potassium from livestock manure, wastewater, litter and biomass ash, crop residue, and food-processing waste, and while currently scale-constrained by a short shelf life and high transportation costs, they can create a complementary regional supply of potassium.
To shape these systems, the United States should build on existing nutrient management programs that establish national nutrient recovery standards, support related innovation, and incentivize production and use of recovered fertilizers. Government engagement can help lower costs, ensure product consistency, and manage contamination risks. It can also help create the adoption pathways needed to build reliable, local markets for recovered potash that can overcome profitability challenges, including large upfront costs and scaling issues. Over time, this would attract investment into emerging recovery technologies that are already operational in some parts of Europe and strengthen US capacity to capture and reuse potassium from domestic waste streams.
An international approach—for the short term
Despite the Trump administration’s efforts to jump-start potash resilience, operating under a business-as-usual mindset may be the only option for the United States in the short term. Mining projects require extended review, start-up periods, and funding support. Stockpiling is a long-term process, and recovery technology and markets need time to develop. Most importantly, none of these approaches alone will allow the United States to be self-sustaining in its production of potash.
Therefore, the United States should also continue to advocate for strengthened international cooperation in securing supply chains for critical minerals through expanded exploration efforts and the development of smarter extraction methods. Initiating multinational discussions on the need for critical minerals beyond energy and technology is crucial: Fertilizers should be the starting point from which to grow those discussions.