Why the US-Canada trade war could change how American farmers grow their crops for years

After U.S.-Canada trade talks collapsed in mid-August 2026, President Trump imposed 50% tariffs on about $20 billion of Canadian imports; Canada retaliated on August 25 with its own 15-50% tariffs on an equivalent value of U.S. goods, effective September 8, covering dairy, agricultural equipment and more. Neither country's list currently touches potash, the potassium-rich fertilizer ingredient the U.S. imports overwhelmingly from Saskatchewan, since American mines supply less than 1% of global demand.

The author, an agriculture and water-quality researcher, warns that if Canada eventually escalates to potash, oil or energy tariffs, the damage would be slower and less visible than the immediate hit China's 2018 soybean tariffs delivered, but potentially longer-lasting: potassium builds up as a soil reserve, so farmers can skip an application for a season or two, but restoring it afterward takes years of extra fertilizer. Combined with fertilizer price spikes already caused by the Iran shipping disruption, and a Farm Bureau survey finding 70% of farmers couldn't afford needed fertilizer this spring, the piece argues uncertainty alone — even before any potash tariff exists — can push farmers to under-fertilize now.

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