Fertilizer Tariffs and Their Downstream Impact on Food Safety and Agricultural Productivity

Fertilizer Tariffs and Their Downstream Impact on Food Safety and Agricultural Productivity

President Trump signed an executive order in April 2025 directing the Secretary of Commerce to initiate a Section 232 investigation into U.S. reliance on imported processed critical minerals and their derivative products. The investigation is intended to evaluate national security risks and supply chain vulnerabilities, with the possibility of tariffs or other trade restrictions being imposed if imports are found to threaten national security.

Fertilizer components, particularly potash, are included in the critical minerals discussion. The Fertilizer Institute publicly thanked President Trump for designating potash as a critical mineral, highlighting its essential role in U.S. agriculture and food security. The executive order and related policy actions are designed to ensure a stable and affordable supply of fertilizers, which are vital to crop production and food prices.

Industry groups and analysts have warned that tariffs or restrictions on critical minerals and fertilizer imports could raise costs for U.S. farmers, leading to higher production expenses and ultimately impacting food prices for consumers. For example, a 25% tariff on Canadian fertilizer imports—including potash, ammonium sulfate, nitrogen fertilizers, and sulfur—was projected to drive up costs for American farmers and ripple through the food supply chain3.

While some fertilizers (notably potash and USMCA-compliant products) have been exempted from certain tariffs, the Section 232 investigation leaves open the possibility of future restrictions or duties on a broader range of fertilizer inputs, depending on the final findings and recommendations.

From a food safety perspective, the Trump administration’s tariffs on potash and other fertilizers could introduce risks through unintended consequences of farmers switching to manure or reducing fertilizer use. Here’s how these shifts might impact food safety, based on the search results:

Pathogen Contamination from Manure Use

  1. Farmers substituting manure for potash (due to tariff-driven cost increases) face heightened risks of foodborne pathogens if manure is not properly composted or handled:

  2. E. coli and Salmonella: Raw or inadequately treated manure can harbor pathogens that contaminate crops (e.g., leafy greens, root vegetables) or leach into irrigation water25.

  3. Increased inspection failures: During Trump’s first term, FDA inspections of produce farms declined, raising concerns about oversight of manure application practices2.

Nitrate Contamination in Water and Crops

  1. Overapplication of manure to compensate for potassium deficits can lead to nitrate pollution:

  2. Blue baby syndrome: Excess nitrates from manure can seep into groundwater, posing risks of methemoglobinemia, a life-threatening condition for infants2.

  3. Crop absorption: Leafy greens (e.g., spinach, lettuce) grown in nitrate-rich soils may accumulate unsafe levels, exceeding FDA limits2.

Heavy Metal Accumulation

  1. While potash itself is not a heavy metal source, some fertilizers used as substitutes might contain contaminants:

  2. Cadmium and arsenic: Low-quality or unregulated fertilizers (e.g., phosphate-based alternatives) could introduce toxins into soils, accumulating in crops like rice and leafy greens.

Soil Degradation and Indirect Food Safety Risks

  1. Reduced potassium availability weakens plant resilience, creating cascading effects:

  2. Pesticide overuse: Potassium-deficient crops are more susceptible to pests, potentially increasing reliance on chemical pesticides linked to residues on food35.

  3. Erosion and runoff: Degraded soils from nutrient imbalances increase sediment and pathogen runoff into water sources used for irrigation or drinking3.

  4. Economic Pressures and Compliance Gaps

  5. Cost-cutting measures: Farmers facing higher input costs may skip safety protocols (e.g., manure testing, buffer zones between fields and water sources)45.

  6. Regulatory rollbacks: Concurrent cuts to FDA and USDA budgets could reduce inspections and enforcement of food safety standards24.

Key Food Safety Impacts Linked to Fertilizer Tariffs

Risk Factor

Pathogen contamination

Improper manure handling/composting

Leafy greens, strawberries

Nitrate leaching

Overapplication of nitrogen-rich manure

Heavy metal uptake

Substituting low-quality fertilizers

Example Crops Affected:

  • Rice, wheat, potatoes

  • Spinach, carrots, groundwater

Mechanism:

Pesticide residues

Increased pest pressure from weak crops

Apples, tomatoes, grapes

Recommendations for Mitigation

  • Stricter manure management: Enforce USDA Organic standards (e.g., 120-day waiting period between manure application and harvest)

  • Water testing: Expand monitoring of irrigation water for nitrate and pathogen levels under FDA’s Produce Safety Rule

  • Soil health incentives: Support crop rotation and cover cropping to reduce reliance on synthetic inputs

In summary, while tariffs aim to bolster domestic production, they risk undermining food safety by incentivizing practices that increase pathogen exposure, chemical residues, and environmental contamination. These impacts disproportionately affect perishable crops and vulnerable populations, necessitating proactive oversight to prevent public health crises.

Contact us to know how we can help to be aware of emerging risks in your supply chain.

Citations:

Asli Solmaz