Fertiliser costs for UK farmers have surged up to 70% due to geopolitical tensions involving Iran, creating a cascading threat to global food prices, according to Grosvenor Group, one of Britain's largest agricultural operators.

Mark Preston, executive trustee of the 349-year-old Grosvenor Group controlled by the Duke of Westminster, warned that fertiliser shortages will produce "dramatic" impacts on food prices worldwide next year. The price increases stem from disruptions to global nutrient supply chains triggered by regional conflict.

Fertiliser represents a core input for crop production. Nitrogen-based and phosphate fertilisers depend heavily on international trade networks, and supply shocks at any major production or export hub reverberate across farming operations globally. The 70% cost increase Preston cited exceeds normal market fluctuations and reflects genuine scarcity rather than speculation.

This matters for two reasons. First, fertiliser costs directly affect farm profitability and production decisions. When input expenses spike, farmers may reduce fertiliser application rates, lower acreage under cultivation, or delay planting cycles. Each response constrains crop yields. Second, food price inflation follows crop production shortfalls with a lag. Grosvenor's warning targets 2025 specifically because fertiliser decisions made now determine next year's harvest volumes.

Broader context strengthens the concern. Global fertiliser markets remain concentrated. Russia and Belarus supply significant phosphate and potash volumes. Production facilities cluster in specific regions. Ammonia, the nitrogen fertiliser precursor, requires natural gas inputs vulnerable to energy supply disruptions. Any shock ripples across continents within months.

UK farmers face particular exposure. British agriculture imports substantial fertiliser volumes and cannot easily substitute domestic production given limited capacity. Smaller operations lack the financial buffers to absorb 70% input increases, potentially forcing consolidation or land withdrawal