When geopolitical shocks hit households, we tend to notice energy prices first. But another shock often follows quickly: fertiliser price spikes that raise farm costs, then food prices.
Disruption to shipping through the Strait of Hormuz has pushed up fertiliser prices again, adding pressure to UK farming and food costs.
The route handles a large share of global trade in oil, gas and fertilisers. Fertiliser markets reacted quickly to the disruption, with urea prices rising by around 50% within four weeks.
The effects are already reaching farms in the UK. The Food and Drink Federation has warned that food inflation could rise further later this year.
A familiar cycle
This is not the first time conflict overseas has disrupted fertiliser supplies.
Prices rose sharply after Russia’s invasion of Ukraine in 2022, driven mainly by higher energy costs, prompting emergency measures from Defra to support UK farmers. Fertiliser shortages and price spikes also contributed to the global food crisis in 2008.
Modern agriculture depends heavily on nitrogen fertilisers, most of which are produced using natural gas. When energy markets tighten, fertiliser prices usually follow.
Nutrients lost in the system
The latest disruption has renewed attention on whether more nutrients could be recovered and reused within the UK instead of being lost through waste systems.
An Agile Initiative research Sprint on nutrient retention in organic waste examined how nitrogen and phosphorus move through food waste, wastewater and green waste streams in Leicester and Leicestershire.
The study estimated that around 4,000 tonnes of nitrogen and 700 tonnes of phosphorus pass through these systems each year. Less than 10% is recovered in forms that can be reused as fertiliser. Most eventually enters waterways through wastewater treatment systems.
The same pattern exists nationally. Large quantities of nitrogen and phosphorus are discharged into UK waters every year, while farming continues to rely on imported fertilisers.
Recovering more fertiliser from waste
The research identified some relatively straightforward improvements, including better nutrient recovery from biodegrading processes and lower plastic contamination in food waste collections.
Other changes would be harder to implement. Existing wastewater infrastructure was not designed to recover nutrients efficiently, particularly once they become diluted in large treatment systems.
The work also pointed to a coordination problem. Responsibility for nutrients is spread across farming, waste, water and industry, with no single body overseeing the system as a whole.
A continuing risk
Fertiliser markets are likely to remain vulnerable to energy shocks and geopolitical disruption.
Recovering more nutrients from domestic waste would not remove that risk entirely. But it could reduce dependence on imported fertilisers and make the food system less exposed to sudden price swings.
This article is based on a blog written by Professor Aidong Yang that was originally published by The Agile Initiative. Original article available here.