The attacks on Iran by the United States and Israel and the subsequent blockades of the Strait of Hormuz have done more than push up the price of oil; they have exposed our reliance on this single waterway for the supply of fertilisers which underpin British agriculture. 
 
As much as 30% of global fertiliser supplies pass through the strait, with UK farmers using around 1.17 million tonnes of fertiliser in 2022. For many, artificial fertilisers are an essential input for maintaining crop yields, while others believe that low input systems, properly managed, could provide us with food much more sustainably, and with much less exposure to global shocks such as wars or natural disasters.
 
For campaigners for more localised, low input farming, approaches such as using crop rotations in which nutrients are replenished through nitrogen fixing by legumes, by the manure of grazing animals, or by the use of compost produced on-farm, offer alternatives to our current high input agricultural systems. With investment in breeding of crop varieties suited to these systems, supporting infrastructure and training for farmers, supporters believe these systems can deliver the food we need – and many hope that crises such as that in the Strait of Hormuz should provide the push we need to transform the sector.

“The lesson of the recent crisis in the Strait of Hormuz, of the Covid pandemic and the Ukraine war, is that these external shocks are not sufficient to transform food systems towards more resilient states. This may be a relief to those who support a doubling down on the industrialisation of agriculture or who profit from it, but it should be a concern for those advocating transformation.”

Higher prices don’t always reduce use

Whatever our views on these arguments, can we expect input price shocks to alter what farmers do in the UK? Common sense suggests that, if prices increase, demand should fall and people should be motivated to change what they buy - but things are a lot more complicated.
 
A global study of previous fertiliser price shocks in 2021 and 2022 found that higher prices do not always lead to lower usage, especially if global crop prices are also high. Fertiliser is not the biggest production cost for many farmers in countries like the UK. Even if fertiliser prices go up more than crop prices, it might still be profitable for farmers to maintain or in some cases even increase inputs.
 
Many other factors also affect how global fertiliser prices affect use at farm-level, including government policy (e.g., input subsidies, stockpiling of fertiliser to buffer against supply volatility, the capacity to use hard and soft power to compete for what is available) and whether prices are rising due to an actual shortage of supply, or to increased costs of energy - which makes the energy intensive production of fertiliser more expensive. 
 
But let’s imagine that farmers did feel motivated to reduce fertiliser use by changing what they produce or how they grow it, spurred by concerns about global price and supply variability - could they actually do it?

The barriers to changing course

Recent work by myself, Ruth Mattock and Tara Garnett at TABLE, explored regenerative agriculture - often cited as a way to reduce reliance on inputs such as fertilisers. Two key aspects of regenerative agriculture we identified were a focus on improving the capacity of farms to maintain and regenerate themselves environmentally and socially, and the decision-making autonomy its broad principles give to farmers. These aspects bring flexibility around how to change, where approaches such as organic farming can seem rigid and discourage engagement. 
 
The problem - as our work with supply chain actors, farmers groups, policymakers and campaigners revealed - is that there are many barriers to on-farm transformation. These barriers to the proactive uptake of regenerative approaches, are also likely to hinder change in response to rising fertiliser costs. Many people we spoke to highlighted how farmers are increasingly dependent on sales to a few very large processing and retail companies. Such firms often demand that produce meets precise standards, focused on how it appears or its suitability for industrial processing. 
 
Often, they also expect a specified amount of produce is available within a strict time window - if the farmers can’t meet any of these criteria their crops may be rejected, sometimes forcing them to plough them back into the ground. For farmers, reducing fertiliser inputs or trying novel practices under these circumstances, could risk their entire business. Gradual reductions in per hectare fertiliser application in the UK since 1983 (averaged across all crops and grasses) could represent the limit of what the current system will accommodate. Without changes in supply chain behaviour, price shocks are likely to either have no effect or to drive farmers out of business, rather than to produce innovative change.

We can’t rely on crises to bring change

The lesson of the recent crisis in the Strait of Hormuz, of the Covid pandemic and the Ukraine war, is that these external shocks are not sufficient to transform food systems towards more resilient states. This may be a relief to those who support a doubling down on the industrialisation of agriculture or who profit from it, but it should be a concern for those advocating transformation.
 
Such shocks can only drive change indirectly, through the actions of ordinary people, politicians and other non-market actors, for whom they might be a wake-up call. Mindful actions by these groups, along with those in the supply chain willing to look beyond short-term self-interest, are required to change our food system strategically; recognising and addressing barriers to change and their interactions, and prioritising public and environmental health over any pushback from vested interests. 
 
We cannot rely on markets to drive change, on external shocks - manmade or natural - to transform things, or on change on-farm alone to address chronic, and increasingly acute, issues of market volatility, food supply vulnerability, diet related poor health, and environmental deterioration.

This article draws on the Sprint project 'Can regenerative agriculture deliver nutritious food and a just food system?', part of the Agile Initiative at the Oxford Martin School and supported by the Natural Environment Research Council [grant number NE/W004976/1].

We have explored the recent conversations around fertiliser, food security and the Strait of Hormuz in two recent issues of our newsletter Fodder: "Unpacking wartime food security and fertiliser narratives" (26 March 2026) and "Volatility until breaking point: The future of fertiliser" (23 April 2026).