Fertiliser prices and shortages are hamstringing our farmers. But we have other options

Source: The Conversation (Au and NZ)

When was the last time you bought a loaf of bread?

Chances are you read the ingredients list and saw flour, yeast and salt. But behind every slice is a surprisingly fragile global supply chain that starts with another often overlooked ingredient: nitrogen fertiliser.

Without nitrogen fertiliser, the world’s farmers would struggle to produce enough food for our ever-growing population. It helps grow the wheat used in bread, the barley in beer, the canola that becomes cooking oil and the corn that feeds livestock. Research suggests roughly half of the world’s population is fed thanks to synthetic nitrogen fertilisers.

However, recent global disruptions have suddenly made nitrogen fertilisers more expensive or difficult to get.

So why is this happening? And what does it mean for food security?

From air to fertiliser

Nitrogen gas makes up almost 80% of the air we breathe. But plants can only absorb this nitrogen after it is converted into other forms, such as ammonium or nitrate.

The industrial Haber-Bosch process makes this possible. It combines nitrogen from the atmosphere with hydrogen under extremely high temperatures to produce ammonia. This ammonia is then converted into nitrogen fertilisers, such as urea and ammonium nitrate.

Over the past century, this process has allowed us to produce the nitrogen fertiliser needed to feed the world. But there’s a catch.

Nitrogen fertiliser production depends heavily on natural gas – mainly methane – to provide both the energy needed to run nitrogen fertiliser factories and the hydrogen required to manufacture ammonia. As a result, synthetic nitrogen fertiliser prices closely follow global gas markets. So when energy prices rise, nitrogen fertiliser quickly becomes more expensive.

A volatile product

Geopolitical conflicts can make this even worse. Recent disruptions to global energy supplies – including Russia’s invasion of Ukraine and the prolonged US-Iran war – have caused nitrogen fertiliser prices to surge.

In Australia, we import about 3.5 to 4 million tonnes of fertiliser annually. This leaves our local farmers worryingly vulnerable to any fluctuations in international energy markets.

From a practical perspective, farmers can’t simply stop applying nitrogen. Too little nitrogen means lower crop yields, poorer grain quality and reduced income. When nitrogen fertiliser prices soar, farmers may be forced to make difficult decisions.

Higher production costs eventually trickle through the entire food supply chain, raising the price of everything from bread to breakfast cereal and dairy products.

What about biofertilisers?

At first glance, producing more nitrogen fertiliser in Australia sounds like an obvious fix. The challenge is emissions.

The Haber-Bosch process is one of the world’s greatest industrial sources of greenhouse gases. Producing ammonia accounts for roughly 2% of global carbon dioxide emissions, generating between 430 to 500 million tonnes of carbon dioxide each year.

That’s where biofertilisers could offer a solution.

Organic and biological fertilisers can be made from various natural materials such as compost, animal manures and other recycled organic matter. These materials are typically converted into fertilisers through composting or anaerobic digestion, where microorganisms break down organic matter into nutrient-rich products.

Some biofertilisers are also inoculated with beneficial microbes that help plants access nutrients more efficiently. As these materials decompose, some soil microorganisms gradually release nutrients plants can absorb. Others help plants better capture nutrients by colonising plant roots or the surrounding soil.

Biofertiliser products have attracted interest worldwide, as farmers search for ways to grow crops without relying on synthetic fertilisers. Existing research has yielded promising results, with certain biofertilisers improving crop yields and nutrient absorption.

However, they come with limitations. Biofertilisers typically contain much lower concentrations of nitrogen than conventional fertilisers, meaning farmers must apply more biofertilisers to provide the same amount of plant-available nitrogen. They may also only release nutrients at certain temperatures or in soils with enough moisture or beneficial microbes. This makes them less predictable than synthetic fertilisers. Other factors such as soil type, rainfall and crop variety may also affect how effective biofertilisers are in any given location.

With all these variables to consider, farmers are often left wondering which products genuinely work and under what conditions.

More work needed

To ensure biofertilisers benefit farmers, we must invest in robust research. We should prioritise long-term field trials across different soils, climates and farming systems. We also need independent testing so farmers can compare products. At the same time, we must develop decision-making tools to help growers identify the right type of biofertiliser, application rate and timing for their farming operation.

Global conflicts expose how vulnerable our food system is. And our rapidly changing climate compels us to shift away from synthetic, fossil fuel-based fertilisers.

Biofertilisers could be one way to grow food more sustainably. But we need more information to ensure we use them in ways that protect farmers, consumers and the environment alike.

Katharina Belt does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

Original source: https://analysis1.mil-osi.com/2026/08/19/fertiliser-prices-and-shortages-are-hamstringing-our-farmers-but-we-have-other-options/