Too Much and Too Little: Fertilizer at the Crossroads of Climate and Food Security

And two actions you can take to reduce unneeded fertilizers

Wars are connected to food security. Iraqi children with US military “meals ready to eat.” US Navy photo by Chief Journalist Suzanne Speight

by Marianne Krasny

At first glance, an article on fertilizer may seem like a real sleeper — not worth your time. But nearly half the people alive today can attribute their lives to increased farm productivity made possible by fertilizers. And as of 2000, nitrogen fertilizers were responsible for feeding 44% of the world’s population, including probably anyone reading this article.

Given how fertilizers feed the world, perhaps it’s not surprising that they are connected to geopolitics, including the Iran War. They are also connected to what we pay at the grocery store, the huge dead zone in the Gulf of Mexico, harmful algal blooms that ruin summer swimming in lakes and streams, and a surprisingly large share of US climate emissions. Let’s explore why and what we can do about it.

“… fertilizer isn’t really an optional thing. If we can’t afford to put a crop in the ground, we then become more dependent on foreign nations to feed our own people.” Angela Guentzl, US Midwest farmer

How Are Fertilizers Linked to the Iran War and Strait of Hormuz?

The Middle East’s natural gas does not just power cars and trucks. It is also a primary ingredient and energy source for producing fertilizer. Middle Eastern countries produce about a third of urea — the most widely traded fertilizer — and nearly half of the sulphur and a quarter of the ammonia worldwide. But since the start of the latest Iran War, fertilizer production has shut down in Qatar and neighboring countries. And if the Strait of Hormuz is closed, fertilizer can’t reach countries that depend on it. Asian countries, which import over 50% of ammonia, sulphur, and phosphates from the Middle East, are particularly hard hit. The US imports about a quarter of its fertilizer. So while US farmers are less vulnerable than farmers in some other countries, they are still worried about what the war means for this year’s crops.

For farmers, less fertilizer means higher prices. Fertilizer accounts for about 40% of a US corn farmer’s costs. Meanwhile, the costs of widely used fertilizers urea and ammonia have risen 24-50% since the start of the Iran War.

“If you’re growing something in the ground right now, you’re losing money.” Senator John Boozman

This is my proud farmer friend Donnie posing with his 2005 corn crop west of Perkins, IA. When I was young, the stalks were much further apart and there was just one ear to the stalk. Now the stalks are close together and hold 2 or 3 ears. This is all due to the chemists who have figured out how to enhance the soil. inkknife_2000

How Do Fertilizers Contribute to Higher Prices at the Grocery Store?

Without fertilizers, the world would have somewhere between 40 and 70% less food. When fertilizer prices go up, farmers face stark choices — put out even more money for fertilizers, face smaller harvests, or quit farming altogether.

Regardless, farmers earn less and consumers see higher prices at the grocery store. Corn, wheat and other crops heavily dependent on fertilizer will likely be the first to feel the fertilizer crunch. But higher costs will eventually spill over to just about everything we eat, from bread to meat to eggs.

“The impact of conflict ripples through our food systems and families will feel it first. Roughly 45 million more people could be pushed into acute hunger this year if conflict in the Middle East persists. Without an adequately funded humanitarian response, it could spell catastrophe for millions already on the edge.”
World Food Program

How are Fertilizers Ruining my Summer Swimming Plans?

Algae love the nitrogen and phosphorus from fertilizers that run off farms into lakes, streams, and oceans. With these extra nutrients, algae reproduce quickly, consuming much of the oxygen in the water. This kills other aquatic life and dead zones ensue. The largest dead zone in the United States — about 6,500 square miles — is in the Gulf of Mexico and occurs every summer as a result of nutrient pollution flowing down the Mississippi River.

Things get worse when algae produce toxins, causing harmful algal blooms. To avoid people and pets getting skin rashes and more serious illnesses, beaches are closed. Harmful algal blooms also contaminate drinking water.

What About Fertilizers and Climate Change?

According to the Union of Concerned Scientists, corn–soybean producers used around 4.5 million metric tons more nitrogen fertilizer than needed in 2023. This resulted in greenhouse gas emissions equal to about 11 million gas-powered cars driven for a year. 

On average, crops only take up about half of the nitrogen in fertilizers. When soil microbes break down the excess nitrogen, they release nitrous oxide, which accounts for about 6% of greenhouse gas emissions. Although it is much less common than CO2, it warms the atmosphere about 270 times faster.

The energy used to produce fertilizers also contributes to fertilizers’ carbon footprint. The production of ammonia emits more CO2 than any other chemical-making reaction.

About 45% of corn grown in the US is used to feed livestock — cows, hogs, and poultry. Another 45% is used for ethanol fuel. From a climate and environmental perspective, swapping out plant based proteins for meat and swapping out solar and wind for ethanol, makes sense. Why use 90% of corn for industries that are neither efficient nor environmentally-friendly?

If the Middle East wars persist, it’s possible that disruptions to fertilizer supply chains will make decision makers rethink US farm policy, just as the oil and gas disruptions are making us rethink solar energy and electric vehicles. If we move away from meat and ethanol, then land that is in corn could be converted to conservation for wildlife and sequestering carbon or agrovoltaics. However, transition to other land uses can threaten farmers’ way of life and income, and thus would require strong government support for farmers.

What Can We Do to Help Farmers Use only the Fertilizers they Need?

Solutions to excess fertilizer are out there. They include precision agriculture that enables farmers to more precisely target when and where to apply fertilizer. Also promising is biochar, a carbon-rich soil amendment made from organic wastes, which enhances soil health and can reduce nitrous oxide emissions from fertilized soils by nearly 20%. Precision agriculture and biochar are both included in the current draft of the US Farm Bill, but the biochar provisions are weak. The bipartisan Biochar Research Network Act would support the research needed to make sure biochar is used effectively across different crops and soils.

TAKE ACTION: Ask Congress to support the bipartisan Biochar Research Network Act.

Another important bill is the Agriculture Resilience Act, which would support a myriad of renewable energy, soil health, and nutrient management practices to mitigate and adapt to climate changes. It also includes specific targets for reducing nitrous oxide emissions from agricultural soils.

TAKE ACTION: Support farmers to reduce climate emissions from fertilizers.