Carbon Footprint Showdown: How to Feed Your Crops (Without Feeding the Atmosphere)

TL;DR

Feeding a field doesn't have to cost the grower or the planet more than it should. Find out whether conventional or controlled-release fertilizer is the more sustainable choice, and how to grow the same harvest with less.

As the tractors roll out and the fields are prepped for planting, every grower faces the same question before a single seed goes in.

Introduction

Fertilizer is what turns a field into a harvest. It has fed generations, and it will feed the next ones too. But in a climate-conscious world, an old question has picked up a new edge: How do we feed our crops without feeding the problem?

It's a startling fact: synthetic nitrogen fertilizers account for 2.1% of global greenhouse gas emissions, and their supply chain emitted more than commercial aviation did in 2018. And most of that footprint isn't made at the factory. Roughly two-thirds of fertilizer emissions happen after it's spread on cropland. How a crop is fed decides how much fertilizer gets bought, how many times the tractor goes out, and how much of what's spread ends up somewhere it shouldn't.

Two Ways to Feed a Field

In this farm-fresh carbon footprint showdown, we're putting two ways of feeding a crop head to head: conventional fertilizer and controlled-release fertilizer (CRF). Which one will come out on top? Let the growing season begin!

Conventional Fertilizer: Everything, All at Once

First up, the familiar favorite. Conventional fertilizer has been the go-to on farms for generations: spread it on, and the nutrients get straight to work in the soil. And it isn't going anywhere: the global fertilizers market is projected to grow from US$230.1 billion in 2025 to US$281.56 billion by 2030.

But there's a catch. A crop can only take up nutrients so fast, and conventional fertilizer delivers them all at once. It's a bit like serving a week's worth of meals on Monday morning. Whatever the crop can't use right away is at risk of being lost before the plant ever gets to it.

To keep the crop fed through the season, growers often have to come back and top it up. In one potato trial in the Netherlands, standard grower practice meant three separate fertilizer applications.

Controlled-Release Fertilizer: Slow and Steady Feeds the Crop

Enter our next contender. Controlled-release fertilizers look like ordinary granules, but each one wears a special coating that decides when its nutrients come out. CRFs are the smaller player for now, but a fast-rising one: the global market is estimated at US$2.54 billion in 2025 and projected to reach US$3.41 billion by 2030.

Here's the clever part: the release depends on soil temperature alone, not on soil type or pH. As the soil warms and the crop starts growing, nutrients flow. When it cools, release slows down. The crop gets a steady supply that follows its appetite rather than the spreading schedule.

That timing pays off. Because nutrient release is synchronized with what the plant actually takes up, CRFs increase nutrient use efficiency by up to 80% compared to conventional urea. More of what goes on the field ends up in the crop. That's why, in field trials, growers could cut nitrogen application by up to about 30% per hectare, with emissions down by roughly 20% to 50%.

It also means fewer trips across the field. In that same Netherlands potato trial, a single CRF application replaced the grower's three conventional ones. Yield still rose by 9%, with €450 per hectare in extra income.

But Won't the Crop Go Hungry?

Less fertilizer sounds great, until you picture a thinner harvest. It's the first thing any grower would ask, and a fair question.

The good news is that CRFs support comparable or improved yields at lower application rates. In trials with root vegetable, brassica and allium growers, yields rose by 8% to 16% compared to standard farm practice. Same harvest, less fertilizer, and sometimes a little extra on top.

So Where Does the Leftover Fertilizer Go?

Remember the nutrients the crop couldn't use in time? They don't sit around waiting. Some wash down through the soil, past the roots and toward groundwater, which is called leaching. Some escape into the air as gas, which is called volatilization. Either way, it's fertilizer the grower paid for that never fed the crop.

Because CRFs release nutrients as the crop needs them, far less is left exposed. In lab trials against conventional urea, CRFs reduced leaching by up to 55% and volatilization by up to 40%.

Does It Hold Up on a Real Farm?

Trial results are a good start, but the real test for a grower is a full season, with whatever weather it brings. Better still, several seasons in a row.

That's what happened with barley in Greece. Over three consecutive years, ICL worked with local barley farmers and Athenian Brewery / Heineken, for whom barley is the most important agricultural input. The farmers switched from conventional fertilization to ICL's CRF OneGo solution, and the CO₂e footprint of their barley dropped by up to 29%.

As the name suggests, OneGo takes one application at the start of the season, where traditional approaches need at least two. Crop performance held, without adding complexity or cost for the farmers. Fewer trips across the field, a smaller footprint, and the same barley in the brewhouse. That's worth raising a glass to. Yamas!

What About the Coating?

If every granule has a coating, it's fair to ask what happens to it once the nutrients are gone. Coatings that stay in the soil raise concerns about microplastics building up over time.

eqo.x, a coating now built into ICL's Agromaster and Agrocote ranges, is the first CRF coating for urea that biodegrades according to European regulation. It's designed to meet the European fertilizer regulations coming in 2028, in line with the EU's Farm to Fork strategy and Soil Strategy for 2030, which aim to cut nutrient loss by at least 50% by 2030.

Down to earth, literally.

Where the Numbers Come From

Unlike our previous showdowns, we didn't run a simulation for this one. Every figure comes from ICL's own reporting and published trials. These are "up to" values from field and lab trials, so results vary by crop, region and conditions.

1. Nutrient use efficiency, application reductions, emissions reductions, the barley OneGo project and eqo.x: ICL 2025 ESG Report, pp. 40–41

2. Leaching and volatilization: ICL, "What Are Controlled Release Fertilizers"

3. One application instead of three, 9% yield, €450/ha: ICL Growing Solutions, "It's a Coating Matter"

4. Yield uplifts of 8–16%: ICL Growing Solutions, Controlled Release Fertilisers

We hereby declare Controlled-Release Fertilizer as the official winner of this fertilizer carbon footprint showdown!

Harvesting the Results: Growing More With Less

When it comes to feeding crops sustainably, controlled-release fertilizer takes the harvest. It needs less fertilizer and fewer trips across the field, keeps more nutrients out of the water and air, lowers emissions, and holds its yields while doing it. In ICL's own words, it's a clear example of doing more with less.

And as the barley project shows, the benefits reach past the farm gate, all the way to the brands that buy the crop.

How are you feeding your fields this season? Share your take with us on social media by tagging #CarbonFootprintShowdown and #DoingMoreWithLess.

Happy growing!