Looking after the soil is one of the most important jobs a farmer can do.

According to the UN’s Food and Agriculture Organization, a third of the world’s soil is now moderately to highly degraded.

But we can do something about this problem before it’s too late.

In Iowa in the US, we're working with soy farmers and our soy oil suppliers to increase the use of cover crops as a way of protecting the soil. This enhances the sustainability of this key ingredient for our Hellmann's brand.

Cover crops can also play a vital role in mitigating the greenhouse gas emissions associated with agriculture, as well as helping prevent erosion and protecting water to positively impact local ecosystems.

We spoke to Stefani Millie Grant, Senior Manager, External Affairs and Sustainability for Unilever North America, and Ben Crook, Senior Director, Dressings & Condiments for Unilever North America, to find out more about the programme.

Why is this programme centred in Iowa?

This is where we get most of our soy oil. Unilever and Hellmann’s have been working with farmers in Iowa since 2013 on sustainable sourcing. In 2018, we relaunched the programme to focus on cover crops and soil health. We had about 120 farmers take part in year one and 300 in year two.

We are growing the programme to eventually include 700–800 farmers. That’s enough to supply 100% of the oil needed for Hellmann’s in the US. And we’re also now replicating this successful approach with a similar programme for Hellmann’s in Mexico.

PepsiCo also offers the same cover crop programme to its corn farmers. The company sources corn in the same supply shed as we source beans. Corn and soy are the standard crop rotation for farmers in Iowa, so they are likely supplying to both companies.

What is the problem with soil erosion in Iowa?

Over decades, through both severe droughts and heavy rains, the nutrient-rich soils of Iowa have been steadily declining. Along with the soil decline, nutrients are running into the Mississippi River and creating the dead zone in the Gulf of Mexico.

Add the increasingly extreme weather events, and farmers are not just losing soil. In many cases, they are starting to lose their livelihoods as their fields become unplantable or they are unable to get into the fields to harvest and sell their crops.

Why does this matter so much to Unilever?

Crops like soy are usually grown by family-owned farms, who sell to processors and suppliers that in turn sell to us. One such family is the Sutters, who have been growing soy for Hellmann’s for three generations, soon to be four. Watch the film below to meet the family.

Supporting our farmers in implementing practices that renew the land for future generations isn’t just good business sense, it’s the right thing to do.

As extreme climate events are becoming a more frequent occurrence, so too are more frequent crop failures. If the land is unable to grow quality nutritious crops, it will be difficult to produce the quality ingredients we use for our brands.

What’s more, as soil health declines, so does the nutritional value of our food. The food we share with family and friends today has up to 25% fewer nutrients than 50 years ago.

What are cover crops and why do we need them?

These are crops that a farmer can plant, usually in the late autumn, to protect the soil after harvest until the next growing season. They are not usually harvested and monetised like the main crop.

Typically, these would be rye grasses, oats or radishes. Although there are opportunities to use a more diverse range of crops, for example pennycress, which is an oilseed.

However, a lot of farmers today no longer use cover crops, as they may have done in previous generations.

In part, this is because they have had access to modern farming technologies and synthetic fertilisers, which can provide good harvests in the short term. But this can put the long-term health of the soil at risk.

Cover crops help slow soil erosion and the loss of nutrients by keeping roots in the ground year-round. This can increase the amount of organic matter in the soil, enhance water availability and smother weeds.

They help control pests and diseases, increase biodiversity and attract pollinators. Over time, they can decrease the need for inputs such as fertilisers and chemicals. By helping retain nutrients, they are also a way to act on climate change, by reducing the greenhouse gases associated with agriculture.

By contrast, bare fields between crop cycles and the practice of heavy tillage reduces the amount of carbon being locked away in the soil and releases much of what is already there, in addition to the loss of the soil itself.

What exactly do farmers gain from taking part?

There are three aspects to the programme – financial investment, technical support and social engagement.

Investment is critical because planting cover crops is an outlay for farmers, often with little financial return, so it may not make business sense in the short term. The farmers will see rewards many times over, but it needs a long-term view. We provide financial support per acre for cover cropping, and we help farmers apply for federal and state funding where available.

In terms of technical assistance, we partner with Practical Farmers of Iowa (PFI), who are known within the state as the experts on cover crops. All farmers have a consultation with PFI to help answer their questions regarding cover crops and soil health practices. Questions may include what seed mix to use and at what rate, and the amount of fertiliser required.

The social engagement aspect is about building a network that the farmers can turn to for support as they try these new practices. When a new farmer joins, they get a welcome call from another farmer who is using cover crops offering support and to be a resource. Farmers also attend learning days and webinars to exchange best practices, as well as lessons learned around soil health.


Cover crops help slow soil erosion and the loss of nutrients by keeping roots in the ground year-round. This can increase the amount of organic matter in the soil, enhance water availability and smother weeds.

Stefani Millie Grant

Is it possible to see the impact of cover crops?

Not always on the surface, but within the soil you can absolutely tell. Healthy soil is rich and dense, and you will find many earthworms. Unhealthy soil is usually powdery and dry with minimal earthworms.

Earthworm tunnels allow roots to penetrate deeper, where they can reach extra moisture and nutrients. Their channelling loosens and aerates the soil and improves drainage.

The impact is most noticeable during rainfall. Healthy soil absorbs the water whereas on unhealthy soil, the water just runs off, taking dirt and nutrients with it.

Farmers that have been using cover crops for several years were better able to withstand the heavy spring rains Iowa experienced this year – something that is expected to get more severe with the impacts of climate change. Many were able to get into their fields to plant earlier than their neighbours and some report that they are now using fewer herbicides.

One farmer shared with us that he can tell the soil health of a field when he drives onto it with his tractor by the firmness of the ground. In fields with healthy soils, the ground is firm under the tractor. Where the soil is unhealthy, he can feel the ground give under the weight.

How should we be taking better care of soil?

Everyone has a role to play in protecting soils for future generations.

Governments can adopt policies that support sustainable food and agriculture. Other companies can join us as partners in programmes such as this, or with industry initiatives like the Sustainable Food Policy Alliance. And we urge individuals to play their part by making the right choice in terms of the brands they buy.

This isn’t something that any one organisation alone can fix. But working together, everything is possible.

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