A quick checkup on the “skin of the Earth”

Q&A with soil scientist Leigh Winowiecki

Planting gnetum, a tropical evergreen species, in the soils of Cameroon. Ollivier Girard, CIFOR
13 May 2022
13 May 2022

One of the biodiverse ecosystems on the planet is the soil beneath our feet. When healthy, a single gram of soil can contain tens of thousands of bacteria and fungi species, serving as the living foundation for all other ecosystems as well as of human food systems, clean water and safety from certain environmental disasters.

And yet, soil receives little attention – and therefore little care. Over half of all agricultural soils are degraded, compromising the lives of more than 3 billion people and costing the world up to USD 10.6 trillion per year.

When and how will this change?

At the 15th session of the Conference of the Parties (COP15) to the United Nations Convention to Combat Desertification (UNCCD) – a two-week global summit where decisions are made on how to better manage land – Landscape News spoke with World Agroforestry soil systems scientist Leigh Winowiecki about the state of the world’s soils and what needs to happen in order for it to change.

Why are you studying soil?

I’m studying soil because it is the foundation of life on land. It is so critically important for climate change mitigation and adaptation, ecosystem restoration, food and nutrition, and security. It’s literally and physically central to our existence. It’s the skin of our Earth.

Agricultural landscapes near Kalawa, Kenya, where Winowiecki has conducted soil projects. Kelvin Trautman
Agricultural landscapes near Kalawa, Kenya, where Winowiecki has conducted soil projects. Kelvin Trautman

Why is soil so often missing in climate change conversations?

So, I’ve been asking this question for a long time, “Why is soil so overlooked?” And I think it’s because soil is so ubiquitous that we take it for granted. We see soil all the time, yet we’ve just not given it the care it needs. And we haven’t made the connection between where our food comes from and the soil.

What is happening to change this?

More and more organizations, institutions and initiatives are recognizing the important role of soil. Now there are several new initiatives, such as the Coalition of Action 4 Soil Health (CA4SH), which took root in the UN Food Systems Summit and continues to grow. This coalition aims to scale soil health globally by addressing key implementation, monitoring, policy and financial barriers constraining land managers from scaling healthy soil practices. The Coalition aims to synergize with other key initiatives to really shine a spotlight on soil.

At the UN Environment Assembly (UNEA), we started talking with different governments to form a declaration on soil health. Now we’ve modified this declaration, and we’re having conversations with a number of countries to see if they will support it for the UN Climate Change Conference later in the year (COP27). There’s a huge opportunity for a recognition of the role soil plays for climate change adaptation and mitigation – soil has the potential to store twice as much carbon as terrestrial and atmospheric pools. So this is something that we can really tap into, and we’re using this opportunity at COP15 to raise awareness about the need for soil health.

How do we increase soil organic carbon?

Having carbon in the soil influences several other important ecosystem services including water holding capacity, which is so needed because droughts are becoming more frequent and lasting for longer. Soil organic carbon also influence nutrient availability from the soil and helps stabilize soil to reduce erosion, just to name a few.

Increasing soil organic carbon is where stewardship really comes in, and making sure we’re promoting, empowering and encouraging farmers, pastoralists, forestry managers and land managers to practice healthy soil options. There have been barriers constraining farmer uptake of healthy soil practices that support this, including policies that don’t encourage healthy soil practices as well as access to data and monitoring tools, implementation and financial incentives. We’re really working to address these.

A single inch of healthy topsoil can take half a century to be produced. Courtesy of Leigh Winowiecki
A single inch of healthy topsoil can take half a century to be produced. Courtesy of Leigh Winowiecki

What policy changes can support healthy soil?

The first one is in countries’ nationally determined contributions (NDCs) to the Paris Agreement, designed by governments to achieve climate change goals. This is a real opportunity. Soil is such an important and obvious place to sequester and store carbon contributing to climate change mitigation.

When we talk to governments, they often say they struggle with access to information and understanding of data on how different practices improve soil carbon. So it’s very important that scientists, research organizations and coalitions make data accessible and transparent to governments, so they can say, “Yes, we will be able to monitor and track soil carbon changes overtime. And we have confidence that we can now include it in our NDCs.”

How is the scientific community helping provide this information?

There’s that old saying, “If you can’t measure it, you can’t monitor it.” But now we know how to monitor soil health. We know what the indicators are and how to do it in the field, and the methodology we developed – the Land Degradation Surveillance Framework (LDSF) – is so robust that it’s been implemented in over 40 countries across the tropics. Now we have statistical models that can be matched with the satellite imagery and can produce accurate maps at a very relevant scale for all land-users of key indicators such as soil organic carbon, soil pH, sand content and erosion prevalence.

Farmer communities gather to learn about soil measurement. Kelvin Trautman
Farmer communities gather to learn about soil measurement. Kelvin Trautman

Given the importance of the role humans play in soil health, how does soil health also help livelihoods?

We have been working for many decades with farmers on the ground. And when a farmer sees improvements in their yield, in the health of their crop, in their crops needing less inputs and less chemicals because the soil is healthier, this is so exciting and empowering for that farmer – and then that farmer will go and teach other farmers. They become really respected and regarded in their community.

Actually, it’s very interesting: there have been several studies on adoption of sustainable management practices, and there are naturally several motivating factors, but it turns out that this kind of social respect – which I think we can all acknowledge in the science or communication sphere – is indeed motivating, in addition, of course, to having higher income, more opportunities, higher yield. So we actually really see farmers at the center of ecosystem restoration.

What are other ways people can help soil health?

If you’re a policymaker, you can put soil health into the policies. If you are an urban dweller, you can work to try and find somewhere to compost your food waste and make sure that it’s going back into the soil. If you have a small veranda, you can care for soil in planters and try to grow some of your own food. If you’re a consumer, you can buy products that promote healthy soil. Every single one of us has a responsibility to care for the soil, and you can do it in very different ways.

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