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Why We Need to Toil for Soil

by

Deborah Bossio

Lead Soil Scientist, The Nature Conservancy

December 2016

Potato sprout in Minzhu Village on the edge of Laohegou Nature Reserve in Pingwu County, Sichuan Province, China. Photo © Nick Hall for The Nature Conservancy
Potato sprout in Minzhu Village on the edge of Laohegou Nature Reserve in Pingwu County, Sichuan Province, China. Photo © Nick Hall for The Nature Conservancy

December 5th marks World Soil Day and it deserves a round of applause. You may ask why, and the answer is simple: Soil is a superstar.

Soil. Dirt. Earth. Substrate. It goes by many names. Yet, all we really need to know is that it’s “life.” Look after the soil and we can feed a growing planet. Let it degrade, and know that this is degradation you can’t repair, and that human civilization would suffer.

Let’s start with some facts. If you think of the planet as one giant organism, then soil is a little like the “skin” of the Earth. First off, there are more living organisms in a handful of soil than there are people on Earth. Second, healthy soil is about food. Ninety-five percent of our food is directly or indirectly produced on our soils. Third, we need soil more than ever. By 2050, global agricultural production must increase by 60 percent. And, if we restore global soil health, we can also help slow climate change, one of the most urgent imperatives of our age.

Soil as a Climate Solution

Soil is an unsung hero in the climate story. It contains two to three times more carbon than the atmosphere. This means that small changes in soil carbon — either improvement or deterioration — can have a big impact on atmospheric carbon. In lay terms, increasing soil organic carbon has two benefits. In addition to helping to mitigate climate change, it improves soil health and fertility. In turn, many management practices that increase soil organic carbon also improve crop and pasture yields. If more carbon is stored in the soil, it will reduce the amount present in the atmosphere, and help mitigate climate change – a process known as “soil carbon sequestration.” It’s a win-win.

We need to get this right, but in recent decades we haven’t. According to the UN Food and Agricultural Organization, we have around 60 years left of harvests if we carry on with “Business- as- Usual,” and the Guardian identified soil loss as one of the 13 global crises we are currently facing. Even more recently, a new paper in Nature confirms that climate change will accelerate the decomposition of soil organic carbon, releasing large amounts of CO2 into the atmosphere, which we can ill afford.

The Nature Conservancy is working with farmers around the world to help preserve & restore our soils and feed a growing population.

A New Energy Around Soil

But there’s hope. Last year was the International Year of Soil, and also the launch of 4p1000 initiative, led by the French government. The Nature Conservancy signed on to this with more than 100 governments and other institutions. I found it encouraging to see such broad uptake.

I and other TNC colleagues attended the UN climate meeting with colleagues from CGIAR and the 4p1000 Research team, presenting new analysis highlighting the crucial role that agricultural soils and their management play. It’s worrying that most agricultural soils have lost a significant part (40 - 60%) of their natural organic carbon. Yet when restored, they offer huge potential carbon storage capacity that can be filled.

The Way Forward

We know in many places what needs to be done. Many are practical: conservation tillage, which entails reducing plowing and leaving the crop residue on fields before and after planting the next crop; cover cropping, which entails planting legumes and other plants that keep soil protected and provide biomass to soil to rebuild organic matter; organic matter recycling and use of perennial crops, which are alive year-round and are harvested multiple times before dying. These are all good practices and there are more. Perhaps less well understood is that we need a combination of these interventions, applied across very large areas of agricultural lands, to make a significant impact for the climate.

TNC and General Mills have just launched a Soil Health Roadmap for a new initiative: ReThink Soil.

Developed by an interdisciplinary team of Conservancy scientists, economists and agriculture experts and made possible through support from General Mills, the Roadmap makes the business case for investing in sustainable soil health practices to achieve unprecedented economic benefits for U.S. farmers and businesses, as well as significant conservation outcomes.

Download

(1.04 MB PDF)

Solutions and ideas within the Roadmap are, of course, transferrable to regions outside of the United States, many of which face similar challenges. In East Africa, similar issues exist before widespread adoption of soil building practices are likely to adopted. These include lack of support for the science and measurement of soil health benefits; economic obstacles; and, like in North America, there are issues of absentee landlordism and land tenure issues, as well as ensuring that the right policies are in place.

Managing soil well requires some work and forward planning. Yet we owe it and ourselves, a debt of responsibility. This World Soil Day, let’s toil for soil the way it toils for us. Gandhi said, “to forget how to dig the earth and to tend the soil is to forget ourselves.” I would add that to forget that we need soil more than soil needs us, is an even greater danger.

“Healthy soil is important to us because it allows us to grow nutritious, beautiful food for our community!” - Tarrant Lanier and Cathy O'Neal, Founders of Victory Teaching Farm in Mobile, Alabama. Photo © Jenn Greene
“Healthy soil is important to us because it allows us to grow nutritious, beautiful food for our community!” - Tarrant Lanier and Cathy O'Neal, Founders of Victory Teaching Farm in Mobile, Alabama. Photo © Jenn Greene
Zosia Russo plays in her grandmother's hugelkultur raised bed in Ormond Beach, Florida. Photo © TNC
Zosia Russo plays in her grandmother's hugelkultur raised bed in Ormond Beach, Florida. Photo © TNC
"Soil gives us the food and trees we need to survive," says Ed in Kenya. Photo © Ed Hewitt
"Soil gives us the food and trees we need to survive," says Ed in Kenya. Photo © Ed Hewitt
"I dig soil!" - Charlie the dog in Mobile, Alabama. Photo © Jenn Greene
"I dig soil!" - Charlie the dog in Mobile, Alabama. Photo © Jenn Greene
Local elementary school groups participate in a habitat restoration workday on the Conservancy’s Gonzales Farm Property in California. Photo © Ethan Inlander
Local elementary school groups participate in a habitat restoration workday on the Conservancy’s Gonzales Farm Property in California. Photo © Ethan Inlander
Danya Gross planting on the Silver Creek Preserve in Idaho. Photo © Bob Law
Danya Gross planting on the Silver Creek Preserve in Idaho. Photo © Bob Law
Women ‘potting’ tree seedlings, Komaza, Kenya. Photo © Ed Hewitt
Women ‘potting’ tree seedlings, Komaza, Kenya. Photo © Ed Hewitt
Azariah Richardson playing in the soil in his local community garden in Atlanta, Georgia. "Mama thinks soil is sacred... I think its squishy!" © Myrian Dormer
Azariah Richardson playing in the soil in his local community garden in Atlanta, Georgia. "Mama thinks soil is sacred... I think its squishy!" © Myrian Dormer

Download

(1.04 MB PDF)

reThink Soil Roadmap

This roadmap outlines how adopting soil health practices on all U.S. corn, soy and wheat croplands could deliver nearly $50 billion in social and environmental impacts annually.