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Superorganism Spotlight: Janet Jansson, PhD, on How the Microbes in Soil Could Help Combat Climate Change

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Here, we’re speaking with biological scientist and Seed Scientific Board Member Janet Jansson, PhD, on her work harnessing microorganisms in soil for planetary health. 

The microorganisms in soil play a crucial role in supporting plant growth and cycling carbon that enters the soil system. Dr. Janet Jansson’s work focuses on microbial communities residing in soil, sediments, and the human gut. Her research also looks at the impact of climate change on microbial communities in prairie and arctic ecosystems.

Continue exploring conversations about the fascinating world of bacteria and the vital role they could play in saving our planet here.

If you were meeting someone at a party, how would you describe the work you do? 

“My work focuses on microorganisms in soil. A lot of people don’t realize that soil is chock full of microorganisms. It’s a living ecosystem, but some people think it’s just dirt. So one of the things I try to relay to people is that soil is more than dirt: It is a functional ecosystem with billions of microorganisms, most of which we don’t understand, but they are very important for our life on Earth. Without microorganisms, we wouldn’t be here on Earth. We need them to survive.

“When I first started working with soil, I had no idea how interesting it was. Then I took a soil microbiology course, and just the thought that you have microorganisms in your own backyard was so exciting to me. I could grab a handful of soil and plate it, and I could see the colonies growing. There are all of these different forms of life that you can grow on an agar plate, and they’re doing all of these things to help the plants to grow and help keep us healthy. It was a whole new world that I had no idea about.”

Without microorganisms, we wouldn’t be here on Earth. We need them to survive.

Dr. Janet Jansson

Are there similarities between how microbial communities work in soil and how they work in the human gut? 

“You can think of a root as being an inside-out gut, in a way. It’s very similar. As an internal organ, the gut attracts beneficial microorganisms that help to digest food. In the root, some microorganisms are inside, but a lot are outside. While the signals in roots are different than in the gut, the root similarly signals back and forth with its microorganisms, recruiting the beneficial ones and repelling the negative ones. They have different microbes, but the same sort of interactions.” 

Does soil also benefit from probiotics? How do you foster “good” bacteria in soil?

“We are studying that now by enriching consortia of microorganisms in soil that have beneficial properties, sort of like a probiotic does for the human gut. An example of a beneficial property is growth promotion—so if you add these consortia, the plant grows better. Another example is helping to protect the plant against drought—so if you add this group of microorganisms that are well-adapted to living in soil to the plant before you plant it in arid soil, the plants often survive much better. And we do know that drought and arid systems are anticipated to be much worse in the future with climate change, so we need to think of ways to protect the plants in drought conditions where water is much less available.” 

What does climate change mean for soil and its microorganisms?

“As the climate changes, and as the environment changes, the community compositions of microorganisms will change, but there will still be microorganisms. Soil microorganisms and microorganisms in general adapt to change. In just a gram of soil, you have hundreds of thousands of different types of microorganisms. Some of them are going to die, because they won’t be able to compete. But the ones that are adapted to warmer temperatures and more arid environments will be able to grow better than those that are less resilient to those changes. So there will always be some kind of microorganisms. In general, microorganisms have a much wider spectrum of growth conditions compared to plants and animals.”

How does soil, in turn, impact climate change? 

“Microorganisms in soil are very important for helping to cycle carbon that enters the soil system. They can carry out good things for us by helping plants draw down carbon from the atmosphere, which reduces the impact of global warming. But they can also be the bad guys and be the ones responsible for the production of greenhouse gasses. So it depends on the particular soil ecosystem where these microorganisms are living whether they’re helping to reduce the negative impacts of climate change or contributing to it.”

Assorted farm soil bacteria sample teeming with life, as seen under a microscope (800x magnification).

How do the microorganisms in soil affect the plants that humans eat?

Microorganisms are important for plant productivity—for getting high yields of crops. Soil microorganisms do many different things to promote plant growth. They can produce hormones that help plants to grow better. They can also protect plants from pathogens by coating the root and protecting the plant from attack. Of course, some microbes are pathogens, but most of them are beneficial. If you compare a plant grown in a sterile soil system to one that has a natural microbial community, the plant that has microorganisms grows much better. That’s because there’s a synergistic interaction between the microorganisms and the plants. 

Is there anything that individuals can do or think about when it comes to how they interact with soil?

If you’re a gardener and want to increase the amount of organic matter in your soil, you can do different things like composting, preventing compaction in the soil, and planting more drought-tolerant crops. Those sorts of things reduce the need for water. If you have the opportunity to manage an ecosystem, you can plant more of a native prairie ecosystem with deep-rooting grasses, which is beneficial for the soil, the environment, the wildlife habitat, as well as the diversity of insects and animals. These native grassland ecosystems will also draw down carbon into the soil through the soil microbial activities. If you have even a small piece of land, you can plant some kinds of plants that attract butterflies and other kinds of insects. If you don’t have land, you can absolutely get planter boxes.

What’s giving you hope?

There are some larger initiatives that are giving me hope. The new mandate to keep some swaths of land for wildlife habitat is a very positive sign. Of course, there’s always the counter resistance to those initiatives. But young people are becoming more educated and aware, since it’s going to be their lives that are primarily impacted. So that gives me a lot of hope, that there’s so much passion by younger people to do something to help this situation.