When we think of climate change solutions, what typically comes to mind is the transportation we use, the lights in our home, the buildings we power and the food we eat. Rarely do we think about the ground beneath our feet.
Kate Scow thinks a lot about the ground, or, more precisely, the soil. She鈥檚 been digging into the science of how healthy soils can not only create productive farmlands, but also store carbon in the ground, where it belongs, rather than in the atmosphere as carbon dioxide.
Looking across the landscape on a spring day at , most people would simply see a flat, mostly barren field. But Scow鈥攁 microbial ecologist and director of this experimental farm at the University of California, Davis鈥 sees a living being brimming with potential. The soil beneath this field doesn鈥檛 just hold living things鈥攊t is itself alive.
Scow likens soil to the human body with its own system of 鈥渙rgans鈥 working together for its overall health. And, like us, it needs good food, water and care to live up to its full potential.
![Kate Scow with students](/sites/default/files/news/campus-news/2017/jun/kate-scow-uc-davis.jpg)
Farmers and gardeners have long sung the praises of soil. For the rest of us, it鈥檚 practically invisible. But a greater awareness of soil鈥檚 ability to sequester carbon and act as a defense against climate change is earning new attention and admiration for a resource most of us treat like dirt.
Soil can potentially store between 1.5 to 5.5 billion tons of carbon a year globally. That鈥檚 equivalent to between 5 and 20 billion tons of carbon dioxide. While significant, that鈥檚 still just a fraction of the 32 billion tons of carbon dioxide emitted every year from burning fossil fuels.
So soil is one bite of a big platter of solutions needed to confront climate change.
But the nice thing about healthy soils, Scow said, is that creating them not only helps fight climate change 鈥 it also brings multiple benefits for agricultural, human and environmental health.
鈥淲ith soil, there鈥檚 so much going on that is so close to us, that鈥檚 so interesting and multifaceted, that affects our lives in so many ways 鈥 and it鈥檚 just lying there beneath our feet,鈥 she said.
Subterranean secrets
Underground, an invisible ecosystem of bugs, or microorganisms, await. In fact, there are more microbes in one teaspoon of soil than there are humans on Earth. Many of them lie dormant, just waiting to be properly fed and watered.
A well-fed army of microbes can go to work strengthening the soil so it can grow more food, hold more water, break down pollutants, prevent erosion and, yes, sequester carbon.
鈥淚 love the word sequestration,鈥 said Scow, who thinks the word is reminiscent of secrecy, tombs and encryption. 鈥淪oil is filled with microbes who are waiting it out. The conditions may not be right for them 鈥 it鈥檚 too dry or too wet, or they don鈥檛 have the right things to eat. They鈥檙e sequestered. They鈥檙e entombed. But if the right conditions come, they will emerge. They will bloom, and they will flourish.鈥
How soil sequesters carbon
Soil sequesters carbon through a complex process that starts with photosynthesis. A plant draws carbon out of the atmosphere and returns to the soil what isn鈥檛 harvested in the form of residue and root secretions. This feeds microbes in the soil. The microbes transform it into the building blocks of soil organic matter and help stabilize the carbon, sequestering it.
鈥淵ou can鈥檛 sequester carbon without microbes,鈥 Scow said. 鈥淭hey鈥檙e far more important than we ever imagined.鈥
Healthy soils
There鈥檚 too much carbon in the atmosphere and not enough in the ground where it can be used. A new effort in California aims to flip that picture.
The state鈥檚 is considered the first in the nation to provide state funding to help farmers and ranchers enhance their soils to reduce greenhouse gas emissions. The $7.5 million program, expected to launch this summer, encourages farming practices known to boost microbial communities underground and sequester carbon.
It鈥檚 easy to ignore. It鈥檚 everywhere and it鈥檚 nowhere. That鈥檚 the challenge. But if soil is alive, it鈥檚 like someone you can create a relationship with. - Kate Scow, microbial ecologist
The program may also open the door for farmers and ranchers to participate in the state鈥檚 carbon market, where they could create and trade carbon offsets under the . In short, they could be paid to store carbon.
An increased demand for compost from farmers and ranchers could also help reduce food waste and landfill emissions.
Soil food
Similar to how people can feed probiotics and prebiotics to the microbes in their guts to improve their health, farmers can use cover crops and apply compost, yard waste and other organic matter to feed microbes in the soil. Reduced tillage, efficient irrigation and other methods also strengthen the soil鈥檚 ability to store carbon.
Such techniques have long been used by farmers to enhance soil鈥攑articularly on organic and small farms.
鈥淭his is ancient knowledge, really,鈥 said Pelaymo Alvarez, outreach director for the Petaluma-based Carbon Cycle Institute and a graduate of 69成人. 鈥淲hen you increase soil organic matter in the soil, good things happen. But climate change is bringing new attention to it. And regardless of climate change, we should be doing this for many reasons鈥攆or productivity, erosion control, drought tolerance. It鈥檚 going back to our roots, no pun intended.鈥
![Aerial view of rangelands in Northern California](/sites/default/files/images/article/20170411_waposoil_024.jpg)
Ranching roots run deep
The roots run deep for Scott Stone at Yolo Land & Cattle Company outside Winters, California. His late father, Hank Stone, bought the 7,500-acre ranch about 40 years ago, and it鈥檚 now owned and operated by Scott and his brother Casey. Stone is as much a natural resources manager as a rancher, with a protective eye on the ranch鈥檚 watersheds, trees, pasture and grass-fed cattle, and a genuine desire to leave the land better than he found it.
He rotates his cattle frequently across the pasture to avoid overgrazing. Most of the ranch鈥7,000 acres鈥攊s in a conservation easement. He avoids fertilizer. And, increasingly, he composts.
Rotting hay bales compost in place; where they once fed the cows, they now feed microbes, growing greener grass and sequestering more carbon as a result. A large mound of compost rests on his lower fields, awaiting application.
鈥淚t鈥檚 the right thing to do,鈥 Stone said. 鈥淎s ranchers, we鈥檙e busy here making a living, and we don鈥檛 get out to tell our story as much as we should.鈥 He wants people to better understand that land stewardship and ranching can work together to protect the whole ecosystem.
Carbon on the range
Sustainably managed ranches like this one, with their swaths of grasses and trees mixed with cow manure and hay, suck up carbon by their mere existence.
鈥淭he first thing to do to store carbon on rangelands is to avoid converting them to other things,鈥 said Kelly Gravuer, who worked on the Healthy Soils Initiative as an intern for the California Department of Food and Agriculture while she was a graduate student in Scow鈥檚 lab. 鈥淏ut people are asking if there are additional things we can do to store carbon, like compost.鈥
When you look at the cow, you think of emissions. But the whole system is actually sequestering carbon. There are so many opportunities in agriculture to move the needle on climate change. - Scott Stone, Yolo Land & Cattle Company
California loses about 20,000 acres of rangeland each year, much of which become greenhouse-gas-emitting housing developments, shopping centers, roads and parking lots. The remaining 63 million acres of rangeland in the state鈥攑art of the 770 million acres nationwide鈥攔epresent significant opportunities for additional carbon storage, and can help offset some of the emissions for which the meat industry is often criticized.
Scientists estimate that U.S. rangelands could potentially sequester up to 330 million metric tons of carbon dioxide in their soils, and croplands are estimated to lock up more than twice that amount鈥攗p to 770 million metric tons. That鈥檚 the CO2 emissions equivalent of powering 114 million homes with electricity for a year.
鈥淲hen you look at the cow, you think of emissions,鈥 Stone said. 鈥淏ut the whole system is actually sequestering carbon. There are so many opportunities in agriculture to move the needle on climate change.鈥
Everywhere and nowhere
Back at Russell Ranch, Scow walks into a field, bending down to pick up a clump of soil. She crumbles it in her hands. She views soil as a metaphor for a world that needs healing.
鈥淚t鈥檚 not a crying baby,鈥漵he said. 鈥淚t鈥檚 easy to ignore. It鈥檚 everywhere and it鈥檚 nowhere. That鈥檚 the challenge. But if soil is alive, it鈥檚 like someone you can create a relationship with.鈥
Media Resources
Kat Kerlin, 69成人 News and Media Relations, .530-750-9195, kekerlin@ucdavis.edu
This article was also published as sponsored content in the