Farmers in Virginia check the outcome of their no-till farming practices. U.S. Department of Agriculture

How Carbon Farming Can Help Solve Climate Change

By David Burton

Under the 2015 Paris agreement, nations pledged to keep the average global temperature rise to below 2C above pre-industrial levels and to take efforts to narrow that increase to 1.5C. To meet those goals we must not only stop the increase in our greenhouse gas emissions, we must also draw large amounts of carbon dioxide (CO2) from the atmosphere.

The simplest, most cost effective and environmentally beneficial way to do this is right under our feet. We can farm carbon by storing it in our agricultural soils.

Soils are traditionally rich in carbon. They can contain as much as five percent carbon by weight, in the form of soil organic matter—plant and animal matter in various stages of decomposition.

But with the introduction of modern agricultural techniques, including the plow, soil organic matter content has dropped by half in many areas of the world, including parts of Canada. That carbon, once stored in the ground, is now found in the atmosphere and oceans as CO2 and is contributing to global warming.

The organic compounds found in soil are the glue that hold soil particles together and help give the soil structure. Like the walls of a building, this structure creates openings and passageways that allow the soil to conduct and store water, contain air, resist soil erosion and provide a habitat for soil organisms.

Plowing breaks apart soil aggregates and allows microorganisms to eat the soil organic compounds. In the short-term, the increased microbial activity releases nutrients, boosting crop productivity. In the long-term the loss of structure reduces the soil's ability to hold water and resist erosion. Ultimately, crop productivity drops.

How Can We Make Soil Organic Matter?

First and foremost, we need to disturb soil less. The advent of no-till and reduced tillage methods have allowed us to increase the carbon content of soils.

No-till and direct-seeding methods place the seed directly into the soil, minimizing the disturbance associated with seedbed preparation. The lack of disturbance allows the roots and crop residues from the previous crops to form soil organic matter. It reduces the degradation of the soil organic matter already present in the soil.

In Canada, we are already benefiting from reduced tillage. In the Prairies, no-tillage agriculture has increased from less than five percent of the land area in the early 1990s to almost 50 percent in 2006.

The situation is a bit more complex in Eastern Canada. The region's soil type and climate make it less easy to build soil organic matter. At Dalhousie's Atlantic Soil Health Lab, we are exploring the potential of various cropping practices to increase soil organic matter content in the soils of Atlantic Canada. While the potential to store carbon may not be as great as in Western Canada, the benefits of increased soil organic matter content are far greater because of the critically low levels of organic matter.

Secondly, we can use more diverse crop rotations. Forage crops—such as grasses, clovers and alfalfa—penetrate the soil with extensive root systems that lead to the formation of soil organic matter. Short rotations dominated by crops that have poor root systems (corn, soybeans) are not effective in building soil organic matter.

Farmers can also build soil organic matter by adding organic amendments such as animal manure, composts, forestry residues (wood chips) or biosolids to the soil.

Using the right amount of fertilizer is also important. Fertilizers can improve plant growth, lead to larger roots and add more plant matter to the soil in the unharvested portion of the crop. However, too much nitrogen fertilizer can result in the production of the powerful greenhouse gas nitrous oxide and offset the benefit of increased soil organic matter formation.

Farmers Need Economic Incentives

Project Drawdown, a non-profit organization that researches solutions to global warming, has estimated that global farmland restoration (building soil organic matter) could remove 14 gigatones (billion tonnes) of CO2.

This would reduce the CO2 in the atmosphere below the current 400 parts per million—a level unpassed for several million years—while developing more fertile, resilient soils to feed people for years to come and keep forests intact.

These approaches seem like obvious solutions. Why are they not more widely adopted? The short answer is economics.

The benefits of drawing down CO2 and building soil organic matter play out over decades. But the costs associated with these practices often do not have increased returns in the short-term.

Farmers often make decisions in response to short-term economic pressures and government policies. Improved soil management is a public good. We need economic tools and short-term incentives that encourage producers to adopt these practices for the good of all.

Reposted with permission from our media associate The Conversation.

Show Comments ()

Silver Nanoparticles in Clothing Wash Out, May Be Toxic

By Sukalyan Sengupta and Tabish Nawaz

Humans have known since ancient times that silver kills or stops the growth of many microorganisms. Hippocrates, the father of medicine, is said to have used silver preparations for treating ulcers and healing wounds. Until the introduction of antibiotics in the 1940s, colloidal silver (tiny particles suspended in a liquid) was a mainstay for treating burns, infected wounds and ulcers. Silver is still used today in wound dressings, in creams and as a coating on medical devices.

Keep reading... Show less
4.4 million premature air pollution deaths could be avoided in Kolkata if emissions are reduced swiftly this century. M M / CC BY-SA 2.0

Study Finds Timely Emissions Reductions Could Prevent 153 Million Air Pollution Deaths This Century

One of the roadblocks to swift action on climate change is the human brain's tendency to focus on threats and stimuli that are an obvious and noticeable part of their everyday lives, rather than an abstract and future problem, as Amit Dhir explained in The Decision Lab.

Now, a study published in Nature Climate Change Monday shows that acting quickly to curb greenhouse gas emissions would also reduce the air pollution that is already a major urban killer, thereby saving millions of lives within the next 40 years.

Keep reading... Show less
Lands threatened by BLM's March 2018 sale include Hatch Point. Neal Clark / SUWA

Trump Administration Sells Oil and Gas Leases Near Utah National Monuments

The Interior Department on Tuesday is auctioning off 32 parcels of public lands in southeastern Utah for oil and gas development.

The Bureau of Land Management's (BLM) lease sale includes more than 51,000 acres of land near Bears Ears—the national monument significantly scaled back by the Trump administration last year—as well as the Hovenweep and Canyons of the Ancients monuments.

Keep reading... Show less
Katharine Hayhoe talks climate communication hacks at the Natural Products Expo West Convention. Climate Collaborative

Katharine Hayhoe Reveals Surprising Ways to Talk About Climate Change

By Katie O'Reilly

Katharine Hayhoe isn't your typical atmospheric scientist. Throughout her career, the evangelical Christian and daughter of missionaries has had to convince many (including her pastor husband) that science and religion need not be at odds when it comes to climate change. Hayhoe, who directs Texas Tech's University's Climate Science Center, is CEO of ATMOS Research, a scientific consulting company, and produces the PBS Kids' web series Global Weirding, rose to national prominence in early 2012 after then-presidential candidate Newt Gingrich dropped her chapter from a book he was editing about the environment. The reason? Hayhoe's arguments affirmed that climate change was no liberal hoax. The Toronto native attracted the fury of Rush Limbaugh, who encouraged his listeners to harass her.

Keep reading... Show less
Rising Tide NA / Twitter

Kinder Morgan Pipeline Protest Grows: Arrests Include a Greenpeace Founder, Juno-Nominated Grandfather

By Andy Rowell

Just because you get older, it doesn't mean you cannot stop taking action for what you believe in. And Monday was a case in point. Two seventy-year-olds, still putting their bodies on the line for environmental justice and indigenous rights.

Early Monday morning, the first seventy-year-old, a grandfather of two, and former nominee for Canada's Juno musical award, slipped into Kinder Morgan's compound at one of its sites for the controversial Trans Mountain pipeline and scaled a tree and then erected a mid-air platform with a hammock up in the air.

Keep reading... Show less

The Grapes of Trash

By Marlene Cimons

German monk and theologian Martin Luther probably said it best: "Beer is made by men, wine by God." It's true—the world loves its wine. Americans, in fact, downed close to a billion gallons of it in 2016. But winemakers create a lot of waste when they produce all that vino, most of it in seeds, stalks and skins.

Keep reading... Show less

Why Mike Pompeo Could Be Even Worse for the Environment Than Rex Tillerson

By Kelle Louaillier

As Secretary of State, Rex Tillerson was one of the most blatant revolving-door cases in the Trump administration and a clear sign that Trump's government was of, by and for the fossil fuel industry. But make no mistake: Mike Pompeo could be far worse.

Keep reading... Show less
Sudan, the world's last male northern white rhino. Ol Pejeta Conservancy

World's Last Male Northern White Rhino Dies

The world's last male northern white rhino has died, leaving only two females left to save the subspecies from extinction, the wildlife conservancy taking care of him announced Tuesday.

The 45-year-old rhinoceros, named Sudan, was euthanized Monday at the Ol Pejeta Conservancy in Kenya.

Keep reading... Show less


The best of EcoWatch, right in your inbox. Sign up for our email newsletter!