-Farm News photo by Darcy Dougherty Maulsby
Iowa Secretary of Agriculture Mike Naig, who spoke at the New Carbon Economy Summit in West Des Moines on Feb. 24, said carbon is connected to the next level of sustainability.

WEST DES MOINES — Iowa farmers know a lot about raising corn and soybeans, but could carbon be the next cash crop? There’s a lot of talk about the new carbon economy, and Iowa’s ag leaders predict that Iowa will be at the heart of this new frontier in many ways.

“Carbon is connected to the next level of sustainability,” said Iowa Secretary of Agriculture Mike Naig, who spoke at the New Carbon Economy Summit on Feb. 24 in West Des Moines. “Two of Iowa’s strengths are agriculture and renewable energy. Farmers have a mindset of continuous improvement, which fits with a low-carbon economy.”

This new carbon economy fits with the mission of the Bioeconomy Institute at Iowa State University. As a global innovator in the bioeconomy, the institute researches ways to derive renewable fuel, energy, chemicals and other useful materials from agricultural resources. While there’s a lot of talk about reducing carbon emissions, there’s a big difference between carbon reduction and carbon removal, said Dr. Robert Brown, director of the Bioeconomy Institute.

“We can talk about reducing the rate at which carbon dioxide enters the atmosphere, but that train has left the station,” said Brown, the keynote speaker at the New Carbon Economy Summit sponsored by BrownWinick Law Firm in Des Moines. “While there’s room for improvement with carbon reduction, that’s not enough.”

Carbon removal is the key.

-Farm News photo by Darcy Dougherty Maulsby
There’s an opportunity for Iowa to be a technology leader in the new carbon economy, says Dr. Robert Brown, director of the Bioeconomy Institute at Iowa State University, who spoke at the New Carbon Economy Summit in West Des Moines on Feb. 24.

“But it’s a lot harder to remove carbon dioxide from the atmosphere than you might think,” Brown said.

That’s why a broad coalition of Iowa’s policy leaders and ag leaders are working together to find practical solutions for a more carbon-free economy. In June 2021, Gov. Kim Reynolds signed Executive Order 9 launching a task force to explore carbon sequestration and the opportunities it presents for economic development in Iowa.

“Iowa is a recognized leader in renewable fuel and food production, making us a natural place to capitalize on the growing nationwide demand for a more carbon-free economy,” Reynolds said.

By July 2021, the Iowa Carbon Sequestration Task Force expanded to include an Agriculture Working Group, with members from ISU, the Iowa Corn Growers Association, Practical Farmers of Iowa and other Iowa ag and conservation groups.

“There are ecological and engineered solutions for carbon removal,” Brown said. “If you put carbon back in the soil, for example, you’re already doing good things for carbon removal.”

Keeping carbon in the soil

Wetlands and grasslands offer effective ways to keep carbon in the soil. Less tillage is also important.

“We can manage better soil carbon with good farming practices,” Brown said.

Beneficial microbes in the soil can offer unique ways to keep carbon in the soil, thanks to a natural process called microbial carbonate precipitation (MCP).

“You see MCP in certain soils in western Iowa,” Brown said. “This looks like limestone from a gravel road, but microbes grew it there from carbon dioxide.”

MCP can be mimicked and used for a number of biotechnologies, such as carbon sequestration. Another option to keep carbon in the soil involves pyrolysis. This thermo-chemical process converts dry organic materials into biochar. Biochar offers the potential to improve soil properties, fertility and carbon sequestration.

“Think of this process like a wood-fired pizza oven,” Brown said.

Like a wood-fired pizza oven, pyrolysis uses high heat to transform a product into something useful. Pyrolysis triggers the chemical decomposition of organic compounds (including biomass like corn stover) under oxygen-starved conditions. This results in a liquid product that can be refined for oxygenated fuel additives and petrochemical replacements, according to the U.S. Department of Agriculture.

Pyrolysis also produces biochar, another beneficial product.

“Biochar is charcoal,” Brown said. “It holds moisture and nutrients and releases them slowly to plants. Biochar helps plants grow, plus it’s a carbon sequestration tool.”

The life-giving aspects of biochar have been known for hundreds of years, Brown said. Recent studies have shown that pre-Columbian residents of the Amazon in South America were home to millions more people than archaeologists first realized. Scientists have analyzed charcoal remains and excavated pottery that provide evidence of sizable villages, deep inside the rainforest. Many experts believe the only possible explanation for how such numbers of people could have existed in the rainforest was “terra preta” – the rich, black soils bio-engineered by the local people using charcoal.

This has implications for modern-day agriculture.

“It turns out that corn stover can work really well for biochar,” Brown said. “There are nutrients in the biochar, which can be applied to the soil, plus the stover left in the field will still help control soil erosion.”

Brown would like to see markets develop where biochar is worth $100 a ton. The Bioeconomy Institute at ISU continues to study the pyrolysis-bioenergy-biochar pathway and its role in a sustainable, low-carbon economy. ISU is working on a pyrolysis/corn stover demonstration project with Stine Seed and other partners. The promise of this technology motivated the researchers to submit their project to the XPRIZE Carbon Removal competition.

This $100 million competition, funded by entrepreneur and business magnate Elon Musk and the Musk Foundation, supports innovative carbon removal technologies.

“We’ll find out in April 2022 if we move forward in this contest,” Brown said.

Leading the new

carbon economy

Brown has years of experience with this type of innovative research, including fast pyrolysis technologies that produce a variety of useful products like bio-oil. More than 10 years ago, Brown and his team worked on a bio-asphalt product that uses the unique properties of lignin (the material that makes plants “woody”) to make a better bike trail.

Around 2010, a start-up company licensed this bio-asphalt technology from the Iowa State University Research Foundation Inc. to produce oak-based bio-oil for a bicycle trail project in Des Moines.

“Bio-asphalt has properties similar to traditional asphalt,” Brown said. “This bio-based product was used to pave a section of the Waveland Trail on the northwest side of Des Moines a decade ago. We’ve sequestered carbon by the linear mile with that project.”

These types of innovations show how agricultural products can help support a low-carbon economy.

“There’s an opportunity for Iowa to be a technology leader in the new carbon economy,” Brown said.