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Biochar emerges as soil amendment for agricultureBiochar emerges as soil amendment for agriculture

Biochar, a soil amendment, has potential as a valuable tool for the agricultural industry with its unique ability to help build soil, conserve water, produce renewable energy and sequester carbon.Biochar can be created from a wide variety of feedstocks, including wood and plant matter, plus manure. 

February 27, 2015

5 Min Read

Biochar has potential as a valuable tool for the agricultural industry with its unique ability to help build soil, conserve water, produce renewable energy and sequester carbon.

Biochar, a soil amendment, is a specialized form of charcoal suitable for use in the soil. The product can be created from a wide variety of feedstocks, including wood and plant matter and even manure.

To create biochar, feedstock is heated to high temperatures under controlled conditions. The biochar-making process is called pyrolysis when no oxygen is present and gasification when low amounts of oxygen are used.

The gas or oil produced from heating feedstock can be used as clean energy. The carbon left behind is biochar. The production process eessentially concentrates carbon that would have been released back into the atmosphere as the plant or manure decays, therefore reducing greenhouse gas emissions.

Biochar is extremely porous which allows it to retain nutrients and water — which plant roots can access when the biochar is added to soil.

Research is underway to quantify nutrient availability to the plant. Since biochar can be made from several feedstocks and in numerous ways, its characteristics and impact on plant health can vary.

International Biochar Initiative

In 2006, the International Biochar Initiative (IBI) was formed during the World Soil Science Congress. The founders acknowledged a common interest in promoting the research, development, demonstration, deployment and commercialization of biochar technology and production.

“The biochar market is still in its early stages,” says IBI’s Thayer Tomlinson. “Different biochars can behave differently in soils depending on the feedstock and conditions of pyrolysis.”

The 2013 IBI report is available online at www.biochar-international.org. The report provides a broad overview of the state of the biochar industry as identified by surveys and other data and provides a snapshot of commercial and non-commercial biochar operations and activities.

One of the highlights of the report is the increase in scientific research. The number of peer-reviewed, biochar-related publications increased nearly five-fold over the last five years. More than 380 papers were published in 2013.

In the spring of 2012, the University of California, Davis (UC Davis) established long-term biochar experimental plots through the university’s Agricultural Sustainability Institute at the Russell Ranch Sustainable Agriculture Facility located near the main UC Davis campus.

The Russell Ranch facility is a 300-acre facility dedicated to investigating irrigated and dry-land agriculture in a Mediterranean climate.

Biochar testing

The UC Davis biochar plots are designed to analyze the impact of the soil amendment in a tomato-corn rotation. Researchers want to better understand how biochar could affect crop yield, plant health, nitrogen cycling and other issues.

The researchers used biochar made with walnut feedstock applied at about 9,000 pounds per acre. It was combined with mineral fertilizer or compost and compared to control plots that received the same mineral fertilizer or compost without biochar.

The data is not yet completely finalized and published, but researchers suggest the yields have been variable. “While we saw an increase in tomato and corn yields in 2013, the tomato rotation in 2014 had lower yields using biochar,” says Deirdre Griffin, a Ph.D. student at UC Davis.

“We are trying to understand how biochar affects soil and crops over the long term,” Griffin said. “We are eager to see the corn in its second rotation in 2015. Field trials will give us invaluable data to help us better understand biochar and if it’s better suited to specific crops.”

The research team plans to publish data once the second corn rotation is analyzed. UC Davis has developed an open-access biochar database available online at www.biochar.ucdavis.edu.

The IBI website also includes a broad list of university research programs and peer reviewed papers, plus manufacturer research data. The information has helped create the IBI Biochar Standards and an IBI Biochar Certification Program so manufacturers can certify that quality standards are met and safe for soil application.

Once certified, biochars can carry the IBI Certified biochar seal on the product label.

“For a sustainable biochar industry to succeed, it must provide certainty to consumers and markets about biochar and its safe use as a soil amendment,” Tomlinson said.


The first company to receive IBI certification was Cool Planet Energy Systems, a developer of small-scale bio refineries for the conversion of non-food biomass into hydrocarbons and biocarbons, including their patent-pending CoolTerra product which utilizes a proprietary process for upgrading biochar into a commercial-ready soil amendment.

The company is backed by investors including Google, BP, and Conoco Phillips.

Last October, Cool Planet unveiled its first commercial-scale production facility for CoolTerra in Camarillo, Calif.  

“We start with the IBI requirements and take it a step further by modifying the pore surfaces from the inside out — neutralizing the pH and activating the surfaces resulting in a product with consistently-high performance,” says Rick Wilson, vice-president of CoolTerra Business for Cool Planet.

“We recognized that other biochars required years of aging before consistent performance advantages were realized,” Wilson said. “CoolTerra is different because our technology accelerates natural chemical processes, completing the conversion in 12 minutes.”

Biochar was the main focus at the December meeting of the California Department of Food and Agriculture (CDFA) Environmental Farming Act Science Advisory Panel. Among the presenters included Johannes Lehmann, IBI’s co-chairman and Peter Hirst, co-owner of New England Biochar LLC and board member of Sonoma Biochar Initiative (SBI).

California the biochar leader?

SBI’s primary mission is to promote the ethical and sustainable production and use of biochar. The company is hosting biochar workshops, conducting research projects and educating stakeholders — including CDFA — on the advantages of biochar as a key tool for sustainable agricultural practices.

“When it comes to biochar technology, we haven’t even begun to build the ‘Model-T’,” said Hirst. “California is positioned to be the leader in biochar, and if CDFA supports widespread field trials we could see huge breakthroughs for the industry.”

Additional research from UC Davis and possible CDFA support could lead to 2015 becoming the defining year in California for biochar use in agriculture.

Growers interested in learning more about biochar research and product manufacturers can visit the IBI website, www.biochar-international.org.

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