Can Biochar Solve Pollution Problems?



Biochar, created from an ancient practice that turns organic waste into a charcoal like substance, is getting a closer look for its potential to help address modern-day problems such as climate change and nutrient-laden runoff.

The material has been lauded over the past decade, with advocates calling it a simple and important tool to capture carbon from the air, soak up stormwater runoff and build up healthier soils in agricultural and urban settings.

But it has not become widespread in either production or use.

That may be changing. A major push by government agencies and other organizations seeks to close research gaps, set quality standards, scale up production — likely with federal aid — and better promote biochar through demonstrations sites in Chesapeake Bay states and beyond.

Advocates hope to see its widespread use within a decade.

In simple terms, biochar is created by turning plant and animal waste into a carbon-rich product by heating them at high temperatures without oxygen. The process is called pyrolysis.

Biochar has been used as a soil amendment in some places around the world for more than a thousand years. Recent research shows that it can suck carbon from the air and store it in the ground, where it can enrich soil for hundreds of years — some call it a biological carbon battery.

The latest Intergovernmental Panel on Climate Change report praises biochar as an important climate change mitigation technique.

It also retains nutrients in the soil, keeping them close to plant roots where they can stimulate both crop growth and the production of microbes that improve soil health.

Farmers in the Bay states could add biochar to not only crop fields, but also to feedlots where it would absorb nutrients and other contaminants, as well as to pastures to improve productivity.

But except for scattered experimental uses, biochar is not widely used in the Bay states. Pennsylvania only has three biochar suppliers or manufacturers. New York has two, while Maryland and Virginia each have one.

In large part, this is because questions remain about its effectiveness, which can change with various soil types and the climate of the application site, as well as the application methods.

To answer those questions, the bipartisan Biochar Research Network Act has been introduced in both houses of Congress. If passed as part of the next Farm Bill, it would allocate $50 million annually to establish a network of up to 20 research facilities across the nation to test the effectiveness of biochar.

Those research gaps are the biggest obstacles to greater use of biochar, according to the December findings from a summit of government agencies, nonprofits organizations, conservation groups and biochar producers.

A paper generated from the gathering seeks to have sustainable and widespread commercial production of biochar available in the next five years.

Biochar “is not a silver bullet, but it is part of a natural climate solution and a tool in soil health,” said Rachel Seman-Varner, senior soil health and biochar scientist in the American Farmland Trust’s climate initiative. The Trust organized the summit, along with the Foundation for Food & Agriculture Research and the National Center for Appropriate Technology.

Participants stressed that biochar is not a onesize fits-all solution. A wide mix of materials have been used to produce biochar, including forest slash piles, animal manure, crop residue, food waste, yard waste, cotton gin waste, hulls of rice and walnuts, and even diapers.

As a result, biochar products can vary greatly in properties and have different impacts based on soil types. The amount of heat used to create biochar can also impact the outcome.

“There’s still a lot we don’t know. The research results have been inconsistent. We need a systematic research effort,” said Chuck Hassebrook, who helped write the paper for the nonprofit National Center for Appropriate Technology. He expressed optimism that this will be accomplished with passage of the research bill now before Congress.

More production facilities will also be needed if biochar is to become mainstream, Hassebrook said. “I think there is a lot of potential here, but it is going to take some early support from the federal government to launch this industry.”

Meanwhile, biochar experiments are popping up nationwide, including in the Bay watershed.

In December, the National Fish and Wildlife Foundation awarded the Center for Watershed Protection $699,500 to- ward a $1.7 million project to use biochar to help capture stormwater and remove nutrients in Waynesboro, VA; Arlington County, VA; Carroll County, MD; Howard County, MD; and Hanover, PA, as well as at transportation sites in Harford and Cecil counties,

MD, and near Middletown, DE.

The biochar used in those projects will serve as a soil amendment in bioretention basins, rain gardens, dry ponds, and tree plantings. It will also promote soil health in conservation landscaping and under solar arrays.

Biochar could be useful in treating sewage, too. At Penn State University, researchers who completed a three-year federally funded biochar project found that wastewater from sewage treatment plants can be run through biochar filters to remove up to 95% of pharmaceuticals.

Sewage treatment plants aren’t equipped to filter out pharmaceuticals, which is a big concern when they discharge into waterways or when biosolids are spread on fields that produce crops eaten by humans.

Meanwhile, the U.S. Department of Agriculture in September named the nonprofit U.S. Biochar Initiative as a partner in a $30-million effort to use the material to lower the carbon footprint of beef production.

There is also a push to allow farmers who produce or use biochar to profit from selling carbon credits. And the USDA recently recognized the use of biochar as a soil amendment in major conservation programs, allowing farmers to apply for funding to help pay for putting biochar on their fields.

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