By Paula Henson
As destructive as slash-and-burn farming has been, it’s more environmentally friendly cousin “slash-and-char” agriculture (dating back to the Amazon basin in 450 AD) seems to have provided a gold mine of sorts right beneath our feet. Literally.
Plant material was burned in such a way (lower temperatures and lower oxygen levels) that produced charcoal instead of ash. Fields of the stuff were buried and, in the 20th century, rediscovered. “Terra preta”, the charcoal-enriched soil was similar to humus: hosting billions of micro-organisms. The organisms produced carbon molecules that adhered to the charcoal, which then increased the soil’s carbon content. Instead of becoming hazardous greenhouse gases (GHG), the carbon from decomposing plants became sequestered by the charcoal-rich soil. (OrganicGardening.com, Biochar)
Dr. Wallace “Marty” Meyer of Bernard Field Station, Pomona College, and speaker at the 2015 Soil In The City Summit, says they have found in their research that there is A LOT more carbon stored in the soil then anything we see above ground. Its actually about 5 to 6 times what carbon is stored in plants and in the atmosphere. Soil looks like a GHG villain but in fact its quite the hero. “The carbon in biochar resists degradation and can hold carbon in soils for hundreds to thousands of years,” says the International Biochar Initiative reports.
Biochar is resistant to chemical and biochemical degradation. Therefore, its use allows carbon sequestration in soils and consequently provides reduction of carbon dioxide to the atmosphere. (Pellegrino Conte, “Biochar, soil fertility, and environment”)
But all this cannot be without controversy. Questions remain about the quality, economic viability and environmental impact of producing biochar. Yet, can the benefits outweigh the costs?
“We can use this simple, yet powerful, technology to store 2.2 gigatons of carbon annually by 2050. It’s one of the few technologies that is relatively inexpensive, widely applicable, and quickly scalable. We really can’t afford not to pursue it.” (BiocharInternational.org, What is Biochar?)
Dr. Brian Von Herzen, founder of The Climate Foundation, spoke at the Summit on the use of Biochar for carbon sequestration. Check out his video
Dr. Brian Von Herzen
About the Author: Paula Henson is an Award-winning landscape designer who started Terra Bella Landscape Design in 1998. A Los Angeles native, she enjoys the unique opportunity to create something that is constantly evolving. The 2007 Los Angeles Garden Show featured one of her designs and she received the “Best Use of Recycled Materials” award for excellence in the 2007 Showcase at Greystone Mansion in Beverly Hills.
She has been featured on HGTV’s Landscaper’s Challenge, has appeared in several award-winning educational DVD programs and served as Vice President of the Board of Governors for the Los Angeles County Commission on Arboreta and Botanic Gardens. She has been a certified Landscape Professional for the city of Santa Monica Sustainable Landscape Program and is currently on the Board of the Greater Los Angeles district of the APLD. Most recently she has been concentrating on water conservation education and rainwater harvesting system.
