One of the more interesting educational offerings at the TCI Expo last month was about biochar, which is a type of charcoal made from biomass—plant or plant-based material such as grass clippings or wood chips—burned in little to no oxygen.

According to biochar expert Michael Wittman, of The Blue Sky Enterprise, biochar has been used successfully by humans for thousands of years as a carbon-rich soil additive. Today, arborists use biochar to support tree nutrition and growth, among other uses.

Biochar is a very stable, long-lasting compost. Therefore, it’s particularly suited for supporting long-lived trees. In addition to helping trees with water and nutrient retention, biochar also helps solve common tree health problems, including:

  • Low organic matter in soils undergoing significant change, such as at construction sites
  • Soil compaction
  • Soil water retention

According to the International Biochar Initiative, biochar is also a powerful tool for combating climate change. “The carbon in biochar resists degradation and can hold carbon in soils for hundreds to thousands of years,” the organization says. “In addition to creating a soil enhancer, sustainable biochar practices can produce oil and gas byproducts that can be used as fuel, providing clean, renewable energy. When the biochar is buried in the ground as a soil enhancer, the system can become “carbon negative.”