Biochar is a solid material obtained from the carbonization thermochemical conversion of biomass in an oxygen-limited environments. In more technical terms, biochar is produced by thermal decomposition of organic material (biomass such as wood, manure or leaves) under limited supply of oxygen (O2), and at relatively low temperatures (<700°C). This process mirrors the production of charcoal, which is perhaps the most ancient industrial technology developed by humankind. Biochar can be distinguished from charcoal—used mainly as a fuel—in that a primary application is use as a soil amendment with the intention to improve soil functions and to reduce emissions from biomass that would otherwise naturally degrade to greenhouse gases.
Creating biochar involves taking common biomass such as sticks, leaves, acorns and sweet gum balls and burning it without air to produce a product similar to charcoal, but that is pure carbon. The process is actually an ancient one. There is evidence of biochar being made in the Amazon rain forest over 2000 years ago. The charred material that comes out of a biochar burner is black as charcoal but still recognizable as sticks or gumballs. However, it easily crumbles into a power when stomped.
When the process is complete, the remaining product is pure carbon. This can be returned to the soil where it helps retain nutrients and water. But it also reduces emissions from biomass that would otherwise produce greenhouse gases.
Hampton Master Gardener, Rhonda Graves, offers a workshop at 1:30 about the making of biochar in Room 103. A small fee of $8 per person is required to attend. Kids 12 and under are free. Call 757-591-4838. Checks can be written out to NNMGA, paid at the event or mailed to the address below:
NNMGA c/o VCE
739 Thimble Shoals Blvd., Suite 1009
Newport News, VA 23606