Alkemik Design Permaculture Blog

What is Biochar and why it is so good.

Biochar, while boasting an ancient history, is actually just gaining popularity among many circles today. While it’s believed that ancient South American cultures would use biochar (or burning agricultural waste, covered in soil) to increase soil productivity, the term wasn’t coined until Peter Read did so in 2005, to describe a substance that looks almost like charcoal, but that is actually biomass carbonized and made into a solid material, used to improve soil functions and reduce greenhouse gas emissions.

Understanding biochar, its use and its demand, however, is somewhat complex, and it starts with a firm grasp of carbon. Carbon is never destroyed. When you pull carbon out of the ground, whatever form it happens to be in, and burn it, you’re releasing it into the atmosphere. If our plant life is not able to take that carbon dioxide in quickly enough, it stays in the atmosphere or it sinks down into the world’s oceans. Then, depending on where it goes, the carbon creates warming effects (i.e. global warming), extreme weather events or issues within the marine food chain.

However, as stated above, the ancient Amazonians had a somewhat simple solution to this scientific problem, that all started with a system they would use to increase their soil fertility. When looking at soil fertility in the region today, it’s often not terribly high. The light-colored, nutrient-poor soil is only usable for short periods of time by agricultural workers, and is then no longer viable. However, some pockets of soil remain that give us a glimpse into the ancient Amazonians’ process.

Thousands of years ago, these civilizations would dig large, deep earthen pits. They would then fill these pits with food scraps, agricultural waste and anything that would decompose organically. They would then set all of this waste on fire and cover it with soil. The practice created a condition allowing for extremely high heat and very low oxygen. The carbon created from burning the waste would then be retained in the soil, rather than being released into the atmosphere. This created soil that was very dark in color, very rich and very nutritious, as it was filled with charcoal, covered in microscopic pores and very dense, working to act as a sponge and hold nutrients that would enrich soil and improve fertility for thousands of years. Biochar is simply the modernization of this process.

In modern processes, organic waste materials (such as food wastes and agricultural wastes) are being saved from being sent to landfills. These wastes are heated to a very high temperature in a low-oxygen environment, creating the biochar you see today.

You’re probably asking — why not just compost? Creating biochar actually sequesters approximately 50 per cent of the carbon that would otherwise be released. Composting only sequesters up to 10 or 20 per cent, while burning the waste only sequesters about 3 per cent. Plus, studies are showing that biochar creates a stable carbon sink, and has the potential to put a huge dent in the carbon dioxide the human race is off putting. It improves soil fertility, increases the water-holding capacity (reducing irrigation needs and saving water), lowers soil density to create well structured soils with larger root mass and then produces larger plants with higher plant yields.


Biochar therefore has the potential to assist with two of the largest sustainability problems in today’s world — the growing amount of trash being produced by the world’s population, as we take a portion of this trash to be used as biochar, instead of being sent to landfills that are being capped off or close to being capped off, as the trash is not going away at the rate at which we’re producing it; and low-performing agricultural fields covering 38 per cent of the world’s terrestrial surface, causing 1 in 7 people to be food insecure.

Biochar is becoming a large movement, though, currently, biochar isn’t popular enough to really contribute to the global carbon budget. However, its expansion of use is being more widely recognized.