Even though it was rainy and breezy, several brave and curious souls arrived at the Michigan Biochar sponsored biochar seminar last Saturday. As mentioned before, Peter Hirst was the featured presenter. Peter is one of the foremost proponents of biochar in the United States. He demonstrated the concepts of pyrolisis, using a few different sizes of burners. One of the most simple was a “TLUD”. It uses the concept of a top down fire, based on the fact that hot air rises, but heat radiates. Made with a paint can and a few food cans, small amounts of biochar are easy to produce. Peter also used the burner that Joe’s been using, the “fat man”, to demonstrate a larger scale retort.
What is biochar good for? What’s the hype all about? Peter also discussed the amazing things biochar does in the soil. Biochar is, essentially, an empty apartment house for the flora, fauna, and minerals in the soil. When mixed with compost and other amendments prior to application, it will store the nutrients and microbiology of the compost and then make it available slowly (over the course of years) to the plants. This has the effect of providing a nutrient bank for the plants and critters such that one application will enrich the dirt immedietly and long term. I learned in conversation that that bank can be refilled, much like your bank account. Instead of allowing nutrients to run off into where you don’t want them, the char will hold them in place and pick up more nutrients as the plants pull out what is stored. Biochar will also hold moisture, helping to keep crops moist during dry times.
As a side benefit, biochar is a pure carbon product that is being returned to the soil instead of returned to the atmosphere. In the process of a tree’s death and decomposition, CO2 is released back into the atmosphere. This process helps to sequester that carbon and return it back into the earth to benefit the life there.
Another frequently asked question that Peter addressed was to compare charcoal and ashes to biochar. The simple answer is that charcoal is produced at lower tempuratures and therefore still contains many of the tars and gasses that are later released to give your food that wood flavor. Biochar is made at much higher tempuratures and is void of the tars and gasses, leaving more room for storage. Biochar is somewhat comparable to activated charcoal. The biggest difference is that activated charcoal is heated even higher than biochar, producing even greater storage capacity and more purity so that smaller amounts can be highly effective. For its purposes, biochar is more cost effective than producing activated charcoal for your soil.