Farm Scale Making of Biochar in Place
If we are going to reduce the amount of carbon dioxide in the atmosphere in order to to stop the greenhouse gas effect, we must do more than conserve energy and use sustainable fuel sources. We have to actually remove carbon dioxide from the atmosphere. Nature already does this. It pulls carbon dioxide out of the atmosphere through photosynthesis and stores carbon in plant matter. But when we burn it or let it compost or rot, the carbon is joined with oxygen again and goes back into the atmosphere as carbon dioxide. The problem gas. To break the cycle, we can actually keep the carbon in the soil by making biochar, charcoal. It's something that farmers can do to help themselves by improving their soil. And help the rest of the planet!
If biochar is going to be used by farmers it has to be able to be made by farmers: it not only has to be relatively convenient for them to put into their fields but also into their already busy workloads. And it has to be in a quantity that can be applied to acres of farmland. It has to be made by the ton!
First, meet Dirk-Jan Rosse, who has been experimenting with making biochar in place. Dirk-Jan Rosse lives in farming country although he calls himself a "digger", running an excavating company. Since childhood he has prowled all over the woods and fields of northern Dutchess County, NY, where he still runs across traces of charcoal-making from the days when it was used to smelt the iron for weapons in the Revolution and Civil War. Dirk-Jan has a lot of surplus wood on his own property. He milled some lumber for his own use, but there was an awful lot more than he needed for himself and there was not much of a local market for firewood. He has been thinking about how to make charcoal at a scale that would suit a farm using equipment available to a farmer. But being in the excavation business, however, he had his own commercial earth-moving gear that you would not really find lying around a farm. This allowed him to ramp up the scale and the speed of making some tests, but on a smaller and slightly slower scale everything could also be done by tractor with a bucket and grapple. He remembered those remains of charcoal pits and kilns. His plan is quite simple: rather than make biochar someplace and then cart it to the field, why not actually make it in the field itself? It would be based on a traditional way: covering a pile of scrap wood, tree clippings, cut-offs, etc. with dirt and letting it pyrolyze right on the spot. The same dirt that forms the "retort" would end up as the home for the charcoal. There is no apparatus required. Just the existing dirt and some bad hay (of which there is plenty where we live). What needed to be tested was the design of the pile, how the wood should be stacked, and what kind of air or smoke openings should be placed.
STEP ONE: MAKING THE STACK Again, the Bobcat can be replaced by a tractor's bucket loader and grapple. It's time to light up! After a few days of smoldering, the pile was ready to be opened. Well, in truth, we were dying of curiosity! Now let's switch to an implement of a different scale... This is only a small fraction of the pile. There is plenty of good carbon to be put into the soil that has been taken out of the air. The experiment is not over. There will be more piles to make biochar and to improve the process: the smoke needs to be burned off, the air-flow improved... the charcoal will need to be matched with appropriate compost... more - videos of the process ....