Down to the Roots: The Appeal of Biochar
November 16, 2020
By Jordan Lonborg
For those of you who are tapped into the world of regenerative farming, or if you are a scholar in the study of ancient Amazonian agricultural farming tactics, biochar is probably a familiar term. If not, let me explain. Biochar is an ancient tool used to increase the fertility of the soil that has started to make a comeback in today’s regenerative farming world. At its essence, biochar is essentially a form of charcoal that is incorporated into compost or directly into the soil profile as a means of storing carbon and nutrients and increasing your soil’s moisture holding capacity.
One of the reasons biochar is making such a huge comeback in today’s regenerative farming world is that it is fairly easy to make. You start with a biomass, in our case, grapevine prunings and fallen logs and brush that we’ve collected while cleaning our forest understory to keep our fire risks down. Add some kind of receptacle, or even just a cone-shaped hole in the ground. You then light the fuel on fire burning the material from the top on down. The gases that are contained in that biomass beneath the fire combust and burn off, but leave almost all the carbon behind. If done properly, there is very little Carbon Dioxide released into the atmosphere (imagine a smokeless fire if you will). Once the fire has burned through your pile of biomass, you are left with a form of nearly pure carbon or biochar. This would be the simplest way of creating biochar for small producers. There are many other forms of production as well. There are larger kiln style burners all the way to industrial style setups that companies like Pacific Biochar are using. But in all cases, the idea is that you are turning raw fuel into a stable form of carbon as efficiently as possible.
Beyond its carbon capturing ability, biochar improves your soil in several ways. Because of its crystalline structure, one gram of biochar can contain – conservatively – over 2000 square feet of surface area. That surface area has the ability to hold on to both nutrients and water molecules and release them slowly, over time as needed. These properties are very similar to those of limestone. Both limestone and biochar are essentially banks and whenever our grapevines need a little cash, they are able to access the needed resources easily. A recent 3-year study conducted by Monterey Pacific Inc. showed that using biochar in conjunction with compost increased both grapevine yield and soil water holding capacity.
Last year, we ran a biochar trial very similar to Monterey Pacific’s here at Tablas Creek. We incorporated ten tons of biochar into some of the compost we made here on the property. We then took that biochar/compost mix and spread it out on the ground of our pig pen. Next, we moved our sheep into that pen and fed them feed harvested from the property on top of the mix for 3 days:
We gathered that compost/biochar/manure mix and spread in our trial block. In the trial block we left 2 rows untreated, treated 2 rows with just compost, 2 rows with compost/biochar mix, and 2 rows with the compost/biochar/manure mix, repeated 3 times (18 rows total). We then seeded all rows with cover crop. It did not take a trained eye to see the difference between the rows that were treated and those that were not. The cover crops were happy in all the rows, but those that had the bio-char and compost mix (like the row on the left in the photo below) had a cover crop that was considerably taller than the rest of the block.
Beyond the fact that biochar has the ability to increase yields of grapevines and soil moisture holding capacity, onsite production of biochar provides an alternative to the burn piles that pollute the air in many farm areas while also releasing massive amounts of CO2 into the atmosphere. Every farming property has to deal with biomass collected from the previous growing season. But choosing to produce biochar with that biomass is a win-win, creating a product that helps our vineyard while significantly reducing air pollution and CO2 release.
Up to this point, we’ve been purchasing biochar for our experiments. In the next couple of months, we’ll be designing a small kiln to trial here on the property. We want to get a feel for the cost, safety, and efficiency of the process. But we feel great about the prospects for this experiment. Whatever canes are left after chipping what we need for our compost program, we will turn into biochar. Whatever wood we collect while clearing the understory of the property to reduce fire hazard and improve access for our flock, we will turn into biochar. The biochar we create will be incorporated into our compost, aerating the pile and helping the composting process, which proceeds better in the presence of oxygen.
So, what do we think the impacts of biochar will be? Better soil fertility and water-holding capacity. A healthier compost pile. Reduced fire hazard and more grazeable land for our herd. Good conditions for the re-growth of native vegetation. More carbon in the soil and less (perhaps dramatically less) CO2 produced. Win-win-win-win-win.
Farm Like the World Depends On It