One hundred and fifty years of burning fossil fuels has cost us dearly. The addition of carbon dioxide from these stored hydrocarbons is in the process of accelerating global climate change. This destabilization of weather ends a 10, 000 year period during which human development was made possible. How we manage our future use of carbon will determine what our future will be like. Biochar is the only carbon-negative activity that the majority of humanity can participate in.

What Can You Do?

Make some charcoal and bury it in the ground. Really! It sounds easy except that the more attention given to producing charcoal that is biologically active, the better the garden plants like the result, aka Biochar.

Photosynthesis removes carbon dioxide from air and sequesters it by converting it to carbohydrates which are stored in plant tissues. With this conversion of atmospheric CO2 to a solid form, the carbon can be transformed to charcoal to be used in the soil. Some scientists have calculated that adopting this as a global practice can bring a net reduction in our atmospheric carbon over time. (1)

We know that the agricultural use of biochar in soil is beneficial. Our mission is to spread this information and to help develop best practices for the use of biochar in temperate soils. Mainstream researchers are just beginning to publish their field data on temperate climate effects in soil. We are getting confirmation that Biochar improves soil cation exchange capacity, soil pH, emulates organic matter and serves as habitat structure for beneficial fungi, bacteria and very small animals. (2)

Backyard Biochar - Sean’s and Kelpies’s demo programs

Larry and I attended the Richland Regional Biochar Conference in May. With federal grant money in the pipeline, the conference was full of entrepreneurs with visions of making big bucks selling biochar to farmers. We think this is putting the cart ahead of the horse. In our opinion, farmers will never be able to afford charcoal from processors who have high capital, labor and transportation costs. Nevertheless, producing charcoal at the grassroots level is possible.

We intend to show farmers and gardeners how to make their own biochar from agricultural and forest debris, making this a true grass roots movement. Kelpie Wilson’s presentation (4) demonstrating small scale pyrolysis was best example of this approach at the conference. Comparing the costs of the two scales of production, backyard (Kelpie and Seachar) and industrial, Kelpie’s kiln cost around $350 to produce and the industrial scale kilns cost upwards of $1,000,000 per model. Sean Barry’s farm scale kiln, which we will be demonstrating, can produce a thousand pounds of charcoal per day for under $4000 investment. This is a kiln suited to Fourth Corner Nurseries scale of production, where we can convert our dry organic waste to biochar and apply it directly to the soil rather than burn it.

The development of industrial scale markets will be difficult, because of the capital, labor and transportation costs involved. By contrast, onsite production for growers will give farmers and gardeners hands-on experience making biochar and learning the benefits of biologically active charcoal.

Making charcoal into biochar: Hydrophobic vs. hydrophilic

Currently, industrially produced charcoal is different from biochar and the process is not geared for making biochar. It turns out that charcoal made at higher temperatures they use, 600 – 800 C, does not produce charcoal that is as useful as material pyrolyzed at 400 degrees C or less.

When the charcoal is first removed from kiln it is coated with an organic sheen which makes it water repellent. Before hydrophobic charcoal is useful microbes need to break down this water repellant layer. Because this takes energy from the productive activity of the microbes, putting hydrophobic charcoal into soil will result in reduced production.

The task, then, is to serve the nutrients to the microbes as they like it. This means getting the charcoal to absorb water which opens up spaces where beneficial microbes can take up residence and makes it possible for the char to adsorb valuable nutrients. Converting hydrophobic charcoal into hydrophilic charcoal before use assures immediate biological function in the soil. There is more than one way to make the conversion.

Rich’s study began with hydrophobic charcoal and has had the best results where charcoal was combined with compost in three crop years of field trials involving fertilizer, compost and biochar. This years’ buckwheat cover crop in the compost/ charcoal trial is quite impressive, but it has taken time for the differences to clearly manifest themselves.

In Larry’s work, by contrast, the charcoal was converted through composting before use in the garden. He demonstrated immediate positive results. Larry composts in well rotted wood chips wetting with a mixture of rainwater and very diluted urine. Rich has subsequently accomplished the same thing by leaving hydrophobic charcoal mixed with hay and urea under a tree all winter.

References

1. Johannes Lehmann, A Handful of Carbon, Nature 447:10 May 2007.

2. Impact of Biochar Amendment on Fertility of a Southeastern Coastal Plain Soil, Novak, Jeffrey M., Busscher Warren J., Laird David L., Ahmedna Mohamed, Watts Don W., and Niandou Mohamed A., Soil Science, February 2009, Volume 174, Number 2, p.105-112, (2009).

3. Charcoal effects on soil solution chemistry and growth of Koeleria macrantha in the ponderosa pine/Douglas-fir ecosystem, Gundale, Michael, and DeLuca Thomas, Biology and Fertility of Soils, Volume 43, p.303-311, (2007).

4. Kelpie Wilson, Backyard Biochar, edited clip of her presentation in Richland.