0
BEK at ALL Power Labs' booth
There have been some recent modifications to the BEK that makes assembly much easier, I was able unpack the three barrels and build the BEK with a wrench and a screw driver in about 30 minutes flat!
Stewart with his barreled BEK
Stewart from Anthroterra in Australia bought the BEK off the floor of the conference to be able to make small samples of characterized biochar. They are doing a lot of interesting work studying the biology and chemistry of biochar interactions in the ecology of soil that effect root growth. They also have an incredible database of magnified photos from their research. see link here: http://anthroterra.com.au/ Because of the presence of pots in the Terra Preta soil, they are studying the effect of creating biochar with clay. The metals naturally present in the clay(ex: alumina, iron, magnesium) seem to have a catalyzing effect during char production which change the physical characteristics of the char. This group is one of the few actively researching the impact of clay for contemporary biochar making.
After the Conference, about 25 attendees went on an organized tour of some Terra Preta sites along the Amazon River.
Local Terra Preta Test Farm
Terra Preta Soil Profile
The first farm that we visited was a local farmer that had three types of soil present on his land: Terra Preta, Terra Mulatta (mixed Terra Preta and local soil), and Oxasol (local soil, clay-like, nutrient deprived)
As we were walking along the farm, the clay pots that are typical of Terra Preta were so common they seemed to be littering the place. It was quite easy to sweep your hand across the ground and grab a handful of the clay pot fragments. Legally the farmers are not allowed to farm on Terra Preta sites because they are considered historical sites, however the Brazilian government does not enforce this law. For this reason only research can be conducted on the land and the farmer can not legally own the land themselves, but this law is believed to be changing soon.
Terra Preta site dig by Embrapa
We visited a second site where the Brazilian group Embrapa (http://www.embrapa.gov.br/english) has been conducting their research. Some charcoal is evident in the profile of some of the Terra Preta trenches that is due to slash and burn practices and possibly tilling practices before that. It is known that these areas have been inhabited for thousands of years, however the historical data of how these lands were used in the last 100 years is lost. Researchers are left to mostly speculation about the anthropological significance of Terra Preta.
Terra Preta research trench
Improved Manioc Root Production
We also visited new biochar trials in the area that seemed to be showing increased growth in local plants, though formal yield comparisons of these crops have not yet been completed. Many in the field are realizing the significance of biochar as a amendment to prevent leaching of fertilizer, and experimenting with various types of implementation such as biochar booms at the bottom of a slope.
Terra Preta soil is around 1000 years old, and at these time scales its hard to say exactly what we can replicate currently to increase the yield of crops on poor soil. I believe the only way we will be able to build a strong case for biochar is to do trial experiments and build our knowledge over time.
Jay
