It has been immensely gratifying to see all the major players join the
http://terrapreta.bioenergylists.org/?q=nodemail list , Cornell folks, T. Beer of Kings Ford, M-Roots guys, DOE chemical engineers, Dr. Danny Day & G.I.T. folks, BestEnergy and Dr. Antel of U.of H.
Here's a post that brings us up to date on TP research:
[Terrapreta] Terra Preta & Soil Quality
Janice Thies jet25 at cornell.edu
Sat Feb 24 19:41:01 CST 2007
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Dear All,
I am extremely heartened by the very positive response to the idea of using
of biochar in agriculture and horticulture and appreciate your desires to
put it to immediate beneficial use in these systems.
My name is Janice Thies. I am a soil microbial ecologist. I have been
working with Johannes Lehmann at Cornell University for the past 6 years on
various aspects of terra preta (microbial ecology in its natural state) and
agrichar (how microbial populations respond to adding biochar to soil). It
took us three years to convince the National Science Foundation that we
were on to something here and to obtain funding for some of the basic
research that is necessary for us to provide the data needed to answer your
questions with confidence. Hence, we are several years behind where we
could have been if funding had been available earlier. Even now, we
continue to seek support for doing the types of tests many of you are most
interested in. The results of our NSF funded research are just now being
published or written up, but we are still a long way from being able to
answer everything.
Currently, there are 10 research laboratories around the world that are
testing char made from bamboo that was prepared at 5 different temperatures
in the range we believe is likely to provide char that will be most
beneficial for both plant production and C sequestration purposes. Rob
Flannigan prepared the char in China and has engaged us all to do a wide
range of testing on it. So, we should have some news about what
temperature range might be best reasonably soon, but it is still early days.
One of the reasons that Dr. Lehmann recommends caution in the use of
biochar can be seen in the paper recently published by Christoph Steiner et
al., mentioned in previous messages. He did get excellent plant growth
responses to adding biochar - as long as mineral fertilizer was also used.
When you look at plant growth in the biochar only treatment, growth was
worse than doing nothing at all (check plots). In the nutrient-poor and
highly leached soils of the tropics, the added biochar likely bound
whatever nutrients were present in the soil solution and these became
unavailable for plant uptake. These results should make you cautious as
well. How fertile a soil needs to be for biochar not to reduce plant growth
or exactly how much fertilizer and/or compost should be added to be sure
there is good, sustained release of nutrients, will likely vary soil to
soil and we simply do not have these data available at present to make
proper recommendations. So, keep this in mind as you do your own trials
with your own soils or mixes. Try to follow good design practices for your
trials, with replicates, so that you can judge for yourself what amount and
type of biochar works best in combination with what amounts and types of
fertilizers or composts you use (depending on the philosophy behind your
cultural practices).
As to the 'wee beasties' or 'critters' as I like to call them, we have made
progress on this front over the last several years. Brendan O'Neill and
Julie Grossman in my laboratory, Sui Mai Tsai, our Brazilian collaborator
at CENA and the University of Sao Paulo, and Biqing Liang, and many others
in Johannes Lehmann's laboratory have been characterizing microbial
populations in three different terra preta soils and comparing these to the
adjacent, unmodified soils near by to them. Brendan found that populations
of culturable bacteria and fungi are higher in the terra preta soils, as
compared to the unmodified soils, in all cases. Yet, Biqing found that the
respiratory activity of these populations is lower (see Liang et al.,
2006), even when fresh organic matter is added. This alone means that the
turnover of organic matter is slower in the terra preta soils - suggesting
that the presence of black C in the terra pretas is helping to stabilize
labile organic matter and is itself not turning over in the short
term. All good news for C sequestration. However, since the respiratory
activity is lower (slower decomposition), this may lead to slower release
of other mineral nutrient associated with the fresh organic inputs. In some
circumstances this is a good thing (maintaining nutrient release over the
growing season), in other circumstances (more immobilization), perhaps
not. We need more work on this to understand the implications of these
results more fully.
Julie Grossman, Brendan O'Neill, Lauren McPhillips and Dr. Tsai have all
been working on the molecular ecology of these soils along with me. So
far, what we know is that both bacterial and fungal communities differ
strongly between the terra pretas and the unmodified soils, but that the
populations are similar between the terra preta soils. These results are
both interesting and encouraging. First, that the terra preta soils
(sampled from sites many kilometers apart) are more similar to each other
than to their closest unmodified soil (sampled within 500 m) tells us that
the conditions in the terra pretas encourage the colonization of these
soils by similar groups of organisms that are adapted them. Our group has
been working on cloning and sequencing both isolates from the terra preta
soils and DNA extracted directly from them. A number of bacteria that were
isolated only from the terra preta soils are related to the actinomycetes,
but have not yet been described yet and are not very closely related to
other sequences of known organisms in the public genetic databases. This is
also very interesting. Some of you will know that actinomycetes have many
unusual metabolic capabilities and can degrade a very wide range of
substrates. Also, many are thermophilic and play important roles in the
composting process. We have yet to fully characterize these organisms, but
are optimistic that in time we can make some recommendations about what
organisms or combinations of organisms might make a good inoculant for
container-based biochar use. Two papers describing these results are in
their final editing stages and will be submitted for publication in the
journal 'Microbial Ecology' within the next few weeks. So, keep an eye out
for them in several months time.
I want to add a word of caution about getting too excited about glomalin.
Another of my students, Daniel Clune, has been working on this topic and
his work suggests that the glycoprotein referred to as 'glomalin' in the
literature - operationally defined as the protein extractable in a citrate
buffer with repeated autoclaving - is not what it has been purported to be.
First, the proteins extractable by this method are from a wide range of
sources, not just arbuscular mycorrhizal fungi. Second, it has a shorter
turnover time than has been suggested. Third, in a test with hundreds of
samples taken from field trials varying in age from 7 to 12 to 34 years,
its relationship with aggregate stability is suggestive at best. Dan's work
is also being written up right now and should also be submitted for
publication soon.
Some field trials with bamboo char have been conducted in China, with very
positive results. Look for upcoming papers from Dr. Zheng of the Bamboo
Institute in Hangzhou. Another student in my laboratory, Hongyan Jin, is
working with the soils from this experiment to characterize the abundance,
activity and diversity of the soil bacteria and archaea. Her first results
will be presented at the upcoming conference on Agrichar to be held in
Terrigal, NSW, Australia, at the end of April/beginning of May this year.
Please be sure to see her poster should you attend this conference.
Lastly, from my personal gardening experiences, I use spent charcoal from
the filters of the 14 aquaria I maintain for my viewing pleasure. I combine
it as about 5% of my mix with 65% peat moss, 10% vermicompost (from my worm
bin in my basement where I compost all my household kitchen waste - aged
and stabilized, not fresh!), 5-10% leaf mulch (composted on my leafy
property in NY), 5-7% perlite to increase drainage, decrease bulk density
and improve water retention and percolation, and some bone meal and blood
meal (to taste :-) ). This makes an excellent potting mix for my indoor
'forest'. I am very much still playing around with this.
I hope this very long posting helps those of you feeling frustrated and
wanting answers. Many labs are working on many fronts, but it is early
days and we are trying to answer some fundamental questions first and then
use the information to guide our field tests and recommendations.
I hope to meet some of you at the Agrichar Conference (see details at the
conference website)
http://www.iaiconference.org/images/IAI_brochure_5.pdfThe Cornell work and that of many of our colleagues in Brazil, China, the
US, Australia and elsewhere will be presented, along with that of many
others actively working on agrichar production and use around the world.
Good luck with your own testing and kind regards,
Janice Thies -
