[Terrapreta] Can crop residue char be used for TP?

[Tom Miles]

Where has biochar made from crop residues like straws and stalks been
demonstrated? Most charcoal has been made from woody, woody materials, like
bamboo, or materials with some structure like rice husk char or densified
peanut hulls. 

 

I am particularly concerned about the effect on water in soil of char made
from low density crop residues. Pyrolysis of switchgrass suggests that it is
not useful for activated carbon. I have not seen examples of switchgrass
char being used for TP. 

 

ARTI (Pune, India) tried char from sugar cane leaves in heavy clay soils and
found that it only waterlogged the soil. AD Karve suggests that it may work
better in sandy soils. We do not knowif Chardust (Kenya) has tried using
their "cane coal" as biochar. 

http://www.bioenergylists.org/en/ARTIcharcoal

http://www.bioenergylists.org/en/taxonomy/term/706

http://www.bioenergylists.org/en/canecoal

 

University of Georgia and EPRIDA have reported good results with pelletized
rice hull char. Is pelletizing necessary? (It can add up to $50/ton to the
cost of the feedstock.) See reports by Julie Gaskin and Danny Day. 

http://terrapreta.bioenergylists.org/taxonomy/term/338/9

http://terrapreta.bioenergylists.org/taxonomy/term/60/9

 

Ogawa, Okimori and others report eh use of rice husk char. 

http://terrapreta.bioenergylists.org/taxonomy/term/238/9

http://terrapreta.bioenergylists.org/taxonomy/term/448/9

 

In April Dynamotive announced a 14 ton trial using corn stalk char in Iowa
at rates of 2.5 t/a and  5 t/a. they hope to increase yield by 20%. I have
not seen any reports about this test since. The USDA ARS National Soil Tilth
Laboratory and Iowa State University are involved in this trial for
Heartland Bioenergy LLC.

http://terrapreta.bioenergylists.org/hearlandllcmay2007

 

We have seen lots of good growth in chars from straws but it is more likely
due to the concentration of nutrients than the char. The EPRIDA and
University of Hawaii (Antal) processes capture soluble nutrients (NPK) to
enrich the char. 

http://terrapreta.bioenergylists.org/taxonomy/term/93/9

 

Tom

   

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