Does Biochar Work? Why?

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josiah hunt

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Sep 30, 2010, 3:56:20 PM9/30/10
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Hello Group,

Perhaps you could help answer this.

This question, as simple as it may seem, is both important and
complex. I have been obsessed with answering this question for the
last two years. I feel as though answer to as to Why it works becomes
more complex as my knowledge expands. There are many things I am
interested to investigate such as:

Particle size of biochar - large v.s. small and the role size plays
(water/nutrient adsorption and release, soil texture, biology, etc.)
Biological factors - Mycorrhizal fungi, N-fixing bacteria, Nematodes,
and how pore-size/feedstock/particle size affect these.
Application rates in local soils - talk about a loaded question,
Hawaii's soils vary greatly.
Composting with Biochar - Comparative CEC, VOC, and effectiveness.

Professor Jonathan Deenik of UH Manoa and some of his students will be
conducting more research into questions such as these with a batch of
plain and composted biochar that I produced and donated. I will meet
with him in a few weeks to talk about the details. I have also begun
donating small amounts to experienced farmers again and would like to
focus in on important aspects.

I am asking any of you who are willing to share your experiences and
questions.

Su Ba, I have seen some postings by you in the Yahoo Group. I have
not met you yet but it sounds like you have been doing quite a bit of
experimenting with biochar. Do you have any insights as to using
biochar in Ka'u, such as drought tolerance? (p.s. I have not found a
wood which made a biochar I did not like, christmas berry included)

Thank you in advance for sharing your thoughts,

- Josiah

Sherri Miller

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Sep 30, 2010, 6:28:13 PM9/30/10
to biochar...@googlegroups.com
Thanks for all your hard work, Josiah. I have another category that I feel should be looked at: chemistry. How does it affect pH for example? Nitrates vs, nitrites, mineral salts, bio-availability of nutrients etc etc. Of course a further questions would be does the biochar itself make changes or the microbes enhanced/attracted by the biochar? What about nutrient cycling and residence time?  I know I am presuming chemical changes, but this seems to be self-evident.

Sherri





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Su Ba

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Oct 1, 2010, 4:49:58 AM10/1/10
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Hi, Josiah! I met you at Dr Cho's Natural Farming seminar at the UH farm in Hilo. I was one of many.

I've been working at improving soil fertility for 6 years now. And although I can now produce crops and am the envy of my neighbors, I still have a long way to go. My soil was so poor when I started that seed potatoes would only send up a few scrawny stems 6"-8" in height, then die back. The largest potato tubers were the size of large marbles, smaller than a ping pong ball. Pretty poor, no? The majority of my field could not retain moisture, while the rest of it waterlogged with every rain. When the waterlogged areas dried out, it was like concrete.

My grandmother taught me gardening as a small child, so I drew upon that training. I started by removing the lava rocks, anything bigger than a hens egg. Then I began rototilling in just about everything I could get my hands on, including char that I made myself. For the first two years I put the char through a hammermill with a one inch screen. It pulverized the char. Most came out as dust with a lot of small pieces. And while the areas with too much drainage improved, the wet areas became mucky and pasty. I added cinder to the muck and ended up with dark paste coated cinder. A problem. I could not produce crops on that muck.

I changed strategy with the char, primarily because I was tired of dealing with charcoal dust. I switched to using the char chunky, using anything two inches or less in size. Bigger pieces I hand crumbled or hit with a hammer if needed. Since my well drained areas were doing better and had crops on it, I started incorporating the chunky char into the muck areas. I also tilled in chunky coral, as opposed to powdered, and bamboo I had run through the hammermill. I did that about every four months. Drainage gradually improved. (These problem areas are atop pahoehoe that should really be hammered, but I can't afford that at this time.) After attending Dr Cho's seminar, I made IMO #4, tilling that into the wetter areas, following it with heavy application of compost and horse manure. I then covered it with a top dressing of the IMO #4, spread a light mulch and added hundreds of worms from my worm bins. This summer has been dry and my wet mucky areas are looking like normal soil. I have been taking advantage of the drought and tilling in more chunky char, covering the soil afterward with a light layer of mulch. I plan to till in a layer of chipped bamboo again then sow some grains of some sort. I will most likely cut some drainage trenches through these areas to aid in drainage, should the winter rains come.

I believe that the chunky char is working out better for me than the finer stuff. Just my opinion and gut feeling.

By the way, on my improved soils, I only lightly rototill between crops. And only at the row area that will be sown, maybe a 12 inch width. The soil between the rows is not rototilled, leaving them "naturally" layered, allowing the compost, mulch and other additions to breakdown. I don't know if that makes a difference on the plants, but my results are good. So I suppose the method works.

...Su Ba


From: josiah hunt <josia...@me.com>;
To: <biochar...@googlegroups.com>;
Subject: Does Biochar Work? Why?
Sent: Thu, Sep 30, 2010 7:56:20 PM

Hello Group,

Perhaps you could help answer this.

This question, as simple as it may seem, is both important and complex.  I have been obsessed with answering this question for the last two years. I feel as though answer to as to Why it works becomes more complex as my knowledge expands.  There are many things I am interested to investigate such as:

Particle size of biochar - large v.s. small and the role size plays (water/nutrient adsorption and release, soil texture, biology, etc.)
Biological factors - Mycorrhizal fungi, N-fixing bacteria, Nematodes, and how pore-size/feedstock/particle size affect these.
Application rates in local soils - talk about a loaded question, Hawaii's soils vary greatly.
Composting with Biochar - Comparative CEC, VOC, and effectiveness.

Professor Jonathan Deenik of UH Manoa and some of his students will be conducting more research into questions such as these with a batch of plain and composted biochar that I produced and donated.  I will meet with him in a few weeks to talk about the details.  I have also begun donating small amounts to experienced farmers again and would like to focus in on important aspects.

I am asking any of you who are willing to share your experiences and questions.

Su Ba, I have seen some postings by you in the Yahoo Group.  I have not met you yet but it sounds like you have been doing quite a bit of experimenting with biochar.  Do you have any insights as to using biochar in Ka'u, such as drought tolerance?  (p.s. I have not found a wood which made a biochar I did not like, christmas berry included)

Thank you in advance for sharing your thoughts,

- Josiah



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