Biochar.

[JWFITZ]

It works. Powerfully so.

Detail:

[url]
http://sanityandsimplicity.blogspot.com/...er-in.html[/url]

[MarkP]

Saw your comment about ancient Hawaiians using char. I had never read this. Where did you get this information?

[JWFITZ]

Damon's father in law put me on the trail, and I found further references in "Native Planters in Old Hawaii" specific to preparing sites for upland taro propagation. I've just planted a new patch in that manner and we'll see how it compares. So far, looks great.

[Guest]

Glad he could be of assistance. Nice to hear your "back online" again as well.

Hawaiians are very knowledgeable in using the land productively. It saddens them to see so many people ruin the land by wasteful means.



Damon Tucker's Weblog

[MarkP]

I found the following excerpt on the web:

"However, not all biochar performs the same. The importance of biochar’s variable chemical composition was illustrated in studies by Goro Uehara, a professor of soil science at the University of Hawaii, who grew plants both with and without biochar made from macadamia nutshells. He says, "As we added more [biochar], the plants got sicker and sicker." Uehara’s colleague, University of Hawaii extension specialist Jonathan Deenik, says that when they repeated the experiment with a more highly carbonized version of the nutshell biochar, which contained lower levels of volatile compounds, "preliminary results in a greenhouse study showed that low-volatility [biochar] supplemented with fertilizer outperformed fertilizer alone by 60%, in a statistically significant difference." This research was presented at the October 2008 annual meeting of the Soil Science Society of America."

It seems to imply that you can under-cook biochar. Previously I had read statements that suggested low temperature cooking was better. To say the answer is probably in the middle is to say you believe either or both of these sources. I tend to believe the source quoted above. JWFITZ, when you make your charcoal, are you attempting to limit the temperature of the process in any way? It sounds as though you are putting biomass in a drum, getting it burning, and slapping the lid on for a while. As charcoal manufacturing processes go this is probably on the cool end of the spectrum because you are using one small drum and not routing the burning gasses to a burner under the retort (drum).

As an aside I offer the town of Centralia, PA, where an underground fire has been smoldering for more than 40 years in the coal seams beneath the town. Coal is a very dense fuel source and terra-pretta would not have any where near that density of carbon in the soil, but I wonder what if any danger there is of the charcoal catching fire. I am tempted to say it could never catch in Puna's wet climate but I read years ago about thick peaty deposits from swamps in FL burning after the swamps were drained.

[JWFITZ]

Hi Damon, Jerry's been a great help. I'll have commercial production of upland table taros within the year.

It would do a lot of us "newcomers" to do a little more cultural research and in a more comprehending manner than is common of the nature of Hawaii and the historical context of the culture here as it has evolved. The book "Native Planters in Old Hawaii" is much to be recommended as a primary source text and will cut quickly through the more Hollywood concepts that float around. The 'aina is foremost and literally the "land that feeds" the the soul of Hawaii is so firmly embedded in agriculture that everything else seems remotely secondary. The only legitimate way I can see to even pretend to live in harmony with that value is in the historic model--very modest homesteads crafted with great respect for the environment and to quietly and insightfully engage in productive husbandry.

It would be a different place if more people shared that value, wouldn't it? And I don't mean as a hobbyist.

It is this core value of Hawaiian living that is least appreciated and that we are in the greatest danger of losing.

[JWFITZ]

Hi Mark,

I can see potential problems with biochar and have observed similar effects. The main risk as I said above is that it appears to be very easy, or so it appears, to overconcentrate nutrients to the level of toxicity. But, our problems with the rainfall we have is retaining soluble minerals, not toxicity.