[Stoves] [biochar] Re: Report on APBC - first two days

[Anand Karve]

Dear Crispin,
it is generally grasses and cereals that are heavy feeders of silica.
I don't think that the forest trees need silica in appreciable
quantities. So adding rock powder to the forest may be increasing the
availability of all the essential minerals, not just silica. I used to
know a German organic farmer, who applied powdered basalt to his
field. He claimed that this powder provided his crop with phosphorus.
I also know of an Indian agronomist who says that the seedling nursery
should be supplied with ash of rice husk, because through it the rice
seedlings get the silica. He claimed that such seedlings grew
healthier than control seedlings growing in a bed of the native soil,
not provided with rice husk ash. ;farmers in the rice growing areas
always grow the seedlings in a bed which was first covered with a
layer of dry leaves and then burned. The farmers always claim that
seedlings raised on such beds grew more vigorously than seedlings
grown on ordinary soil. This could be a biochar effect, but the
agricultural textbooks claim that this practice sterilizes the soil
and rids it of weed seeds.
Yours
A.D.Karve

2011/9/20 Crispin Pemberton-Pigott <crispinpigott at gmail.com>:
> Reposted after notification of failure to deliver.
>
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> Dear AD
>
>
>
> I presume you have heard about a fad (craze? activity?) in Europe of walking
> through damaged forests and adding powdered rock with several claims made
> about how that assisted the forest to regain health.
>
>
>
> Do you think this is rooted in the silica availability? Or is the claim
> spurious? It is reported from the UK as well but I have not read details.
>
>
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> If the crop/forest in question would benefit from added, freshly broken
> rock, does it not make sense that adding rice hull biochar (which is more
> than 1/2 silica) would have equal effect?
>
>
>
> The electrical properties mentioned by Tom certainly grabbed by attention.
>
> Charged clay particles (which just means they are smaller than 2 microns) in
> an electrically conductive environment with lots of finely structured silica
> (basically a sponge) might release the needed minerals more efficiently than
> otherwise might be the case.
>
>
>
> Combined with Ron's report that there are a wide variety of chars with very
> different properties if will not surprise me to find that your poor results
> trying biochar amendment and the success in other places can all be fit into
> a single paradigm. You need the right kind to char to get any benefit where
> you are.
>
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>
> Thanks
>
> Crispin
>
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> +++++++
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> Dear Crispin,
>
> the so called insoluble minerals in the soil actually do dissolve in water,
> albeit in extremely small quantities. They cannot be detected in tests using
> only chemistry based on their detection in a test tube by using specific
> reagents. All minerals absorbed by plants growing in nature come from this
> soil solution. Powdering rocks helps the process of dissolving the minerals
> in water, and that is why addition of rock powder to a field often gives
> higher yield than a field to which such dust is not added. Even silica has
> to be dissolved in water, before plants can take it up. Silica and silicates
> constitute almost 30% of the earth's crust, and therefore it is the most
> abundently available mineral in the soil. Therefore I don't think that
> adding more silica to the field would give you higher yield.
>
>
>
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-- 
***
Dr. A.D. Karve
Trustee & Founder President, Appropriate Rural Technology Institute (ARTI)