[Terrapreta] Charcoal costs

[Kevin Chisholm]

Dear Richard

Richard Haard wrote:
>
>
>
>
> On Dec 9, 2007, at 8:34 PM, Kevin Chisholm wrote:
>> Dear Richard
>>
>> Richard Haard wrote:
>>> S,K,J,N and Tom
>>>
>>> Jim and I have been discussing CEC and soil nutrition and charcoal 
>>> for a few rounds offline and the apparent anomaly of my data not 
>>> showing a boost in CEC with charcoal addition.
>> Could it be that with low temperature char, still containing 
>> volatiles and/or products of incomplete charring, the future CEC 
>> sites are presently blocked, but that with some combination of 
>> microbial action and weathering over several years, the tars and 
>> volatiles still on the char will be decomposed or removed to yield an 
>> "active" char?
>
> It is going to be interesting to follow this in these plots.
Yes indeed. Reports from elsewhere allude to a "time effect".

...del...

>>
>> They used char which was much smaller than the lump and stick 
>> charcoal you used. Two differences between your protocol and theirs 
>> were washing and finer size.
>
> Yes since the CEC test is so easy to have done I have been thinking to 
> try washing some of my stockpile.
What about the possibility of trying methanol and perchlorethylene as 
solvents, in addition to a water leach?
> My Charcoal 1 is a fine powder from John F
Oh. I missed that.
> This is a big reach, but is it possible that there was sampling bias? 
> Specifically, is it possible that when taking samples, the large lumps 
> of char were removed inadvertently in the field, or perhaps by 
> screening at the Lab?
>>
> I assume there is sampling error. But did the best I can by taking 12 
> cores from each of my 28 - 17 foot plots. We used gloves and screened 
> the samples after drying.
Your data for the Charcoal 1 and Charcoal 2 tests is as follows:

......................OM..........CEC
1: Charcoal 1   4.9            12.25
2: Charcoal 1   5.75         10.4
3: Charcoal 2   4.7            13.05
4: Charcoal 2   5.2            11.35
5: Control        4.6            10.9
6: Control         4.2            9.85

I am guessing that the "background organic matter" in the control soil 
used for Charcoal 1 (Fine) and Charcoal 2(Lump/Stick) tests was 
basically constant.
I am also guessing that Tests 1 and 3 were "Low Charcoal Additions" and 
Tests 2 and 4 were "High Charcoal Additions", based on the higher 
reported OM contents. If these guesses are correct, then the CEC results 
are counterintuitive... Low Char additions give high CEC and High Char 
additions give low CEC. The consistent anomaly suggests that sampling 
error was not a concern.

Scatter in analyses seems to be about 1 CEC unit, or +/- .5 units around 
the true value. In tests 1 and 3, with presumably the same weight of 
Char additions, the coarse char gives a larger CEC, within scatter 
limits, but Tests 2 and 4 give a lower CEC, within scatter limits. Char 
size effects may have been eliminated in teh Lab... possibly they 
pulverized all samples for consistency within their analytical procedure.

>> Note also that your units for CEC seem to be cmole/kg while Cheng et 
>> al use mmole/kg. How does one convert between teh different units.?
>
> Steiner et al used cmole/kg , my samples i neglected to look at the 
> report sheet - sorry / mine are MEQ/100g. Same as Jims
>
> Good question . no idea at all how to convert between the 3. The data 
> sets are relative anyway.
>
> Any chemists out there?
It would be very helpful if we had conversion factors so that work 
reported by different Researchers using different units could be compared.
>>
>>
>> How did you measure crop yields? Did you see much difference between 
>> the various plots?
>
> I am working on my report now. This discussion is helping. No above 
> ground differences in Swiss Chard yields or appearance or with Aster 
> subspicatus. With the Lonicera involucrata - a native shrub there were 
> differences both above ground and with roots after the lifter-shaker 
> removed them from the ground.
>
> It was very difficult to physically measure this however. I now 
> appreciate the work that agricultural researchers accomplish. The best 
> I could do is to stand back and look.
If you, as a "good Grower", couldn't see a difference, then there was 
probably no significant difference.

QUESTION: Is it possible that your "control soil" was "adequately good" 
and that the char additions did not remove any "limits to growth?" Would 
you consider the CEC of the "Control soil" as "below minimum 
requirements for normal growth", "adequate for normal growth", or "above 
the level required for normal growth?"
>
> <>
>
> This is charcoal 1 (Johns) , I will prepare a posting of the root 
> images soon.
>
> Next Seasons production from the plots will be much simpler to 
> analyze, a single species -a nitrogen loving shrub I will explain in 
> my report.
Thanks very much for your reports. They are very helpful. I look forward 
to future comment and reports.

Best wishes,

Kevin
>
>
>
>>
>>
>> Best wishes,
>>
>> Kevin
>>
>>
>>>
>>>
>>> Here are some quotes from Steiner et al (2007) and my comments that 
>>> might be interesting for this topic of CEC and charcoal in soil.
>>>
>>> Paper cited: Long term effects of manure, charcoal and mineral 
>>> fertilization on crop production and fertility on a highly weathered 
>>> central Amazon upland soil
>>> abstract here<
>>> ------------------------------------------------------------------------ 
>>>
>>>
>>> >
>>>
>>> from Steiner et al et al p 2
>>>
>>> Terra Preta research has shown that oxidation on the edges of the 
>>> aromatic backbone and adsorbtion of other OM to charcoal is 
>>> responsible for the increased CEC, although the proportion of these 
>>> two processed is unclear (Liang et al 2006)
>>> cited  Liang B et al Black Carbon increases cation exchange capacity 
>>> in soils Soil Sci Soc Am J 70:1719-1730
>>>
>>> and from page 12 - ' the period of this study might have not been 
>>> sufficient for oxidation'
>>>
>>> 'and SOM was only effective at increasing CEC levels above pH 5.5 
>>> which is consistent with the blockage of exchange sites by either Al 
>>> or Fe at lower values ---- In our study only plots fertilized with 
>>> CM had pH values higher than 5.5 and increased CEC. '
>>>
>>> His charcoal was derived from a secondary producer and manually 
>>> crushed ( not special charcoal and made with a technique identical 
>>> to our charcoal 2 = heap burn)
>>>
>>> Definitions of his treatment blocks
>>>
>>> C  control
>>> L  leaf litter
>>> LB   simulated slash and burn (burned litter)
>>> F    inorganic fertilizer
>>> CM  chicken manure
>>> 2CO  compost
>>> 2CC   charcoal
>>> 2CO+F  compost +F 2CC+F   charcoal + F
>>> CC+CO  Charcoal + Compost
>>> 2CC+CO   Charcoal + Compost
>>> 2CC+CO+F Charcoal + Compost + Fertilizer
>>> 2CCp charcoal pieces
>>>
>>> From Table 2 page 11 of Steiner et al soil Chemical Properties after 
>>> first harvest (CEC only)
>>>
>>> (cmole+kg-1)
>>>
>>> Steiner et al  after first harvest values first -  then my own after 
>>> first harvest (charcoal 1 then charcoal 2)
>>> C 1.61          9.85
>>> L 1.52
>>> LB 1.73
>>> F 2.16 12.05
>>> CM 12.55
>>> 2CO 1.94 11.9
>>> 2CC 1.80 10.4,11.9
>>> 2CO+F 2.45 12.3
>>> 2CC+F 1.94 10.1, 11.25
>>> 2CC+CO  1.8 10.95, 12.3
>>> 2CC+CO+F 2.11 12.7, 12
>>> 2CCp 1.65
>>>
>>> Interesting pattern here. Charcoal 1 showed the best indication of 
>>> enhanced growth above ground and roots. I might speculate the lower 
>>> CEC values represent greater nutrient utilization. Additionally, CEC 
>>> may be incidental to the role of charcoal in soil. We should include 
>>> also biological factors in our considerations.
>>> In terms of biological contribution to beneficial effects of 
>>> charcoal additions Steiner et al concluded
>>>
>>> The conditions of ADE (Amazon Dark Earth) are ideal for maximum 
>>> biological N2 fixtation. About 77% of the ADE sampled showed 
>>> positive incidence of /Aspospirillum sp./ compared to only 10 % of 
>>> the Ferralsols. Charcoal provides a good habitat for the propagation 
>>> of useful microorganisms such as free living nitrogen fixing 
>>> bacteria and mycorrhizal fungi. Ogawa holds the charcoals weak 
>>> alkalinity, porosity and ability to retain water and air responsible 
>>> for stimulation of microbes (citations excluded).
>>>
>>> Steiner et al did conclude that
>>> 'Charcoal proved to sustain fertility if an additional nutrient 
>>> source was given. Even though significantly more nutrients were 
>>> exported from the charcoal plots (with higher yields) the available 
>>> nutrient contents of the soil did not decrease in comparison to just 
>>> mineral fertilized plots'
>>>
>>> In addition he demonstrated highest mineral losses in plots treated 
>>> with Chicken Manure, followed by compost, then litter and control.
>>> Rich H
>>>
>>
>>
>>