[Terrapreta] Charcoal agriculture: not ready for prime time

[Kevin Chisholm]

Dear Sean

Sean K. Barry wrote:
> Hi Kurt, and All,
> 
> There has been some mention that charcoal amendments alone or
> charcoal and fertilizers, even organic fertilizers like chicken
> manure seem to only increase soil productivity for maybe the first 3
> or 4 years after application.  The original Terra Preta soils have
> and do seem to retain their fertility for perhaps centuries. There is
> a difference. 

Shouldn't it be relatively easy for a Researcher to analyse "Old TP" and 
   "New TP" and see what were the differences?

  Some have proposed that the difference is in the size
> and/or variety of a healthy soil microorganism population. 

Does anyone know of any methodical tests that have been done to support 
this hypothesis? This seems to me to be one of the advantages of having 
charcoal in the soil... the "microorganism motel" concept. If indeed the 
concept is valid, evidence should be easy to get, and when it is easy to 
get, there is usually lots of it. :-)

  In this
> vain, then, does anyone think it would be reasonable to say that
> charcoal could be inoculated with Vesicular-arbuscular mycorrhizal
> (VAM) fungi or other beneficial soil microorganisms? Maybe this is
> part of "the recipe" for making "Neo Terra Preta"?  Maybe a census of
> the soil microbes in the original Terra Preta could give us some
> clues about this theory as the possible key ingredient for a working
> "Neo Terra Preta" soil?

VAM might indeed be a vital "component" in TP. Is anyone on the List 
doing any tests involving TP and VAM?

Best wishes,

Kevin


> 
> Regards,
> 
> SKB ----- Original Message ----- From:
> rukurt at westnet.com.au<mailto:rukurt at westnet.com.au> To:
> terrapreta at bioenergylists.org<mailto:terrapreta at bioenergylists.org> 
> Sent: Tuesday, May 29, 2007 8:40 PM Subject: Re: [Terrapreta]
> Charcoal agriculture: not ready for prime time
> 
> 
> Tom Miles wrote:
>> 
>> My thought was more modest:  a concentration of charcoal left in a
>>  poor soil from any natural cause could have resulted in abundant 
>> growth and  inspired terra preta. Studies that I have linked on the
>>  terra preta site have shown that the nutrient impact of fires in 
>> grasslands only lasts for about a year, and slash and burn about
>> three years. Forest fires, however, can leave some substantial
>> pockets of char.
>> 
>> 
>> 
>> Tom
>> 
>> 
>> 
> Nutrient impacts of fires are most likely due to the ash and not the
>  charcoal, which is mainly left on the surface anyhow. I believe that
> for maximum impact the char has to be ground somewhat and 
> incorporated and possibly impregnated with other nutrients.
> 
> Kurt
> 
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