[Terrapreta] Abstract on Charcoal in soil

[Kevin Chisholm]

Dear Michael

I might be missing something, but doesn't this test seem to test the 
benefits of soil nutrients rather than the benefits of Terra Preta?

Wouldn't these tests have been more enlightening if a more reasonable 
soil base had been chosen?

It would appear that all forms of carbon are considered as equal, when 
this is not necessarily the case. Indeed , it is likely that 
carbohydrate carbon, cellulostic carbon, and charcoal carbon serve very 
different functions.

Best wishes,

Kevin



Michael Bailes wrote:
> Abstract  Application of organic fertilizers and charcoal increase nutrient
> stocks in the rooting zone of crops, reduce nutrient leaching and thus
> improve crop production on acid and highly weathered tropical soils. In a
> field trial near Manaus (Brazil) 15 different amendment combinations based
> on equal amounts of carbon (C) applied through chicken manure (CM), 
> compost,
> charcoal, and forest litter were tested during four cropping cycles with
> rice (*Oryza sativa* L.) and sorghum (*Sorghum bicolor* L.) in five
> replicates. CM amendments resulted in the highest (*P* < 0.05) cumulative
> crop yield (12.4 Mg ha−1) over four seasons. Most importantly, surface soil
> pH, phosphorus (P), calcium (Ca), and magnesium (Mg) were significantly
> enhanced by CM. A single compost application produced fourfold more grain
> yield (*P* < 0.05) than plots mineral fertilized in split applications.
> Charcoal significantly improved plant growth and doubled grain production
> if fertilized with NPK in comparison to the NPK-fertilizer without charcoal
> (*P* < 0.05). The higher yields caused a significantly greater nutrient
> export in charcoal-amended fields, but available nutrients did not decrease
> to the same extent as on just mineral fertilized plots. Exchangeable soil
> aluminum (Al) was further reduced if mineral fertilizer was applied with
> charcoal (from 4.7 to 0 mg kg−1). The resilience of soil organic matter
> (SOM) in charcoal amended plots (8 and 4% soil C loss, mineral 
> fertilized or
> not fertilized, respectively) indicates the refractory nature of 
> charcoal in
> comparison to SOM losses over 20 months in CM (27%), compost amended (27%),
> and control plots (25% loss).
> http://www.springerlink.com/content/6655755v113437g3/
> Feb 2007
> Christoph Steiner1 [image: Contact
> Information]<http://www.springerlink.com/content/6655755v113437g3/#ContactOfAuthor1>, 
> 
> Wenceslau G. Teixeira2, Johannes Lehmann3, Thomas Nehls1,
> Jeferson Luis Vasconcelos de Macêdo2, Winfried E. H. Blum4 and Wolfgang 
> Zech
> 1
> 
> Does this article abstract say that Charcoal kept SOM in the soil for
> longer?
> 
> 
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