North American Fruit Explorers mailing list at ibiblio

["Martha L. Davis" <martha_davis@earthlink.net>]

There has been some interesting research done to try and mimic the very black 
and fertile soil (tierra prieta ?) in certain areas of tropical south 
america.  Apparently this soil is man made in the archaeological past and the 
black was from charcoal. The study was a comparison between charcoal mixed 
with existing soil, charcoal mixed with existing soil and compost, and 
compost mixed with existing soil.  The one that did the best was the 
charcoal, compost, existing soil, mix.  I wonder if the charcoal somehow is 
able to improve the cation exchange rate and help hold the nutrients in the 
soil that would be otherwise washed away.  If I were having a hard time with 
sandy soil especially where organic matter breaks down quickly I would think 
this was worth a try.


Martha