[Terrapreta] Spreadsheet for Calculating Basic "New Terra Preta" Economics

[Kevin Chisholm]

I have posted a Spreadsheet to the Terra Preta site at:

http://terrapreta.bioenergylists.org/chisholm051308

Basically:
1: If you know the cost of charcoal, it tells you how much the $ value 
of your yield and other $ benefits must increase,
or
2: If you know the $ value of yield and other benefits, it tells you how 
much you can afford to pay for the charcoal,

for the investment to meet your "investment Criteria."

Best wishes,

Kevin