More about growing tea with biochar in Sri Lanka, from an eariler comment on this blog.
1. “Biochar: Can it put the tea industry back in the black?”, Dr. J.C. Krishnaratne, http://www.sundaytimes.lk/120624/business-times/biochar-can-it-put-the-tea-industry-back-in-the-black-3850.html
In summary, it says that the Sri Lanka tea fields are in bad shape due to erosion and long-term overuse of chemical fertilizers, that biochar can and should help, and that char could be made out of the Gliricidia trees that are already quite widespread and grow well in that region.
2. A response to the above article by Hemal de Silva, http://dl.dropbox.com/u/52700813/Biochar.pdf
In summary, he says that while biochar is certainly good for tea soils and yields, the economic situation is more complicated, lack of re-investment money means biochar may not be sufficient to solve the industry’s money-losing problems, by itself. He suggests that looking at particular tree species, Pentadesma butyracea and Garcinia indica (Kokum) might provide a better economic result.
I was unaware of the economic picture and have never heard of these tree species, so it’s very interesting.