This is the title of a masters thesis by Jake Northup from Iowa State University that has been getting kudos from the international biochar community…

“… Many biochar-based substrates produced plants with shoot dry mass greater than or equal to the control. These results demonstrate the potential for biochar to replace perlite and eliminate the limestone amendment needed for commercial greenhouse soilless substrates based on sphagnum peat. Soilless substrates containing biochar as a replacement for perlite and limestone can successfully be used for greenhouse plant production.”

The full thesis can be accessed from here… http://lib.dr.iastate.edu/etd/13399/#