Forestry-waste
biochar was tested as a commercial substrate (peat:lapillus
1:1 v/v) amendment in growing tomatoes (Solanum lycopersicum L.). Substrates were 0% (control),
5%, 10%, 20%, and 40% (% v/v) biochar-enriched and
were characterized for their textural and physicochemical properties.
After harvesting, tomato production (i.e., plant and fruits), quality
(e.g., nutrition and nutraceutics), and safety (i.e., biochar-related
pollutants) were assessed according to the different growing media.
10-to-40% biochar-enriched substrates only exceeded the pH threshold
set by L.D. 75/2010. Ni and Mn exhibited a similar trend between substrates
and fruits, while Cr, Pb, and Cd were absent. Plant biomass increased
(up to 11–29%) according to biochar content, which conversely
diminished fruit production (∼25–60% reduction). Only
acenaphthene exhibited an increasing profile (11–12 μg
kg–1) according to the treatments, nevertheless
complying with the European regulations. PLS-DA confirmed practice
suitability by substrate–crop correlation, providing prediction
models for quality and safety assessment.