Biochar and Compost Blends for Enhancing Crop Production in California

California has a unique combination of a massive and diverse agricultural economy, Mediterranean climate with temporally skewed precipitation, and declining water tables in nearly all agricultural zones within the state.  This joint project between Charborn LLC and USDA ARS took place in the ARS' San Joaquin Valley Agriculture Research Center, in the heart of California's agricultural regions. One of the goals of this project was to determine the effect of biochar and biochar/compost blends on enhancing crop growth.  Experimental treatments included soil amendment with biochar (B), biochar plus compost (BC), biochar plus compost plus sulfur (BCS), and the soil control (C). The ratio for BC treatment was 77% biochar and 23% compost; for BCS 71% biochar, 22% compost, and 9% high-sulfur content rock dust.  Both blends were incubated for three months before application in the field experiment. For the biochar treatment, no post-production activation or inoculation was performed. A dehydrator onion was planted as the bioassay crop.  Growth parameters were measured periodically over the three biochar and the control treatments.  Preliminary results showed that onion biomass from the three biochar treatments was not significantly different from the soil control before bulb formation.  However, the BC and BCS treatments showed greater biomass than the B and C treatments after bulb formation.  Final yield and harvest data will be available in August.