Water Conservation in Biofuels Development: Greenhouse and Field Crop Production with Biochar

Biochar incorporation in soils has the potential to remove carbon from the atmosphere and to improve soil quality. This research focused on evaluation of the benefit of biochar incorporation in an Arizona soil. Different concentrations of biochar (charcoal from mesquite biomass-derived black carbon) were added to soil in greenhouse experiments. Seven common or potential Southern Arizona crops (alfalfa, wheat, cotton, grain and sweet sorghum, barley and switch grass) were evaluated in the greenhouse experiment. In this experiment; increased biochar concentration treatments produced greater height and biomass production in alfalfa. Sorghum biomass production also increased with biochar concentration. There were no significant differences in biomass production in wheat and barley with increased biochar concentration. Switch grass biomass production had a significant negative correlation with increased biochar concentration. Sweet sorghum biomass production was evaluated in a field experiment conducted at the University of Arizona Red Rock Agricultural Center. A relatively small amount of biochar was incorporated in the top 20 cm of soil in one treatment and soil only was the other treatment: there were no significant differences in yield.Water characteristic curves and bulk densities were measured for biochar/soil mixes. The FASE model was used to simulate evapotranspiration and crop yield for the field sorghum experiment and for several crops grown in the Valsequillo Irrigation District, Puebla, Mexico with measured soil parameters. The model predicted no significant increase in sorghum yield for the level of biochar incorporated in the soil. An increase in yield was predicted for Valsequillo crops