Biochar ameliorates crop productivity, soil fertility, essential oil yield and aroma profiling in basil (Ocimum basilicum L.)

The combined application of biochar (BC) and chemical fertilizer (CF) increased crop and essential oil yield in two successive years (2013 and 2014) in basil (Ocimum basilicum). Organic carbon (OC) content increased under both: BC and BC mixed with CF treatments. The increase in OC ranged from 5.55% to 29.26% in the first year and 2.73-30.58% in the second year, respectively. Addition of biochar also led to increase in the soil microbial biomass carbon and soil microbial biomass nitrogen, suggesting that the higher concentration of biochar promotes the overall microorganism population. Soil dehydrogenase enzyme activity was 27% higher over the control in BC treatment. In the second harvest (2014), the urease activity increased from 7.4% to 39% in BC + CF treatment. Essential oil constituents (aroma compounds) did not change in biochar amended pots. The results show that the amendment of biochar with chemical fertilizer offers an appropriate alternative strategy to achieve higher crop productivity and essential oil yield in basil without compromising the aroma quality of the oil. Strategic addition of biochar in fertilizer regime has the concomitant advantage of enriching soil fertility for long-term sustainable agriculture with potential to reduce chemical fertilizer inputs. (C) 2016 Elsevier B.V. All rights reserved.