Field Examinations on the Application of Novel Biochar-Based Microbial Fertilizer on Degraded Soils and Growth Response of Flue-Cured Tobacco ( L.).

Southwestern China is receiving excessive chemical fertilizers to meet the challenges of continuous cropping. These practices are deteriorating the soil environment and affecting tobacco ( L.) yield and quality adversely. A novel microbially enriched biochar-based fertilizer was synthesized using effective microorganisms, tobacco stalk biochar and basal fertilizer. A field-scale study was conducted to evaluate the yield response of tobacco grown on degraded soil amended with our novel biochar-based microbial fertilizer (BF). Four treatments of BF (0%, 1.5%, 2.5% and 5%) were applied in the contaminated field to grow tobacco. The application of BF, BF and BF increased the available water contents by 9.47%, 1.18% and 2.19% compared to that with BF respectively. Maximum growth of tobacco in terms of plant height and leaf area was recorded for BF compared to BF. BF, BF and BF increased SPAD by 13.18-40.53%, net photosynthetic rate by 5.44-60.42%, stomatal conductance by 8.33-44.44%, instantaneous water use efficiency by 55.41-93.24% and intrinsic water use efficiency by 0.09-24.11%, while they decreased the intercellular CO concentration and transpiration rate by 3.85-6.84% and 0.29-47.18% relative to BF, respectively ( < 0.05). The maximum increase in tobacco yield was recorded with BF (23.81%) compared to that with BF. The present study concludes that the application of BF improves and restores the degraded soil by improving the hydraulic conductivity and by increasing the tobacco yield.