Engineered Biochar as Soil Fertilizer

Abstract

Biochar, a heterogeneous carbonaceous material, has multifaceted application potential for environmental management. Biochar has been commonly used for contaminant removal from soil and water systems, soil quality improvement, soil C-sequestration, inoculant carrier, etc. Surface area, pore space, surface functional groups, pH, cation exchange capacity (CEC), and nutrient contents are a few key properties that determine the potential of biochar application. Raw materials and pyrolysis conditions are the determining factors for these aforesaid properties of biochar. Biochar production from lignocellulosic biomass and biosolids at moderate pyrolysis temperatures (350–600 °C) are commonly recommended for waste management. Despite its multifaceted application potential, biochar utilization at widescale is limited due to certain incompatibilities with the environmental systems. To overcome the incompatibilities between biochar properties and environmental conditions, engineering of biochar by using different additives and modifications in pyrolysis conditions are getting wider attention nowadays. In this chapter, we have explored the potential of engineered biochar as soil fertilizer. A bibliometric analysis was performed to collate the literature and to see the research trend of engineered biochar as soil fertilizer. Studies reported that engineering of biochar leads to improvement in its surface and physicochemical properties. Engineered biochar with improved properties helps in enhancing soil physicochemical, nutrient, and biological properties after amelioration. Improvement in soil properties showed better crop productivity in some pot/laboratory experiments. Overall, we observed that the research on exploring engineered biochar as soil fertilizer is comparatively limited as compared to its exploration as contaminant adsorbent and source of energy production.