Effect of Augmented Fast-Pyrolysis Biochar on Soil Fertility.

Although selection of feedstock and slow pyrolysis reaction conditions are aimed at maximizing biochar production and properties of interest (e.g. surface area and reactivity, nutrient content and availability, liming capacity, etc.), feedstocks of low ash/mineral content will be preferred for fast pyrolysis biomass-to-bio-oil systems. Furthermore, reaction conditions for bio-oil production are set to maximize yield and quality of volatile organics, with biochar being produced as a by- or co-product. As such, fast pyrolysis may result in biochar of limited agronomic value. This study was aimed at improving agronomic value of yellow pine (Pinus taeda L.) fast pyrolysis biochar. Biochar was both used to sorb extracts from anaerobically digested dairy manure solids and mixed with limestone quarry fines to improve its nutrient content and liming capacity. Selected extractions were used to assess biochar and soil nutrient content and availability, and a greenhouse study was conducted to evaluate the treated biochar (BiocharG) effects on foxtail millet (Setaria italica L.) growth in acidic soil. Biochar_G improved both soil fertility and millet growth. Biochar_G can significantly improve crop yield in acidic and nutrient‐poor soils.