Physical and Chemical Characterization of Biochars From Fast Pyrolysis of Three Biomass Feedstocks.

Physical and Chemical properties of biochars depend on the feedstock type and pyrolytic conditions. The relationship of biochar characterization and its reactivity in soil as fertility amendment, sorbing agent, and C-sequestering ability is not well understood. Biochars from fast pyrolysis (at 650 ⁰C) of three biomass feedstock sources such as corn stover (Zea mays L.), switchgrass (Panicum virgatum L.), and Ponderosa Pine wood residue (Pinus ponderosa L.),  were characterized for physical properties (particle size, and density) and chemical properties (pH, EC, total N and C, CEC, CCE, ash content, P, K, S, Ca, and Mg). The pH of biochars was varied from slightly acidic to highly alkaline. In general, the fast pyrolysis of biomass feedstocks enhanced the total C and N, ash content, CEC, and nutrient status (N, P, K, S, Ca, Mg), which ensures their capability as soil amendment and C-sequestration agent. Biochars were evaluated for their sorption characteristics which can influence the partitioning behavior of plant essential nutrients such as N and P.  Liming potential of these biochars were also determined by studying their effect on chemical properties of acidic soil during incubation.