Characterization of Plant Biomass Derived Black Carbon (Biochar) as Soil Amendment by X Ray Powder Diffraction

The approach of combining pyrolysis or pyrogasification processes for energy production with biochar addition to soil takes advantage of biochar's proven ability to retain cations, remove CO2 from atmosphere, regenerate degraded lands and reduce environmental pollution. To evaluate the full potential of biochar as soil amendment, precise knowledge of its structural features, related to the thermochemical process conditions, and adsorptive properties, related to the minerals absorbed during crop cycles, is needed. To this aim, X­ray powder diffraction has been used to analyze sub­micrometric properties of biochar and biochar added soil. The structural properties have been monitored during the growing cycle of zucchini crop (Cucurbita pepo L.) in an alkaline soil from South of Italy. Diffraction patterns taken before, during and after the zucchini crop cycle have been analyzed by qualitative, quantitative and morphological analyses. The crystalline content of zucchini leaves and fruits has been also determined. X­ray powder diffraction profiles of soil and soil/biochar mixtures have been compared by using multivariate analysis.