A Method for Quantifying Recent Soil Organic Carbon and Geogenic Carbon in Reclaimed Minesoils Planted with Miscanthus and Corn for Biofuel Production.

A method for quantifying recent soil organic carbon and geogenic carbon in reclaimed minesoils planted with Miscanthus and corn for biofuel production

David A. Ussiri Jose G. Guzman and R. Lal

Abstract

In recent years Miscanthus has emerged as a promising energy crop, predominantly due to its low input requirements and high biomass production potential in temperate climate. However, land requirement for dedicated biofuel crop production may become a limiting factor for achieving the renewable fuel requirement mandate. Therefore, field trials to compare Miscanthus, corn and native C₃ grass for biomass yield and carbon sequestration have been established in southern Ohio marginal lands which were surface mined for coal and reclaimed. The site had been under grassland twenty five years since reclamation. Coal particles which were incorporated during mining and reclamation limit the accurate quantification of ecosystem carbon budgets in these soils. A method for distinguishing geogenic (coal) carbon from recently accumulated organic carbon based on different stable carbon isotope from coal will be presented. The average δ¹³C composition of C3 grass and coal was -27.5‰, and -24.5‰, respectively. The δ¹³C isotope composition of reclaimed minesoil ranged from -24.85 to -27.2‰, suggesting a variable contribution of geogenic OC to soil organic carbon of the reclaimed minesoil site.