Investigating Rapid Pedogenesis of Biosolid-Amended Lime Spoils Using VNIR Spectroscopy

Joshua Chaney
Undergraduate (Environmental & Plant Sciences)
Dr. Scott Demyan
Environment and Natural Resources

Anthropogenic soils present challenges for characterization and monitoring due to their strong contrasts with surrounding natural soils and their high spatial heterogeneity. Using visible-and near-infrared (VNIR) spectroscopy can potentially offer a less expensive and more rapid assessment method for anthropogenic soils, as specific spectral features can be associated with different soil properties.This research aimed to determine whether VNIR spectroscopy can be used to characterize unique pedogenic processes occurring in anthropogenic soils formed from lime spoil treated with biosolids. Representative soil pedons were sampled at a site in Barberton, Ohio with a legacy of soda ash production waste deposition and recent reclamation through biosolids. Spectral features associated with calcium sulfate and calcium carbonate minerals such as gypsum, ettringite, and calcite will be explored as proxies for characterizing how much weathering has taken place. These calcium minerals are significant indicators of weathering, because the neoformation and dissolution of these minerals can be important indicators of initial pedogenesis in these soils. It is hypothesized that samples with higher pH and electrical conductivity will also have higher calcium sulfate mineral abundance as estimated by the peak size at 1748 nm in the VNIR spectra. This rapid indicator could be used to make future assessments of pedogenesis occurring in these soils or other similar sites more efficient. Furthermore, evaluating soil spatial and temporal variability on these large sites can allow for specific intra-site management plans, otherwise not previously possible due to a lack of soils information.