BIOGEOCHEMISTRY OF RECLAIMED SAND-MINED SOILS IN THE ATLANTIC COASTAL PLAIN, CAROLINE COUNTY, VIRGINIA, USA

The removal of top soils in surface mining processes are known to significantly change the soil biogeochemistry and functions in affected landscapes. The removal of vegetation cover, erosional losses, alteration of soil structure, and changes in hydraulic conductivity typically initiate the post mining changes in the soil environment and consequently affect the soil biomes and overall chemistry. This study analyzes the changes in soil biogeochemisty and potential recovery 25 years following reclamation of mined lands in Caroline County in the Virginian Coastal plains, USA. The sites analyzed include: 1) mined and reclaimed for agriculture, 2) mined and abandoned, 3) agriculture and not mined, and 4) an undisturbed forested site.

Soil variables analyzed in 40 soil cores (160 samples) include pH, soil texture, organic matter, P, K, Mg, Ca, cation exchange capacity (CEC), Al, S, Bo, Zn, Fe, Cu, and Mn. All macro and micronutrients were measured using the Mehlich 3 extraction method. Bacterial and fungal communities were isolated through 16S bacterial sequencing and internal transcribed spacer (ITS) sequencing, which covers fungal community identities for next-generation sequencing. Identification of plant community composition through diversity count in randomly selected patches and calculation of Shannon-Weiner Diversity Index (H’) was also used in evaluating soil conditions and vegetation recovery after mining. The results from this work will provide insight on the post sand mining soil recovery process under natural conditions and under agricultural reclamation with significant top soil, lime, fertilizer and organic matter amendments.