Soil-Based Productivity Models for Evaluating Reclamation Success of Coal-Mined Lands.

Since the passage of Public Law 95-87, Surface Mining Control and Reclamation Act (SMCRA) of 1977, prime farmland reclamation success has been evaluated primarily by crop yield testing.  Many states, such as Illinois and Indiana, require that reclamation success be based on crop production of mined-land compared to an approved reference or other guidelines.  In practice, if mined-land does not meet crop yield-based requirements in the specified time period, the process of crop yield testing can continue for many years.  Landowners, mine operators, and regulators have voiced a need to expediate this process.  The objective of our work was to develop a soil-based model to replace the current crop yield-based system and to characterize mined-land for diagnostic purposes.  Georeferenced corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.) yield (depending upon location), cone penetrometer test (CPT), apparent electrical conductivity (EC_a), elevation and terrain derivatives, fertility, and other site characteristic measurements were acquired on fields at the Lewis Mine site in southwestern IN, the Cedar Creek Mine site in western IL, and the Wildcat Hills Mine site in southern IL.  Soil-based productivity models were developed using principal component analysis (PCA) and logistic regression to assign probabilities of meeting crop yield standards at the sub-field level.  Results indicate that compaction and water availability primarily influence a field’s ability to meet crop yield standards across time.  Validation of models among fields and sites is encouraging, thus we recommend modeling soil variability as a diagnostic tool to identify problematic field areas and to complement yield-based requirements.