Begun in 1993, the SoilerMaker Project creates synthetic soil by mixing composted coal ash, tylosin cake and chipped organic material with subsoil.  Difficulties in utilizing the silt-sized coal ash include dust, high pH with the dissolution of lime, and expansion and exothermic reactions with the addition of moisture.  The tylosin is an organic by-product of antibiotic production by Eli Lilly and has a moisture content of 75% giving it a sludge-like consistency.  The chipped organic material consists of yard trimmings, brush, leaves, and pallets.  Research has focused on developing the best mix, determining plant response, and evaluating environmental response.  The benefits of this project include the economic management of by-products, the beneficial reuse of by-products, and the production of a material that can be economically used for land reclamation and conserve natural topoil.

Greenhouse studies using the soil indicate that as little as 25% of the synthetic soil in a soil mix can increase yield.  While no metal uptake or leaching has been detected, high boron concentrations are a concern.  In a pilot study with the Department of Natural Resources (DNR), coal ash, tylosin cake and leaves were mixed and stabilized but not composted and used for reclamation of a coal mining spoils site that had been barren for 25 years.  The mixture was applied in the spring at 50 to 75 tons/acre and tilled into the top 7 inches of soil.  While the plant (grasses) response was good, adjustment of the pH took approximately 1 month, leading to a recommendation for fall application.