The disclosed invention describes a novel approach to the utilization of the fine mineral matter derived from coal and/or coal refuse (a by-product of coal refining) to convert a non-biodegradable plastic into a biodegradable plastic. The fine mineral matter could also be based on volcanic basalt, glacial rock dust deposits, iron potassium silicate and other sea shore mined deposits. The conversion of the non-biodegradable plastic into biodegradable plastic in soil further increases nutrients availability in soil with the transition metals released as a result of biodegradation of the biodegradable plastic.