Bacterial Properties, Carbon-Nitrogen Profile, and Plant Growth Potential of Limestone Mining Overburden

Limestone mining generates an overburden that is unsuitable for plant growth.The research analyzed bacterial properties, organic carbon and total nitrogen status, and texture of overburdens compared to topsoil, and the effect of compost on corn growth in the greenhouse.Results showed that the overburdens had lower bacterial populations than the topsoil.17 isolates revealed diverse colony properties and cell morphologies.Among them, 16 were Gram-negative, and one was Gram-positive bacteria; five rod-shaped and 11 cocci-shaped bacteria were found.Five isolates formed the endospores.Topsoil had higher organic-C and lower total-N, resulting in higher C/N than overburden.The acidity of overburden was slightly higher than topsoil.The topsoil texture was silt, while the overburden was sandy loam.The study indicated that overburdens were less fertile regarding bacterial population and C and N status.However, the high volume of compost amendment enhanced the ability of overburden in supporting plant growth.