Humus of reclaimed Cu post-flotation tailings Humus content and composition of soil from reclaimed Cu post-flotation tailings (Bor, Serbia)

Abstract

The aim of this work was to determine the content and composition of the humus in the Technosols from reclaimed post-flotation tailings of the Bor copper mine (Serbia). Part of the tailings was reclaimed about 20 years ago by restoring the topsoil with arable soil and planting trees and grasses. Humus parameters were used as indicators for the success of the reclamation. Samples of the natural soil, which served as a borrow pit for the reclamation of the tailing, were analyzed as a control. The humus composition was assessed on the basis of the ratio of humic acids to fulvic acids (Ch/Cf), the ratio of humic acids to total organic carbon (C) (Ch/C) and the ratio of fulvic acids to total organic C (Cf/C). Descriptive statistics, correlation and PCA were used to analyze the data. The decrease in humus content is due to the weak inflow of organic residues into the soil due to the weak development of the vegetation. A significant increase in Cf/C and a decrease in Ch/Cf values are probably the result of the degradation of humus substances under the conditions of a very acidic environment and a lower leaching of fulvic acids. The decrease and degradation of humus in the soil are the result of unfavorable soil quality and unfavorable re-vegetation as a result of inadequate reclamation measures.

Keywords

• humic acids
• fulvic acids
• humus degradation
• technosols