Effect of a one-time application of municipal biosolids on plant growth at a metal mine tailings impoundment, five years of results

摘要

Vegetation growth is often limited in metal mine spoils under semi-arid climatic conditions. This study was conducted to determine whether a one-time biosolids application, limestone and wood residue addition could enhance the establishment of vegetation on metal mine spoil under these conditions. Municipal sewage sludge (as biosolids) were applied at a rate of 0 Mg/ha (control), 22.4 Mg/ha, 44.8 Mg/ha, and 67.2 Mg/ha, to the Kennecott Utah Copper Corporation tailings impoundment located near Magna, Utah. Five test sites on the impoundment were monitored for five years, beginning in 1994. Above ground biomass production, percent cover of individual plant species, and the concentration of heavy metals in plant tissue were evaluated. A conclusion of the study is that biosolids application enhanced the plant growth capability of the tailings significantly. The increase in biomass and percent cover was proportional from the control rate to the 67.2 Mg/ha application rate.