Plant Response to Liming Materials and Biological Amendments on Acid Mine Tailing

The application of inorganic and organic amendments can alleviate acid mine drainage and modulate nutrients availability to plants growing on acid mine tailing. Two greenhouse experiments were conducted to examine the effects of liming materials (calcium carbonate, Portland cement, magnesium-bearing materials, bone flour) and compost on the yield of two plants grown on acid mine tailing. In the first experiment, subsamples of acid mine tailing were treated with calcium carbonate (CaCO₃, reagent grade), peat moss-shrimp waste compost (PSC) and bone flour (BF). Corn (Zea mays L.) was used as test plant. All treatments received a basic N, P and K fertilization and were arranged in a randomized complete block design with three replications. The ANOVA of treatment effects on dry matter yield (DMY) of corn indicated significant main effects of amendment source and amendment rate. In general, lime, BF and PSC application stimulated corn growth. In all CaCO₃ treatments, the significantly highest corn yield was obtained with plot receiving PSC. In the second experiment, ryegrass (Lolium multiflorum Lam.) was grown on an acid mine tailing treated with various rates of commercial Portland cement alone or mixed with three magnesium (Mg) materials. The combination of cement and Mg materials resulted in higher increase of pH and DMY of ryegrass over cement alone. Average shoot DMY of ryegrass grown with the various liming materials followed the sequence of: (cement + magnesium oxide) > (cement + magnesium hydroxide) > (Portland cement + magnesium carbonate) > cement alone > control. There was a significant positive relationship between DMY of ryegrass and some chemical properties of the growing media. The results indicate that commercial Portland cement may be effectively used with magnesium-bearing materials for reducing acid mine drainage. These alkaline materials could be used for improving yields of plants.