Establishing vegetation on Kimberlite mine tailings: 1. Defining the problem and selecting species.

Abstract

Natural revegetation of Kimberlite tailings deposited after extraction at Cullinan in the Transvaal is extremely slow. Laboratory studies showed the high alkalinity (pH = 9, 8 in water), lack of available N and P and poor moisture retention arising from the coarse texture (+ 64% > 2 mm) and dark grey colour, to be the principal limitations to plant establishment. Remarkable responses to N and P were obtained in a glass-house trial in which Sorghum bicolor PNR 988 was used as an indicator crop. In the presence of added N and P and with enhanced moisture conditions, several species showed promise. The most successful of these were Chloris gayana, Cynodon aethopicus, Cynodon dactylon, Paspalum vaginatum, Eragrostis curvula, Melolotus alba and Medicago sativa

Keywords: alkalinity; chloris gayana; colour; condition; cullinan; cynodon aethiopicus; cynodon dactylon; eragrostis curvula; establishment; kimberlite; laboratory studies; limitations; medicago sativa; melilotus alba; mine dump rehabilitation; moisture; paspalum vaginatum; ph; revegetation; sorghum bicolor; south africa; transvaal; vegetation