Effect of soil pollution and addition of coal fly ash on germination of Jatropha curcas and Pennisetum clandestinum: An initial approach to phytoremediation of Bamangwato Concession Ltd (BCL) Cu/Ni mine, Botswana
Mining and smelting at BCL-Cu/Ni mine in Selebi-Phikwe, Botswana has been
reported to have resulted in soil acidity and heavy metal contamination. Phytoremediation can beused to rehabilitate such soils. Research has shown Jatropha curcas and Pennisetum clandestinumas promising phytoremediators. The present study was conducted on soil collected east and west of mine smelter to analyze effect of heavy metals and soil acidity on germinationof Pennisetum clandestinum (Kikuyu) andtwo Jatropha accessions from Tsamaya (J09) andMosetse (J05), Botswana. Coal fly ash from Morupule power station, Palapye, Botswana, wasadded to soil to also assess its effect on seed germination in contaminated soils. Germinationpercentage, coefficient rate of germination, shoot length, root length, shoot dry weight, root dryweight, root: shootratio, vigour index and tolerance index of both species grown in soil withoutcoal fly ash were reduced (p<0.05).Kikuyu failed to germinate in soil collected closest to themine smelter (2.5 km west). Coal fly ash increased (p<0.05) the above mentioned parameters inboth species and Kikuyu managed to germinate in soil with coal fly ash. The ability of Jatropha carcas species to germinate in polluted soil indicates tolerance to heavy metal stress and soil acidity unlike Kikuyu. Keywords: Heavy metals; soil acidity; phytoremediation; coal fly ash; germination
