Performance and remediation potential of Chrysopogon aciculatus (Retz.) Trin. grown in nickel-contaminated soils

The performance and remediation potential of Chrysopogon aciculatus (Retz.) Trin. grown in nickel contaminated soil was assessed. Six contamination regimes of 50, 100, 150, 200, 250 and 300 mg Ni/kg soil and control were set up in three replicates each. Chrysopogon aciculatus established from tillers were allowed to grow six weeks before data collection started. Data were collected weekly on ground cover, chlorophyll index and concentrations, total carotenoids and yield at maturity. Soil Ni concentrations were determined at pre-plant and post-harvest stages. Ground cover was not significantly different among the treatments. Ni contaminated treatments had the highest chlorophyll index at 10 and 12 weeks after planting. Chlorophyll a concentration was highest in 150 mg Ni/kg treatment (T₁₅₀) at 12 WAP. T₁₅₀ also had the least Chlorophyll b concentration at 12 WAP.  T₂₀₀ and T₂₅₀ had low total carotenoids at 12 WAP. Dried shoot and root from T₃₀₀ had the highest Ni concentrations. Grass grown in T₂₀₀ accounted for the highest soil Ni uptake (% Ni remediated) with 96.4%. Soil Ni contents were reduced in all treatments. It is concluded that C. aciculatus can tolerate Ni contamination in soil and therefore can be used as a turf grass on Ni polluted soils.